A 54-year-old man is brought to the emergency department 1 hour after an episode of loss of consciousness that lasted 3 minutes. Since awakening, he has had weakness of the left arm and leg, and his speech has been slurred. He has had a fever for 10 days. He has not had vomiting or headache. He was treated for bacterial sinusitis 3 weeks ago with amoxicillin-clavulanate. He has hypertension, hypothyroidism, hypothyroidism, hyperlipidemia, and type II diabetes mellitus. Current medications include amlodipine, hydrochlorothiazide, metformin, simvastatin, aspirin, and levothyroxine. His temperature is 101.4°F (38.6°C), pulse is 106/min, and blood pressure is 160/90 mm Hg. He is alert and oriented to person, place, and time. Examination shows multiple petechiae on his trunk and painless macules over both palms. A new grade 3/6 systolic murmur is heard best at the apex. He follows commands, but he slurs his words and has difficulty naming common objects. There is left facial droop. Muscle strength is 4/5 in the left upper and lower extremities. Deep tendon reflexes are 3+ on the left side and 2+ on the right side. The left big toe shows an extensor response. Fundoscopic examination shows retinal hemorrhages with white centers. Lab report is attached.
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Which of the following is the most likely cause of these findings?
Septic emboli cause the neurologic complications of infective endocarditis (IE), which include ischemic stroke, intracerebral hemorrhage, and/or cerebral microabscesses. Up to 40% of patients with IE experience symptomatic neurologic complications, and up to 80% have embolic findings on the brain imaging. IE has a broad range of presentations, ranging from acute illness to a subacute or insidious course. This patient shows signs of acute illness with constitutional and cardiac symptoms, as well as multiple areas of stroke (left limb weakness suggests right motor cortex involvement, anomic aphasia suggests left temporal involvement, and dysarthria/facial droop indicate brainstem involvement), indicating multiple emboli to the brain. He also has microscopic hematuria due to emboli to the kidneys. This patient should have an emergent non-contrast head CT to rule out hemorrhage, but there is no specific treatment (e.g., thrombolytics) for septic embolism. Instead, antibiotic treatment to reduce the risk of recurrent embolism is indicated.
Ruptured arteriovenous malformation is incorrect. Arteriovenous malformations (AVM) can arise anywhere in the body but can be particularly problematic in the central nervous system. AVMs are found in up to 20% of adults, though they manifest more often with recurrent seizures or cerebrovascular accident (either ischemic or, more commonly, hemorrhagic). In the case of a cerebrovascular accident, the presentation would be similar to what is described in this case. However, AVMs are symptomatic in less than 0.5% of the population and are most often diagnosed before a patient turns 40.
Ruptured saccular aneurysm is incorrect. Saccular aneurysms are often unknown to the patient unless they are diagnosed incidentally or rupture and cause neurological symptoms. In the case of a rupture, signs and symptoms of subarachnoid hemorrhage typically develop rapidly; thunderclap headache, nausea/vomiting, and rapid progression to coma, and eventually, death is common. This patient has no history of headache, nausea, or vomiting, which effectively rules out SAH.
Todd’s paralysis manifests as a temporary unilateral weakness (usually of the arm and/or leg) following a seizure, which is sometimes accompanied by generalized aphasia. Patients in the postictal state are also commonly confused, disoriented, and/or somnolent. While this patient has unilateral weakness and confusion following a loss of consciousness, his aphasia is more characteristic of ischemia in the language center of the left temporal lobe rather than a seizure.
Herpes simplex encephalitis (HSE) is typically characterized by a prodromal phase (fever, headache), followed by acute or subacute encephalopathy with focal neurological deficits, seizures, altered mental status, and behavioral changes. This patient also presents with fever, focal deficits, and encephalopathy. However, HSE would not explain this patient’s heart murmur, skin findings, retinal hemorrhages, or kidney injury.
