[Actinomycosis infection of the cerebellum]

The case is presented of a 37-year-old male with a cerebellar abscess due to Actinomyces israelii. The patient was admitted after dental surgery because of fever and symptoms indicative of raised, intracranial pressure. No abnormalities were detected in peripheral blood and cerebrospinal fluid. CT scan revealed a space-occupying lesion in the left cerebellar hemisphere with perifocal oedema and occlusive hydrocephalus. After emergency external ventriculostomy complete removal of the mass was achieved in a two-stage surgical procedure. Culture of the pus under anaerobic conditions resulted in a growth of Actinomyces israelii, Peptostreptococcus anaerobius and Bifidobacterium adolescentis. A 20-day regimen of antibiotics including penicillin G 10 million U x 3/d and clindamycin 900 mg x 3/d was administered. The patient made a full recovery. Pathogenesis and therapeutic principles of CNS infections due to Actinomyces israellii are discussed.