Brachial plexus palsy can occur due to a variety of conditions causing dysfunction of the brachial plexus nerve network. In infants, obstetrical complications often result in brachial plexus palsy or erb’s palsy. In adults, brachial plexus palsy can result due to a number of reasons including:
- Traction injury
- Radiation injury
- Motor vehicle accidents
- Blunt trauma
- Gunshot wounds
- Compression due to tumor
What Causes a Friday Night Palsy?
Stretch injuries caused by stretching of the nerves usually recover within four to six months. One of the conditions caused by stretching of the nerves is Sleep palsy. Sleep palsy is often reported in patients who were intoxicated and slept on their arm at night after an alcohol binge. The condition has also been termed Friday Night Palsy and Saturday Night Palsy.
The condition is caused by a compression of the radial nerve as it circles around the humerus when the arm is stretched against a firm object. When a person is intoxicated and falls asleep in an unusual position with his arm thrown over the back of a chair or sofa, the radial nerve is pressurized, which in turn compresses the brachial plexus causing damage resulting in pain and numbness. In some cases, the entire arm can show signs of numbness and weakness and neurological evaluation often reveals weakness in muscles of the arm. Winging of the scapula occurs from weakness of the serratus anterior or rhomboid muscles.
Recovery from the Friday Night Palsy
The nerve function recovers over time ranging anywhere from weeks to many months, sometimes taking well over a year for the function to return to normal. A quicker recovery indicates that the nerve fibers were injured, but not completely dead. If the arm was severely bent causing acute nerve damage, then the nerve fibers at the injury site are nearly dead and the remaining stumps of nerves must send out new nerves to replace the dead nerves, which can be an extremely slow process. In the most severe cases if the compression is severe and prolonged, a more serious form of this condition called ‘Crush Syndrome’ may occur. Extended period of immobilization can cause skeletal muscle injury leading to muscle decay and cause rhabdomyolysis. The condition may result in acute renal failure, which is potentially fatal with an extremely high rate of morbidity.
- Marchini C et al. Saturday night brachial plexus palsy. Neurophysiology. 2007; 28 (5), 279-81.
- Sathornsumetee S, & Morgenlander JC. Friday night palsy: an unusual case of brachial plexus neuropathy. Clin neurol and neurosurg. 2006;108 (2), 191-2. http://www.ncbi.nlm.nih.gov/pubmed/16412841
- “Causes of Erb’s Palsy.” Causes of Erb’s Palsy. N.p., n.d. Web. 17 July 2013. <http://www.erbpalsy.org/causes.html>.
- Devitt BM et al. Saturday night palsy or Sunday morning hangover? A case report of alcohol-induced Crush Syndrome. Arch Orthop Trauma Surg. 2011 Jan;131(1):39-43.
- Radial Neuropathy. http://www.ncemi.org/cse/cse0919.htm