[Intimal fibrosis of cerebellar arteries--a contribution to the pathogenesis of neurovascular syndromes].

Cross-compression of cranial nerves at the brain stem by an arterial loop appears to be responsible for several dysfunction syndromes like trigeminal neuralgia and hemifacial spasm. The pathogenesis of these syndromes still remains obscure; some authors call atherosclerosis of the cross-compressing vessel a local pathogenetic factor. Histological examination of the lower cerebellar arteries, obtained at autopsies of humans without cranial nerve dysfunction, was carried out. There was no evidence of significant atherosclerotic changes of distant cerebellar arteries even in places predisposing to intimal thickening by haemodynamic reasons. The adventitia and arachnoidea contributed 30% to the vessel wall and may be the substrate of the reported local vessel thickening in neurovascular compression syndromes.