Progressive encephalomyelitis with rigidity, diabetes mellitus and retinopathy: An anti-GAD syndrome

A 59-year-old woman with a past history of pigmentary retinopathy developed progressive encephalomyelitis with rigidity (PEWR) characterized clinically by cerebellar ataxia, pyramidal signs and stiffness with painful muscle spasms. At the same period, retinopathy strikingly worsened, Her serum contained antibodies against glutamic acid decarboxylase (GAD). She developed diabetes mellitus under corticotherapy, which was inefficient. Neurologic signs dramatically improved with diazepam and high dose of intravenous immunoglobulin (i.v. Ig). Anti-GAD antibodies have been described in stiff man syndrome, but in only one previous case of PEWR. Presence of such autoantibodies in serum and improvement following i,v. IgG infusion strongly suggest an autoimmune mechanism involving, in our case central nervous system, pancreas and probably retina.