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Cerebral infarction due to presumed haemodynamic factors in ambulant hypertensive patients.

The role of haemodynamic factors in the pathogenesis of cerebral infarction is unclear. Watershed or distal field infarction is most often caused by haemodynamic mechanisms. Watershed cerebral infarcts can now be identified in stroke survivors using CT scanning. The clinical findings are presented of 14 patients with cerebral infarction in whom haemodynamic factors contributed to the stroke. Evidence for this diagnosis includes (i) a history of posture-related or exercise-induced syncopal attacks or neurological deficits before and in some cases after the stroke, (ii) the demonstration of watershed or distal field infarction on CT scan, (iii) commencement of symptoms after increase in antihypertensive medications, and (iv) improvement following reduction of treatment. Regional cerebral hypoperfusion may be a more common cause of cerebral infarction than is generally thought. Particular care should be exercised when potent antihypertensive medication is prescribed for elderly hypertensive patients.