carpel tunnel syndrome

Question 1

cause of carpal tunnel syndrome

Answer 1

primary
- idiopathic

secondary
- space occupying lesion (tumours, hypertrophic synovial tissue, #, callus, osteophytest)
- metabolic and physiological (pregnancy, hypothyroidism, acromegaly, obesity, RA)
- infection
– neuropathics (DM, alcoholism)
family
hobby/ job (repetitive trauma)

Question 2

clinical features of carpel tunnel syndrome

Answer 2

sensory loss in median nerve distribution (radial 3.5 digits)
discriminative touch lost -> light touch -> 2 pt discrimination -> thenar waste/ weak
awaken at night due to pain/ numb, relieved via shake/ dangling/ rubbing

+ve tinel sign (tingling on percurssion of nerve)
+ve phalen’s sign (flex wrist -> symptoms)

Question 3

investigations of carpel tunnel syndrome

Answer 3

clinical dx is adequate

however nerve conduction velocity/ EMG can confirm

Question 4

treatment of carpal tunnel syndrome

Answer 4

avoid repetitive wrist movement
wrist splint; night time splint in neutral position
medical: NSAIDs, local corticosteroids injection/ oral
sx decompression: transverse carpal ligament inccision to decomparss median nerve

Question 5

indications for sx in carpal tunnel syndrome and complications

Answer 5

indications:
- numb + tingling +/- sensory loss, weakness +/- muscle atrophy, unresponsive to conservative tx

complications
- injury to median motor branch,palmar cutaneous branch or superficial transverse vascular arch,local pain, scar fomration

Question 6

what are the bones in the hand

Answer 6

some lovers try position that they cant handle

medial to lateral, bottom to top layer

• scaphoid, lunate, triquetral, pisiform
• trapezium, trapezoid, capitate, hamate

Question 7

what is the carpal tunnel and what is in it

Answer 7

narrow passaeway found on anterior portion of wrist

9 tendons surrounded by synovial sheath + median n.

• 1x flexor pollicis longus
• 4x flexor digitorum profundus
• 4x flexor digitorum superficialis

Question 8

what are the border of the carpal tunnel

Answer 8

formed by 2 layers: deep carpal arch and superficial flexor retinaculum

deep carpal arch: concave on palmar side
- lateral (scaphoid and trapezium tubercles), medially (hook of hamate and pisiform)

flexor retinaculum: thick connective tissue, turns carpal arch into carpal tunnel by bridging the space between medial and lateral parts of arch (from lateral side and inserts on medial sid eof carpal arch)

Question 9

how to test for median, ulnar and radial nerve sensory areas? areas restricted to these nerves

Answer 9

median nerve - distal phalanges of index and middle fingers
ulnar nerve - middle and distal phalanges of little fingers
radial nerve - over first dorsal interosseus muscle between first and second metacarpals

Question 10

how to test power of the medial nerve? muscle innervated

Answer 10

LOAF

• lateral two lumbricals: difficult to test
• opponens pollicis - oppose patient’s thumb and little finger and resist
• abductor pollicis brevis - place dorsum of hand on flat surface and ask patient to lift thumb to ceiling against resistance, feeling thenar eminence for power of abductor pollicis brevis
• flexor pollic brevis

Question 11

motor muscle you will test during exam for median, ulnar, radial nerve

Answer 11

median - abductor pollicis brevis
radial - metacarpophalangeal extensors (extension of the fingers at the knuckles)
ulnar - palmar interossei (abduction of finger)

Question 12

investigations you can do before offering patient treatment for carpal tunnel syndrome

Answer 12

nerve conduction studies
- as symptoms of carpal tunnel syndrome can be mimicked by higher (more proximal) lesions of median nerve, can be characteristic by loss of sensation over thenar eminence due to involvement of palmar cutaneous branch and loss of relevant forearm flexors
or
due to cervical nerve root lesions (secondary to cervical disc herniation) or thoracic outlet syndrome

and also help determine severity

Question 13

what complications can occur after sx of carpal tunnel syndrome

Answer 13

scar information - high risk area for keloid or hypertrophic scars
scar tenderness - occur in up to 40% of patients
wound infection
nerve injury - palmar cutaneous branch of the median nerve (liees superficial to the retinaculum) + motor branch to thenar muslce (leaves radial side of median nerve to distal exten of standard incision)

fail to relieve symtpoms - if retinaculum is incompletely divided

Question 14

what is carpal tunnel syndrome

Answer 14

median nerve compression at the level of flexor retinuculum