Superficial Radial Nerve (Wartenberg Disease)

Compression mononeuropathy of the superficial branch of radial nerve in the distal forearm

Radial nerve, arises from C5–8, provides motor function to the extensors of the forearm, wrist, and fingers. Provides motor function for supinators of forearm. Superficial radial nerve provides sensory function to posterior forearm via posterior cutaneous nerve and the web of skin between the thumb and index finger.

Superficial radial nerve (SRN) becomes susceptible to injury as it pierces deep fascia to become SC between the tendons of the extensor carpi radialis longus and brachioradialis muscles.

Synonym(s): Wartenberg syndrome entrapment; Cheiralgia paresthetica; Prisoner's palsy; Handcuff disease; Radial sensory nerve entrapment

The incidence is not known.

It is rare, although often is not recognized.

Wrist compression (ie, tight bands, tape, watches, archery guards, gloves, or straps of a racquetball racquet, cast, soft tissue mass)

Direct trauma in contact sports

Laceration and post surgical injury

Sports involving repetitive pronation and supination at the wrist (eg, batting, throwing, and rowing)

Determine whether pain or sensory deficit is the primary symptom. If pain is the main complaint, then De Quervain's disease seems a more likely diagnosis (1)[C].

Duration of symptoms

Location of symptoms

Characteristics of symptoms to suggest sensory involvement

Symptoms primarily limited to the dorsoradial aspect of the distal forearm and hand (wrist, hand, dorsal thumb, and index finger)

Paresthesias (numbness and tingling)

Hyperesthesia

Less commonly, pain or burning

Positive Tinel sign along the radial aspect of the midforearm

Wrist flexion, ulnar deviation, and pronation place traction on the nerve and increase symptoms.

Sensation deficit on the dorsoradial aspect of the forearm and/or hand

Finkelstein test typically negative, as opposed to De Quervain's syndrome, which usually has positive Finkelstein test

With SRN injury, pain can be present with thumb abduction and adduction, differentiating this from De Quervain's syndrome in which extension and flexion create more symptoms.

Lidocaine test: Because the terminal branch of the lateral antebrachial cutaneous nerve often shares distribution with the SRN, its compression can mimic that involving the SRN.

Diagnostic nerve block to the cutaneous nerve in the proximal forearm just distal to the cubital crease and adjacent to the cephalic vein may help define its contribution to any pathology (2)[C].

Nerve conduction study may be inconsistent, but helpful. Indicated if the symptoms are persistent, surgery is being considered, or if the diagnosis is in doubt (2)[C].

The most common technique records the sensory nerve action potentials from the web space between the thumb and index finger with stimulation originating in the distal forearm.

Sensory action potential, conduction velocity, and amplitude are decreased.

Motor testing of radial nerve is normal.

De Quervain's syndrome

Intersection syndrome

Lateral antebrachial cutaneous neuropathy

Thumb carpometacarpal arthritis

C6 radiculopathy