A 57-year-old man comes to the emergency department with right arm and leg weakness, first noticed about 2 hours ago when he could not grip a pen. He is now unable to shake hands and walks with a mild limp. The patient has also had a mild, constant headache the past several days that he attributes to stress from a new project at work. His past medical history is significant for hypertension and hyperlipidemia, and he does not smoke or consume alcohol. His blood pressure is 180/100 mm Hg, and pulse is 80/min. There is mild asymmetry of the lower face, decreased muscle strength in the right arm, and positive Babinski sign on the right side. Sensory examination is normal. Blood glucose is 210 mg/dL. ECG shows sinus rhythm with occasional premature ventricular beats. Noncontrast CT scan of the head reveals no abnormalities. Which of the following is the most likely cause of this patient's symptoms?

Question

A 57-year-old man comes to the emergency department with right arm and leg weakness, first noticed about 2 hours ago when he could not grip a pen.  He is now unable to shake hands and walks with a mild limp.  The patient has also had a mild, constant headache the past several days that he attributes to stress from a new project at work.  His past medical history is significant for hypertension and hyperlipidemia, and he does not smoke or consume alcohol.  His blood pressure is 180/100 mm Hg, and pulse is 80/min.  There is mild asymmetry of the lower face, decreased muscle strength in the right arm, and positive Babinski sign on the right side.  Sensory examination is normal.  Blood glucose is 210 mg/dL.  ECG shows sinus rhythm with occasional premature ventricular beats.  Noncontrast CT scan of the head reveals no abnormalities.  Which of the following is the most likely cause of this patient's symptoms?

Quizplus · Accepted Answer

11ec25c8_d55e_3315_bc81_dde1ef937d94_MD0003_00 This patient shows signs of a lacunar stroke in the internal capsule. Lacunar infarcts occur due to occlusion of deep penetrating arteries in the brain. These vessels are located in highly turbulent regions of the cerebrovascular system and therefore are most susceptible to vascular disease related to hypertension, diabetes, hyperlipidemia, and smoking. The underlying pathology is a combination of microatheroma formation and lipohyalinosis that ultimately leads to thrombotic small-vessel occlusion. Due to their small size, lacunes are often not appreciated on noncontrast CT scans obtained shortly after the event. lacunar stroke Lacunar infarcts commonly occur in the internal capsule and may lead to pure motor hemiparesis due to injury of the corticospinal (posterior limb) and corticobulbar (genu) tracts. Patients typically have weakness equally involving the contralateral face, arm, and leg. Sensory deficits, mental status changes, seizure, and cortical signs are typically absent. internal capsule (Choice A) Subdural hematomas result from traumatic rupture of the bridging veins. Patients usually have headache, altered mentation, seizures, and/or focal neurologic deficits. Noncontrast head CT classically reveals a concave hemorrhage that crosses suture lines. (Choice B) Carotid artery dissection usually results from trauma and may cause ischemic stroke due to thromboembolism or hypoperfusion. Patients typically experience head or neck pain followed by partial ipsilateral Horner syndrome (eg, ptosis and miosis without anhidrosis) due to damage of postganglionic sympathetic fibers. (Choice C) Carotid artery thrombosis typically leads to profound neurologic deficits (eg, contralateral homonymous hemianopsia, hemiparesis, hemisensory loss) due to ischemic infarction of the cerebral hemisphere. Cortical signs and altered mental status are also usually present. (Choice D) Cerebral vasospasm may occur in the setting of cocaine/amphetamine use, which typically causes hemorrhagic or ischemic stroke involving the major cerebral arteries and is therefore less likely in this patient given the normal findings on head CT. (Choice E) Cerebral sinus thrombosis typically occurs in patients with hypercoagulable conditions (eg, contraceptive use, malignancy) and can present with headache, altered mentation, seizures, and focal neurologic deficits. The diagnosis is confirmed with MRI of the brain with venography as head CT scan often shows no abnormalities. (Choice F) Meningeal artery tears typically occur due to traumatic head injury and result in epidural hematoma. Patients may have altered consciousness, headache, nausea/vomiting, and focal neurologic deficits. Head CT scan shows acute hemorrhage in a biconvex pattern that does not cross suture lines. (Choices G) Subarachnoid hemorrhage typically occurs due to a ruptured saccular aneurysm and presents with thunderclap headache associated with brief loss of consciousness and meningismus. Noncontrast head CT scan shows acute hemorrhage between the arachnoid and pia mater. Educational objective: Lacunar strokes occur due to microatheroma formation and lipohyalinosis in the small penetrating arteries of the brain. They often affect the internal capsule and result in pure motor hemiparesis. Hypertension, hyperlipidemia, diabetes, and smoking are major risk factors. References: Lacunar versus non-lacunar syndromes. (http://www.ncbi.nlm.nih.gov/pubmed/22377873) Lacunar infarction and small vessel disease: pathology and pathophysiology. (http://www.ncbi.nlm.nih.gov/pubmed/25692102)

A 57-Year-Old Man Comes to the Emergency Department with Right