leep is an essential part of life. Humans spend approximately one
third of their lives sleeping. Although once considered a passive
state, sleep is marked by differing levels of brain activity as the
sleeper cycles
through light stages of sleep (stages 1 and 2), deep sleep (stages 3
and 4) and
REM (rapid eye movement) sleep. REM sleep in the past was also called
paradoxical sleep. During this stage of sleep, brain activity
closely resembles
that of wakefulness, there is the occurrence of dreaming, muscles are
paralyzed with the exception of eye movements and respiratory
muscles, and
there are rapid eye movements. Although the precise function of
sleep and
dream sleep has not been completely clarified, it is clear that
sleep is necessary
for normal health and clear mental functioning.
Sleep problems are frequent in Parkinson disease, affecting up to 80-
90% of PD
patients at some time during the course of their disease. Sleep
problems may be
manifested as nighttime sleep disruption, abnormal
behaviors during sleep or excessive daytime sleepiness
(Comella 2003). The negative impact of sleep
problems on quality of life and daytime
functioning is well described. The effect of
sleep problems extends to the caregiver and
family. Some patients with sleep problems
observe that their motor symptoms may be
more severe and their overall functioning
more impaired following a poor nights sleep.
Sleepiness during the day can affect attention,
thinking and memory, and may cause
disruption of social relationships. This article
will describe some of the more common sleep
problems faced by people with Parkinson disease and
emphasize the need to report these to your neurologist.
S
RESEARCHReports
Nighttime Sleep
Disturbances
Sleep fragmentation is
the disruption of sleep
during the night. Often PD
patients will find that falling asleep
is not difficult, but they may awaken
frequently and sometimes find i t
difficult to fall back to sleep. It has many
causes. Sleep fragmentation may arise
due to recurrent symptoms of PD,
with increased difficulty rolling over,
recurrence of tremor, and feelings of
stiffness, restlessness and discomfort
(Factor, McAlarney et al. 1990). When
monitored overnight, there is an increase
in muscle tone that corresponds to these
complaints (Askenasy and Yahr 1985).
These recurrent symptoms and increased
muscle tone may be improved by the
addition of a long acting levodopa
preparation at bedtime, or the judicious
use of small doses of rapid release regular
levodopa at the time of awakening.
Another cause of sleep fragmentation in
PD is the occurrence of sleep apnea or
hypopnea, a respiratory disturbance
during sleep in which normal breathing
is impaired either through partial
obstruction of the airways (obstructive
sleep apnea) or secondary to a reduced
drive to breath (central sleep apnea).
Sleep apnea is a common disorder in the
non-parkinsonian population. It is
associated with cardiovascular (heart)
problems and stroke. In PD patients
complaining of daytime sleepiness
referred to a sleep laboratory, sleep
apnea has been found in up to 20%
(Arnulf 2005). The clues that someone
may have sleep apnea includes the
occurrence of heavy snoring and pauses
in breathing, or choking during the
night. These clues, however, are not
found in every patient. If suspected, the
diagnosis of sleep apnea is made through
a sleep study (polysomnography). Sleep
apnea, particularly obstructive sleep
apnea, is treatable using a variety of
methods, including continuous positive
airway pressure (CPAP). Treatment may
markedly improve the quality of
nighttime sleep and daytime alertness.
BY: CYNTHIA L. COMELLA
Professor, Neurological Sciences
Movement Disorders Center
Rush University Medical Center
Chicago, IL