Focal Neurological Deficit
Focal neurological deficit (‘stroke syndromes’) is the exception to the general rule of expedient reduction of MAP in hypertensive emergencies.
The CT scan shows an acute ischaemic stroke with left middle cerebral artery sign.
Why is it the exception?
Elevated BP, in the context of acute stroke, is often a physiological response rather than an underlying cause.
The majority of strokes (>80%) are either embolic or thrombotic (i.e. not haemorrhagic). Consequently any attempts to reduce MAP may, because of damaged autoregulatory mechanisms, compromise blood flow causing further ischaemia and worsening of the neurological deficit.