- Discussion:
- its essential to consider the
differential dx and to examine the patient from the neck down to the finger tips;
- in taking the history, be sure to inquire as to whether the patient's main complaint is hand/wrist pain versus paresthesias;
- it is also important to distinguish between paresthesias and loss of sensation;
- some patients will have paresthesias but normal two point discrimination and vice versa;
- note anomalous anatomical variations of the cutaneous nerves may complicate the examination;
- in the report by J. Peter MD et al 2002, the authors studied the microanatomy of the communicating branches between the ulnar and
median nerves in 26 adult cadaver hands to explain diminished sensibility in the fourth and fifth fingers we had observed in
2 patients after complete transection of the median nerve;
- two new variations of the communicating branch were observed;
- in the first variation the communicating branch originated proximally from the third common digital nerve to distally
join the ring finger ulnar digital nerve and the small finger radial digital nerve;
- in the second variation the ramus communicans traversed perpendicularly between the 3rd and 4th common digital nerves with a crossover of nerve fibers;
- ref: Internal anatomy of the communicating branch between the ulnar and median nerves in the hand and its relevance to volar digital sensibility
J. Peter W. Don Griot, MD January 2002 Volume 27 Number 1
- C-spine Physical Exam
-
C6 radiculopathy:
- should cause pain in the neck, shoulder, lateral arm, radial forearm, dorsum of hand, and tips of thumb and index finger;
- distribution of pain is less extensive and more proximal, whereas paresthesia's predominate distally;
- in some individuals, a C6 lesion will manifest as a depressed or absent
biceps reflex;
- in others, an abnormal
brachioradialis or wrist extensor reflex can be found;
- note that if thenar atrophy is due to cervical disk disease, one would expect disease at the C8 or T1 levels, and pain down little finger (rather than thumb);
- Exam of the Hand:
- vascular Exam (see:
diff dx)
-
thenar atrophy:
- thenar atrophy may be present in cases of long duration;
- it is
abductor pollicis brevis which atrophies, and if this atrophy is severe the thumb cannot be pronated;
-
tinel's sign: tapping over the
median nerve at the wrist crease produces paresthesias in the hand;
- this test is least sensitive but most specific;
- references:
Tinel's sign and the carpal tunnel syndrome. Stewart JD, Eisen A. BMJ 1978;2:1125-6.
-
phalen's test: wrist flexion test: performed by resting the elbows on a table and allowing the wrists
to fall into complete volar flexion for 1 minute - this may reproduce the wrist paresthesia;
- this test is most sensitive
- note: after 1 min., normal hands may develop symtoms;
-
wrist flexion - provocative test:
- involves wrist flexion and median nerve compression at the wrist;
- if symptoms appear with in 20 sec, then there is a sensitivity of 82% and specificity of 99%;
- reference:
- A new provocative test for carpal tunnel syndrome. Assessment of wrist flexion and nerve compression. JBJS. Vol 80-B. No 3. May 1998. p 493.
- if pt is unable to flex wrist as result of pain or limited motion, direct compression of median nerve is accomplished by applying pressure w/ thumb in
interval between
palmaris longus &
FCR tendons at level of the distal wrist flexion crease for 1 to 2 min duration;
Carpal tunnel syndrome. An evaluation of the provocative diagnostic tests.
The carpal tunnel syndrome: diagnostic utility of the history and physical examination findings.
Katz JN, Larson MG, Sabra A, et al. Ann Intern Med 1990;112:321-7.
Clinical tests for carpal tunnel syndrome in contemporary practice
