We all move when we sleep. Some people move more than others.
It is not unusual for a person to have one or two jerking
movements of the legs, arms, or whole body when just falling
asleep. These are normal events and may happen every night
or not at all. We call these jerking movements “sleep
starts” or “hypnic jerks”.
Most people change position during sleep, changing from
back to side, side to side, onto the stomach, etc. People
sometimes awaken or can be totally unaware of these movements.
Pain from any source can devastate sleep. Back, knees and
shoulders lead the list, but pain in any part of the body
can disrupt sleep and lead to movement. A normal change
in sleep position can trigger pain and disrupt sleep, causing
moving during sleep is normal, some movements are not normal
and some normal movements can occur excessively. These abnormal
movements and excessive normal movements are sleep disorders.
As a result of these disorders a person may experience poor
quality sleep, discomfort, injuries and daytime symptoms.
When it is suspected that a person is experiencing a sleep
movement disorder, a polysomnogram is often required to
identify the type of abnormality and its severity. Some
of the common sleep movement disorders seen during a polysomnogram
are described below.
Restless Legs Syndrome
Restless Legs Syndrome is a condition that causes uncomfortable
sensations in the muscles, primarily in the legs, and is
relieved by moving. Symptoms typically begin late in the
day gradually becoming more intense throughout the night
and resolve after a night of sleep. This condition makes
sleep onset difficult and can be a cause of significant
Periodic Limb Movements
Periodic limb movements (PLMs) are recorded in about half
of the sleep tests performed at The Sleep Center. PLMs are
rhythmical contractions of muscles in the extremities, primarily
the legs. In order to be categorized as PLMs, the movements
must meet standards of type of contraction, electrical strength,
frequency and duration.
PLMs vary from rare and weak to frequent and strong. They
may result in disruption of sleep. The disruption can be
severe and result in many symptoms such as frequent nighttime
awakenings and daytime sleepiness. When a person experiences
symptoms with documented PLMs, the condition is called Periodic
Limb Movement Disorder.
Sleep Walking and Talking
Walking and/or talking during sleep are not uncommon occurrences
during childhood. These occurrences become less frequent
with maturity and usually disappear. There are times when
there are reasons to be concerned about these activities
during childhood and certainly if they persist into adulthood.
REM Behavior Disorder
REM Behavior Disorder can be described as a person physically
acting out their dreams while asleep. It occurs during the
portion of sleep that we associate with dreaming, Rapid
Eye Movement (REM) sleep. A person with this problem will
often injure themselves or their bed partner by punching
and kicking. Nighttime awakenings and daytime sleepiness
are symptoms associated with this disorder.
Seizures can occur during sleep and sometimes only occur
during sleep. Seizures result in movement. Depending on
the portion of the brain affected by the seizure, the movements
may appear normal, resemble movements seen with other sleep
disorders, appear to be typical seizure movements, or are
strange and unique movements.