Use

This test is used for evaluating patients suspected of having stiff-person syndrome (classical or focal forms such as stiff-limb or stiff-trunk) and progressive encephalomyelitis with rigidity and myoclonus. Stiff-person spectrum disorders include classical stiff-person syndrome, focal stiff-person forms, and progressive encephalomyelitis with rigidity and myoclonus (PERM). Paraneoplastic and idiopathic autoimmune causes can be differentiated by a neuronal IgG antibody profile. Common manifestations include stiffness, spasms, heightened startle responses, and falls. The GAD65 antibody serves as a common biomarker for stiff-person spectrum and is linked to autoimmune diseases like type 1 diabetes and thyroid disease, usually without accompanying cancer.