Progressive encephalomyelitis with rigidity and myoclonus

A rare stiff person syndrome spectrum disorder characterized by limb and truncal rigidity, stimulus-sensitive spasms, myoclonus, hyperekplexia, autonomic disturbance, and brainstem involvement or other neurological defects. The condition is progressive and potentially life-threatening, especially due to respiratory failure. It may be associated with the presence of glycine receptor or glutamic acid decarboxylase antibodies, as well as thymomas or lymphomas.