[A case of hemifacial spasm associated with a cerebellar hematoma].

This is a report of a hemifacial spasm associated with a cerebellar hematoma. A 60 year-old female was admitted to our hospital due to severe vertigo and nausea. On admission, the neurological examination showed drowsy conscious level, cerebellar sign dominant on the left side, and left hemifacial spasm. CT scans disclosed a large hematoma in the left cerebellar hemisphere. An angiography revealed a dominant left PICA, but showed neither vascular malformation nor aneurysm. An emergency removal of the hematoma was carried out by using suboccipital craniectomy. Three days after the surgery, the patient's left hemifacial spasm disappeared completely. She had never suffered from left hemifacial spasm prior to this cerebellar bleeding. The hemifacial spasm was thought to be due to either the compression of the left facial nerve by the PICA which had been displaced by the cerebellar hematoma, or to the fact that the nucleus of the left facial nerve might have been stimulated by the hematoma, and the hemifacial spasm might have been caused as a result of the stimulation. The total removal of the hematoma and the postoperative CSF leakage might have decompressed the facial nerve. It was considered that this might be similar to microvascular decompression.