[Cavernous malformation of the brain stem: clinical symptom and its surgical indication]

Clinical features and surgical indication of cavernous malformation (CVM) of the brain stem are reviewed, based on the analysis of five personally encountered cases and nineteen previously reported cases. Nineteen out of these twenty four cases presented sudden onset of neurological deficits suggesting brain stem hemorrhage. Although the majority of those patients with acute onset improved gradually within a couple of weeks, all cases, except for six cases treated with radical removal following their first bleeding episodes, presented recurrent hemorrhages, and one third of them died due to the repeated hemorrhages. The other six cases presented progressive neurological deficits with insidious onset. They were first diagnosed as brain stem gliomas or multiple sclerosis. All except two cases treated with radical removal of the CVM died within a year. Surgical indication of the cerebral CVM is still controversial, because its clinical presentations and natural history have been unclear. Recent clinical application of magnetic resonance imaging enables us not only to make a preoperative diagnosis accurately, but also to evaluate the operability in relation to its anatomical location. Because of an apparent disposition towards repeated hemorrhages, surgical removal should be considered for the symptomatic CVM in the brain stem, on which microsurgical manipulation would be possible with an acceptable risk in many cases.