Seronegative Autoimmune Limbic Encephalitis: A Case Report.

Autoimmune encephalitis (AE) is an immune-mediated disorder of the central nervous system (CNS). Its definitive diagnosis relies on the identification of a specific antibody. Autoimmune limbic encephalitis (LE) is a subset of AE characterized by inflammation of the limbic cerebral cortex. Cognitive decline, behavioral disturbance, and seizures are its cardinal manifestations. We present the case of a 70-year-old man with subacute progressive gait imbalance, cognitive impairment, and psychiatric manifestations. Extensive serum and cerebrospinal fluid (CSF) investigations did not reveal any abnormality. Autoimmune and paraneoplastic encephalitis antibody panels were negative. Magnetic resonance imaging (MRI) and positron emission tomography (PET) brain scans suggested LE. He responded well to immunotherapy. This case illustrates that AE must be suspected in the appropriate setting, even in the absence of a specific antibody. These patients should be given the benefit of early immunotherapy.

Rituximab in Neuromyelitis Optica Spectrum Disorders: Our Experience.

BACKGROUND: Neuromyelitis optica (NMO) is an inflammatory demyelinating central nervous system disease, with recurrent attacks of severe bilateral optic neuritis and longitudinally extensive transverse myelitis. Aggressive immunosuppression is essential to prevent clinical relapses and permanent disability. Rituximab, a monoclonal antibody to CD20, has been found effective in several reports and small uncontrolled studies. There is a paucity of data regarding its use in Indian patients. OBJECTIVES: The aim of this study was to report the results of rituximab treatment in NMO spectrum disorders (NMOSDs) in the Indian scenario. METHODS: This study is a retrospective, observational study including 13 NMOSD patients treated with rituximab. After initial therapy in the acute episode with IV methylprednisolone and if needed plasma exchange, therapy was initiated as a cycle of intravenous rituximab, two doses 2 weeks apart of 1 g each. Subsequent cycles were advised at intervals of every 6 months. The primary outcome measure was annualized relapse rate (ARR), defined as a number of clinical attacks per year. Clinical adverse events were recorded throughout the study. RESULTS: In the study, mean ARR reduced from 2.61 to 0.09 after therapy (P = 0.000685). Of 13 patients, 8 (61.54%) were completely relapse free after starting treatment with rituximab. Treatment was well tolerated and no serious adverse events were noted. CONCLUSIONS: The treatment of NMOSDs with rituximab in Indian patients reduces the frequency of relapses and is well tolerated.