Sleep problems in subacute myelo-optico neuropathy (SMON)

Subacute myelo-optico neuropathy (SMON) patients typically suffer from sequelae that cause sleep disturbances. We sought to examine the prevalence of sleep problems among SMON patients. We conducted a questionnaire-based survey concerning sleep problems among 106 SMON patients, and 110 age- and gender-matched control participants. The prevalence of subjective insomnia (6 ≤ Athens Insomnia Scale score) was 89.6% among SMON patients, which was significantly higher than among control participants 54.4%. Sleep quality measured with the Pittsburgh Sleep Quality Index (PSQI) revealed that the prevalence of poor sleepers (6 ≤ PSQI score) was higher among SMON patients than control participants (75.6% vs 39.6%, respectively). Subscale analyses of rapid eye movement sleep behavior disorder screening questionnaire revealed that scores on two items ("dreams match nocturnal behavior" and "limb movements") were significantly higher among SMON patients than control participants. In addition, daytime sleepiness scores were significantly higher among SMON patients than control participants (4 ≤ Epworth Sleepiness Scale scores: 54.0% vs 29.0%, respectively). The current study revealed that most SMON patients suffer from insomnia with dissatisfactory sleep quality, likely due to their long-term physical sequelae. Moreover, SMON patients showed higher rates of daytime sleepiness and sleep medication intake, which could be related to reduced activity during the day, as well as insomnia.