Ch. 17 - Peripheral nerve entrapments, injuries, and tumors Flashcards
Where does peripheral nerve entrapment occur most commonly?
Near joints (e.g. 2/2 bone or joint disorder, as nerve passes under tendinous arch)
Population most affected by carpal tunnel syndrome
Women 4x more than men; patients who perform unusually strenuous work with their hands
Contents of the carpal tunnel
Median nerve and flexor tendons
What systemic conditions are associated with carpal tunnel syndrome?
Pregnancy and lactation, OCP use, rheumatoid arthritis, myxedema, acromegaly
Sxs of carpal tunnel syndrome
Pain (worse at night), numbness, tingling (mostly in lateral 3 digits)
What sxs would indicate median nerve dysfunction in prolonged carpal tunnel syndrome?
Wasting of thenar muscle, weakness of abductor pollicis brevis, diminished sensation in lateral 3 digits
Carpal tunnel syndrome diagnosis
EMG - prolonged sensory latency, diminished amplitude of sensory action potentials, denervation potentials in thenar muscles
Tinel’s sign
Tapping over median nerve elicits tingling/pain in lateral 3 digits of hand (but little diagnostic value in carpal tunnel syndrome)
Carpal tunnel syndrome tx
Conservative first (wrist splint), decompression surgery if refractory
How does ulnar nerve entrapment at the elbow present?
Paraesthesia and numbness in ring and little fingers of hand, wasting of hypothenar eminence and interossei muscles, weakness, ‘claw hand’
Classic patient with ulnar nerve compression at wrist
Men using heavy jack hammers or wire-cutting shears, and motorcyclists (repetitive trauma over ulnar aspect of hand causing compression at pisohamate hiatus)
Thoracic outlet syndrome
Entrapment neuropathy of brachial plexus at root of neck
Major presenting features of thoracic outlet syndrome
Arm pain, motor weakness and sensory loss 2/2 compression of lower trunk of brachial plexus
Erb’s palsy
Damage to upper trunk of brachial plexus
Klumpke’s palsy
Damage to lower trunk of brachial plexus (C8 and T1)
