[Crossed cerebellar diaschisis in hydrocephalus--a case report].

A case of hydrocephalus in which a crossed cerebellar diaschisis with single photon emission CT (SPECT) using 123I-iodoamphetamine (123I-IMP) disappeared by a ventriculo-peritoneal shunting operation, was reported. A 54-year-old female had a clipping surgery for a aneurysm of the left middle cerebral artery on April 9, 1987. Post-operatively, she had a transient mild aphasia. Cerebral blood flow (CBF) study with 123I-IMP-SPECT had showed low perfusion in the left frontal and temporal lobe. But after a month, clinical symptom and CBF findings had improved. She had been doing well after the discharge until October, 1987, when she developed disorientation. CT on re-admission showed the ventricular dilatation with periventricular low density (left greater than right). 123I-IMP-SPECT study showed the crossed cerebellar diaschisis which was a low perfusion in the left frontal, temporal, parietal, thalamus, basal ganglionic area and in the opposite cerebellum. A ventriculo-peritoneal shunting operation was performed which brought the disappearance of the crossed cerebellar diaschisis and the clinical improvement. The phenomenon of crossed cerebellar diaschisis has been reported in a lot of literatures. However, those diseases were located in unilateral supratentorium. It has been speculated that crossed cerebellar diaschisis is the transneural metabolic change through the cortico-ponto-cerebellar pathway by supratentorial lesion. Crossed cerebellar diaschisis in hydrocephalus has not been reported so far.(ABSTRACT TRUNCATED AT 250 WORDS)