title: Focal intracranial infections due to Propionibacterium acnes: report of three cases.
abstract: OBJECTIVE
  Except for its role in shunt infections, Propionibacterium acnes has been of little interest to neurosurgeons. The rarity and indolent nature of focal intracranial infections by P. acnes limit their recognition. Three cases of serious intracranial infection due to this organism are described. CLINCAL PRESENTATION: Three patients with histories of immunosuppression and neurosurgical procedures developed nonspecific, delayed presentations (5 wk to 5 yr after surgery) of intracranial infections. In two patients, radiological investigations showed enhancing lesions that were later found to be brain abscesses. A subdural empyema was found in the third patient.
  
  
  METHODS
  All three patients underwent surgical drainage of the purulent collections. P. acnes was isolated in each case, and each patient was treated with a 6-week course of intravenous penicillin. All three patients made good recoveries, and subsequent imaging showed no recurrence of the infectious collections.
  
  
  CONCLUSIONS
  P. acnes is an indolent organism that may rarely cause severe intracranial infections. This organism should be suspected when an intracranial purulent collection is discovered in a patient with a history of neurosurgical procedures. Immunosuppressed patients may be susceptible to this otherwise benign organism. Surgical drainage and treatment with intravenous penicillin should be considered standard therapy.
authors.affiliation: Department of Neurosurgery, University of Minnesota School of Medicine, Minneapolis 55455, USA.
authors.forename: R M
authors.initials: RM
authors.lastname: Chu
authors.forename: R P
authors.initials: RP
authors.lastname: Tummala
authors.forename: W A
authors.initials: WA
authors.lastname: Hall
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000382:microbiology / Q000473:pathology; D013354:Empyema, Subdural / Q000175:diagnosis / Q000188:drug therapy / Q000382:microbiology*; D005260:Female; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy / Q000382:microbiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011425:Propionibacterium acnes / Q000302:isolation & purification*; D014057:Tomography, X-Ray Computed