Patients with Primary Cervical Dystonia have Significant Sleep Impairment and Polysomnographic Abnormalities

The non-motor symptoms in Primary Cervical dystonia (CD) include sleep disturbances. The objective was to study the sleep disturbances and polysomnographic characteristics in patients with CD. The study was conducted at the department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS) hospital, Bangalore, India, as a cross sectional study. Patients with CD were assessed by questionnaires to evaluate severity of the CD, depression, restless leg syndrome, sleep quality, self-esteem, and daytime sleepiness and polysomnography analysis was done. Fifty patients of CD were recruited of which 37 (61.7%) were males and 23 (38.3%) females. Polysomnography was analysed in 13 patients and 13 controls. Age of presentation was 40.5 ± 11.6 years and duration of symptoms was 2.5 ± 3.2 years. The sleep disturbances were seen in 30%. Depression correlated with sleep impairment (r = 0.59, p < 0.05) self-esteem (r = 0.58, p < 0.05), excessive daytime sleepiness (r = 0.25, p = 0.05). REM sleep duration was significantly reduced compared to that of the controls. Patients with cervical dystonia had decreased propensity for spindle generation and maintenance, increased delta power. This study describes the high frequency of sleep abnormalities in patients and spindle density reduction with CD. The patients have occupational challenges and difficulty in carrying out their activities of daily living.