REM Sleep Disorder Causes

The exact cause of REM sleep behavior disorder (RBD) is unknown, although the disorder may occur in association with various degenerative neurological conditions such as Parkinson disease, multisystem atrophy, diffuse Lewy body dementia, and Shy-Drager syndrome. In 55% of persons the cause is unknown, and in 45%, the cause is associated with alcohol or sedative-hypnotic withdrawal, tricyclic antidepressant (such as imipramine), or serotonin reuptake inhibitor use (such as fluoxetine, sertraline, or paroxetine) or other types of antidepressants (mirtazapine).

RBD often precedes the development of these neurodegenerative diseases by several years. In one study, 38% of patients diagnosed with RBD subsequently developed Parkinson disease within an average time of 12-13 years from the onset of RBD symptoms. The prevalence of RBD is increased in persons with Parkinson disease and in multisystem atrophy where it is observed in 69% of these patients. The relationship between RBD and Parkinson disease is complex; however, not all persons with RBD develop Parkinson disease.