A 38-year-old woman comes to the physician with left facial numbness and paresthesias for the last 3 days. She is a known intravenous drug user. One month ago, she had an episode of blurry vision in her right eye and vertigo that resolved spontaneously. One year ago, she was admitted to the hospital with fever to rule out endocarditis. Transesophageal echocardiography at that time showed no vegetations but did demonstrate a small secundum-type atrial septal defect. The patient's past medical history is also significant for hypothyroidism, migraine disorder, and hypertension.
Her temperature is 37.2 C (99 F) , blood pressure is 140/88 mm Hg, and pulse is 85/min. Her body mass index is 28 kg/m². The patient is awake and in mild distress. Examination shows a pale right optic disc, right relative afferent pupillary defect, and reduced sensation on the left side of the face. Motor examination shows a slight pronator drift in the right upper extremity with increased tone and hyperreflexia. She also has mild dysmetria in the left upper extremity.
MRI of the brain with and without gadolinium is performed; the T2/FLAIR sequence is shown in the image below.

Which of the following would be most helpful in confirming the diagnosis in this patient?

Question

A 38-year-old woman comes to the physician with left facial numbness and paresthesias for the last 3 days. She is a known intravenous drug user. One month ago, she had an episode of blurry vision in her right eye and vertigo that resolved spontaneously. One year ago, she was admitted to the hospital with fever to rule out endocarditis. Transesophageal echocardiography at that time showed no vegetations but did demonstrate a small secundum-type atrial septal defect. The patient's past medical history is also significant for hypothyroidism, migraine disorder, and hypertension.
Her temperature is 37.2 C (99 F) , blood pressure is 140/88 mm Hg, and pulse is 85/min. Her body mass index is 28 kg/m². The patient is awake and in mild distress. Examination shows a pale right optic disc, right relative afferent pupillary defect, and reduced sensation on the left side of the face. Motor examination shows a slight pronator drift in the right upper extremity with increased tone and hyperreflexia. She also has mild dysmetria in the left upper extremity.
MRI of the brain with and without gadolinium is performed; the T2/FLAIR sequence is shown in the image below.

Which of the following would be most helpful in confirming the diagnosis in this patient?

Quizplus · Accepted Answer

11ec193a_988d_f34d_853d_dd0f70ff9143_MD0002_00 This patient likely has multiple sclerosis (MS). The diagnosis of MS requires evidence of central nervous system deficits disseminated in time and space based on clinical features alone, or a combination of clinical and radiologic findings. T2-weighted MRI typically shows multifocal ovoid white matter lesions in the periventricular, juxtacortical, infratentorial, or spinal cord areas. Characteristic lesions are seen in >90% of patients with clinically definite MS; however, ischemia can have a similar appearance. Lumbar puncture is usually performed when clinical features and neuroimaging are equivocal. Cerebrospinal fluid (CSF) may show oligoclonal IgG bands (>95%) and elevated IgG index (~90%). Opening pressure and other CSF findings are typically normal. Although this patient's presentation likely represents MS, her history of intravenous (IV) drug use and multifocal neurologic deficits raise suspicion for endocarditis with septic embolization to the brain. Lumbar puncture is appropriate in this setting to make a definitive diagnosis. (Choice A) Brain biopsy is typically performed for tissue diagnosis of a suspected brain tumor. It may be considered in rare occasions when the diagnosis remains elusive despite less invasive workup such as lumbar puncture. (Choice B) Advanced HIV can present with neurologic manifestations such as HIV encephalopathy (triad of cognitive impairment, mood, and movement disorders), cytomegalovirus or herpes simplex encephalitis, and CNS toxoplasmosis or lymphoma. Although this patient is at risk for HIV given her history of IV drug use, her presentation is more suggestive of MS. (Choice D) MR angiography can be performed in the setting of acute stroke to detect vascular stenosis/occlusion, malformation, and aneurysm. Stroke is less likely given this patient's age <50 and controlled hypertension. (Choice E) Systemic embolization can occur in patients with deep venous thrombosis or right-sided endocarditis in the setting of an atrial septal defect. Embolic showering typically affects the cortex rather than the periventricular regions, as seen in MS. In addition, embolic stroke is not usually associated with optic neuritis, making transesophageal echocardiogram less helpful in confirming the diagnosis. Educational objective: Multiple sclerosis is characterized by central nervous system deficits disseminated in time and space. T2-weighted MRI typically shows multifocal ovoid white matter lesions in the periventricular, juxtacortical, infratentorial, or spinal cord areas. Cerebrospinal fluid analysis can support the diagnosis in atypical cases and usually shows oligoclonal IgG bands and elevated IgG index. __________ References: Revised diagnostic criteria of multiple sclerosis. (http://www.ncbi.nlm.nih.gov/pubmed/24424194)

A 38-Year-Old Woman Comes to the Physician with Left Facial