What are the other Names for this Condition? (Also known as/Synonyms)

• Cheiralgia Paresthetica
• Wrist Drop
• Wristwatch Neuropathy

What is Radial Nerve Dysfunction? (Definition/Background Information)

• Radial Nerve Dysfunction is a disorder of the radial nerve (that controls movement in the forearm and back of the hand) characterized by decreased movements of the arm and wrist, and loss of sensations on the back of the arm, forearm, or hand. The disorder is also variously known as Pinched Radial Nerve, Entrapment of Radial Nerve, or Radial Nerve Neuropathy. The condition is a form of isolated nerve dysfunction (IND)
• The most common causes of Radial Nerve Dysfunction include fracture of the arm bones and activities that cause compression of the radial nerve, either at the wrist or arm. The signs and symptoms of the condition includes difficulty straightening the arm at the elbow, weakness in hand grip, and drooping of the wrist and fingers
• The treatment for Radial Nerve Dysfunction includes treating/managing the underlying cause, physical therapy, administration of medications for symptom control, and surgery, if needed. The prognosis is generally good for mild to moderate cases with appropriate treatment; severe cases may cause irreversible nerve damage and associated complications

 Who gets Radial Nerve Dysfunction? (Age and Sex Distribution)

• Radial Nerve Dysfunction can occur at any age; it depends upon the causative factors
• There is no gender, racial, or ethnic group predilection observed

 What are the Risk Factors for Radial Nerve Dysfunction? (Predisposing Factors)

The risk factors associated with Radial Nerve Dysfunction may include:

• Direct trauma to the region, from a variety of factors such as:
  • Accidents
  • Sports injury: Any athletic/sporting activities that involve high-force impact
  • Fall injuries
  • Occupational injury; use of power tools causing repeat trauma
• Alcoholism
• Obesity

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Radial Nerve Dysfunction? (Etiology)

Any damage to the radial nerve can adversely affect the arm and wrist, resulting in a set of signs and symptoms. This is known as Radial Nerve Dysfunction. Commonly, the damage occurs from a trauma (cut injury or blunt force), nerve compression, or poor blood supply to the affected region.

The following are the causes for Radial Nerve Dysfunction:

• Fracture of the humerus (the upper arm bone)
• Injury to the underarms (axilla)
• Prolonged constriction of the wrist such as from wearing a tight bracelet or watch strap
• Falling asleep with one's arm hanging over the arm-rest of a chair, compressing the radial nerve over the arm. Pressure to the upper arm from any odd arm positions during sleep
• Sitting in a chair for several hours such that the armrest compresses the underside of the forearm
• Falling on the arm or receiving a blow to the arm
• Motor vehicle accidents
• Wartenberg syndrome: It is the entrapment of the superficial branch of the radial nerve with only sensory symptoms, but no movement disorder
• Improper use of crutches (in which case it is termed Crutch Palsy)

In some cases, the cause of Radial Nerve Dysfunction may remain unidentified.

What are the Signs and Symptoms of Radial Nerve Dysfunction?

The common signs and symptoms of Radial Nerve Dysfunction include:

• Abnormal sensations such as numbness, tingling, or burning sensation
• Sharp pain over the hand or forearm, thumb side (radial surface) of the hand, or the fingers nearest to the thumb (first and middle fingers)

The following symptoms may also be present:

• Loss of reflexes
• Difficulty straightening the arm at the elbow
• Difficulty bending the hand back at the wrist or even clenching one’s fist
• Trouble moving the wrist and the fingers
• Weakness in hand grip
• Drooping of the wrist and fingers or unable to straighten the wrist or fingers; hence, the condition is also known as Wrist Drop
• Muscle twitching and cramping

How is Radial Nerve Dysfunction Diagnosed?

The diagnosis of Radial Nerve Dysfunction may involve:

• Complete evaluation of medical history along with a thorough physical exam. The diagnosis is usually based on the symptoms experienced by the individual and physical exam findings by the physician
• Blood tests, as needed
• An X-ray of the arm may be undertaken to rule-out fracture of the upper arm bones
• Electromyography (EMG): It is a test to check the health of the muscles and nerves that control the muscles
• MRI scan of the head, neck, and shoulder, to examine other possible causes of nerve dysfunction
• Nerve conduction velocity studies
• Electromyography (EMG): A diagnostic procedure to help detect neuromuscular abnormalities
• Some possible tests for sensation such as temperature, touch, and vibration, to assess how well an individual feels or responds to stimuli
• Biopsy of the nerve: A tissue biopsy of the affected nerve is performed and sent to a laboratory for a pathological examination. A pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis. Only in some rare cases, a nerve biopsy may be performed

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Radial Nerve Dysfunction?

The possible complications associated with Radial Nerve Dysfunction include:

• Debilitating pain
• Hand deformity; muscle contracture
• Partial or complete loss of sensation in the hand
• Partial or complete loss of wrist or hand movement
• Recurrent or unnoticed injury to the hand, due to loss of hand sensation
• Paralysis of the limb
• Inability to participate in sports activities
• Decreased quality of life
• Treatment complications

 How is Radial Nerve Dysfunction Treated?

The goal of treatment of Radial Nerve Dysfunction is to maximize the ability to use one’s hand and arm. The treatment measures may include the use of medications (for treating the symptoms), therapy, and surgery (if required).

• Over-the-counter analgesics or prescription pain medications to control pain
• Anticonvulsant medicines (phenytoin, carbamazepine, gabapentin, and pregabalin) or antidepressants (such as amitriptyline) to reduce stabbing pain
• Steroid (prednisone) injections around the nerve to reduce the swelling
• In severe cases, braces, splints, or other medical devices that permit one to use the hand
• Physical therapy to enhance muscle strength
• Image-guided nerve block procedure, if necessary
• Limiting activities to prevent injury from a loss of sensation

For individuals who do not respond to prolonged conservative treatment, surgical intervention techniques that release the compression around the nerve may be performed (decompression).

In some individuals, the condition may heal spontaneously even in the absence of any treatment.

 How can Radial Nerve Dysfunction be Prevented?

 Preventive measures for Radial Nerve Dysfunction may include:

• Undertaking appropriate treatment of any underlying condition that places one at risk for the condition
• Avoiding prolonged pressure on the upper arm (while sitting, sleeping, or doing any particular activity), which can help prevent most cases of Radial Nerve Injury
• Avoiding other behaviors that can result in nerve damage, such as awkward positions and poor posture
• Avoiding any traumatic/repetitive injury that places one at an increased risk for the condition is also helpful
• Obese individuals should maintain proper diet control and adequate physical exercise
• Drinking alcohol in moderation

What is the Prognosis of Radial Nerve Dysfunction? (Outcomes/Resolutions)

The prognosis of Radial Nerve Dysfunction is based upon the cause of the disorder.

• If the cause of nerve dysfunction is known, then the prognosis is typically good, because Radial Nerve Dysfunction can be treated successfully, and a complete recovery ensured
• If the cause of nerve dysfunction is unidentified, then the outcome may be unpredictable. In some cases, there may be a partial or complete loss of movement or sensation in the affected arm
• Sometimes, the nerve pain may be uncomfortable and last for a long period

Additional and Relevant Useful Information for Radial Nerve Dysfunction:

Radial Nerve Dysfunction is known by several names.

• Radial Nerve Dysfunction is also known as Handcuff Neuropathy, since it may result from tight handcuffs compressing a branch of the radial nerve
• It is also known as Honeymoon Palsy that occurs when an individual sleeps with his/her arm under their spouse’s head
• It is also known Wristwatch Neuropathy that occurs by wearing a tight watch strap

Saturday Night Palsy (another term for Radial Nerve Dysfunction) is caused by drinking too much alcohol and falling asleep with the underside of the arm compressed by the bar edge or bench, etc.