Cerebrovascular Disease
Definition of stroke
A stroke or
cerebrovascular accident (CVA) is typically an event of sudden onset (although
it can occur over hours in some patients where a major vessel is slowly
thrombosing). It is due to an interruption of blood supply to an area of
the central nervous system (CNS) that causes irreversible loss of tissue at the
core with a penumbra of compromised tissue around the area that may still be
salvageable. If the disturbance in blood flow is temporary it causes a transient
ischaemic attack or TIA. This is often a harbinger of a stroke. Stroke is
common and its consequences depend on the vessel that has been occluded.
Investigation of
stroke
· History and examination
· Computed tomography (CT)/magnetic
resonance imaging (MRI)
· Blood tests including full blood
count, erythrocyte sedimentation rate, renal function, glucose and lipids
· Electrocardiogram (ECG) which may be
repeated and prolonged if a cardiac source for the stroke is suspected
Other investigation may
include an ECHO cardiogram and imaging of the blood vessels
and/or a CSF examination and this depends on the type of stroke (see
Table 64.1).
Rare causes of stroke
The most common causes
of stroke are atherosclerosis and embolic disease from the blood vessels to the
brain and the heart. The other causes are quite rare. Other syndromes that
resemble stroke include mitochondrial disease (see Chapter 63),
where there can be a sudden onset of neurological deficits due to problems in
the mitochondria and not in the vasculature. Such events in the brain
typically do not obey vascular territories when investigated with MRI for
example.
Treatment of stroke
· Consider local thrombolysis if a
single major vessel is involved: e.g. basilar artery/venous sinus
•
Acutely
(if <3–4 hours) and no contraindication thrombolysis
•
Treat
any risk factors eg stop smoking, lower-cholesterol etc and start
aspirin/perindopril/statin
•
Heparin
if major venous sinus thrombosis
• Surgery,
if recognizable lesion causing stroke is identified e.g. >70%
carotid artery stenosis/aneurysm
•
Rehabilitation
therapy
