To the Editor We read with interest an article published by Gelfand et al1 on a series of 49 patients with encephalitis, not otherwise specified (ENOS) diagnosed by brain biopsy. The authors suggested that ENOS was the most common initial histopathologic diagnosis among all types of encephalitis and standard histologic evaluation is unlikely to yield specific causes unless additional analyses are performed. We believe that such a conclusion is unwarranted because the authors did not report either the indication for biopsy or the prebiopsy diagnosis of the patients included in the study.
Zou Y, Bai HX, Tao Y. Diagnosing Encephalitis, Not Otherwise Specified. JAMA Neurol. 2015;72(6):725-726. doi:10.1001/jamaneurol.2015.0545