Abstracts

Rationale: Non-herpetic acute limbic encephalitis (NHALE) is a cause-unknown, inflammatory disease entity that affects the limbic system restrictedly. We report here a case of NHALE with transient severe mental disorder. Although the patient had severe psychiatric symptoms, he could recover with mild intelligence retardation. Methods: A fourteen-year old boy developed a complaint of right-upper-limb paralyses, dysarthria and headache. These symptoms improved within several hours. However, psychiatric symptoms such as anxiety and fretfulness, and fever were developed. Brain magnetic resonance (MRI) showed a hyperintensity lesion in the left parahippocampal gyrus on fluid-attenuated inversion recovery (FLAIR) images. EEG showed high-voltage slow wave in bilateral frontal pole. Analysis of the cerebrospinal fluid (CSF) showed slight increase of leukocyte count. An anti-GluRdelta2 IgM antibody was positive in blood. We diagnosed him NHALE. Results: He was administered acyclovir (10mg/kg/day), steroid pulse therapy (500mg/kg/day, 3 days), followed by high dose gamma globulin therapy (0.4g/kg/day, 5 days). After that his fever mildly decreased. As his psychiatric symptoms (character disorder, visual and auditory hallucination) were getting worse, he needed to be sedated. He transferred to our hospital because he needed to be hospitalized in the psychiatric ward. He was treated with high dose gamma globulin therapy (0.4g/kg/day, 5 days) followed by steroid pulse therapy (1000mg/kg/day, 3 days). Afterwards, his psychiatric symptoms improved mildly. After he was discharged, he was with mild intelligence retardation as an aftereffect, and yet he was able to pass the entrance examination for high school. Conclusions: We treated a patient with NHALE. He recovered from severe psychiatric symptoms within 2 months. We report this case with a few similar cases in the past literatures.