Neuronal cell loss in the dorsal raphe nucleus and the superior central nucleus in myotonic dystrophy: a clinicopathological correlation.

A quantitative study of neurons in the dorsal raphe nucleus (DRN) and the superior central nucleus (SCN) was performed in seven patients with myotonic dystrophy (MyD), five of whom showed hypersomnia, and in eight age-matched controls. The densities of neurons in the DRN and the SCN were significantly lower in MyD patients with hypersomnia than in MyD patients without hypersomnia and control subjects. There was an appreciable positive correlation in the density of neurons between the DRN and the SCN in all MyD patients. These data suggest that the neuronal loss of the DRN and the SCN is associated with the presence of hypersomnia in MyD.