Sweating During REM Sleep: Physiological Mechanisms and Clinical Implications
Sweating during REM sleep is primarily caused by autonomic dysregulation, with reduced sweating compared to other sleep stages due to changes in thermoregulatory sensitivity.
Physiological Mechanisms of Sweating During Sleep
- During REM sleep, there is a significant decrease in sweating compared to both non-REM sleep and wakefulness, due to a reduced slope in the relationship between body temperature and sweat production 1
- Sweating responses vary according to sleep stages, with a gradation pattern showing highest sweating in slow-wave sleep, intermediate in stage 1-2, and lowest during REM sleep 1
- The reduced sweating in REM sleep is explained by decreased sensitivity of the thermoregulatory system rather than a change in the temperature threshold that triggers sweating 1
Clinical Conditions Associated with Abnormal Sweating During REM Sleep
- Obstructive sleep apnea (OSA) is strongly associated with increased sleep-related sweating, which correlates with higher blood pressure and reduced REM sleep percentage 2
- Treatment of OSA with CPAP significantly reduces sweating episodes during sleep and is associated with lower blood pressure and increased REM sleep 2
- In infants with apparent life-threatening events (ALTE), significantly higher transepidermal water loss (sweating) has been observed during non-REM sleep compared to healthy controls 3
- Primary sleep hyperhidrosis (excessive sweating) may be treated with anticholinergic medications like oxybutynin when it significantly disrupts sleep quality 4
Autonomic Regulation During REM Sleep
- REM sleep is characterized by distinctive patterns of autonomic nervous system activity, including changes in heart rate variability and thermoregulation 2
- In patients with congenital central hypoventilation syndrome (CCHS), hypoventilation occurs during all sleep stages but is typically less severe during REM sleep compared to non-REM sleep 5
- Thoracoabdominal asynchrony, a well-known phenomenon during REM sleep in infants, occurs due to loss of rib cage stabilization from inspiratory intercostal muscle inhibition 5
- During REM sleep, the typical pattern of thoracoabdominal asynchrony includes paradoxical rib cage movement during inspiration in children with chronic lung disease 5
Pathological Sweating During REM Sleep
- Hyperhidrosis during sleep can be secondary to underlying sleep disorders, with sympathetic overactivity being the major mechanism 6
- In REM sleep behavior disorder (RBD), autonomic dysregulation may occur alongside the loss of normal muscle atonia, though sweating is not a primary feature 5
- Patients with narcolepsy may experience excessive sweating during sleep, potentially related to orexin deficiency in addition to sympathetic overactivity 6
- Medications, particularly serotonergic antidepressants, can induce or exacerbate REM sleep abnormalities and potentially affect autonomic functions including sweating 5
Clinical Approach to Abnormal Sweating During REM Sleep
- Polysomnography is essential to confirm the diagnosis when abnormal sweating during sleep is reported, allowing differentiation between various sleep disorders 7
- Environmental safety measures and appropriate treatment of underlying sleep disorders are crucial for managing symptoms 7
- For primary sleep hyperhidrosis without an identifiable cause, anticholinergic medications may be considered when symptoms significantly impact sleep quality and daily functioning 4
- Regular monitoring of treatment efficacy and potential side effects is necessary for patients with sleep-related sweating disorders 7