Cerebellar infarction in the area of the posterior cerebellar artery. Clinicopathology of 28 cases

We report a neuropathological study of cerebellar infarctions involving the territory of the posterior inferior cerebellar artery (PICA) in 28 cases. Fifteen cases involved the PICA territory only. In 13 cases infarctions in the anterior inferior cerebellar artery (AICA) territory and/or in the superior cerebellar artery (SCA) territory were also present. A thorough post-mortem study of the arterial supply of the brain from the heart up to the cerebellar arteries, including the cervical spine segment of the vertebral arteries was performed in 27 cases. The territory of the cerebellar infarcts has been ascertained. In 15/28 cases (54 percent), infarction involved the PICA territory only (17 infarcts). All of these cases had a benign outcome and death was due to another cause. Six of these were recent infarctions. None had evidence of swelling and tonsillar herniation. Infarcts were generally of small size and involved the entire PICA territory in only 2 cases. Most of these cases were unexpected discovered at autopsy. Cerebellar infarction in the territory of the medial branch of the PICA (9/17 infarcts) drew grossly a set square with a dorsal base and a ventral top headed for the IVth ventricle. Five out of these cases were associated with infarction in the dorsal and lateral medullary territories. Retrospective clinical study showed that they had been unnoticed or overshadowed by other neurological disorders (4 cases), or presented as Wallenberg's syndromes (4 cases), or as a pure vestibular syndrome (due to an infarction involving only the cerebellum) mimicking an acute labyrinthine disorder (1 case). Infarctions in the territory of the lateral branch of the PICA (5/17 infarcts) always occurred without medullary involvement. All of them were unexpectedly discovered at autopsy, and were unnoticed during the life (3 infarcts) or were overshadowed by other neurological disorders (2 infarcts). That was also the case in 2 cases of infarction in the whole PICA territory (3/17 infarcts). Thus infarctions strictly localized to the entire PICA territory only were rare. Thirteen/28 cases (46 p. 100) of infarction in the whole PICA territory were associated with infarction in the AICA and/or the SCA territories. This resulted from an association with other infarctions and not from an abnormally large territory of the PICA. Cerebellar swelling with brain stem compression and tonsillar herniation occurred 8/13 cases (62 p. 100). There were other massive median and paramedian brain stem infarctions involving midbrain, pons or medulla in 55 p. 100 of 13 cases.(ABSTRACT TRUNCATED AT 400 WORDS)