The Diagnostic Utility of Brain Biopsy Procedures in Patients with Rapidly Deteriorating Neurological Conditions or Dementia

Object: Obtaining brain biopsy specimens is often the diagnostic test of last resort for patients with unexplained neurological conditions, particularly those with a rapidly deteriorating neurological course. The goals of this analysis were to determine the diagnostic sensitivity of brain biopsy specimens in these types of patients and retrospectively identify features of these disorders that may have enabled an earlier diagnosis, which may prevent the need for diagnostic brain biopsy procedures in the future.

Methods: The authors reviewed the case records of all brain biopsy procedures that had been performed at a single tertiary care institution between January 1993 and April 2002 in 171 patients. Patients with HIV or nonlymphomatous brain tumors were excluded from this analysis because the utility of brain biopsy specimens for these conditions has been determined front previous studies. A subgroup analysis of this cohort was performed in the 64 patients who had comprehensive medical records and a clinical syndrome involving a progressively deteriorating neurological condition of less than 1 year in duration. The overall sensitivity of brain biopsy procedures for diagnostic purposes in the cohort was 65% (111 of 171 patients). The two most common diagnoses in the subgroup with rapidly deteriorating neurological conditions were primary central nervous system (CNS) B-cell lymphoma in 20.3% (13 patients) and Creutzfeldt-Jakob disease in 15.6% (10 patients), followed by viral encephalitis in 14.1% (nine patients) and CNS vasculitis in 9.4% (six patients). Clinical symptoms and laboratory data were compared among the diagnostic groups.

Conclusions: These results will help guide the evaluation of patients with neurological conditions that are difficult to diagnose and will provide a foundation for further prospective studies.