[Mixed connective tissue disease--various neuromuscular complications prior to the elevation of antibody to RNP].

A 47-year-old woman with mixed connective tissue disease (MCTD) was reported. She developed various neuromuscular complications including carpal tunnel syndrome, narrowing of visual field, dysesthesia on face and extremities and weakness before elevation of antibody to RNP. On the examination of biopsied specimens of muscle and peripheral nerve, myositis and demyelination were suspected, respectively. Electroencephalography showed diffuse slowing which was without clinical evidence of the central nervous system involvement and was normalized by the treatment with prednisolone. Present case seems to provide some insights into the neuromuscular complications in MCTD.