Subacute Noninfective Inflammatory Encephalopathy: Our Experience and Diagnostic Problems

INTRODUCTION: Immune dysregulation associated encephalopathies present with significant psychiatric manifestations and only a few soft neurological and general systemic features. They are generally resistant to treatment with psychiatric medications. Generalized orthostatic myoclonus and faciobrachial dystonic seizures are mistaken as Creutzfeldt-Jakob disease and subacute sclerosing panencephalitis. PATIENTS AND METHODS: Forty-two patients seen during 2010–2015 and diagnosed as noninfective encephalopathy were analyzed. Those patients with infective causes and those who had significant features of systemic manifestations of vasculitis and other disorders of central nervous system were excluded from the study. They were investigated with cerebrospinal fluid imaging, electroencephalogram (EEG), and antibody profile. RESULTS: More than 70% patients had psychiatric manifestation as presenting features and reported to psychiatrist. Three patients had paraneoplastic and others N-methyl-D-aspartate, voltage-gated potassium channel, thyroid peroxidase, antinuclear antibody related, and few were due to unknown antibody. CONCLUSION: Serious diagnostic errors are common and early diagnosis is based on high degree suspicion in patients presenting with new-onset refractory psychosis. Soft neurological features should be looked for and EEG serves as a very sensitive tool in establishing organicity.