MOVEMENT DISORDERS (S FOX, SECTION EDITOR)
Disturbances of Sleep and Alertness in Parkinson’s Disease
Published online: 19 April 2018
Springer Science+Business Media, LLC, part of Springer Nature 2018
Purpose of Review Parkinson’s disease (PD) is the second most common neurodegenerative disorder. Sleep dysfunction is one of
the most common non-motor manifestations of PD that has gained significant interest over the past two decades due to its impact
on the daily lives of PD patients, poorly understood mechanisms, and limited treatment options. In this review, we discuss the
most common sleep disorders in PD and present recent investigations that have broadened our understanding of the epidemiol-
ogy, clinical manifestations, diagnosis, and treatment of disturbed sleep and alertness in PD.
Resent Findings The etiology of impaired sleep-wake cycles in PD is multifactorial. Sleep dysfunction in PD encompasses
insomnia, REM sleep behavior disorder, sleep-disordered breathing, restless legs syndrome, and circadian dysregulation. Despite
the high prevalence of sleep dysfunction in PD, evidence supporting the efficacy of treatment strategies is limited.
Summary We are at the opportune time to advance our understanding of sleep dysfunction in PD, which will hopefully lead to
mechanisms-driven interventions for better sleep and allow us to approach sleep as a modifiable therapeutic target for other non-
motor and motor manifestations in PD.
Keywords Parkinson’s disease
Excessive daytime sleepiness
REM sleep behavior disorder, circadian rhythm disorder
In his famous monograph, An Essay on the Shaking Palsy in
1817, Dr. James Parkinson masterfully described the clinical
features of a common movement disorder named after him
Parkinson’s disease (PD). This monograph withstood the testa-
ment of time and remains a stellar example of the power of
clinical observation. Among many aspects of PD, Dr.
Parkinson described disturbed sleep in his patients with shaking
palsy. He wrote “In this stage, the sleep becomes much dis-
turbed. The tremulous motion of the limbs occur during sleep,
and augment until they awaken the patients, and frequently with
much agitation and alarm…When exhausted nature seizes a
small portion of sleep, the motion becomes so violent as not
only to shake the bed-hangings, but even the floor and sashes of
the room”. Two centuries later, physicians and allied health
professionals hear similar stories from patients and their care-
givers. Disorders of sleep and wake have become well-
recognized non-motor manifestations of PD, with significant
impact of quality of life and safety in the PD population.
Despite of the high prevalence of sleep disorders in PD,
proper recognition by medical and scientific communities
took a while. Throughout this process, several milestones
are worthy of emphasis as they demonstrate significant and
unique features of disturbed sleep in PD. Reports of sleep-
related breathing problems in post-encephalitic parkinsonism
first emerged following the 1918 influenza pandemic .
Another milestone was the recognition of excessive daytime
sleepiness and sleep attacks among patients treated with do-
pamine agonists with its important safety and medicolegal
implications . Recognition of REM sleep behavior disorder
as one of the earliest markers of synuclein-specific neurode-
generation has had a revolutionary impact on the field .
Recently, emerging evidence of circadian dysregulation in
PD has opened a new clinical and research avenue, position-
ing the circadian system as a novel diagnostic and therapeutic
target in PD and neurodegeneration [4•].
This article is part of the Topical Collection on Movement Disorders
* Aleksandar Videnovic
Movement Disorders Unit, Massachusetts General Hospital,
Boston, MA 02114, USA
Division of Sleep Medicine, Harvard Medical School, Boston, MA,
MGH Neurological Clinical Research Institute, 165 Cambridge
Street, Suite 600, Boston, MA 02446, USA
Current Neurology and Neuroscience Reports (2018) 18: 29