Differential Diagnosis of Carpal Tunnel Syndrome : Wheeless' Textbook of Orthopaedics

- see carpal tunnel syndrome

- Overuse Syndromes:
- include muscle pain, tendinitis, fibrositis, epicondylitis, & psychological conditions that may contribute to disability;

- Vascular Pathology

- Anatomic Diff Dx:
- Cervical Root Impingement
- combination of nerve entrapment & radiculopathy (C6-C7) is not uncommon & is sometimes referred to as double crush syndrome;
- radiculopathy is identified by occurrence of proximal radiation of pain above shoulder, paresthesias with coughing or sneezing, or pattern of motor or sensory disturbances beyond distribution of median nerve;
- correct diagnosis is established by noting the function of the muscles innervated by C6-C7 portions of radial nerve (ie function of wrist extensors and triceps);
- in addition, w/ thenar atrophy, consider the diagnosis of T1 radiculopathy;
- dx is made by noting the function of the muscles innervated by the T1 portion of the ulnar nerve (hypothenar and interossei muscles);
- Thoracic Outlet Syndrome
- Compression at Ligament of Struthers:
- ligament of Struthers is a band of fibrous tissue which connects the supra-condylar bone spur (present in a minority of patients) to medial epicondyle of the humerus;
- compression at this level will cause atrophy of forearm flexors as well as the thenar muscles;
- Pronator Teres Syndrome
- compression in forearm either between heads of pronator teres or under the superficialis arcade;
- typically there is pain in median nerve distribution & Tinel's sign in the mid to upper forearm;
- AIN may also become compressed, w/ finding of loss of the teminal flexion of the thumb and index finger;
- if there is thenar atrophy and loss of AIN muscles (FPL, FDP, P.Q.), then CTS is unlikely;
- also consider FPL rupture;
- Median Artery
- in majority of cases, median nerve artery ends w many branches in FDS muscle, proximal to wrist level;
- in about 1-2% of pts, it participates in palmar circulation;
- ref: Can simple release relieve symptoms of carpal tunnel syndrome caused by a persistent median artery? Clinical experience.
    - Ulnar Neuropathy:
   - is considered since no more than half pts w CTS carpal tunnel syndrome can reliably report location of their paresthesias;
          - see ulnar nerve and cubital tunnel syndrome