carpal tunnel syndrome Flashcards
what is it?
peripheral neuropathy caused by acute or chronic compression if the median nerve by the transverse carpal ligament
what are the causes?
mostly idiopathic
secondary to many conditions - RA - synovitis means less space
consequence of fractures around the wrist
bilateral - repetitive stress
symptoms worse at night
what is the pathophysiology?
inflammation of nearby tendons -> oedema -> compression of median nerve
what forms the carpal tunnel?
formed by carpal bones and the flexor retinaculum
what does the median nerve pass through the carpal tunnel along with?
9 flexor tendons
4x flexor digitorum superficialis
4x flexor digitorum profundus
1x flexor pollicis longus
what does the median nerve supply?
motor innervation to LOAF muscles and sensory innervation to palmar aspect of hand, thumb, index, middle and radial half of ring finger
what would swelling within the confines of the carpal tunnel result in?
median nerve compression
what are the median LOAF muscles?
Lumbricals I and II
Opponens pollicis
Abductor pollicis brevis
Flexor pollicis brevis
what are the symptoms?
parathesiae in medial innervated digits ( thumb and radial 3 1/2 fingers) worse at night
tingling in first three digits
relieved by shaking the hand
palmar sensation spared
what are the signs?
loss of sensation and/or muscle wasting of the thenar muscles eminence
numbness, weakness
decreased grip strength
what special tests can be used?
Tinel’s test
Phalen’s test
what investigations are used?
test abductor pollicus brevis
nerve conduction studies - slowing of conduction across the wrist
what is the management?
wrist splints at night to prevent flexion
corticosteroid injections
what are the surgical managements?
carpal tunnel decompression - division of the transverse carpal ligament under local anaesthetic
