Sensitivity of radionuclide brain scan and computed tomography in early detection of viral meningoencephalitis.

The sensitivity of radionuclide imaging and computed tomography (CT) was evaluated in 25 patients for early detection of viral meningoencephalitis. Diagnosis was based on clinical evidence, cerebrospinal fluid (CSF) studies, electroencephalography (EEG) and radionuclide imaging. Computed tomography with contrast enhancement was performed within four days after onset of neurological signs or symptoms in 23 patients; no significant findings such as low-absorption abnormalities, mass effect or abnormal enhancement were seen. Radionuclide imaging demonstrated a sensitivity of 90% in the detection of viral meningoencephalitis; the temporal lobe was most commonly involved in patients with herpes encephalitis. Radionuclide imaging should be considered as the first diagnostic procedure in suspected early viral meningoencephalitis.