title: Transcerebellar stereotactic biopsy for lesions of the brainstem and peduncles under local anesthesia.
abstract: OBJECTIVE
  For certain brainstem lesions, a diagnostic biopsy is required for treatment planning. We reviewed the indications, safety, and diagnostic effectiveness of a transcerebellar stereotactic biopsy using local anesthesia and sedation.
  
  
  METHODS
  We retrospectively reviewed hospital records for all adult patients with symptomatic lesions of the pons and/or cerebellar peduncle who underwent an awake transcerebellar stereotactic biopsy at our institution over a 7-year period. Our technique features several modifications from the standard method and was performed under local anesthesia with patients in the semi-sitting position.
  
  
  RESULTS
  Our rate of diagnostic success (92%) was comparable to those in other published reports. However, only 5 (42%) of 12 biopsy-derived diagnoses were consistent with those predicted from preoperative magnetic resonance imaging. There were no deaths, and the only neurological complication was a cranial nerve palsy. Diagnoses in the 13 cases included infiltrative glioma (), metastases (), lymphoma (), encephalitis (), and reactive astrogliosis ().
  
  
  CONCLUSIONS
  Tissue diagnosis of lesions in the brainstem and cerebellar peduncles continues to be a significant challenge, with the potential for major morbidity. With appropriate patient selection, however, awake transcerebellar biopsy is a safe and effective procedure that can change clinical management and provide important prognostic information.
authors.affiliation: Department of Neurological Surgery, University of California San Francisco, San Francisco, California CA 94143-0112, USA.
authors.forename: Nader
authors.initials: N
authors.lastname: Sanai
authors.forename: Scott P
authors.initials: SP
authors.lastname: Wachhorst
authors.forename: Nalin M
authors.initials: NM
authors.lastname: Gupta
authors.forename: Michael W
authors.initials: MW
authors.lastname: McDermott
mesh_terms: D000328:Adult; D000368:Aged; D000772:Anesthesia, Local / Q000379:methods*; D001706:Biopsy; D001933:Brain Stem / Q000473:pathology*; D020295:Brain Stem Neoplasms / Q000175:diagnosis* / Q000473:pathology; D002531:Cerebellum / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013238:Stereotaxic Techniques; D013681:Tegmentum Mesencephali / Q000473:pathology*