A 58-year-old right-handed man is brought to the emergency department with sudden onset of severe difficulty speaking and weakness that developed over a few seconds while he was at work. His other medical problems include hypertension, hyperlipidemia, severe left atrial enlargement (seen on previous echocardiogram), mild bilateral carotid disease with recent carotid ultrasound showing

Question

A 58-year-old right-handed man is brought to the emergency department with sudden onset of severe difficulty speaking and weakness that developed over a few seconds while he was at work. His other medical problems include hypertension, hyperlipidemia, severe left atrial enlargement (seen on previous echocardiogram), mild bilateral carotid disease with recent carotid ultrasound showing <30% stenosis, type 2 diabetes mellitus, and autosomal dominant polycystic kidney disease. He is not compliant with his medication regimen. The patient smokes a pack of cigarettes a day and drinks alcohol occasionally. His blood pressure is 156/96 mm Hg and pulse is 124/min and irregularly irregular. His body mass index is 35 kg/m². There are no carotid bruits. The patient speaks in very short sentences and has difficulty finding words while trying to speak. He is awake and alert but has difficulty following simple commands. There is a forced conjugate gaze preference to the left, neglect of the right visual field, and severe right lower facial droop. He has marked weakness and sensory loss in the right arm and mild weakness and sensory loss in the right leg. His fingerstick glucose value is 345 mg/dL. Which of the following is the most likely cause of this patient's current condition?

Quizplus · Accepted Answer

11ec25c8_d5b0_9946_bc81_e515e59aa193_MD0003_00 This patient has acute onset of word-finding difficulties and impaired language comprehension, consistent with a likely ischemic stroke causing global aphasia. The problem is localized to the left hemisphere. In addition, the presence of a forced gaze preference to the left (damage to frontal eye fields) and a right homonymous hemianopsia (damage to upper and lower optic radiations traveling in the lateral temporal and parietal lobes) suggests involvement of a large area of the lobar/cortical middle cerebral artery (MCA) territory of the dominant hemisphere. This is consistent with a large-vessel occlusion (likely distal M1 segment of the left MCA). His right-sided weakness (face/arm > leg) is also consistent with a left frontal cortex lesion and supports vascular involvement of a large area of the left/dominant hemisphere supplied by the left MCA. Ischemic strokes can be thrombotic or embolic in etiology, with atherosclerotic-related thrombotic strokes the most common. However, the presence of an irregularly irregular rhythm in a patient with a history of structural heart disease (severe left atrial enlargement likely due to poorly controlled hypertension) is strongly suggestive of a cardioembolic etiology in paroxysmal atrial fibrillation. The very rapid onset of severe focal neurologic deficits in this patient most likely suggests an embolus causing obstruction of blood flow through the left MCA. In contrast, an unstable ruptured atherosclerotic plaque with a propagating thrombus on its surface would cause the development of focal neurologic symptoms at a relatively slower rate. (Choice B) This patient has several vascular factors that put him at risk for ischemic strokes secondary to large-artery atherosclerotic disease. This can manifest as carotid disease or intracranial large-vessel (eg, MCA, anterior cerebral artery) focal atherosclerotic disease; both can lead to in-situ vessel thrombosis and/or atherothromboembolism. Given this patient's recent carotid ultrasound showing <30% stenosis (risk of carotid disease-related stroke increases with stenosis >30% and even more so with stenosis >50%) and absence of a carotid bruit on examination, there is a lower probability of at least an ipsilateral carotid atherothromboembolic event. (Choice C) Patients with type 2 diabetes can develop a hyperglycemic nonketotic state that leads to altered mental status and focal neurologic deficits. Although this patient's serum glucose is elevated, a symptomatic hyperglycemic nonketotic state usually occurs at glucose >600 mg/dL (more often >1000 mg/dL). (Choice D) Polycystic kidney disease is associated with an increased risk of berry aneurysms that can rupture and cause subarachnoid hemorrhage (SAH). However, SAH usually presents with severe headache and impaired level of consciousness. Focal neurologic findings are uncommon with SAH. (Choice E) Subcortical lacunar strokes are due to an occluded single penetrating branch of a large cerebral artery (eg, MCA, basilar artery). They can present with pure motor (most common), ataxic hemiparesis, pure sensory, sensorimotor stroke, or dysarthria with clumsy hand. Patients typically develop symptoms over a short period with slow progression over the next 24-36 hours. However, they usually do not have cortical signs (eg, aphasia, agnosia, neglect, apraxia, hemianopsia), as seen in this patient. Educational objective: Embolic strokes usually have sudden onset with maximal symptoms at the beginning. They occur more commonly in patients with a history of structural cardiac disease (eg, atrial fibrillation, endocarditis). Patients with atrial fibrillation PLUS existing structural heart disease have an increased risk of cardioembolic strokes. References: Epidemiology of ischemic stroke subtypes according to TOAST criteria: incidence, recurrence, and long-term survival in ischemic stroke subtypes: a population-based study. (http://www.ncbi.nlm.nih.gov/pubmed/11739965) Cardiac disorders and stroke. (http://www.ncbi.nlm.nih.gov/pubmed/9484617)

A 58-Year-Old Right-Handed Man Is Brought to the Emergency Department