Occlusion of the basilar artery. A clinical and pathological study of thirteen autopsied cases.

The present report dealt with thirteen autopsied cases of basilar artery occlusion. The age of the patients ranged from fifty one to seventy six years with a mean age of fifty six years, and there were eleven males and two females. Basilar artery occlusion was found in one in every 160 autopsies. The average length of the clinical course of the disease was five months. Many patients had a history of hypertension, diabetes mellitus, and cerebrovascular attacks. The neurological signs and symptoms of basilar artery occlusion extremely varied and were complicated. In our series, occular bobbing, palatal myoclonus, Foville syndrome, and Millard - Gubler syndrome are significant. Arteriosclerotic thrombosis is the most important etiologic factor. The site of occlusion was most frequently encountered in the lower third of the basilar artery. Areas of softening were prominent in the midbrain and the pons. In the cerebellum, softenings were present particularly in the areas supplied by the superior cerebellar artery. Infarcts in the thalamus and the temporo-occipital lobes supplied by the posterior cerebral artery were observed very frequently. The distribution of softening was related to the site of occlusion of the basilar artery and the collateral circulation through the Willis ring.