An autopsy case of myotonic dystrophy with mental disorders and various neuropathologic features

An autopsy case of myotonic dystrophy (MD) is reported. The patient was a 5 8-year-old male. He presented with muscular weakness and muscular atrophy a t the age of 33 and was diagnosed as having MD from myotonic symptoms (i.e. percussion and grip myotonia) at 49 years old. Mental disorders including a delusional hallucinatory state, mental slowness, indifference, and lack o f spontaneity as well as visual cognitive impairments were noted at the age of 55. He showed Parkinsonism and died of septic shock. T2-weighted magnet ic resonance imaging demonstrated diffuse cortical atrophy with a marked fr ontal atrophy and high-intensity signals in the white matter. Single photon emission computed tomography demonstrated hypoperfusion in the frontal cor tex. Neuropathologic observation revealed neuronal loss in the superficial layer of the frontal and parietal cortices and extensive neuronal loss in t he occipital cortex, intracytoplasmic inclusion body in the nerve cell of t he medial thalamic nuclei, neuronal loss and presence of Lewy bodies in the substantia nigra and locus ceruleus corresponding to the pathologic featur es of Parkinson's disease, as well as abnormalities of myelin in the white matter. The present case suggests that in MD brain, various neuropathologic changes may occur and they contribute to the mental disorders.