[Clinical spectrum, neuroimaging and therapeutic response to neurological syndromes associated with anti-GAD65].

Neurological syndromes associated with anti-GAD65 antibodies include limbic encephalitis, cerebellar ataxia, drug-resistant epilepsy, stiff-person syndrome spectrum, and overlap syndromes. Their pathophysiology is linked to GABAergic dysfunction and neuronal hyperexcitability. In Latin America, evidence is limited; in a regional review, cases associated with anti-GAD antibodies represented 2.37% of antibody-confirmed autoimmune encephalitis, suggesting underreporting and incomplete clinical characterization. The objective of this study is to describe the clinical characteristics, neuroimaging findings, and therapeutic response in a series of anti-GAD65 cases, as well as to conduct a literature review. This is a retrospective series of four patients from the High Specialty Medical Unit No. 71, Torreón, Coahuila, Mexico. Clinical, imaging, and treatment variables were analyzed. Anti-GAD65 antibodies were determined in serum using ELISA. Diverse phenotypes were observed, with involvement of the hippocampus, cerebellum, and brainstem. Intravenous immunoglobulin, corticosteroids, and rituximab were used, with variable response. The heterogeneity of the anti-GAD65 spectrum hinders timely diagnosis and management, which is still not standardized. Larger regional studies are needed to improve characterization and optimize therapeutic strategies.