A 78 year old right-handed male collapses and is brought into accident and emergency. He seems to follow clear one-step commands but he gets very frustrated as he cannot answer questions. He is unable to lift his right hand or leg. He has an irregularly irregular pulse and his blood pressure is 149/87. He takes only aspirin and frusemide. What is the most likely diagnosis?
A. Left cortical infarct
B. Right internal capsule infarct
C. Left cortical haemorrhage
D. Left internal capsule haemorrhage
E. Brainstem haemorrhage
Ans: Lesion localization
(A)This male has most likely suffered a left cortical infarct (A), probably as a result of an embolus secondary to atrial fibrillation. Treatment with warfarin would have reduced his annual risk of stroke from roughly 5 to 1 per cent. It is a left-sided infarct because of the contralateral (right) hemiparesis and dysphasia (involvement of the dominant cortex). It is not a capsular (B and D) or brainstem (E) event as the patient has an expressive dysphasia which implies involvement of Brocca’s area which is cortical. It is more likely to be ischaemic than haemorrhagic (C). Roughly 80 per cent of strokes are infarcts, 20 per cent haemorrhagic and in this case there is a plausible embolic explanation coupled with only mild hypertension.
Haemorrhagic strokes tend to occur in younger patients with severe hypertension and a family history (pointing to an anatomical anomaly). However, they cannot be differentiated clinically and a CT is required to confirm the stroke subtype.