Nerve Palsies in the Limbs Flashcards
Nerves of the limbs
Nerve roots
Brachial/sacral and lumbar plexus
Peripheral nerves
Peripheral nerve of the upper limbs
Axillary Radial Musculocuteneous Ulnar Median
Peripheral nerve of the lower limbs
Sciatic
Femoral
Common Peroneal
LFCN
Upper limb nerve palsies
Brachial plexus
Peripheral nerves
Brachial plexus palsies
Upper - Erb’s (C5,6)
Lower - Klumpke’s (C8, T1)
Total brachial plexus (C5, T1
Peripheral nerve palsies
Musculocuteneous (none)
Axillary (nerve palsy secondary to trauma)
Radial (nerve palsy secondary to compression or entrapment)
Ulnar (cubital tunnel syndrome)
Median (carpal tunnel sundrome)
Erb’s palsy
C5, 6 (+/-C7) Waiter’s Tip position: Shoulder is adducted and internally rotated Elbow is extended and pronated Wrist is flexed
Klumpke’s palsy
Traction of C8, T1
Very rare
Affects small muscles of hand - claw hand
Which nerve wraps around the surgical neck of the humerus?
Axillary nerve
What does the axillary nerve innervate?
Deltoid and Teres Minor
Supplies skin over lateral arm- regimental badge area
Causes of axillary nerve palsy
Shoulder dislocation
Fracture of surgical neck of humerus (more commonly in osteoporosis
Which nerve runs in the radial groove of the humerus?
From medial to lateral
Radial nerve
Presentation of radial nerve palsy in axilla
Loss of elbow extension, wrist extension and sensory changes forearm and hand
Presentation of radial nerve palsy in arm
Loss of wrist extension and sensory loss
Presentation of radial nerve palsy in forearm
Loss of finger extension (PIN)
Presentation of radial nerve palsy at wrist
Loss of sensation (SRN)
What are the components of the carpal tunnel?
Floor - carpal bones
Roof - flexor retinaculum
Contents - FDS x4, FDP x4, FPL and median nerve (ie 9 tendons and a nerve)
Causes of carpal tunnel syndrome
Developmental Trauma Swellings Inflammatory Metabolic
Trauma as a cause of carpal tunnel syndrome
Distal radius fracture
Swellings as a cause of carpal tunnel syndrome
Ganglion
Fibroma
Lipoma
Inflammatory causes of carpal tunnel syndrome
Rheumatoid
Gout
TB
Amyloid
Metabolic causes of carpal tunnel syndrome
Pregnancy
Mucopolysaccharidoses
Hypothyroidism
Carpal tunnel syndrome presentation
Nocturnal pain and parasthesia in part or all of the median nerve distribution
Wasting of the thenar muscles
Where is the cubital tunnel?
Between medial epicondyle and olecranon, with fascial bands from FCU as roof
Presentation of cubital tunnel syndrome
Numbness on ulnar side of hand and difficulty with fine tasks
Ulnar nerve palsy presentation
Muscle wasting =>
1st webspace
Guttering
Hypothenar wasting
Ulnar claw hand (distal lesion has worse clawing as long flexors are intact)
Sacral plexus ventral rami
L4 to S4
Sciatic nerve branches
L4-S3
Tibial nerve and common peroneal nerve
Which nerve wraps around neck of fibula?
Common peroneal nerve
Common peroneal nerve palsy presentation
Foot drop
Lumbar plexus branches
L1-5 Main branches => LFCN Femoral Obturator
What is meralgia parasthetica?
Altered sensation and pain of the lateral thigh
Compression of LFCN as it travels under lateral border of inguinal ligament
LFCN
Lateral femoral cutaneous nerve
What does the musculocutaneous nerve innervate?
Biceps brachii
Brachialis
Coracobrachialis muscles
Lateral cutaneous nerve of the forearm
What does the median nerve innervate?
Flexor muscles in the forearm
Thenar muscles
Lateral two lumbricals
What does the ulnar nerve innervate?
Flexor carpi ulnaris
Flexor digitorum profundus
Intrinsic muscles of the hand
What are the intrinsic muscles of the hand?
Palmaris brevis
Medial two lumbricals
Hypothenar muscles
Interossei muscles
Which muscles does the radial nerve innervate?
Triceps brachii
Anconæus
Brachioradialis
Extensor carpi radialis longus
