Question 1

A 67-year-old woman is brought to the office by her son. He reports that his mother has had periodic confusion, memory loss, and poor sleep and seems "kind of out of it sometimes." These symptoms have gradually worsened over the past 1-2 years. The patient occasionally sees "strangers in the backyard," who are not there when her son looks for them. More recently, she has begun walking more slowly and has fallen twice in the past month without any significant injuries. The patient has a history of hypertension and depression. She does not drink alcohol or use illicit drugs. On physical examination, she walks slowly and has mild bilateral hand tremors and mild bilateral lower limb rigidity. On cognitive examination, the patient appears to be oriented to person and place, and can recall 1 of 3 items in 5 minutes; she can state the days of the week forward but does not cooperate with stating them backward. Chemistries, complete blood count, vitamin B₁₂, and thyroid function tests are normal. Serum treponemal test is nonreactive. MRI of the brain shows mild generalized cortical atrophy. Which of the following is the most likely diagnosis in this patient?

Accepted Answer

This patient's 1- to 2-year history of periodic confusion accompanied by visual hallucinations and parkinsonian motor symptoms (eg, tremors, rigidity) is suggestive of dementia with Lewy bodies (DLB), the cause of 10%-20% of dementias in the United States. DLB is characterized by alterations in consciousness, fluctuations in cognition, visual hallucinations, parkinsonism, and relatively early compromise of executive functions. Repeated falls and sleep disturbance are characteristic. At autopsy, Lewy bodies, eosinophilic intracytoplasmic inclusions representing accumulations of alpha-synuclein protein, may be seen in neurons of the substantia nigra, locus coeruleus, dorsal raphe nucleus, and substantia innominata. Pharmacotherapy of DLB consists of carbidopa-levodopa for parkinsonism and cholinesterase inhibitors for cognitive impairment. If psychotic symptoms persist, a low-dose second-generation antipsychotic, rather than a first-generation antipsychotic, is preferred due to the severe neuroleptic sensitivity seen in these patients. (Choice A) Alzheimer disease typically presents with early and prominent memory loss. The core clinical features of cognitive fluctuations, visual hallucinations, and parkinsonism in this patient make DLB more likely. (Choice C) Major depressive disorder is characterized by persistent depressed mood and syndromal neuro-vegetative symptoms. Although mild cognitive impairment and psychotic features can occur in major depression, this patient's parkinsonism and fluctuating cognition would not be consistent with depression. (Choice D) Normal-pressure hydrocephalus is characterized by cognitive changes (eg, decreased attention and concentration, apathy), changes in gait, and urinary incontinence. Visual hallucinations and sleep impairment are not common. MRI characteristically shows ventriculomegaly that is out of proportion to the degree of sulcal widening. (Choice E) Lewy bodies are a pathologic finding also present in Parkinson disease. The key distinction between these 2 conditions is the early appearance of cognitive fluctuations and dementia in DLB, whereas dementia occurs late in the course of Parkinson disease (much later than the emergence of motor symptoms). In addition, visual hallucinations are not common in Parkinson disease unless they are due to dopaminergic medications given to treat the underlying illness. Educational objective: Dementia with Lewy bodies causes cognitive fluctuations, visual hallucinations, and parkinsonism. Cognitive symptoms may precede, or appear along with, parkinsonian features. References: Clinical presentation and differential diagnosis of dementia with Lewy bodies: a review. (http://www.ncbi.nlm.nih.gov/pubmed/24150834) Lewy body disease: clinical and pathological "overlap syndrome" between synucleinopathies (Parkinson disease) and tauopathies (Alzheimer disease). (http://www.ncbi.nlm.nih.gov/pubmed/29629495)

Question 2

A 75-year-old man is brought to the office by his daughter due to increasing confusion over the past 3 weeks.  His daughter noticed that he has had trouble writing, using a computer, and keeping track of his calendar.  The patient's wife died 4 weeks ago and since then, he has not been sleeping well and taking doxylamine at bedtime has not helped much.  Other medical conditions include chronic obstructive pulmonary disease and hypertension.  The patient takes amlodipine and tiotropium.  Temperature is 36.1 C (97 F), blood pressure is 140/90 mm Hg, pulse is 105/min, and respirations are 18/min.  The patient is oriented to person but not to time or place.  Extraocular movements are normal.  Lungs are clear to auscultation bilaterally.  Reflexes are 2+ and strength is normal.  His gait is ataxic and his speech is dysarthric.  Complete blood count, urinalysis, and serum chemistries are normal.  CT scan of the head reveals mild cortical atrophy but is otherwise normal.  Which of the following is the most appropriate next step in management?

Accepted Answer

11ec25c8_d15f_66ed_bc81_d33f2962a623_MD0003_00 This patient's memory impairment, ataxia, and dysarthria that developed 3 weeks after initiation of doxylamine (an anticholinergic sleeping medication) is most likely due to chronic anticholinergic toxicity caused by the combined anticholinergic effects of doxylamine and tiotropium. Many medications with anticholinergic properties can cause toxicity at therapeutic doses, particularly in combination; elderly psychiatric patients taking multiple medications and young children are at highest risk. Removal of the anticholinergic medication generally leads to symptom resolution; therefore, doxylamine should be discontinued in this patient. Chronic anticholinergic toxicity often presents with subtle, nonspecific symptoms (eg, confusion, altered mental status, dysarthria), and more classic findings typical of acute toxicity (eg, tachycardia, hyperthermia, flushed dry skin, urinary retention) are often absent. Therefore, anticholinergic toxicity should always be considered in patients taking multiple medications with nonspecific symptoms. For example, impaired memory, gait disturbance, and confusion (common in the elderly) may be mistakenly attributed to aging or other disease processes when the actual cause is cumulative anticholinergic effects. (Choice A) Donepezil is a cholinesterase inhibitor used to treat Alzheimer dementia (AD), which has an insidious onset. This patient's rapid onset of symptoms (3 weeks) is not consistent with AD. (Choice B) Selective serotonin reuptake inhibitors are primarily used to treat depression. Although this patient's cognitive impairment and sleep disturbance could be caused by depression, his abnormal neurologic examination (gait ataxia and dysarthria) is inconsistent with a psychiatric diagnosis. (Choice D) An electroencephalogram (EEG) can be used to characterize and stage dementia. The rapid onset of symptoms in this patient is suggestive of an alternate diagnosis and an EEG would not be the next best step. (Choice E) Pre- and post-lumbar puncture gait assessment is used to diagnose normal pressure hydrocephalus (NPH), a condition characterized by a change in mental status, ataxia, and incontinence (not present in this patient). A rapid time course is uncommon in NPH, and abnormal findings (eg, ventricular enlargement) would likely be present on CT scan of the head. (Choice F) Transfer to an assisted living facility could be appropriate in patients diagnosed with dementia and at risk for falls. However, a thorough evaluation for reversible causes of a patient's symptoms should be performed first. Educational objective: Patients treated with multiple anticholinergic medications (eg, elderly psychiatric patients) are at risk for chronic anticholinergic toxicity, which often presents with subtle and nonspecific findings not typical of acute anticholinergic toxicity. Removal of the anticholinergic medication leads to resolution of symptoms. References: Chronic anticholinergic use and the aging brain. (http://www.ncbi.nlm.nih.gov/pubmed/23183138)

Question 3

A 15-year-old girl is brought to the emergency department due to pain in her arms, legs, and lower back.  The patient has sickle cell disease and in the past has been hospitalized for pain crises and pneumococcal sepsis.  Her current symptoms began this morning, but she is out of her medications, including oxycodone, hydroxyurea, and penicillin.  Temperature is 37.6 C (99.7 F), blood pressure is 158/88 mm Hg, pulse is 110/min, and respirations are 24/min.  Pulse oximetry is 99% on room air.  The patient is alert but anxious.  Cardiac examination shows a flow murmur.  The lungs are clear to auscultation.  The abdomen is soft with no organomegaly.  The legs and back are moderately tender to palpation.  Morphine is given for pain control, and 1 hour afterward the patient is suddenly unable to move her left side.  Examination shows 1/5 strength in the left upper and lower extremities and 5/5 strength in the right upper and lower extremities.  Sensation is also diminished on the left side.  Fingerstick glucose is 110 mg/dL.  CT scan of the head shows no acute pathology.  Which of the following is the best next step in management of this patient?

Accepted Answer

11ec25c8_d15d_e04b_bc81_e1ccc27567c1_MD0003_00 This child with sickle cell disease (SCD) has sudden-onset unilateral weakness without intracranial hemorrhage, findings concerning for an ischemic stroke. SCD increases the risk of ischemic stroke due to intimal hyperplasia and stenosis of large arteries, as well as occlusion of vasculature by adherent, stiff, sickled red blood cells. Vascular and oxidative injury leads to recruitment of inflammatory cells and activation of the coagulation cascade. Precipitating factors may include acute drops in oxygenation or hemoglobin (often seen in pain crises). This patient is at increased risk of SCD complications due to not taking hydroxyurea, which decreases frequency of pain crises by increasing fetal hemoglobin. Treatment of stroke in SCD patients is exchange transfusion (ie, slowly removing the patient's blood and replacing it with allogeneic blood), which lowers the relative percentage of sickled cells compared to healthy red blood cells. By decreasing RBC sickling, exchange transfusion increases the oxygen-carrying capacity of the blood and improves hyperviscosity, limiting further occlusion. Exchange transfusion also decreases the risk of stroke recurrence. Simple transfusion (ie, packed red blood cell transfusion) should be performed when exchange transfusion is not available. (Choice A) Antiplatelet therapy is an appropriate treatment for many non-SCD patients with ischemic stroke when stroke is due to atherosclerosis, small vessel disease, or thromboembolism. However, stroke in SCD patients has a different etiology (ie, alteration in cerebral hemodynamics due to sickled red blood cells); antiplatelet therapy has not been shown to improve stroke outcomes or prevent recurrent stroke in SCD, unlike exchange transfusion. (Choice B) Due to impaired splenic function, SCD increases the risk of life-threatening infections caused by encapsulated bacteria (eg, Streptococcus pneumoniae). However, acute neurologic deficits in an afebrile patient make infection less likely and blood cultures and antibiotics unnecessary. (Choice D) Intravenous heparin, which can treat deep venous thrombosis and pulmonary embolism, is not typically used in acute ischemic stroke management due to risk of intracranial hemorrhage. (Choice E) Naloxone reverses the effects of opioid overdose, which typically presents as a decreased level of consciousness and respiratory depression; tachypnea, present in this patient, would not be seen. In addition, acute, unilateral weakness is not associated with opioid overdose. Educational objective: Exchange transfusion is the treatment of ischemic stroke in patients with sickle cell disease. Replacing sickled cells with healthy red blood cells increases oxygen-carrying capacity and improves hyperviscosity, limiting further occlusion. References: Therapeutic red cell exchange transfusion as an adjuvant therapy for management of sickle cell crisis in adults. (http://www.ncbi.nlm.nih.gov/pubmed/29962749) How I treat and manage strokes in sickle cell disease. (http://www.ncbi.nlm.nih.gov/pubmed/25824688)

Question 4

A 26-year-old woman comes to the emergency department with numbness and weakness of both legs.  Throughout the prior day, she felt like her legs kept "going to sleep" and on waking this morning, she had difficulty standing up and walking.  She also reports urinary urgency and 2 episodes of involuntary urine leakage.  The patient has no history of back pain or trauma.  Four years ago, she was diagnosed with type 1 diabetes mellitus, and her glycemic control is maintained by continuous subcutaneous insulin infusion pump.  One year ago, she was evaluated for right eye pain and impaired vision, but these resolved spontaneously in a week.  Temperature is 36.9 C (98.4 F), blood pressure is 134/78 mm Hg, and pulse is 76/min.  Visual acuity and pupillary reflexes are normal.  Muscle strength in the right and left lower extremities are 3/5 and 4/5, respectively.  Patellar reflexes are 3+ on both sides, and plantar reflexes are upgoing.  Sensation to vibration, light touch, and pain is decreased in both legs.  Her fingerstick glucose level is 144 mg/dL.  Which of the following is the most likely cause of this patient's current symptoms?

Accepted Answer

11ec25c8_d14e_ec21_bc81_01f0d2b2636b_MD0003_00 This patient likely has multiple sclerosis (MS), an autoimmune inflammatory demyelinating disorder of the central nervous system (CNS) that typically presents with neurologic deficits disseminated in space and time in women age 15-50. MS should be suspected in patients with >2 distinctive episodes of CNS dysfunction with at least some resolution that cannot be explained by a single lesion. Symptoms occur over hours to days and then improve over weeks to months, although some may be permanent. Common initial symptoms may include: > Optic neuritis: monocular visual loss, painful eye movements, and afferent pupillary defectTransverse myelitis: motor and sensory loss below the level of the lesion with bowel and bladder dysfunction. Patients initially have flaccid paralysis (spinal shock), followed by spastic paralysis with hyperreflexia.Internuclear ophthalmoplegia: demyelination of the medial longitudinal fasciculus resulting in impaired conjugate horizontal gaze in which the affected eye (ipsilateral to the lesion) is unable to adduct and the contralateral eye abducts with nystagmusCerebellar dysfunction: intention tremor, ataxia, and nystagmus Optic neuritis: monocular visual loss, painful eye movements, and afferent pupillary defect Transverse myelitis: motor and sensory loss below the level of the lesion with bowel and bladder dysfunction. Patients initially have flaccid paralysis (spinal shock), followed by spastic paralysis with hyperreflexia. Internuclear ophthalmoplegia: demyelination of the medial longitudinal fasciculus resulting in impaired conjugate horizontal gaze in which the affected eye (ipsilateral to the lesion) is unable to adduct and the contralateral eye abducts with nystagmus Cerebellar dysfunction: intention tremor, ataxia, and nystagmus (Choice A) This young patient without cardiovascular risk factors is unlikely to have had a stroke. In addition, anterior cerebral artery occlusion would lead to acute-onset contralateral leg weakness. (Choice B) Diabetic polyneuropathy causes symmetric sensory loss in a "stocking-glove" distribution. It occurs insidiously, approximately 5 years after a diagnosis of type 1 diabetes mellitus, and can have associated decreased/absent ankle reflexes initially with progression to involve other reflexes. Severe cases may be associated with muscle weakness. (Choice C) Guillain-Barré syndrome leads to rapidly progressive ascending muscle paralysis generally preceded by infection (eg, Campylobacter jejuni, viruses). Associated symptoms often include reduced/absent reflexes and paresthesias. Optic neuritis is not characteristic. (Choice E) A symptomatic parasagittal meningioma would likely cause progressive neurologic deficits (eg, bilateral lower extremity weakness/numbness) and seizure due to growth and compression of localized brain structures. Patients may also develop symptoms of elevated intracranial pressure (eg, headache, nausea/vomiting). (Choice F) Vitamin B₁₂ deficiency occurs due to long-standing poor absorption (eg, pernicious anemia, Crohn disease) or lack of dietary animal products (eg, vegan diet). Patients typically develop subacute combined degeneration of the spinal cord leading to progressive symmetric sensory loss/paresthesias, sensory ataxia, and spastic muscle weakness. Educational objective: Multiple sclerosis should be suspected in young women with neurologic deficits disseminated in space and time. Common presentations include optic neuritis (eg, monocular blindness, painful eye movement) and transverse myelitis (eg, motor and sensory loss below the level of the lesion, incontinence). References: Diagnosis and differential diagnosis of multiple sclerosis. (http://www.ncbi.nlm.nih.gov/pubmed/23917094) Diagnostic criteria for multiple sclerosis: 2010 revisions to the McDonald criteria. (http://www.ncbi.nlm.nih.gov/pubmed/21387374)

Question 5

A 25-year-old woman comes to the office due to intermittent double vision, dizziness, and unsteady gait for the last several days.  During the past year, she has had several episodes of numbness and dizziness, and her symptoms were attributed to anxiety.  She does not use tobacco or alcohol.  Her brother died of subarachnoid hemorrhage.  Blood pressure is 130/70 mm Hg and pulse is 76/min.  On attempted left gaze, her left eye abducts and exhibits horizontal nystagmus, but her right eye remains stationary.  When she attempts to look to the right, her right eye abducts and exhibits horizontal nystagmus, but her left eye remains stationary.  The patient is able to converge both eyes without any associated nystagmus.  Which of the following is the most likely site of the lesion in this patient?

Accepted Answer

11ec25c8_d14a_0a20_bc81_5bc6588901e8_MD0003_00 This young woman with neurologic deficits disseminated in space and time (eg, diplopia, ataxia, vertigo, numbness) most likely has multiple sclerosis, an inflammatory demyelinating disorder characterized by white matter lesions in the central nervous system. Her pattern of eye movement dysfunction is consistent with internuclear ophthalmoplegia, a disorder of conjugate horizontal gaze in which the affected eye (ipsilateral to the lesion) is unable to adduct and the contralateral eye abducts with nystagmus. Convergence and the pupillary light reflex are preserved. conjugate horizontal gaze Internuclear ophthalmoplegia results from damage to the heavily myelinated fibers of the medial longitudinal fasciculus (MLF). The MLF is a paired neural tract that mediates communication between CN III (oculomotor) and CN VI (abducens) nuclei, allowing for coordinated horizontal eye movements. Unilateral MLF lesions can occur with lacunar stroke in the pontine artery distribution; however, bilateral lesions are classically seen in multiple sclerosis. (Choice A) A lesion of the abducens nerve would result in a lateral rectus palsy with inability to abduct the eye. (Choice B) The Edinger-Westphal nucleus provides preganglionic parasympathetic outflow to the eye. Damage to this structure would result in an ipsilateral fixed and dilated pupil that is nonreactive to light or accommodation. Edinger-Westphal nucleus (Choice C) Myasthenia gravis is characterized by antibody-mediated destruction of acetylcholine receptors at the motor end plate. Patients typically present with fluctuating and fatigable ocular (eg, diplopia, ptosis) and bulbar weakness (eg, dysphagia). Internuclear ophthalmoplegia is not characteristic. (Choice D) The lateral geniculate nucleus is located in the thalamus and relays visual information to the ipsilateral primary visual cortex. Damage to this structure would result in a contralateral homonymous hemianopsia. (Choice E) A lesion of the medial lemniscus would result in contralateral loss of vibration, proprioception, and light touch. (Choice G) Oculomotor nerve palsy is characterized by mydriasis, ptosis, and "down and out" deviation of the ipsilateral eye. This may occur with nerve compression (eg, posterior communicating artery aneurysm) or microvascular nerve ischemia (eg, diabetes mellitus). Nerve compression is more likely to cause mydriasis as parasympathetic fibers are situated on the periphery of the oculomotor nerve. (Choice H) A lesion of the optic chiasm would result in bitemporal hemianopsia. This may occur with anterior communicating artery aneurysms or tumors within the sella turcica (eg, craniopharyngioma, pituitary adenoma). (Choice I) A lesion of the optic nerve (eg, optic neuritis) would result in monocular vision loss. (Choice J) Trochlear nerve palsy is typically traumatic or idiopathic and presents with vertical diplopia that worsens when the affected eye looks down and toward the nose (eg, walking downstairs, reading). Patients may compensate by tucking the chin and tilting the head away from the affected eye. Educational objective: Internuclear ophthalmoplegia is a disorder of conjugate horizontal gaze that results from damage to the medial longitudinal fasciculus (MLF). The affected eye (ipsilateral to the lesion) is unable to adduct and the contralateral eye abducts with nystagmus. Unilateral MLF lesions can occur with lacunar stroke in the pontine artery distribution; however, bilateral lesions are classically seen in multiple sclerosis. References: Images in clinical medicine. Bilateral internuclear ophthalmoplegia in multiple sclerosis. (http://www.ncbi.nlm.nih.gov/pubmed/23323922) Internuclear ophthalmoplegia: MR-anatomic correlation. (http://www.ncbi.nlm.nih.gov/pubmed/3105283)

Question 6

A 32-year-old woman is brought to the emergency department by her husband after having an episode of generalized tonic-clonic seizure 30 minutes ago.  The patient was watching television when she suddenly started convulsing.  The seizure stopped spontaneously after a minute, but she has been lethargic and confused since then.  She has no prior history of seizures.  According to her husband, the patient has had headaches, fatigue, and irritability for the past 2-3 weeks.  She has also had several episodes of pain in her hand joints and wrists, which she attributed to an increased workload as a restaurant chef.  The patient has no significant medical history, recent travel, or sick contacts.  The only medication she takes is an oral contraceptive.  Temperature is 38.1 C (100.5 F), blood pressure is 130/80 mm Hg, pulse is 89/min, and respirations are 12/min.  The patient is lethargic but follows instructions.  She has an erythematous rash involving both cheeks.  There is no tongue laceration, but small oral mucosal ulcers are present.  The neck is supple, and other signs of meningeal irritation are negative.  Neurological examination shows normal muscle strength and deep tendon reflexes.  There is mild swelling and tenderness of the hand joints.  Laboratory results are as follows:  A noncontrast CT scan of the head is unremarkable.  Which of the following is the most likely diagnosis for this patient?

Accepted Answer

11ec25c8_d15d_440a_bc81_d5c43bd489ec_MD0003_00 This patient with a generalized tonic-clonic seizure has evidence of multijoint arthritis, facial rash, oral ulcers, and mild pancytopenia, suggesting a diagnosis of systemic lupus erythematosus (SLE). SLE is a multisystem inflammatory disorder that can affect almost any organ. Central nervous system manifestations commonly include vasculitis, thrombotic or thromboembolic disease (eg, antiphospholipid syndrome), seizures, and transverse myelitis. Cerebrospinal fluid findings may be normal or reflect mild inflammation (eg, slight elevation in CSF leukocytes, lymphocytosis). Given the subacute nature of this patient's symptoms, an inflammatory condition such as SLE is more likely than an infectious disease. (Choice A) Cerebral vein thrombosis usually results in a slowly worsening headache. Focal neurologic deficits and seizure can occur. However, a low-grade fever, malar rash, and pancytopenia would be atypical. (Choice B) Disseminated gonococcal infection often manifests with polyarthritis, tenosynovitis, and skin findings (eg, painless pustules). Disseminated gonococcus would not explain this patient's seizures or pancytopenia. (Choice C) Herpes encephalitis typically presents with acute (<1 week) altered mental status or focal neurologic findings. This patient has had symptoms for 2-3 weeks and has joint pain and a malar rash. (Choice D) Hyperthyroidism typically presents with weight loss, heat intolerance, tremor, anxiety, and loose stools. Seizure is not commonly associated with hyperthyroidism. (Choice E) Most adult patients with parvovirus infection are asymptomatic or have flu-like symptoms, although a minority may develop arthritis or aplastic anemia. Mild pancytopenia would be atypical, and seizures are extremely rare. (Choice F) Rheumatoid arthritis can cause symmetric hand arthritis, low-grade fever, anemia, and thrombocytopenia; however, seizures and a face rash are uncommon. Educational objective: Systemic lupus erythematosus is a multisystem inflammatory disease that can present with central nervous system findings such as a generalized tonic-clonic seizure.

Question 7

An 84-year-old woman is brought to the emergency department due to 2 weeks of progressive confusion.  She has a history of mild dementia and lives in an assisted living facility.  Her caregiver reports that during the past several months she has become progressively weaker, and she has fallen down on several occasions and is now using a walker.  In her usual state, the patient recognizes most of the staff, converses appropriately, and performs daily activities with minimal assistance; however, for the past week, she has been more confused and sleeping most of the time.  She has also developed a mild headache.  The patient has had no fever, vomiting, or urinary symptoms.  Her other medical problems include hypertension and osteoarthritis.  Blood pressure is 138/76 mm Hg and pulse is 74/min and regular.  She is somnolent but arousable.  The patient does not recognize her caregiver and gives several inaccurate answers but is able to follow simple instructions.  Muscle strength is 4/5 on the right side and 3/5 on the left.  Plantar reflex is upgoing on the left.  Which of the following is the most likely diagnosis?

Accepted Answer

11ec25c8_d15a_abf5_bc81_cfc08795c859_MD0003_00 This elderly patient with a history of falls has most likely developed a chronic subdural hematoma (SDH) due to traumatic head injury. SDH occurs when shearing forces tear the bridging veins, causing them to slowly bleed into the subdural space. subdural space Symptoms of SDH develop gradually as they occur secondary to the rupture of low-pressure vessels. Acute SDH typically produces symptoms 1-2 days after onset, whereas chronic SDH presents insidiously, weeks after the initial injury. Clinical manifestations of chronic SDH often include headache, somnolence, and confusion. Patients may also have focal neurologic deficits (eg, contralateral hemiparesis) due to compression of the underlying cerebral cortex. Non-contrast head CT usually shows a crescent-shaped hypodensity that crosses the suture lines. Non-contrast head CT (Choice A) Dementia typically presents with progressive cognitive dysfunction (eg, memory loss, language abnormalities) that interferes with the ability to perform activities of daily living. Decreased level of consciousness and focal neurologic deficits are not characteristic. (Choice B) Infarction of the internal capsule typically occurs due to lacunar stroke and can result in acute contralateral hemiparesis due to corticospinal tract injury in the posterior limb. However, lacunar infarcts typically lack impaired consciousness or cortical signs (eg, aphasia, neglect). (Choice C) Toxic-metabolic encephalopathy can be caused by infection, toxins, or metabolic derangements (eg, electrolytes disturbance, uremia, hyperammonemia). Patients typically present with confusion, lethargy, and neuromuscular findings (eg, bradykinesia, asterixis) due to global cerebral dysfunction. Focal neurologic deficits are not characteristic. (Choice D) Normal-pressure hydrocephalus can cause cognitive disturbances, although headaches and weakness worse on one side than the other is atypical. Gait difficulties would be characterized by ataxia, and urinary incontinence is classic. Brain imaging reveals ventricular enlargement that is out of proportion to sulci enlargement. (Choice E) Transient limb weakness following partial seizure activity is known as postictal (Todd) paralysis. Although subdural hematoma may cause seizure with postictal paresis and confusion, other features of seizure (eg, convulsions, tongue-biting, incontinence) are not evident in this patient. Educational objective: Elderly patients are at higher risk for subdural hematoma due to increased fall risk and cerebral atrophy. Chronic subdural hematoma often presents insidiously weeks after the initial injury with headache, somnolence, confusion, and focal neurologic deficits. References: Causes, epidemiology, and risk factors of chronic subdural hematoma. (http://www.ncbi.nlm.nih.gov/pubmed/10918008) Chronic subdural haematoma in the elderly. (http://www.ncbi.nlm.nih.gov/pubmed/11807186)

Question 8

A 48-year-old man comes to the emergency department due to 3 days of nausea and vomiting.  For the past 4 weeks, the patient has also had increasingly severe headaches.  He had a kidney transplant 2 years ago for glomerulonephritis and takes immunosuppressants.  Temperature is 38.2 C (100.7 F), blood pressure is 140/90 mm Hg, and pulse is 70/min.  The patient is awake but drowsy.  Examination shows neck stiffness.  Cranial nerves are intact.  Muscle strength is normal, but deep tendon reflexes are brisk.  CT scan of the head shows no other abnormalities.  Results of cerebrospinal fluid analysis results are as follows:  Which of the following is the most likely cause of this patient's symptoms?

Accepted Answer

Explanation: 11ec25c8_d144_3dbb_bc81_afd671a1601a_MD0003_00 This patient's progressive headache, vomiting, low-grade fever, and nuchal rigidity raises suspicion for meningitis. Most cases of meningitis are caused by common bacterial pathogens (eg, Streptococcus pneumoniae, Neisseria meningitidis). However, these organisms typically cause severe, life-threatening manifestations within hours or a few days of inoculation (Choice C). In this case, there are several features that suggest cryptococcal meningitis, including the following: Use of immunosuppressant medication: Cryptococcus neoformans is inhaled and subsequently forms a lifelong latent infection in the lung. Most patients remain asymptomatic, but those with severe immunocompromise (eg, AIDS, solid-organ transplantation, immunosuppressant medications) can develop reactivation with CNS spread. Subacute manifestations: Cryptococcus produces capsular proteins that clog cerebrospinal fluid outflow, leading to slowly progressive symptoms (eg, headache, vomiting, confusion) of elevated intracranial pressure. Characteristic lumbar puncture findings: Cryptococcal meningitis is marked by elevated opening pressure and cerebrospinal fluid evidence of lymphocytosis, mildly elevated white blood cell count, low glucose, and mildly elevated protein. Diagnostic confirmation requires identification of the encapsulated yeast in cerebrospinal fluid (eg, India ink stain) or on polysaccharide antigen testing. (Choice B) Herpes encephalitis occurs when herpes simplex type 1 moves in a retrograde fashion along the trigeminal nerve and attacks the temporal lobe. Patients usually have acute (<1 week) fever, confusion, seizure and/or neurologic deficits. Cerebrospinal fluid analysis typically shows significant red blood cells. This patient's normal CT scan of the head and long-standing symptoms make this diagnosis less likely. (Choice D) Patients with subarachnoid hemorrhage can have initial normal noncontrast head CT. However, cerebrospinal fluid analysis generally reveals significant red blood cells that do not decrease in quantity between tubes 1 and 4. In addition, patients generally have sudden-onset, severe headache, not one present for weeks. (Choice E) Toxoplasma encephalitis typically presents over weeks with headache, focal neurologic deficits, and/or seizure. CT scan of the head generally shows numerous ring-shaped lesions in the brain parenchyma. Most cases occur in patients with advanced AIDS. Educational objective: Patients with severe immunosuppression (eg, AIDS, solid-organ transplantation, immunosuppressant medications) are at increased risk for cryptococcal meningitis. Most cases are marked by subacute, progressive headache, vomiting, fever, and nuchal rigidity. Cerebrospinal fluid typically shows lymphocytosis with a mildly elevated white blood cell count, mild protein elevation, and low glucose.

Question 9

A 68-year-old hospitalized man is evaluated for new-onset leg weakness. Six days ago, he was admitted to the hospital due to fever, right leg pain, and swelling. Physical examination showed right lower extremity edema, erythema, warmth, and tenderness from the foot to the midcalf. Leukocyte count was 16,000/mm³, and venous Doppler ultrasonography revealed patent leg veins without thrombosis. Blood cultures grew Staphylococcus aureus. The patient was treated with intravenous antibiotics, and his leg symptoms improved. However, this morning he had trouble getting out of bed due to significant leg weakness. The patient has a history of hypertension, type 2 diabetes mellitus, coronary artery disease, and systolic heart failure. He also has chronic low back pain from a work-related injury. The patient has had worsening mid-back pain over the last 2 days. Temperature is 38 C (100.4 F), blood pressure is 130/80 mm Hg, and pulse is 88/min. Physical examination shows normal mental status and cranial nerves. Abdominal examination reveals a suprapubic mass. There is midline tenderness over the lower thoracic vertebral area. Upper extremity strength is normal, but he is not able to lift either lower extremity against gravity. Which of the following is the best next step in management of this patient?

Accepted Answer

11ec25c8_d147_4afd_bc81_694e33bd3de2_MD0003_00 Spinal epidural abscess (SEA) is a rare infection of the epidural space that may threaten the spinal cord and result in paralysis. Most cases are due to hematologic spread from a distant infection (eg, cellulitis, bone/joint), intravenous drug use, or direct inoculation during a spinal procedure. Staphylococcus aureus is the most common (65%) causative organism. SEA classically results in the triad of fever, back pain, and neurologic deficits; however, all 3 symptoms are present in a minority of cases. Most patients initially develop severe, focal back pain that progresses over days to nerve root pain ("shooting/electric") and more severe neurologic manifestations (motor weakness, sensory changes, bowel/bladder dysfunction, paralysis). The diagnostic test of choice is MRI of the spine due to high sensitivity early in the course of illness and excellent localization of infection extent. Treatment with broad- spectrum antibiotics and aspiration/surgical decompression is usually required. MRI of the spine (Choice A) Brain lesions usually manifest with unilateral neurologic findings. This patient with isolated, bilateral lower extremity weakness, S aureus bacteremia, and point tenderness over his thoracic spine is much more likely to have a spinal cord process. (Choice B) The suprapubic mass is likely a distended bladder due to urine retention from spinal cord injury. Abdominal imaging is not required at this time. (Choice C) S aureus bacteremia can cause infective endocarditis, which may manifest with systemic (eg, fever, myalgia, malaise), skin (eg, splinter hemorrhages), and pulmonary symptoms (eg, dyspnea, chest pain). This patient likely developed SEA from S aureus cellulitis and has significant bilateral lower extremity weakness; urgent MRI of the spine is needed. (Choice D) Lumbar puncture is required for suspected meningitis (fever, headache, altered mental status, meningeal symptoms) but is not typically performed in patients with suspected SEA due to low diagnostic sensitivity and risk of central nervous system inoculation. (Choice F) Nerve conduction studies are useful in peripheral nervous system dysfunction (eg, entrapment syndrome, polyneuropathies); however, this patient has bilateral weakness, fever, focal spine tenderness, and known S aureus bacteremia. Due to high risk of SEA, MRI of the spine should not be delayed. (Choice G) A tagged leukocyte scan is sometimes used to diagnose osteomyelitis, especially in the setting of metal implants (which may preclude MRI); however, MRI is more sensitive for SEA and should be performed in most patients. Educational objective: Spinal epidural abscess may present with fever, focal back pain, and neurologic dysfunction. Evaluation includes urgent MRI of the spine. Most patients require treatment with broad-spectrum intravenous antibiotics and prompt drainage/surgery.

Question 10

A 40-year-old man comes to the emergency department due to severe headache associated with photophobia and nausea for the past several hours.  The patient reports mild cold symptoms a week ago.  He has a 2-year history of hypertension and has smoked a pack of cigarettes daily for 15 years.  His father died of stroke at the age of 75.  Temperature is 37.7 C (100 F), blood pressure is 170/100 mm Hg, and pulse is 92/min and regular.  He appears to be uncomfortable and had an episode of nonbilious vomiting in the emergency department.  Neurologic examination shows 4/5 motor strength and 2+ deep tendon reflexes bilaterally in the upper and lower extremities.  Sensation to light touch and pinprick is normal.  CT scan of the head without contrast is shown below.  Which of the following is the most likely cause of this patient's headache?

Accepted Answer

11ec25c8_d159_9a84_bc81_a153e77bf3e2_MD0003_00 This hypertensive patient with acute severe thunderclap headache (maximal intensity reached in <1 minute) and symptoms of meningeal irritation (eg, nausea/vomiting, photophobia) is suffering from nontraumatic subarachnoid hemorrhage (SAH). Other features may include seizure or focal neurologic deficits (uncommon). Nontraumatic SAH is most commonly due to a ruptured saccular (berry) aneurysm. subarachnoid hemorrhage CT scan without contrast is the preferred initial imaging study and typically reveals acute hemorrhage (high-density signal) surrounding the brainstem and basal cisterns. This patient has bleeding in the frontal interhemispheric cistern (red arrow), left sylvian cistern (blue arrow), and peripontine cisterns (green arrows). Those with negative head CT scans and suspected SAH should undergo lumbar puncture, which classically reveals elevated opening pressure and xanthochromia. Patients with a confirmed diagnosis should be evaluated further with cerebral angiography and treated with surgery (craniotomy with aneurysm clipping) or endovascular methods (coiling/stenting of the aneurysm). (Choice A) Cerebral amyloid angiopathy is the second most common cause of intracerebral hemorrhage after hypertension and is typically lobar in location. It most often occurs in patients age >75 and is due to abnormal beta-pleated amyloid protein deposition in cerebral blood vessels, leading to arteriopathy and vessel fragility. Cerebral amyloid angiopathy (Choice B) Aseptic meningitis can present with severe headache, nausea/vomiting, photophobia, neck stiffness, and fever; however, CT scan of the head is usually normal. (Choice C) Cerebral arteriovenous malformation is the most common cause of intracerebral hemorrhage in children. (Choice D) Cerebral venous thrombosis typically occurs in patients with hypercoagulable conditions (eg, contraceptive use, malignancy) and presents with headache, confusion, seizures, and focal neurologic deficits. The diagnosis is confirmed using MRI of the brain with venography as CT scan often reveals no abnormalities. (Choice E) Hypertensive encephalopathy is characterized by marked blood pressure elevation with progressive headache, nausea/vomiting, and nonlocalizing neurologic symptoms (eg, confusion, restlessness) due to cerebral edema. Acute hemorrhage on CT scan of the head is not characteristic. (Choice G) Vertebral artery dissection typically occurs with head/neck trauma and presents with local pain and focal neurologic deficits due to cerebral ischemia caused by thromboembolism or hypoperfusion. Concomitant disruption of the posterior inferior cerebellar artery often leads to lateral medullary (Wallenberg) syndrome (vertigo/nystagmus, ipsilateral cerebellar signs, loss of pain/temperature sensation in the ipsilateral face and contralateral body, bulbar weakness, ipsilateral Horner syndrome). Educational objective: Nontraumatic subarachnoid hemorrhage is most commonly due to ruptured saccular (berry) aneurysm and typically presents with thunderclap headache and symptoms of meningeal irritation (eg, nuchal rigidity, photophobia, nausea). Noncontrast CT scan usually reveals acute bleeding around the brainstem and basal cisterns. References: Worst headache and subarachnoid hemorrhage: prospective, modern computed tomography and spinal fluid analysis. (http://www.ncbi.nlm.nih.gov/pubmed/9737490) Management of aneurysmal subarachnoid hemorrhage. (http://www.ncbi.nlm.nih.gov/pubmed/19114880)

Question 11

A 38-year-old woman comes to the emergency department due to a 3-day history of left arm and leg numbness.  She also reports urinary urgency and incontinence but has no fever or dysuria.  The patient was diagnosed with multiple sclerosis 10 years ago after an episode of right eye vision loss.  She was taking disease-modifying therapy but stopped after being symptom-free for several years.  Temperature is 37 C (98.6 F), blood pressure is 130/80 mm Hg, and pulse is 88/min.  Sensation to light touch and pin prick is diminished on the left side.  Neuroimaging reveals new areas of demyelination compared to previous MRIs.  Which of the following is the most appropriate next step in management of this patient?

Accepted Answer

This patient with multiple sclerosis (MS), who now has new neurologic deficits (eg, left hemisensory loss, urinary incontinence) and areas of demyelination in the setting of medication discontinuation, is likely experiencing an acute MS exacerbation. Patients with MS exacerbation and disabling symptoms are typically treated with glucocorticoids (eg, intravenous methylprednisolone) as this hastens neurologic recovery. Mild sensory symptoms generally do not require corticosteroids. Plasmapheresis should be considered in patients with MS flare who are refractory to corticosteroid therapy (Choice G). (Choice A) Baclofen is a muscle relaxant that can be used to treat symptoms of muscle spasticity in MS; however, it does not hasten neurologic recovery from an acute MS flare. (Choices B and F) There is not enough compelling evidence to recommend the use of cyclophosphamide or intravenous immunoglobulins for MS exacerbation. (Choice C) Gabapentin may improve symptoms of neuropathic pain in patients with MS; however, it would not hasten neurologic recovery from an acute MS flare. (Choice E) Interferon beta and glatiramer acetate are disease-modifying agents used for chronic maintenance therapy as they decrease the frequency of exacerbations in patients with relapsing-remitting or secondary, progressive forms of MS. These agents have no proven role in the treatment of acute exacerbations. Educational objective: Acute exacerbations of multiple sclerosis with disabling neurologic symptoms are typically treated with glucocorticoids (eg, intravenous methylprednisolone). Plasmapheresis should be considered in patients who are refractory to corticosteroids. Interferon beta or glatiramer acetate can be used as chronic maintenance therapy in patients with relapsing-remitting or secondary, progressive forms of multiple sclerosis. References: Current and emerging therapies in multiple sclerosis: a systematic review. (http://www.ncbi.nlm.nih.gov/pubmed/22783370) Management of acute exacerbations in multiple sclerosis. (http://www.ncbi.nlm.nih.gov/pubmed/20182574)

Question 12

A 20-year-old woman comes to the emergency department in January due to severe myalgias, fever, headache, and nausea that developed 4 hours ago. She has also had several episodes of nonbloody emesis over the past hour. The patient was feeling well this morning before her symptoms started. She does not use tobacco, alcohol, or illicit drugs. The patient has no known medication allergies. Temperature is 40.3 C (104.5 F), blood pressure is 100/70 mm Hg, and pulse is 115/min. She is confused and has difficulty concentrating. Lung examination is normal. There is marked tenderness to palpation of the muscles along her extremities, which are mottled and cool to the touch. Complete blood count reveals a white blood cell count of 28,000/mm³ with 12% bands. A noncontrast head CT is unremarkable. Which of the following is the best next step in management of this patient?

Accepted Answer

11ec25c8_d15e_a39c_bc81_f1a966702521_MD0003_00 This young adult has an abrupt onset of fever, vomiting, and severe myalgias with findings of mottled skin, cool extremities, and confusion. This rapid progression of symptoms over 4 hours is concerning for meningitis with septicemia caused by Neisseria meningitidis. Early meningococcal infection typically causes an acute onset of nonspecific symptoms (eg, fever, headache, vomiting). However, key features that should prompt consideration of meningococcal disease include severe myalgias (eg, marked leg pain), which are often more painful than those in viral illnesses, and signs of poor perfusion (eg, cold hands/feet, mottled skin) reflecting myocardial depression (possibly interleukin-6-mediated). In addition, symptoms progress rapidly (over 12-24 hours) and may include a petechial/purpuric rash, nuchal rigidity, and altered mental status. Leukocytosis with elevated immature white blood cells (ie, bands) is common. Prompt recognition and evaluation of early meningococcal infection is crucial because the illness can quickly progress to shock, disseminated intravascular coagulation, multiorgan failure, and death. Patients with suspected meningococcal infection should undergo a lumbar puncture. Blood cultures should be drawn prior to antibiotic therapy, which should not be delayed while waiting for lumbar puncture to be performed. Treatment is ceftriaxone. (Choices A and E) Influenza (often treated with supportive care and oseltamivir) can cause the abrupt onset of fever, headache, and myalgias and, in rare cases, be complicated by myositis and encephalopathy. Although this patient should be tested for influenza, her lack of respiratory symptoms, rapid deterioration, altered mental status, severe myalgias, leukocytosis with bandemia, and skin mottling warrant prompt evaluation and empiric treatment for bacterial meningitis. (Choice B) Gastroenteritis, which can present with sudden-onset vomiting and fever, can lead to dehydration requiring intravenous fluids and antiemetics. However, this patient's severe myalgias and altered mental status make this diagnosis unlikely. Although the patient should receive fluids and antiemetics, holding her for observation only without performing additional workup and providing empiric meningitis treatment would be inappropriate. (Choice C) Lower extremity pain and tachycardia may raise suspicion for pulmonary embolism, which can be diagnosed by chest CT scan with contrast. However, symptoms also typically include dyspnea and cough; high fever, altered mental status, and marked leukocytosis would not be expected. Educational objective: Early meningococcal meningitis presents with nonspecific symptoms that rapidly progress over 12-24 hours and may include a petechial/purpuric rash, nuchal rigidity, and altered mental status. Signs of poor perfusion and severe myalgias should prompt a lumbar puncture to evaluate for Neisseria meningitidis infection. References: Meningococcal sepsis. (http://www.ncbi.nlm.nih.gov/pubmed/20485712) Which early 'red flag' symptoms identify children with meningococcal disease in primary care? (http://www.ncbi.nlm.nih.gov/pubmed/21375891)

Question 13

A 32-year-old man is brought to the emergency department after his coworkers found him confused, disoriented, and bleeding from the nose. The patient's medical history is significant for an episode of major depression. He is currently taking no medication. According to his friends, he was in his normal state of health this morning when he came to work. He then spent the morning cutting several bushes and trees to clean the area for a new road construction. Temperature is 42 C (108 F), blood pressure is 110/70 mm Hg, respirations are 16/min, and pulse is 120/min and regular. BMI is 40 kg/m². The patient's skin is warm and dry, and his neck is supple with no stiffness. The pupils are symmetric, midsize, and reactive to light. There is active bleeding from the right nostril. Deep tendon reflexes are symmetric. No Babinski sign is present. The patient moves all the extremities but is unable to speak or follow simple commands. Skin on his extremities has several scratch marks, likely from thorn injuries. Which of the following is the most likely diagnosis?

Accepted Answer

11ec25c8_d147_e73e_bc81_8b8389d781f0_MD0003_00 This patient with severe hyperthermia, encephalopathy, and epistaxis that developed while working outside has exertional heat stroke (EHS). EHS is characterized by core temperature ≥40 C (104 F) with CNS dysfunction (eg, altered mental status). Unlike nonexertional heat stroke, which typically affects individuals at the extremes of age who are incapable of obtaining adequate fluids and removing themselves from a hot environment, EHS occurs most commonly in those exposed to hot/humid environments while performing extreme physical activity (eg, landscaping, as with this patient). Risk factors include obesity, poor physical fitness, lack of acclimatization, and certain medications/drugs (eg, anticholinergics, alcohol, amphetamines) that impair thermoregulation. In addition to CNS dysfunction, other common manifestations of EHS include tachycardia, tachypnea, and flushing. Diaphoresis may or may not be present, depending on fluid status, and hypotension may occur. Complications include rhabdomyolysis, disseminated intravascular coagulation (DIC) (resulting in coagulopathic bleeding, as seen in this patient with epistaxis), and end-organ dysfunction (ie, renal/hepatic failure). Management includes patient stabilization (eg, airway, breathing, circulation), rapid cooling techniques (eg, ice water immersion), fluid resuscitation, and treatment of end-organ dysfunction. (Choice A) Anticholinergic toxicity can cause confusion, tachycardia, and temperature elevations; however, severe hyperthermia ≥40 C (104 F) is unexpected. Furthermore, most patients have other signs of anticholinergic toxicity (eg, pupillary dilation, flushing). (Choice C) Malignant hyperthermia affects genetically susceptible individuals during anesthesia involving agents like halothane and succinylcholine. Diffuse muscle rigidity is also expected. (Choice D) Meningococcal meningitis can cause fever and mental status changes and is associated with DIC. However, it would be expected to cause neck stiffness and petechial rash. Furthermore, it would be unlikely to cause such high fevers or develop so rapidly in a patient who was in his normal state of health this morning. (Choice E) Salicylate toxicity causes fever and mental status changes; however, patients typically present with nausea and vomiting. Furthermore, significant hyperpnea is typically seen due to activation of the medullary respiratory center. Educational objective: Heat stroke is characterized by core temperature ≥40 C (104 F) with CNS dysfunction (eg, altered mental status). It occurs most commonly in those exposed to hot/humid environments while performing extreme activities. Complications include rhabdomyolysis, disseminated intravascular coagulation, and end-organ dysfunction.

Question 14

A 54-year-old man comes to the office due to shortness of breath at night. He has also felt weak but has had no dyspnea on exertion or leg swelling. His wife adds that the patient has had occasional cough while eating and that his speech is slightly slurred. He has no chronic medical conditions and is a lifelong nonsmoker. Vital signs are within normal limits. BMI is 25 kg/m². On physical examination, the soft palate and uvula are completely visualized. The tongue is mildly atrophic with visible fasciculations. The lungs are clear on auscultation and heart sounds are normal. The abdomen is flat and moves outward during expiration. There is no extremity edema. Chest x-ray shows elevated hemidiaphragms but no parenchymal opacities. Compared to a healthy individual's tests, this patient's pulmonary function testing is most likely to reveal which of the following findings?

Accepted Answer

11ec25c8_d15c_59a8_bc81_fb250a84d05e_MD0003_00 This patient with shortness of breath at night has features concerning for amyotrophic lateral sclerosis (ALS). Dysphagia (eg, coughing when eating), dysarthria, and tongue atrophy with fasciculations are manifestations of bulbar-onset ALS. Diaphragmatic involvement (ie, diaphragmatic weakness) can lead to paradoxical breathing movement (ie, expansion of the abdomen on expiration rather than inspiration) and elevation of the diaphragm on chest x-ray. This results in poor inspiratory strength, shallow breathing, and hypoventilation. Patients often report orthopnea (eg, shortness of breath while in bed) because when they are in a recumbent position, gravity is not assisting with lung expansion. Like in all causes of respiratory muscle weakness (eg, Guillain-Barré syndrome), pulmonary function studies in ALS demonstrate a restrictive pattern due to an extrinsic limitation of lung expansion. This includes a reduction in total lung capacity, forced vital capacity (FVC) (the amount of air forcibility exhaled after maximal inspiration), and forced expiratory volume in 1 second (FEV₁), resulting in a normal or increased FEV₁/FVC ratio. Maximal inspiratory pressure (reflecting diaphragmatic strength) and maximal expiratory pressure (reflecting abdominal strength) are also reduced. However, because the pulmonary parenchyma and alveoli are unaffected in ALS, the diffusion capacity of the lungs for carbon monoxide (DLCO), a measurement of alveolar gas exchange, remains normal. This contrasts with intrinsic pulmonary causes of restriction (eg, pulmonary fibrosis), which limit diffusion of gas across the alveoli, reducing the DLCO. (Choices A, C, and E) A decrease in DLCO suggests impaired gas exchange due to intrinsic lung pathology. This patient's restrictive lung disease is due to an extrapulmonary cause: chest wall and diaphragm weakness due to ALS. (Choice D) Patients with chest wall and diaphragm weakness have lower vital capacity due to an inability to fully expand the lungs. Even if forced expiration is minimally impaired, which is unlikely in this patient with weakened respiratory musculature, this results in decreased forced vital capacity. Educational objective: Amyotrophic lateral sclerosis often causes weakness of the muscles of respiration, resulting in a restrictive pattern on spirometry (ie, reduced vital capacity, forced expiratory volume in 1 second [FEV1], forced vital capacity [FVC] with a normal or increased FEV1/FVC ratio), with reduced maximal inspiratory and expiratory pressure. The diffusion capacity for carbon monoxide, a measurement of alveolar gas exchange, is preserved.

Question 15

A 43-year-old man presents to your office complaining of periodic involuntary head turning and head fixation to the right side.  Physical examination reveals a hypertrophied left sternocleidomastoid muscle.  What is the most likely diagnosis?

Accepted Answer

This patient suffers from torticollis, a focal dystonia of the sternocleidomastoid muscle. Dystonia is defined as sustained muscle contraction resulting in twisting, repetitive movements, or abnormal postures. It may be focal (affecting only one muscle) or diffuse. Torticollis can be congenital, idiopathic, secondary to trauma or local inflammation, or drug-induced. Medications commonly responsible include the typical antipsychotics, metoclopramide, and prochlorperazine. (Choice A) Parkinson's disease is characterized by resting tremors, bradykinesia, rigidity, and postural instability. It is not associated with focal dystonia. (Choice B) Essential tremor is a form of intention tremor affecting the upper extremities, head, voice, and other body parts. Essential tremor resolves during sleep and often improves with alcohol consumption. Rigidity and dystonia are absent. (Choice C) Chorea is a movement disorder characterized by brief, irregular, unintentional muscle contractions. Movements tend to flow from one to another but are not repetitive or rhythmic. (Choice D) Akathisia is a sensation of restlessness that causes the patient to move frequently. (Choice F) Athetosis refers to slow, writhing movements that typically affect the hands and feet. Athetoid movements are characteristic of Huntington's disease. Chorea and athetosis often occur together. (Choice G) Tourette syndrome is a disorder characterized by involuntary, stereotyped, repetitive movements and vocalizations called tics. Common tics include shoulder shrugging, blinking, grimacing, and coprolalia (swearing). (Choice H) Hemiballismus is unilateral, violent arm flinging caused by damage to the contralateral subthalamic nucleus. Hemiballismus is very disruptive but tends to be self-limited. (Choice I) Myoclonus is the involuntary jerking of a muscle or muscle group. Unlike chorea, it can be rhythmic or patterned and is usually initiated by contraction or relaxation. Educational Objective: Torticollis is a common form of focal dystonia involving the sternocleidomastoid muscle. It can occur idiopathically but is very often medication-related. Discontinuation of the causative agent(s) may improve symptoms.

Question 16

A 47-year-old woman comes to the office due to a recent change in mood.  The patient says, "I began feeling really down about 3 months ago, but I can't think of anything that may have caused this.  I'm also much more irritable with my family and friends than I used to be."  She has no history of psychiatric illness.  She also notes, "I've been having a lot of problems at work.  It's a lot harder to plan and organize my day than it used to be, and I've been missing a lot of deadlines."  The patient is very concerned about her symptoms because her father died in his mid-60s, 10 years after developing similar symptoms.  Temperature is 36.9 C (98.4 F), blood pressure is 119/77 mm Hg, pulse is 64/min, and respirations are 14/min.  She is fully oriented but scores a 24/30 on the Montreal Cognitive Assessment (normal: ≥26), losing points on tests of executive function.  On examination, she demonstrates abrupt and random jerking movements throughout the extremities and face.  Extraocular movement testing reveals delayed initiation of saccades, but slit lamp examination is normal.  Gait is normal.  The patient is unable to maintain her grip on grip testing.  Sensation is intact in the distal extremities.  Which of the following is the most likely diagnosis?

Accepted Answer

11ec25c8_d148_aa8f_bc81_2fc974f0f10f_MD0003_00 This patient's cognitive dysfunction, psychiatric symptoms, chorea (ie, abrupt, jerking movements that seem to travel from one muscle group to the next), delayed saccades, motor impersistence (ie, inability to sustain grip), and family history are consistent with a diagnosis of Huntington disease (HD). HD is an autosomal dominant CAG trinucleotide repeat expansion disease. Psychiatric manifestations may include depression, irritability, psychosis, and/or obsessive-compulsive symptoms. Because motor symptoms of HD are often subtle in its early stages, psychiatric and cognitive symptoms may be the earliest manifestations. With no known disease-modifying treatment, HD is inevitably fatal; death usually occurs 10-20 years following initial symptom onset. (Choice A) Severe major depressive disorder can present with significant cognitive impairment in elderly patients (often called "pseudodementia"), which may be mistaken for a dementing syndrome. This patient's clinical presentation is more consistent with HD. (Choices B and F) Ataxia (impaired smooth movement coordination) is the hallmark finding of both Friedreich ataxia and spinocerebellar ataxia and often presents as impaired gait; it is notably absent in this patient. Friedreich ataxia is an autosomal recessive GAA trinucleotide repeat expansion disease characterized by neurological impairment (eg, limb ataxia, sensory neuropathy), insulin resistance, and cardiomyopathy. Spinocerebellar ataxia type 1 is an autosomal dominant disorder that presents with cerebellar ataxia and cranial nerve dysfunction (eg, dysarthria). (Choice C) Frontotemporal dementia presents with executive dysfunction and personality change. This patient's presentation with chorea and saccades is better explained by HD. (Choice E) Parkinson disease is characterized by resting tremor, rigidity, and bradykinesia. (Choice G) Wilson disease is an autosomal recessive disorder of impaired copper metabolism that presents with liver disease and neuropsychiatric findings. Although Wilson disease may be characterized by prominent neurological and psychiatric findings (eg, dysarthria, dystonia, depression), essentially all patients with neurological signs/symptoms have evidence of corneal copper accumulation on slit lamp examination (ie, Kayser-Fleischer rings). Educational objective: Huntington disease (HD) presents with psychiatric symptoms (eg, depression, irritability), cognitive impairment, and chorea. HD is an autosomal dominant CAG trinucleotide repeat expansion disorder with no known disease-modifying treatment. References: Huntington's disease: a clinical review. (http://www.ncbi.nlm.nih.gov/pubmed/28817209)

Question 17

A 76-year-old woman is brought to the emergency department by her son with 2 days of intermittent confusion, daytime somnolence, and decreased oral intake.  Her medical conditions include mild dementia, hypertension, and type 2 diabetes mellitus.  The son says that the patient has been talking to people who are not there and wandering around the house in the middle of the night.  She has no history of recent falls.  Medications include valsartan and metformin.  Temperature is 37.2 C (99 F), blood pressure is 100/60 mm Hg, and pulse is 100/min and regular.  The patient is easily distracted and disoriented to time and place.  Neck is supple.  She can move all 4 extremities.  Cardiopulmonary examination is normal.  Abdomen is soft and nontender.  Fingerstick glucose level is 155 mg/dL.  Which of the following is the most appropriate next step in management?

Accepted Answer

11ec25c8_d144_d9fc_bc81_897c669669de_MD0003_00 Mental status changes are commonly due to delirium; however, delirium is frequently under-recognized. The Confusion Assessment Method (CAM) improves delirium identification and differentiates it from other cognitive disturbances (eg, dementia, depression). The CAM assesses 4 fundamental features of delirium: acute change (eg, hours to days) and fluctuating course (eg, intermittent)inattention (eg, easy distractibility)disorganized thinking (eg, confusion)altered consciousness (eg, daytime somnolence) acute change (eg, hours to days) and fluctuating course (eg, intermittent) inattention (eg, easy distractibility) disorganized thinking (eg, confusion) altered consciousness (eg, daytime somnolence) This patient has all 4 features (delirium diagnosis formally requires both features 1 and 2 plus either feature 3 or 4). Notably, in patients with preexisting cognitive deficits (eg, advanced age, dementia), delirium may be the only sign of acute illness (eg, afebrile, no dysuria). This patient also has hallucinations and sleep-wake reversal, which are common with delirium but not essential for diagnosis. Delirium indicates acute brain failure and should be considered a medical emergency. Common causes of delirium include infection (eg, cystitis, pneumonia), adverse drug effects, dehydration, and electrolyte/metabolic disturbances. Initial evaluation includes a history and physical examination, medication review, complete blood count, metabolic panel, and urinalysis. This will identify most causes of delirium; however, advanced workup should follow any abnormal clinical findings or negative initial evaluation. (Choices A and C) CT scan of the head is indicated in patients with altered mental status when history (eg, trauma, anticoagulation) or physical examination (eg, focal weakness, papilledema) suggests intracranial pathology. Lumbar puncture is typically used to diagnose meningitis or encephalitis. However, this patient has no concerning history, focal neurologic findings, fever, or meningismus, so more common delirium causes should be ruled out first. If initial workup is negative or treatment response is inadequate, neuroimaging and lumbar puncture should be considered. (Choice B) Electroencephalogram (EEG) can identify occult seizures as the cause of altered mental status. Patients with a concerning history (eg, stroke, trauma, critical illness) or inadequate response to delirium treatment require EEG to rule out nonconvulsive seizures as a cause of delirium. (Choice D) Ammonia is neurotoxic and elevated levels can cause delirium. Hyperammonemia most commonly results from acute or chronic liver failure (eg, cirrhosis), which would be evident on initial evaluation (eg, jaundice, aminotransferase elevation). Educational objective: Delirium is common but under-recognized. The Confusion Assessment Method improves delirium identification using its fundamental features of acute-onset, fluctuation, inattention, disorganized thinking, and altered consciousness. Initial evaluation is directed at the most common causes, but further assessment should follow any abnormal findings or negative initial evaluation. References: Evaluation and management of delirium in hospitalized older patients. (http://www.ncbi.nlm.nih.gov/pubmed/19069020)

Question 18

A 38-year-old hospitalized woman is evaluated for new-onset confusion. The patient has a prolonged history of Crohn disease and was admitted 2 days ago due to worsening abdominal pain, nausea, and watery diarrhea. She tested positive for Clostridioides (formerly Clostridium) difficile infection and is receiving oral vancomycin and intravenous fluids. Her gastrointestinal symptoms have been improving, but since yesterday the patient has been incoherent, disoriented, and unsteady. She has no other medical conditions but has had small bowel resections due to stricture and fistula in the past and has lost 10 kg (22 lbs) over the past 6 months. The patient does not use tobacco, alcohol, or illicit drugs. Temperature is 36.6 C (98 F), blood pressure is 120/70 mm Hg, and pulse is 92/min with no orthostatic changes. BMI is 19.5 kg/m². On examination, she is not oriented to time or place. Pupils are equal and reactive to light. Abduction of the right eye is limited and elicits bilateral horizontal nystagmus. Motor strength and deep tendon reflexes are normal throughout. Finger-to-nose and heel-to-shin testing are normal, but the gait is wide based. Which of the following is the most likely cause of this patient's neurologic symptoms?

Accepted Answer

11ec25c8_d15b_4836_bc81_a1e9f218886b_MD0003_00 This patient with Crohn disease had multiple small bowel resections complicated by significant weight loss, a finding that suggests malnutrition. She developed altered mental status, a lateral-gaze palsy (eg, limited eye abduction) with horizontal nystagmus, and a wide-based gait after receiving intravenous fluids, which raises concern for Wernicke encephalopathy (WE). WE is a neurologic complication of thiamine deficiency; it classically manifests as the triad of ataxia, encephalopathy (eg, lethargy, disorientation), and oculomotor dysfunction (eg, nystagmus, gaze palsies). It is usually associated with long-standing alcohol abuse; however, WE can be associated with any form of chronic malnourishment (eg, short-gut syndrome, anorexia). Iatrogenic WE can be precipitated in malnourished patients by the administration of dextrose (which this patient likely received as a maintenance fluid), which depletes the last remaining stores of thiamine, a vitamin cofactor for enzymes involved in glucose metabolism. There are no diagnostic laboratory studies to confirm WE; therefore, intravenous thiamine supplementation should be promptly administered if the diagnosis is suspected. Korsakoff syndrome, a late-stage complication of WE, is characterized by significant retrograde and anterograde amnesia, often with confabulation. Up to 80% of patients with alcohol use disorder who have WE develop Korsakoff syndrome; however, it occurs less frequently in WE patients who are nonabusers. (Choice A) Immune-mediated demyelination occurs in a variety of diseases, including Guillain-Barré syndrome (GBS) and multiple sclerosis. GBS typically causes a rapidly progressive, ascending paralysis with hyporeflexia, and multiple sclerosis causes neurologic deficits (eg, diplopia, focal weakness, bowel/bladder dysfunction) disseminated in time and space. Altered mentation is rare and occurs subacutely with severe disease. (Choice B) Medication-induced delirium is common with anticholinergics, benzodiazepines, or opiate medications, but is not expected with vancomycin. Although delirium is associated with confusion and disorientation, focal neurologic deficits are unexpected. (Choice C) Bacterial or fungal meningoencephalitis can cause focal neurologic deficits and altered mentation, but they are typically associated with fever, headache, and meningismus. (Choice E) Symptoms of vertebrobasilar artery occlusions are dependent on the area involved but often cause ataxia or altered mentation. However, diplopia, hemiparesis/paraparesis, or Wallenberg syndrome (loss of pain/temperature in the ipsilateral face and contralateral body) are common. In addition, cerebellar examinations (eg, finger-to-nose; heel to shin) are typically positive. Educational objective: Wernicke encephalopathy is a neurologic complication of thiamine deficiency; it classically manifests as the triad of ataxia, encephalopathy, and oculomotor dysfunction. It is usually associated with long-standing alcohol abuse; however, it may be caused by any disorder that causes chronic malnourishment (eg, short-gut syndrome). Treatment is with intravenous thiamine.

Question 19

A 29-year-old woman comes to the clinic for routine follow-up.  Five years ago, she experienced an unprovoked generalized tonic-clonic seizure.  At that time, phenytoin was prescribed, and the patient has been on a stable dose since.  She has not experienced seizure recurrence.  MRI of the brain performed following the initial episode was normal.  She has no other medical problems and is a lifetime nonsmoker.  The patient's family history is negative for neurologic disease.  She is in a stable relationship and is contemplating pregnancy.  Blood pressure is 123/72 mm Hg and pulse is 75/min.  Neurologic examination is unremarkable.  Serum phenytoin level is 11 mcg/mL (therapeutic range, 10-20 mcg/mL).  Electroencephalogram is normal.  Which of the following is the best next step in management of this patient?

Accepted Answer

Discontinuing phenytoin in this patient who has a history of unprovoked seizure but has been seizure free >2 years is a reasonable consideration. Given her lack of identifiable brain disease, normal EEG, absence of familial epilepsy, and positive initial response to therapy, this patient is at a low risk for seizure recurrence. In addition, phenytoin is a known teratogen capable of causing fetal hydantoin syndrome (eg, orofacial clefts, microcephaly, nail/digit hypoplasia, cardiac defects, dysmorphic facial features). Given its known teratogenicity, phenytoin should be discontinued in women of reproductive age who are considering becoming pregnant and have a low risk of seizure recurrence. A personalized slow taper is indicated as rapid withdrawal may result in seizure recurrence (Choice A). (Choice B) Increasing the dose of phenytoin in this patient who has a 5-year seizure-free period and is considering becoming pregnant is inappropriate; it would expose her to additional dose-dependent side effects (eg, drowsiness, diplopia, ataxia) and increase the likelihood of her offspring being born with congenital defects. (Choice C) Brain MRI is indicated as part of the initial workup of new-onset seizure in adults to identify structural abnormalities (eg, tumor, infarction). However, follow-up MRI is unlikely to provide additional useful information in this patient, who has a previously normal MRI, has remained seizure free, and has a normal neurologic examination. (Choice E) Like phenytoin, valproic acid is an antiepileptic drug that has been linked to an increased risk of congenital anomalies such as neural tube defects (eg, spina bifida) and dysmorphic facial features. Educational objective: Phenytoin is an antiepileptic drug with known teratogenic effects (eg, fetal hydantoin syndrome). Women of childbearing age who have a low risk of seizure recurrence may safely discontinue phenytoin if considering becoming pregnant; however, the medication should be slowly tapered as rapid withdrawal may result in seizure recurrence. References: Stopping antiepileptic drugs: when and why? (http://www.ncbi.nlm.nih.gov/pubmed/20730110) Pregnancy, epilepsy, and anticonvulsants. (http://www.ncbi.nlm.nih.gov/pubmed/18472485)

Question 20

A 64-year-old woman comes to the physician with a 10-day history of progressive difficulty walking and poor balance.  Two days ago, she fell at home but did not sustain any injuries.  Her chronic back pain is worse than usual and is especially bothersome at night.  She has no headaches, trauma, bowel or bladder incontinence, or loss of consciousness.  The patient's past medical history is significant for type 2 diabetes mellitus, hypertension, transient ischemic attack, and breast cancer status post lumpectomy followed by chemoradiation 2 years ago.  Her blood pressure is 162/78 mm Hg and pulse is 73/min.  Physical examination shows an unsteady gait, bilateral leg weakness, increased deep-tendon reflexes, and decreased pinprick sensation in both lower extremities up to the umbilicus.  There is percussion tenderness over the lower thoracic spine.  Digital rectal examination shows good sphincter tone.  Mental status, memory, and cognition are intact.  Which of the following is most likely responsible for this patient's clinical presentation?

Accepted Answer

11ec25c8_d157_5092_bc81_ab0612ad07c2_MD0003_00 This patient's presentation suggests epidural spinal cord compression (ESCC), likely from recurrent breast cancer presenting with metastasis. Other malignancies which commonly affect the spine are lung, renal, and prostate cancers and multiple myeloma. The thoracic spine is the most frequently affected level (60%), followed by the lumbar spine (30%). Most patients present with progressively worsening back pain. Pain is usually worse in the recumbent position (due to distension of the epidural venous plexus when lying down) in contrast to back pain from degenerative joint disease, which improves with recumbency. Bilateral lower-extremity weakness is present in about 60% of patients. Sensory loss below a spinal level and gait ataxia may occur. Paraplegia and bowel or bladder dysfunctions (eg, fecal or urinary retention/incontinence) are late findings. Examination shows focal point tenderness in the spine, exaggerated deep-tendon reflexes in the legs, and upgoing plantar reflexes. In this patient, given the T10 sensory level (umbilicus), the cord injury is likely at the T8 level. In the acute phase of spinal cord injury, patients can develop spinal shock and have absence of reflexes and flaccid paraplegia. Given that this patient has had symptoms for 10 days, the reflexes and tone generally become increased by this time. (Choice A) Brainstem ischemic strokes typically cause focal unilateral neurologic deficits such as "crossed signs" (eg, ipsilateral cranial nerve deficit, contralateral hemiplegia). Patients often present with acute deficits that can progress over hours but not days. Pain is not a feature of stroke. (Choice B) Diabetic polyneuropathy usually presents with symmetrical sensory loss that affects primarily the distal lower extremities. Patients have loss of pain, temperature, proprioception, and vibratory sensation; unlike in myelopathy, deep-tendon reflexes are diminished or absent. Back pain is not present. (Choice C) Guillain-Barré syndrome presents with diminished or absent but not hyperactive reflexes. (Choice D) The classic triad of normal-pressure hydrocephalus is cognitive dysfunction, gait difficulty (wide-based gait), and urinary incontinence. It is usually not associated with lower-extremity weakness or back pain. (Choice F) Spinal cord infarction generally presents with abrupt symptoms such as weakness (may progress to paraplegia/quadriplegia), loss of pain and temperature sensation (anterior spinal artery infarct), and autonomic dysfunction. This patient's symptoms have evolved gradually, making acute spinal cord infarction less likely. Educational objective: Neoplastic epidural spinal cord compression presents with worsening focal back pain, bilateral lower-extremity weakness, sensory loss, and gait ataxia. Bowel/bladder disturbances are late findings. In the acute phase of spinal cord injury, patients can develop spinal shock with absence of reflexes and flaccid paraplegia as a result. References: Spinal cord compression. (http://www.ncbi.nlm.nih.gov/pubmed/22547256)

Exam 1: Medicine

A 43-year-old man presents to your office complaining of periodic involuntary head turning and head fixation to the right side. Physical examination reveals a hypertrophied left sternocleidomastoid muscle. What is the most likely diagnosis?