Can Brachial Plexus Injury Occur During Sleep?
Yes, brachial plexus injury can occur during sleep, particularly when the arm is malpositioned for prolonged periods, especially in the context of alcohol consumption or other factors that impair normal protective reflexes and position changes. 1
Mechanism of Sleep-Related Brachial Plexus Injury
The primary mechanism involves compression of the brachial plexus from prolonged immobilization in abnormal positions, similar to the well-known "Saturday night palsy" that affects individual peripheral nerves. 2, 1
Key Contributing Factors:
- Prolonged arm hyperabduction (≥90°) during sleep creates traction and compression on the brachial plexus 3
- Alcohol consumption impairs normal sleep arousal mechanisms that would typically prompt position changes when nerves are compressed 1
- Direct compression from sleeping on the shoulder and arm can cause nerve injury without any acute traumatic event 1
- Bilateral injury is possible when both arms are immobilized in hyperabducted positions, though this carries a particularly poor prognosis 2
Clinical Recognition
This type of injury presents differently from acute traumatic brachial plexopathy:
- Delayed symptom onset may occur, with paralysis not evident until 24-48 hours after the compression event 4
- Symptoms include paralysis of the shoulder, arm, and/or hand with paresthesias and altered sensation 4
- Temperature and color changes in the limb may occur due to autonomic nervous system involvement 4
Important Caveats
This is distinct from typical traumatic brachial plexus injuries, which usually result from high-energy mechanisms like motor vehicle accidents, falls, or penetrating trauma. 5, 6 The sleep-related compression mechanism represents an uncommon but documented cause of brachial plexopathy. 1
Risk factors that increase vulnerability to position-related nerve injuries include: diabetes mellitus, peripheral vascular disease, alcohol dependency, arthritis, and preexisting neurologic symptoms. 3
Diagnostic Approach
- MRI of the brachial plexus with dedicated protocol is the gold standard imaging modality if symptoms persist beyond initial conservative management 7, 8, 9
- Electrodiagnostic studies (EMG/NCS) help assess severity and location of nerve injury 9, 6
- Imaging should be delayed approximately 1 month after injury to allow resolution of hemorrhage and edema if traumatic hematoma is suspected 8, 9
Management
Most compression-related brachial plexus injuries from sleep malposition are managed conservatively with physical therapy to maintain range of motion and monitoring for spontaneous recovery. 7 However, recovery may be incomplete, particularly in bilateral cases. 2