Central nervous system disorders

V./4.5.: Presentation

V./4.5.1.: Asymptomatic occlusive carotid artery disease

Proximal occlusion of the supraaortic arteries (e.g. brachiocephalic artery, common carotid or internal carotid artery) may be asymptomatic since blood supply from the collaterals could prevent permanent damage. (Question 4). Collaterals exist between ICA and ECA through the facial, temporal superficial, middle meningeal or ophthalmic arteries. Distal, intracranial collaterals are the ACoA and PCoA. Sometimes even leptomeningeal anastomoses take part in arterial circulation.

In patients without sufficient collateral circulation such as in communicating artery agenesis, ICA occlusion result in both MCA and ACA territories (see the particular case). In the anatomic variation with PCA originating from ICA and ACoA is not developed, total hemispheric infarction may occur with poor prognosis.

V./4.5.2.: Transient ischemic attack (TIA)

According to recent studies, stroke risk after TIA is high. Immidiate examination and treatment may decrease stroke risk after TIA.

As mentioned before, TIA means that clinical symptoms last max 24 hours by definition. However, if symptoms last longer then 1-hour permanent parenchymal damage could be found by modern neuroimaging techniques. In most patients TIA last few minutes as everyday practice show.

V./4.5.3.: Ischemic stroke

Sudden onset of neurological deficit (focal, loss of consciousness) last at least 24 hours or lead to death in the same period. In some patients, gradual or continuous worsening may be a result of repeated embolisation, growing thrombi or brain swelling.

In ischemic lesion of total ICA and/or MCA occlusion malignant media syndrome may develop, which is a life threatening condition. At least 50% of the MCA territory will be damaged by the infarction. This is a large ischemic area with marked cytotoxic and vasogenic oedema with the possibility of transformation into space occupying lesion with midline shift, increased intracranial pressure and herniations. MCA occlusion could be accompanied by ACA or PCA occlusion (variant circulation).