Focal intracranial infections due to Actinomyces species in immunocompetent patients: diagnostic and therapeutic challenges.

OBJECTIVE: Actinomyces spp. are often underestimated as causes of central nervous system infection because they are not looked for routinely and are difficult to detect. We try to determine the optimal management of these problematic intracranial infectious diseases in neurosurgical practice.
METHODS: Five cases of intracranial suppurations due to Actinomyces spp. treated between December 2007 and February 2009 are reported. The relevant clinicobacteriologic features and treatment outcomes are analyzed.
RESULTS: There were two brain abscesses, two subdural empyemas, and one frontal sinus pyomucocele with intracranial extension. Among them, three cases were previously operated and two patients were previously treated for otorhinolaryngeal infection. All cases were immunocompetent. In addition to Actinomyces sp., three patients had coinfectious bacteria (Pseudomonas aeruginosa, Staphylococcus warneri, and Escherichia coli). Complete resolution of the infection was achieved by means of aggressive surgical treatment and relatively short course of antibiotic therapy with a full recovery.
CONCLUSION: Actinomycotic focal cerebral infections may occur with greater frequency than previously recognized. Polymicrobial bacteria may be seen. This rare anaerobic organism should be considered in patients with a history of head trauma, previous surgery, or otorhinolaryngeal infection who present with a long duration of neurologic symptoms with or without an accompanying fever. Patients may be candidates for surgical debridement with relative shorter term of antibiotic therapy (ciprofloxacin).