[Listeria monocytogenes abscess of the brain]

Listeriosis commonly involves the central nervous system. Meningoencephalitis and rhomboencephalitis are the most frequent manifestations. Brain abscesses are rare.We report the case of a 63-year-old man treated with steroids for a long period; he was hospitalized for hemiparesis, confusion and fever. Clinical examination revealed meningeal signs, right hemiparesis and Parinaud syndrome. Initial CT scan was normal. The CSF contained 520 white cells/mm3 with predominance of polymorphonuclear neutrophils. An acute meningo- rhombencephalitis in an immunodepressed patient was suggested. The diagnosis of listeriosis was confirmed by blood cultures. Amoxicillin and gentamycin were started. The outcome on day 4 was severe with coma and tetraparesis. Brain MRI revealed a left peduncle abscess which descended deep into the brain reaching the internal capsule. The final clinical outcome involved residual right hemiparesis and left oculomotor nerve (III) palsy.Brain stem abscess is an uncommon form of listerial central nervous system infection. Listeria monocytogenes infection should be considered in patients with altered cell-mediated immunity that develop local neurologic deficits, a diagnosis which pursued rapidly with repeated blood cultures. Successful treatment requires early antibiotic therapy with ampicillin and gentamycin.