Differential diagnosis of CTS

Differential diagnosis of CTS & other disorder

CTS vs C6 radiculopathy

The two conditions can coexist.

C6 radiculopathy:

	Neck and shoulder pain
	Weakness in C6 innervated muscles, reflex changes
	Sensory loss restricted to the thumb
	The absence of nocturnal paresthesias, and reproduction of the paresthesias with root compression maneuvers.

CTS vs Pronator Syndrome

The most proximal median nerve entrapment.

Median nerve enters the forearm passing between the two heads of the pronator teres and then deep to the arch of the flexor digitorum superficialis, continuing between the flexor digitorum superficialis and flexor digitorum profundus in the forearm.

There are four reported sites of compression

	supracondylar process/ligament of struthers
	lacertus fibrosis (bicipital aponeurosis)
	pronator teres: most common site of compression caused by muscle hypertrophy or thickening of the aponeurotic fascia between the two heads of the pronator teres.
	flexor digitorum superficialis arch: second most common, fibrosis of the flexor digitorum superficialis arch

Symptoms & Signs:

	Pain in the proximal forearm, fatigue with exercise, and hand numbness.
	Pain usually worsens with activity, with numbness and parathesias in hand.
	Nocturnal symptoms seen with carpal tunnel syndrome are typically absent.
	Negative Phalen's test
	Weakness of the median innervated muscles is rare.

Provocative tests.

	Resisted pronation of the forearm for 30 to 60 seconds demonstrates compression at pronator teres when symptoms are reproduced.
	Resisted elbow flexion and supination of the forearm can localize compression to the lacertus fibrosis.
	Resisted long-finger flexion localizes the lesion at the level of the flexor digitorum superficialis (FDS) arch.
	The supracondylar process can be palpated on the medial humeral surface and confirmed with radiographs.
	EMG/NCV is inconsistent and diagnosis should be made clinically.

Flexor pollicis longus

	innervated by anterior interosseous nerve.
	flexion of the distal phalanx of the thumb not involved in CTS.

CTS vs Anterior Interosseous Syndrome

The anterior interosseous nerve (AIN) is a purely motor nerve branch from the median nerve.

A rare compression syndrome

Signs & symptoms:

	Vague discomfort in the proximal forearm
	Parathesias and numbness are rare
	Excessive supination/pronation, seen in baseball pitcher or hockey/lacrosse player, seems to aggravate the AIN.

Diagnosis is made clinically.

CTS vs de Quervain's Syndrome

Associated with activities that require forceful grasp coupled with ulnar deviation or repetitive use of the thumb.

Those at risk include golfers, fly fishers, racquet sport players, knitters, laboratory technicians, filing clerks, and mail sorters.

Tenosynovitis develops in the Abductor pollicis longus (APL) and Extensor pollicis brevis (EPB) tendons that are held in a groove of the radius by a firm segment of the extensor retinaculum.

Signs & Symptoms:

	Pain in the radial aspect of the wrist and thumb, aggravated by movement of the wrist and thumb.
	If inflammation is severe, the dorsal sensory branch of the radial nerve can become irritated, and patients complain of pain and paresthesias radiating to the thumb, dorsum of the hand, and index finger.
	There is an increased frequency of trigger finger and carpal tunnel syndrome in patients with de Quervain's syndrome.
	Physical exam: swelling and tenderness proximal to the radial styloid.
	Finkelstein's test: pain when the thumb is flexed into the palm while the examiner ulnarly deviates the wrist.