| Abstract: | Anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis is a type of immune-mediated encephalitis, which is a new category of treatment-responsive paraneoplastic encephalitis. In patients with this disease, electroencephalography (EEG) shows non-specific findings, but recently, a unique EEG pattern, named the extreme delta brush, was detected in 40% of adult patients and was suggested to be specific to this type of encephalitis. Here, we describe a two-year-old boy with anti-NMDAR encephalitis, who presented with speech arrest and disturbances of gait and cognition several weeks after developing febrile convulsions. In the early stages of the disease, EEG showed 14–16?Hz, continuous, fast waves characterized by a high amplitude (200–500?µV), very diffuse spreading, and a sharp morphology, during light sleep only, which was compatible with extreme spindles. As the patient’s symptoms worsened, this finding was replaced by rhythmic, diffuse, high-voltage, slow waves. Immediately after immunomodulatory therapies, including intravenous methylprednisolone and immunoglobulin, his clinical manifestations and EEG abnormalities appeared to improve. We propose that although the extreme spindle is a non-specific finding of this type of encephalitis, early EEG monitoring might be necessary to detect not only the extreme delta brush pattern, but also non-specific findings, including extreme spindles, which would aid early diagnosis and treatment. |
