Related Experiment Video
Updated: Jul 15, 2026

Quantifying Infra-slow Dynamics of Spectral Power and Heart Rate in Sleeping Mice
Published on: August 2, 2017
Periodic leg movements in narcolepsy patients: impact on sleep architecture
1Sleep Disorders Center, King Saud University, Riyadh, Saudi Arabia. ashammam2@gmail.com
Introduction:
We assessed the effect of periodic leg movements (PLMs) on sleep architecture in narcolepsy patients by comparing sleep patterns in narcoleptics of comparable age with and without PLMs.
Methods:
Patients diagnosed with narcolepsy between January 1999 and December 2005 were divided into those with PLM index >or= 5/hr and <5/hr. Each patient underwent polysomnographic recording followed by a multiple sleep latency test (MSLT).
Results:
There were 47 patients, of mean age 28.9 +/- 1.8 years, 31 (66%) with PLM index >or= 5/hr and 16 (34%) with PLM index <5/hr. Arousal index, PLM arousals and total number of arousals were all significantly higher in narcoleptics with PLM index >or= 5/hr than in those with PLM index <5/hr. Significant correlations were found between PLM index and arousal index, stage shifts, Stage 1 and average sleep latency on MSLT.
Conclusions:
Our findings demonstrated that narcolepsy patients with PLMs have a higher arousal index and increased PLM arousals compared with narcolepsy patients without PLMs. The contribution of the above to the perceived sleep quality and daytime sleepiness is not clear.
Related Concept Videos
Narcolepsy
Sleep-Wake Cycles
NREM Sleep
NREM sleep comprises four progressive stages that seamlessly merge:
Restless Leg Syndrome and Night Terrors
The exact cause of RLS is not fully understood, but it is believed to involve dopamine, a neurotransmitter that helps regulate muscle movement. Imbalances in dopamine levels...
REM Sleep Behavior Disorder
RBD is significantly associated with...
Stages of Sleep
Before sleep begins, in wakefulness, the brain exhibits primarily beta waves, which are high in frequency and low in amplitude, indicating alertness...
Substance Use Disorders Affecting Sleep
Understanding the concepts of physical dependence,...

