Cerebellar abscess: the significance of cerebrospinal fluid diversion

Cerebellar abscesses that are often ominously silent have a significant mortality. Sudden total occlusion of cerebrospinal fluid (CSF) pathways makes an aggressive surgical approach mandatory. Our neurosurgical unit at Wentworth Hospital, Durban, South Africa, prospectively instituted a protocol for patients with cerebellar abscesses with reference to CSF diversion with the aim of improving outcome. Our 13-year experience with this approach to cerebellar abscesses is presented.

Since 1983, patients with cerebellar abscesses have been managed according to a standard protocol. In 1987, a policy of aggressive CSF diversion was prospectively instituted. This involved immediate CSF diversion in any patient with over or incipient hydrocephalus, even if fully conscious. The associated hydrocephalus was diagnosed on initial computed tomographic scans. CSF diversion was performed by means of a ventricular drain, inserted in the reception area under local anesthesia. The period from January 1983 to December 1995 was analyzed, and the impact of aggressive CSF diversion on patient outcome was evaluated.

Seventy-seven patients with cerebellar abscesses during the 13-year period under review were studied. Thirty-four patients were treated before the introduction of the policy of aggressive CSF diversion. Of these patients, 10 died, resulting in a mortality of 29% and a morbidity of 21%. Forty-three patients were treated after the institution of the new policy of CSF diversion. Of these patients, five died, resulting in a mortality rate of 11.6% and a morbidity rate of 14%.

Although surgical drainage of a cerebellar abscess and eradication of the primary septic source and appropriate antibiotic coverage are necessary, the management of hydrocephalus, or even incipient hydrocephalus, is of paramount importance.