Nystagmus and REM-density during sleep in patients with various brain lesions.

The subjects of this study were 25 patients. Sixteen cases with nystagmus referable to brain stem lesion were divided into two groups; one group was 7 vertical nystagmus (vertical group) and the other group was 9 horizontal nystagmus (horizontal group). Other 9 cases consisted of congenital group (4 cases), cerebellar group (3 cases) and labyrinthine group (2 cases). Normal controls were 8 male volunteers who had no history of particular psychiatric and somatic illness. The results were as follows: 1) Nystagmus observed during wakefulness in all nystagmus groups disappeared during all stages of sleep. 2) The vertical component of nystagmus in the vertical group showed significantly enhanced REM-density compared with that of normal subjects. 3) Both horizontal and vertical REM-densities of the horizontal and labyrinthine group were almost as high as those of normal subjects. 4) Both REM-densities of the congenital group were significantly lower than those of normal subjects. 5) The horizontal REM-density of the cerebellar group was significantly higher than that of normal subjects.