Vasculitis, intracranial

When infectious it may be bacterial and associated with meningitis; tuberculous meningitis is typically associated with arteritis involving the circle of Willis.

Some fungi like mucor, aspergillus and actinomyces have a specific tendency to invade vessel walls and produce infarction and haemorrhages. So-called mycotic aneurysms are usually due to bacterial arteritis and not to fungi (see mycotic aneurysm in bacterial endocarditis). Viruses, such as herpes virus, frequently involve vessels mainly of the temporal lobes and insula; gummous arteritis is the most striking feature of syphilitic arteritis.

Noninfectious vasculitides are an heterogeneous group in which different mechanisms are involved. In polyarteritis nodosa and vascular collagen diseases, such as systemic lupus erythematosus, vessel wall damage is most likely due to the deposition of immune complexes; in other diseases like giant cell arteritis, Wegener's granulomatosis, sarcoidosis, Takayasus arteritis, granulomatous angiitis, a cell mediated pathological mechanism is involved.

Arteritis is found in other systemic diseases such as Behcet's disease, Kawasaki's disease and in drug abuse (cocaine).

Clinical presentation varies according to the underlying disease and preferential venous or arterial involvement (see infarction cerebral, venous thrombosis intracranial).

Main findings include repeated strokes and multiple infarctions. MR shows nonspecific vascular ischaemic lesions; angiography only rarely shows involvement of medium-size arterioles with focal narrowings and dilatations.

GS