ABSTRACT
INTRODUCTION The earliest description of sleep problems of Parkinson’s disease (PD) dates back to the original description of PD by James Parkinson (1817) where he states, “His attendants observed, that of late the trembling would sometimes begin in his sleep, and increase until it awakened him: when he always was in a state of agitation and alarm” (1). This is probably the fi rst description of nocturnal tremor and night-terror or confusional episodes that complicate sleep of people with PD. In spite of sleep dysfunction being a key aspect of the nonmotor symptom complex (NMS) of PD, sleep disturbances related to PD have received specifi c and focused diagnostic and therapeutic attention in many previous studies (2-9). The evidence base for treatment of various aspects of sleep dysfunction and its assessment by validated tools, such as the PD Sleep Scale (PDSS), have emerged in the last 10 years (10,11). Studies have also highlighted that the burden of a range of sleep dysfunction that occurs in PD is a key determinant of quality of life of patients and caregivers (12,13). Awareness has also grown that sleep problems can also affect early untreated PD and “poor nights” for people with PD may occur not only in advanced PD but also in early untreated PD or even precede the motor symptoms with a signifi cant adverse effect on daytime functioning and functional capacity (such as driving) as well as quality of life (12-16). Certain sleep disorders may provide useful diagnostic information in differentiating between parkinsonian syndromes, such as multiple system atrophy (MSA) and progressive supranuclear palsy (PSP), and may be important prognostic indicators of neuropsychiatric disturbances and dementia, whereas others may be precipitated by the treatment of PD (17).
