Peripheral nerve entrapment Flashcards
What are the 2 upper limb compressive neuropathies?
carpal tunnel syndrome
cubital tunnel syndrome
Describe the process of nerve entrapment that leads to functional impairment
compression
ischaemia
demyelination of nerve
affects ability of nerve to conduct
What is carpal tunnel syndrome?
median nerve compression by the flexor retinaculum
Carpal tunnel syndrome symptoms
tingling/pain digits 1,2,3 + 0.5 thenar eminence wasting (poor prognosis) worse at night relieved by shaking/hanging hand decreased dexterity more common in women 30-55
Carpal tunnel syndrome management
splinting
local steroid injections
treatment of underlying cause if secondary
decompression surgery - divides tunnel roof (flexor retinaculum)
Causes of secondary carpal tunnel syndrome
diabetes pregnancy hypothyroidism acromegaly radial fracture rheumatoid arthritis renal failure space-occupying lesion (eg tumour)
Carpal tunnel syndrome tests
Tinel’s
Phalen’s
flexion compression (most sensitive + specific)
electrophysiology = nerve conduction studies (can quantify degree of severity)
What is cubital tunnel syndrome?
ulnar nerve compression at elbow
Carpal tunnel syndrome differentials
C6 radiculopathy (get MRI)
proximal sites compression (rare) - FDS, pronator syndrome
non organic/non anatomical cause
Cubital tunnel syndrome differentials
C8/T1 radiculopathy
thoracic outlet syndrome
pan coasts tumour
Cubital tunnel syndrome symptoms
postural (leaning on elbow/night symptoms)
established compression (numbness + weakness)
altered sensation 4.5 + 5th digits
Wartenburg’s sign = 5th digit drifts off
wasting 1st dorsal interosseous
clawing
froment’s sign
Tinel’s
Cubital tunnel syndrome investigations
nerve conduction study
xray - look for arthritic elbow
Cubital tunnel syndrome treatment
nocturnal splints
surgery on failure of non-operative/motor weakness present/sensation loss present
