Observational Study of the Relation between Parkinson's Disease and Sleep Apnea.

BACKGROUND: Parkinson's disease is characterized by numerous non-motor symptoms, including sleep disorders. Sleep apnea has been reported in a substantial proportion of patients with Parkinson's disease, but it is unclear whether it has significant consequences for the quality of life of those affected or whether it is associated with other manifestations of the disease.

OBJECTIVE: To verify whether sleep apnea is associated with more severe motor and non-motor clinical features in Parkinson's disease.

METHODS: Parkinson's disease patients underwent polysomnography to diagnose the presence of sleep apnea (apnea-hypopnoea index >10). Participants also underwent an extensive assessment, blinded to sleep apnea status, to determine disease severity, quantitative motor indices, motor subtypes, treatment complications, and sleep, autonomic, psychiatric, and sensory dysfunctions. Cognitive status was also determined with a complete neuropsychological assessment. Results were assessed using regression analysis adjusted for age, sex, and disease duration.

RESULTS: Of 92 patients examined, 19 had sleep apnea (21%) and 73 did not. We found no significant differences in motor and non-motor symptoms or signs between apneic and non-apneic Parkinson's disease patients. The use of different apnea-hypopnoea index cut-offs (>5 and >15) produced similar results.

CONCLUSIONS: Our results show that sleep apnea is not associated with more severe motor or non-motor manifestations in Parkinson's disease. More studies including control groups are needed to confirm the implications of those results.