Brain biopsy for encephalitis.

Brain biopsy is justified in patients suspected of having encephalitis or viral encephalopathy because those patients are most likely to be helped if a diagnosis is made rapidly and with the greatest certainty possible. Neurosurgeons are occasionally reluctant to undertake brain biopsy because the procedure is diagnostic rather than therapeutic in intent. However, using currently available techniques a 1 cm3 sample of brain tissue can be taken with very low risk of morbidity or mortality. We recommend that the sample be taken from the anterior portion of the inferior temporal gyrus on the more affected side in patients with herpes simplex encephalitis, and from an area of maximum demonstrated involvement in other situations, using stereotactic techniques and intraoperative ultrasound as necessary. The risk to the operating surgeon and to the other members of the operating team appears very low in all of the situations discussed in this chapter. However, the authors feel that every patient should be approached as if he carries the hepatitis B virus. As indicated, the incidence of contracting hepatitis B after sustaining needle stick exposure to blood from persons positive for hepatitis B surface antigen is 10-15%. Conjunctival contamination by splash from the wound is a known method of inoculation of surgeons with hepatitis B virus and is a possible means for transmission of other viral diseases. We recommend that every patient be approached as if he has hepatitis B, not because the agent diseases discussed are known to be as infectious as hepatitis B, but because constant vigilance and careful technique offer the best protection to the surgeon and the members of the operating team in most situations, and because one can never be certain what agent diseases a given patient may harbor. With the exception of the Creutzfeldt-Jakob virus, the agents responsible for all of the viral diseases discussed are inactivated by standard procedures for sterilization of operating room instruments. Procedures necessary to inactivate the Creutzfeldt-Jakob disease virus have been presented. In the report documenting transmission of Creutzfeldt-Jakob disease through human growth hormone preparations the authors state, "We are once again dramatically reminded that human tissues are a source of infectious disease, and that any therapeutic transfer of tissue from one person to another carries an unavoidable risk of transferring the infection.(ABSTRACT TRUNCATED AT 400 WORDS)