[A case of degenerative type of progressive myoclonus epilepsy]

This report describes a patient with degenerative type of progressive myoclonus epilepsy (PME), who showed slowly progressive deterioration of the central nervous system; intellectual impairment, dysarthria, and involuntary movements, particularly action myoclonus and dystonia. The patient was a 19-year-old woman who had no hereditary factors. At the age of 4, she developed action myoclonus in the upper limbs bilaterally. Her condition became gradually worse, and at the age of 15, she was admitted to our hospital because of involuntary movement in the upper limbs. First physical examination revealed mild mental retardation, action myoclonus, dystonia, and delayed adolescence. As giant SEP characteristic of PME and Ramsay Hunt syndrome was found, she was tentatively diagnosed as having Ramsay Hunt syndrome without epilepsy, and delayed adolescence. Now, she is 19 years old, and unable to walk alone because of involuntary movements and paralysis. But she has not developed epilepsy. As she has not been compatible with progressive myoclonus epilepsy (PME) and progressive myoclonic ataxia (PMA) classified by Marseille Consensus Group, she has been diagnosed as having an atypical PME syndrome.