Saturday Night Palsy

Original Editor - Ahmed M Diab
Top Contributors - Ahmed M Diab and Kim Jackson

Introduction

An object or surface pressing directly onto the upper medial arm or axilla for a prolonged period of time causes Saturday night palsy, a compressive neuropathy of the radial nerve. The radial nerve is composed of C5 to T1 nerve roots, which arise from the posterior segment of the brachial nerve plexus. It begins by running deep to the axillary artery, then passes inferiorly to the teres minor before wrapping down the medial aspect of the humerus and resting in a spiral groove. Radial nerve compression results in a nerve palsy that impairs motor and sensory function. The term "Saturday night palsy" stems from the connection between Saturday night carousing and the resulting stupor, which can cause a prolonged period of immobility during which nerve compression can occur. The result of this compression is a nerve palsy that impairs motor and sensory function. Also, the term "honeymoon palsy" has been used to describe Saturday night palsy.

Aetiology

It's possible that intoxicated people lose the reflexive ability to adjust their positions while they're sleeping. The classic scenario involves a person dozing off with their arm dangling over a chair or other hard surface, which causes compression in the axilla. Likewise, a person who falls asleep on another person's arm and subsequently compresses their nerve is said to have "honeymoon palsy." Despite the fact that these are the more commonly known presentations, it is important to remember that Saturday night palsy can result from abnormal positioning or use of the limbs that can compress by a similar mechanism. Using crutches improperly, wearing compressive clothing or accessories, wearing a blood cuff for an extended period of time, and more are examples of this.

Epidemiology

• The prevalence of Saturday night palsy has been estimated at 2.97 per 100,000 men and 1.42 per 100,000 women.
• In the United States, it ranks as the 4th most common mononeuropathy, and it is also very common elsewhere in the world.
• It has been observed in patients of all ages due to the injury's mechanism, which is not age-specific.

History

• Patients frequently describe how their symptoms follow heavy alcohol consumption and then unnatural sleeping positions.
• If there is no alcohol consumption, patients might describe another mechanism by which compression would have been unnaturally applied to the upper medial arm or axilla.
• Patients might withhold this information unless prompted because it might not be recognised as the triggering event.
  

Clinical Presentation

• The onset of symptoms may take several days following the initial insult, resulting in a delayed presentation.
• Numbness, weakness, tingling, pain, or any combination of these symptoms may be reported by patients.
• Physical examination may reveal a characteristic wrist drop caused by the loss of extensor muscle function controlled by the radial nerve branches and the preservation of flexor muscle function supplied by other nerves in the hand and arm. As a result, the wrist and fingers cannot be extended at the metacarpophalangeal joints. The ability to extend the thumb is also lost, which makes it difficult to open the hand and grasp objects. Any healthcare provider should be aware that patients can still extend their fingers at the level of the proximal and distal interphalangeal joints because the ulnar nerve controls these.
• The triceps reflex, which is controlled by radial nerve innervation, may also be lost in patients.
• Sensory deficits commonly affect the posterior or lateral upper arm, with symptoms distributing distally to affect the posterior forearm, posterior hand, and posterolateral aspect of the lateral three and  a half digits.

Evaluation

• Many patients with a clear medical history and physical examination may not need additional diagnostic testing because the evaluation and diagnosis of Saturday night palsy are primarily clinical in nature.
• Additional diagnostic methods, however, may be useful for assessing potential complications and causes as well as for determining prognosis.
• In order to distinguish between cervical radiculopathies, brachial plexopathies, and peripheral neuropathies, electromyography and nerve conduction studies can localise lesions anatomically.
• Ultrasound is a low-cost, low-risk modality that can help visualise the nerve and spot areas of disruption or damage. It can also be very helpful in detecting obvious nerve disruption early on and accelerating early surgical intervention in these cases.
• Magnetic resonance imaging (MRI) can provide fine detail that ultrasound cannot and can also identify which muscles have been affected. It can also screen for additional disease process, neurologic disorders, and spot tissue masses.
• X-ray imaging can detect fractures, dislocations, and bony tumours that may be the source of nerve damage.

Management

Wrist splint

Saturday night palsy is primarily focused on physical rehabilitation; a soft wrist splint that maintains the wrist extended during physical therapy. Nevertheless, it is essential that one allow for passive range of motion of the affected extremity during rehabilitation, which a dynamic splint can provide.

• Supportive care, such as nonsteroidal anti-inflammatory drugs (NSAIDs), systemic corticosteroids, steroid injections, and rest, can be added to the previous measures.
• Some new therapeutic strategies include using ultrasound to deliver localised injections to speed recovery. Surgical management is reserved for severe radial nerve injuries or cases where the compression is caused by an intrinsic process such as a mass, bone, spur, or cyst.

Physiotherapy role

• Exercises for hand tingling and numbness.

• Trans-cutaneous nerve stimulation (TENS) for neuropathic pain in the affected region.

Differential Diagnosis

• Traumatic causes include humeral fractures, which are a common cause of radial nerve injury. Other common causes include severe blunt trauma, crush injuries, puncture wounds, and stab wounds.
• Anterior glenohumeral shoulder dislocation can rarely result in a radial nerve injury and should be considered in any patient who has physical exam findings that are consistent with this.
• Any surgery or injection involving anatomy associated with the path of the radial nerve can result in iatrogenic injury.
• Nerve palsy can be caused by internal compression caused by cysts, masses, tumours, muscle hypertrophy, and fibrinous tissue.
• Isolated palsies can be caused by repetitive overuse or neurologic diseases, and some patients have been found to have acute ischemic strokes after presenting with isolated symptoms.

Prognosis

• The Saturday night palsy prognosis is determined by the extent of the injury, which is determined by the force and duration of compression.
• Mild damage causes neuropraxia, a transient conduction block that does not result in nerve degeneration. This type of injury almost always results in a partial recovery.
• Moderate damage causes axonotmesis, which is characterised by axonal damage and Wallerian degeneration with incomplete or late recovery.
• Severe injury causes neurotmesis, which is characterised by complete axon degradation and Schwann cell death, with a low likelihood of complete recovery. Patients with this level of injury will almost always require surgical intervention.
• The degree of damage can be complicated to determine based solely on electromyography, and early prognosis prediction can be hard to do.
• Recovery is slow, with even mild cases taking at least 2-4 months and often more time.

Complications

• Failure to consider a broad differential diagnosis can lead to complications, such as missing a severe disease or illness. It is critical to determine the cause of radial nerve deficits because treatment can vary greatly from case to case.
• The main complication of true compressive Saturday night palsy is the inability to recover, which can be an indication for surgical exploration. The surgical options afterward include nerve grafting, nerve transfers, tendon or muscle transfers, and a variety of other techniques. As with most surgical procedures, there may be a variety of complications related to intraoperative issues and post-surgical infections.
• Furthermore, partial recovery is common in these cases, and long-term disability can be a challenge. Prolonged and regular physical therapy can be exhausting, but it is necessary for regaining some functionality.

• Failure to consider a broad differential diagnosis can lead to complications, such as missing a severe disease or illness. It is critical to determine the cause of radial nerve deficits because treatment can vary greatly from case to case.
• The main complication of true compressive Saturday night palsy is the inability to recover, which can be an indication for surgical exploration. The surgical options afterward include nerve grafting, nerve transfers, tendon or muscle transfers, and a variety of other techniques. As with most surgical procedures, there may be a variety of complications related to intraoperative issues and post-surgical infections.
• Furthermore, partial recovery is common in these cases, and long-term disability can be a challenge. Prolonged and regular physical therapy can be exhausting, but it is necessary for regaining some functionality.

Multidisciplinary Team (MDT) Approach

• The team-based approach is ideal for managing patients with Saturday night palsy.
• In order to rule out alternative causes for a new-onset neurological deficit, the initial healthcare provider who evaluates a patient with Saturday night palsy should make sure they are thoroughly evaluated.
• Additionally, a neurologist should be properly referred for the purpose of arranging an electromyogram and other diagnostic or therapeutic procedures.
• Physical therapy should also be recommended.
• Patients should be instructed on supportive measures.
• There should be a set timeline in place to enable early surgical intervention, if considered necessary, and appropriate surgical follow-up in such cases.
• In any case, patients should be given realistic expectations regarding the procedure for recuperation, which might not be as simple or convenient as they had hoped.