Lower prevalence of sleep disturbances in familial versus sporadic Parkinson's disease: a questionnaire based study

Parkinson's disease (PD) is a debilitating neurodegenerative disorder affecting 1.5% of all above 55 years of age. Sleep related complaints are commonly reported in patients with PD and may form an important determinant of their quality of life. Interactions among genetic and environmental factors may play an important role in the development of and also explain the difference in sleep disturbances in these groups. The aim of our study was to compare the prevalence and distribution of various sleep disorders in patients with familial PD versus those with sporadic PD. Consecutive patients with sporadic and familial PD were evaluated with detailed clinical history; examination and questionnaire on sleep related problems over a two year period. The study included a total of 134 patients, 104 had sporadic PD and 30 had familial PD. Insomnia and rapid eye movement (REM) sleep behavior disorders (RBD) were significantly common in sporadic group (26.9%and 25%) as compared to familial group (3.3%and 0%, P=0.006 and 0.002) despite comparable disease severity scores and duration of disease (P=0.116). Clinical RBD and other sleep disturbances are much less common in patients with familial PD as compared with those with sporadic PD.