[Locked-in syndrome with bilateral midbrain infarcts--report of an autopsy].

A case of "Locked-in" syndrome with bilateral midbrain infarcts was reported. A 51-year-old man had a memory disturbance and a change of his personality after head trauma, and then became rapidly "Locked-in" state. He was quadriplegic and bulbar paralytic, but ocular movements were preserved. Left VAG showed the narrowing of the basilar artery and there was a striking anastomosis between the SCA and PICA. Neuropathological findings were as the following; 1) The lateral two third of bilateral cerebral peduncles were extensively infarcted. 2) There were contusion of the left frontal orbital surface and the ischemic infarction of the left frontal white matter. 3) Two small infarcted lesions were found in the ventral pons without involving the pyramidal tracts. 4) Additional findings were retrograde degeneration of the medial nucleus of the left thalamus from the left frontal orbital lesion, and were loss of the Purkinje cells and neurons of pontine nucleus from the infarction of the middle cerebellar peduncle. Tegmentum of the midbrain, pons and medulla were preserved, which was considered to be due to the anastomosis of the SCA and PICA. Bilateral midbrain infarcts are responsible lesions in this case and it seems that "Locked-in" state is not synonymous with the "Ventral pontine syndrome".