Atypical presentations of subarachnoid haemorrhage

Sir, I was interested to read the report on atypical presentations of subarachnoid haemorrhage (SAH) by Johnston and Robinson.1 The following case serves as a reminder that prominent focal neurological signs may occur in SAH, occasionally dominating the clinical picture and causing diagnostic confusion, particularly in the context of a false-negative computed tomography (CT) scan. A previously well 51-year-old man presented with sudden onset of headache and right-sided weakness. On examination, he was aphasic with a right homonymous hemianopia and dense right-sided weakness. CT head was performed 6 hours after the onset of symptoms and was normal. The possibility of SAH was considered but was felt to be unlikely given the prominent focal signs, absence of nuchal rigidity and vomiting, and normal CT (which has a 95% sensitivity for the diagnosis of SAH within the first 24 hours2). Early middle cerebral artery infarction was felt to be more likely, particularly as routine tests confirmed the presence of diabetes and hypertension. A decision was taken to treat supportively and repeat the CT in 2–3 days to confirm the presence of ischaemic stroke.