Nonparaneoplastic Anti-GAD Limbic Encephalitis: Seizure Outcome and Long-term Neuropsychological Follow-up After Immunotherapy.

Antibodies against glutamate decarboxylase (GAD-Abs), especially GAD65 antibodies, are associated with limbic encephalitis (LE) manifested by temporal lobe epilepsy and neuropsychological deficits. We present the case of a 42-year-old Greek woman with nonparaneoplastic anti-GAD LE, discussing the therapeutic management and highlighting the role of neuropsychological assessment. The patient underwent functional and structural brain studies and was investigated longitudinally over a 6-year period with a battery of neuropsychological tests that were designed to document her intellectual function and verbal and visual memory. The patient suffered from refractory temporal-impaired awareness seizures and memory impairment that was mediated by autoimmune nonparaneoplastic LE and comorbid autoimmune disorders (ie, Hashimoto thyroiditis and vitiligo). Neuroimaging studies demonstrated hyperintensities in the medial temporal lobes bilaterally on T2WI MRI sequences. Serial EEGs showed bitemporal intermittent delta activity as well as epileptiform discharges. Tumor blood markers and onconeural antibodies were negative. Immunological screening revealed extremely high GAD-Abs titers in both serum and CSF, as well as the presence of CSF oligoclonal bands. Neuropsychological testing revealed anterograde amnesia with relative preservation of more remote, premorbid memories. The patient underwent first-line immunotherapy followed by immunosuppressive maintenance treatment that led to a reduction of seizures, EEG improvement, and a significant decline in GAD-Abs titers. Neuropsychological evaluations at 5 months, 1 year, and 6 years posttreatment demonstrated improvement, particularly in recent memory and everyday functionality. In this case of anti-GAD LE, the long-term seizure reduction and the improvement of neuropsychological deficits were most likely related to the immunotherapy.

Parkinsonism in autoimmune diseases.

Parkinsonism can be manifested and complicate either systemic or organ-specific autoimmune diseases. Even though it is a rare co-morbidity, it merits attention from clinicians as it affects the quality of life of patients. In systemic autoimmune diseases such as systemic lupus erythematosus, antiphospholipid syndrome and Sjogren's syndrome reported cases of parkinsonism are attributed to the underlying disease and its mechanisms, whether this is brain vasculitis or immune complexes. Regarding antibody-mediated autoimmune neurological disorders, parkinsonism is, in most cases, a manifestation within the spectrum of each disorder and is attributed to the action of humoral and cellular immunity in brain regions such as the basal ganglia. Depending on the pathophysiology, immunotherapy can be effective, while Parkinson's specific therapies are usually less effective.