Cheiralgia paresthetica is an uncommon cause of wrist and hand pain and numbness. It also is known as handcuff neuropathy and Wartenberg syndrome. The onset of symptoms usually occurs after compression of the sensory branch of the radial nerve. Radial nerve dysfunction secondary to compression by tight handcuffs, wristwatch bands, or casts is a common cause of cheiralgia paresthetica. Direct trauma to the nerve may result in a similar clinical presentation. Fractures or lacerations frequently disrupt the nerve completely, resulting in sensory deficit in the distribution of the radial nerve. The sensory branch of the radial nerve also may be damaged during surgical treatment of de Quervain tenosynovitis.
Cheiralgia paresthetica manifests as pain and associated paresthesias and numbness of the radial aspect of the dorsum of the hand to the base of the thumb. Because significant interpatient variability exists in the distribution of the sensory branch of the radial nerve owing to overlap of the lateral antebrachial cutaneous nerve, the signs and symptoms of cheiralgia paresthetica may vary from patient to patient.
What are the Symptoms of Cheiralgia Paresthetica
Physical findings include tenderness over the radial nerve at the wrist. A positive Tinel sign over the radial nerve at the distal forearm is usually present.
Decreased sensation in the distribution of the sensory branch of the radial nerve is often present, although, as mentioned, the overlap of the lateral antebrachial cutaneous nerve may result in a confusing clinical presentation.
A positive wristwatch sign also may be present. Flexion and pronation of the wrist and ulnar deviation often cause paresthesias in the distribution of the sensory branch of the radial nerve in patients with cheiralgia paresthetica.
How is Cheiralgia Paresthetica diagnosed?
Electromyography can help identify the exact source of neurological dysfunction and clarify the differential diagnosis; this should be the starting point of the evaluation of all patients thought to have cheiralgia paresthetica. Plain radiographs are indicated in all patients who present with cheiralgia paresthetica to rule out occult bony pathological processes. Ultrasound imaging is also useful in identifying abnormalities of the superficial radial nerve.
Based on the patient’s clinical presentation, additional tests, including complete blood cell count, uric acid level, erythrocyte sedimentation rate, and antinuclear antibody testing, may be indicated.
Magnetic resonance imaging (MRI) of the wrist is indicated if joint instability or abnormal mass is suspected. Injection of the sensory branch of the radial nerve at the wrist serves as a diagnostic and therapeutic maneuver and may be used as an anatomical differential neural blockade to distinguish lesions of the sensory branch of the radial nerve from lesions involving the lateral antebrachial cutaneous nerve.
Cheiralgia paresthetica is often misdiagnosed as lateral antebrachial cutaneous nerve syndrome.
Cheiralgia paresthetica also should be differentiated from cervical radiculopathy involving the C6 or C7 roots, although patients with cervical radiculopathy generally present not only with pain and numbness but also with reflex and motor changes. Cervical radiculopathy and radial nerve entrapment may coexist as the “double crush” syndrome.
The double crush syndrome is seen most commonly with median nerve entrapment at the wrist or carpal tunnel syndrome. It should be remembered that radial nerve compression has many causes and the nerve can be compressed anywhere along its path.
Causes of Compressive Radial Neuropathies
Modified from Markiewitz AD, Merryman J. Radial nerve compression in the upper extremity. J Am Soc Surg Hand . 2005;5:87–99.
|High radial nerve||Trauma|
|Fractures: Diaphyseal, distal third of the humerus|
|Anomalous muscles and arteries|
|Idiopathic: Nerve torsion or localized constrictions|
|Muscular effort: Lateral triceps|
|External compression: Casts, crutches, braces, sleeping positions, tourniquets, walkers|
|Radial nerve||Radial tunnel: Pain without muscular weakness|
|Anatomy: (1) Fibrous band, (2) vasculature leash (of Henry), (3) extensor carpi radialis brevis, (4) arcade of Frohse, (5) distal edge of supinator|
|Musculature compression: Rowers, tennis players, weightlifters|
|Metabolic: Pseudogout (joint swelling), rheumatoid arthritis|
|Tumor: Synovial chondromatosis, ganglion, bicipital bursitis|
|Infection: Septic arthritis|
|External compression: Casts|
|Posterior interosseous nerve||Same sites as the radial tunnel|
|Surgical: Arthroscopy portals|
|Tumor: Scapholunate ganglion, lipoma, intramuscular myxoma, ganglion|
|Arteriovenous malformation, vasculitis|
|Trauma: Dislocated radial head|
|External compression: Casts, weight|
|Idiopathic nerve constriction|
|Superficial branch||Wrist ganglion|
|Anatomical: Fascia at brachioradialis/extensor carpi radialis brevis|
|External compression: Casts, watch bands|
The first step in the treatment of cheiralgia paresthetica is the removal of the cause of pressure on the radial nerve. A trial of nonsteroidal antiinflammatory drugs (NSAIDs) or cyclooxygenase-2 (COX-2) inhibitors represents a reasonable next step.
For patients for whom these treatment modalities fail, injection of the sensory branch of the radial nerve at the wrist with a local anesthetic and steroid should be considered. Ultrasound guidance may improve the accuracy of needle placement and decrease the incidence of needle-related complications.
For persistent symptoms, surgical exploration and decompression of the nerve are indicated.
Radial nerve block at the wrist is a relatively safe block, with the major complications being inadvertent intravascular injection and persistent paresthesia secondary to needle trauma to the nerve. This technique can be performed safely in the presence of anticoagulation by using a 25- or 27-gauge needle, albeit at increased risk for hematoma, if the clinical situation dictates a favorable risk-to-benefit ratio.
These complications can be decreased if manual pressure is applied to the area of the block immediately after injection. Application of cold packs for 20-minute periods after the block also decreases the amount of post-procedure pain and bleeding the patient may experience.
Radial nerve block at the wrist is an effective treatment for the symptoms of cheiralgia paresthetica.
Careful neurological examination to identify preexisting neurological deficits that may later be attributed to the nerve block should be performed in all patients before beginning radial nerve block at the wrist when treating cheiralgia paresthetica.
If cheiralgia paresthetica is identified early, removal of the offending pressure and radial nerve block with a local anesthetic and steroid should lead to marked improvement in most patients.