Altered sensation and weakness Flashcards
Hand nerve distributions (median, radial, ulnar)…
What is carpal tunnel syndrome?
- CTS results from compression of the median nerve as it passes through the carpal tunnel at the wrist
- (the carpal tunnel is formed by the space between the transverse carpal ligament and the carpal bones)
What are some conditions which predispose to carpal tunnel syndrome?
- diabetes mellitus
- hypothyroidism
- rheumatoid arthritis
- pregnancy
- acromegaly (excess growth hormone production)
- trauma (eg. wrist fractures)
What are the clinical features of carpal tunnel syndrome?
- pain and/or paraesthesia in the median nerve distribution (can radiate distally to fingers or proximally to the elbow)
- thenar muscle strength decreases in advanced disease
What investigations should be done for carpal tunnel syndrome?
- Phalen test
- Tinel test
- (nerve conduction studies)
What is the management for carpal tunnel syndrome?
- wrist splint, corticosteroid injection
- surgical decompression (by division of the carpal transverse ligament)
What is vibration white finger (aka. HAVS)?
- HAVS = hand arm vibration syndrome
- a secondary form of Raynaud’s (thought to be caused by continual industrial exposure to vibration)
What are the symptoms of HAVS (vibration white finger)?
- tingling/numbness in digit tips
- excessive whiteness in cold
- reperfusion pain (when blood supply returns to tissue after a period of ischemia)
What is ulnar nerve entrapment (cubital tunnel syndrome)?
- when the ulnar nerve becomes compressed as it passes behind the medial epicondyle or through Guyon canal in the wrist
What are some predisposing factors to cubital tunnel syndrome?
- local trauma (eg. fractures of the elbow)
- prolonged leaning on the elbow
- elbow synovitis
What are the clinical features of cubital tunnel syndrome?
- pain and/or paraesthesia in the medial side of the elbow, which radiates to the medial side of the hand and the ulnar nerve distribution
- pain often exacerbated by elbow flexion
- may result in atrophy of the hypothenar eminence and intrinsic muscles of the hand (majority of which are supplied by the ulnar nerve)
- in severe cases, ulnar clawing of the hand can occur
What investigations should be done for cubital tunnel syndrome?
- palpation of the nerve behind the medial epicondyle may provoke symptoms
- (nerve conduction studies)
Ulnar clawing of hand…
What is the management for cubital tunnel syndrome (ulnar nerve palsy)?
- corticosteroid injection
- surgical decompression (if sensory symptoms persist or if there’s muscle wasting)
What is radial nerve palsy (‘Saturday night palsy’)?
- compression of the radial nerve at the axilla
What are the predisposing factors to radial nerve palsy (Saturday night palsy)?
- typically an intoxicated patient who falls asleep with their arm hanging over the back of a chair (‘Saturday night palsy’)
- fractures of the humeral shaft
What are the clinical features of radial nerve palsy (Saturday night palsy)?
- wrist drop (wrist extensors are paralysed)
- reduced grip strength (wrist flexors do not function well when wrist is in a flexed position)
- paralysis of the triceps
- sensory loss in the radial nerve distribution
What is the management for radial nerve palsy?
- wrist splint
- fracture/dislocation reduction can provide relief
- (if no solution then tendon graft or nerve graft indicated)
What is common peroneal nerve palsy?
- the common peroneal nerve wraps around the neck of the fibula, and is in a vulnerable position
What are the predisposing factors to a common peroneal nerve palsy?
- it may be damaged by fractures of the neck of the fibula
- or pressure from a tight bandage or plaster cast
What are the clinical features of a common peroneal nerve palsy?
- foot drop (plantar flexed and inverted): caused by paralysis of ankle/foot extensors
- high-stepping gait (due to foot drop)
- loss of sensitivity over the anterior and lateral aspects of the leg and dorsum of the foot and toes
What is the management for a common peroneal nerve palsy?
- pressure on nerve should be relieved and splint applied
- nerve-conduction studies
What are the motor function and sensory function of the axillary nerve?
- motor function: innervates teres minor and deltoid muscles
- sensory function: ‘regimental badge’ area
What does scapular winging suggest there is damage to?
- long thoracic nerve damage
- (long thoracic nerve derives from the brachial plexus)
All the muscles in the hand are supplied by the ulnar nerve, except LOAF which are supplied by the median nerve…
- L : lateral two lumbricals
- O : opponens pollicis
- A : abductor pollicis brevis
- F : flexor pollicis brevis
