Successful immune moderation treatment for progressive encephalomyelitis with rigidity and myoclonus.

Progressive encephalomyelitis with rigidity and myoclonus (PERM) is a rare disease. PERM consists of the same symptoms as stiff person syndrome, in addition to sensory, brainstem and autonomic features. We herein report a case of PERM in a 48-year-old woman who initially presented with spasticity of the lower limbs and subsequently developed upper limb spasticity, perioral myoclonus and restlessness after three months. The onset of potentially fatal dysautonomia was observed at the peak of the disease. Treatment with high-dose immunoglobulin (400 mg/kg, 5 days), levetiracetam and azathioprine resulted in a drastic and sustained improvement of these symptoms. This is an interesting case of PERM in which the patient showed a dramatic improvement following immune moderation.