Carpal Tunnel Syndrome Flashcards
1
Q
Define carpal tunnel syndrome
A
The symptom complex brought on by compression of the median nerve in the carpal tunnel
2
Q
What are the causes/risk factors of carpal tunnel syndrome?
A
• Idiopathic
• May be secondary to:
- Tenosynovitis: Overuse, rheumatoid arthritis, other inflammatory rheumatic disease.
- Infiltrative diseases of the canal/increased soft tissue: Amyloidosis, myeloma, myxoedema, acromegaly.
- Bone involvement in the wrist: Osteoarthritis, fracture, tumour.
- Fluid retention states: Pregnancy, nephrotic syndrome.
-Other: Obesity, menopause, diabetes, end-stage renal disease
3
Q
What are the symptoms of carpal tunnel syndrome?
A
- Gradual onset, intermittent hand numbness or pain, with waking up at night-time, relieved by shaking or flicking the wrist.
- Numbness is typically confined to the palmar aspect of the thumb and fingers (not the little finger).
- On awakening, patients may have difficulty extending or flexing fingers.
- The patient may also complain of clumsiness, especially during fine-motor tasks and weakness.
- Involvement of both hands is helpful in making the diagnosis.
4
Q
What are the signs of carpal tunnel syndrome?
A
- Thenar muscle weakness –especially the abductor policis brevis; weak thumb abduction.
- Thenar muscle atrophy
- Sensory abnormalities to pinprick that are predominantly over the palmar aspect of the first 3 fingers and lateral half of the fourth, with sparing of the thenar eminence, is the most useful finding.
- Tinel’s Test: Tapping the carpal tunnel causes symptoms.
- Phalen’s Test: Flexion of the wrist for 1 min causes symptoms
5
Q
What investigations are carried out for carpal tunnel syndrome?
A
- ESR - normal; excludes rheumatological causes.
- TFTs - normal
- EMG - EMG is the diagnostic test of choice. Focal slowing of conduction velocity in the median sensory nerves across the carpal tunnel.
- USS - SOL may be identified.
- MRI - SOL may be identified.
