Spontaneous bilateral chronic subdural haematoma of the posterior fossa. Case report and review of the literature.

INTRODUCTION: Chronic subdural haematomas of the posterior fossa in adults without a history of trauma are very rare. To our knowledge, only 15 cases have so far been reported in the literature, including those with anticoagulation therapy. A case of spontaneous bilateral infratentorial chronic subdural haematoma associated with anticoagulation therapy in an alive adult is presented and the relevant literature is reviewed. CASE REPORT: A 70 year old female presented with progressive dizziness, vertigo and gait ataxia. She was on anticoagulation therapy for heart disease. Neuro-imaging revealed bilateral infratentorial subdural masses. The subdural masses were suspects for chronic subdural haematomas by neuroradiological criteria. Because of the progressive symptomatology, the haematomas were emptied through burrhole trepanations. Chocolate-colored fluid, not containing clotted components, gushed out under great pressure. The source of bleeding could not be identified. The patient recovered well from surgery, but died 4 months later shortly after admission to another hospital from heart failure. DISCUSSION: The chronic subdural haematomas in this patient may have been due to rupture of bridging veins caused by a very mild trauma not noticed by the patient and possibly aggravated by the anticoagulation therapy. Infratentorial chronic subdural haematoma should at least be a part of the differential diagnosis in elderly patients with cerebellar and vestibular symptomatology even without a history of trauma.