Divergent presentations of anti-GAD autoimmunity: a comparative analysis of two neurodegenerative cases.

We describe two women presenting with cortico-basal syndrome (CBS) and upper motor neuron-motor neuron disease (UMN-MND), respectively, both with high-titre GAD-Abs in serum and CSF. Both patients showed progressive motor impairment with elevated NFL levels. IVIg therapy was administered without meaningful clinical benefit, suggesting neurodegeneration as the primary phenotypic driver.