Periodic limb movements and sleep apnoea

Area of Science:

• Sleep Medicine
• Neurology
• Respiratory Medicine

Background:

• Obstructive Sleep Apnoea (OSA) is a common sleep disorder.
• Periodic Leg Movements (PLMs) are characterized by repetitive limb movements during sleep.
• The relationship between PLMs and OSA severity requires further investigation.

Purpose of the Study:

• To investigate the relationship between Periodic Leg Movements (PLMs) and the severity of Obstructive Sleep Apnoea (OSA).
• To compare the prevalence of PLMs in OSA patients with those in narcolepsy, idiopathic PLM disorder, and healthy controls.

Main Methods:

• Polysomnography was used to assess PLMs in 52 OSA patients, 38 patients with narcolepsy or idiopathic PLM disorder, and 88 healthy controls.
• PLMs were defined by specific criteria for tibialis anterior EMG activity duration, amplitude, and event frequency.
• Patients and controls were aged between 20 and 50 years.

Main Results:

• The overall prevalence of PLMs in OSA patients (27.6%) was similar to healthy controls (20.5%).
• A higher prevalence of PLMs was observed in mild OSA patients (40.7%) and narcolepsy patients (50%).
• Prevalence of PLMs decreased with increasing OSA severity, with only 12.5% in severe OSA, indicating an inverse relationship.

Conclusions:

• There is an inverse relationship between the severity of Obstructive Sleep Apnoea and the manifestation of Periodic Leg Movements.
• Severe OSA, with its associated respiratory events and arousals, may suppress or mask the occurrence of PLMs.
• Further research is needed to understand the complex interplay between OSA severity and PLM prevalence.