Upper Limb Nerve Injuries Flashcards
Lower motor neuron arises from?
Anterior horn cell
UMN vs LMN?
UMN- flexed posture if chronic, increased tone, brisk reflexes and sensory level
LMN- wasting fasciculations, flaccid tone, reduced reflexes, weakness in either a myotonia distribution or a peripheral nerve distribution, dermatomal or peripheral nerve distribution of sensory loss
What are pyramidal weakness?
Flexor muscles stronger than extensors
C5 myotome corresponds to?
Deltoid for shoulder abduction
C6 myotome corresponds to?
Biceps, brachial is and brachioradialis- for elbow flexion
C7 corresponds to?
Triceps superficial forearm extensors and superficial forearm flexors- elbow extension, wrist extension and flexion
C8 corresponds to
Forearm extensors, deep forearm flexors- finger extension/ flexion
T1 corresponds to?
Intrinsic hand muscles- finger abduction
Biceps reflex?
C5 reflex conveyed through musculocutaneous nerve
Supination jerk?
C6 reflex through radial nerve
Triceps jerk?
C7 reflex conveyed through radial nerve
Finger jerk?
C8 reflex conveyed through median and ulnar nerve
Nerve root impingement can cause?
Sensory loss, weakness and reflex loss and pain
Avulsion injury?
Root gets pulled off cord
Neuropraxia?
Stretching injury of nerve, damaging myelin, so impaired transmission
Neuromas?
Primary tumours of nerve and nerve sheath, connective tissue growth, causing compression
Rupture can be of?
Axon, complete resectioning of the nerve
Motor cycle injury causes?
Flail arm , so wasting of deltoid and supraspinatus
Erbs palsy?
Traumatic injury of C5-C6, shoulders get stuck or falling out of bed.
Weakness of muscles, but preserved hand functions
Otherwise known as waiter’s tip
Klumpke’s palsy?
Clutching an object falling from height
Injury to C8 T1
Supplying median nerve and ulnar nerve
Preserves arm, but fingers or wrist unable to flex, weakness of small muscles of the hand and sensory loss hand and inner border of forearm
Could cause claw hand
What else can cause nerve injuries?
Pancoast tumours,
Pain in shoulder girdle and inner arm
important to look for ipsilateral horners syndrome T1
Radiation induced brachial plexopathy?
Mean 6 years post radiation
Pain is not a feature
Predilection for upper brachial plexus
Idiopathic brachial neuritis?
Inflammation affects random parts of brachial plexus, varies with root and nerve
Severe pain over days, as diminishes followed by weakness and wasting
Mono-basic recurrent, asymmetrical, thickening and enhancement
Thoracic outlet syndrome?
Compression sites between:
- Between anterior and middle scalene muscles
- Beneath clavicle in the costoclavicular space
- Beneath tendon of pec minor
Neurogenic thoracic outlet syndrome can cause?
Paresthsia, numbness and weakness,
Not localised to specific nerve distribution
Aggravated by elevation or sustained use of arms or hands
Vascular thoracic outlet syndrome?
Forearm fatigue within minutes of use.
Swelling and cynaosis
Collateral venous patterning over the ipsilateral shoulder, chest wall and neck.
Rarely pain, pallor and coldness (arterial involvement).
Lower BP on affected arm, diminished distal pulses.
Long thoracic nerve comes from?
C 567 and supplies serratus anterior
Compression of median nerve happens?
Wrist- carpal tunnel
And elbow
Median nerve innervates?
L ateral 2 lumbrical
O pponens pollicis
Abductor pollicis brevis
Flexor pollicis brevis
Compression of median nerve results in?
Thenar wasting
Carpal tunnel syndrome causes?
Diabetes Pregnancy Hypothyroidism Rheumatoid arthritis Repetitive strain
Tinels test?
Percussions over any nerve and getting tingling in the distribution of that nerve
Phalens test?
Flexion of wrist a minute
Anterior interosseous nerve coming of median nerve may be compressed?
Between 2 heads of pronator teres
May be damaged in careless blood taking and use of screwdriver
Anterior interosseous nerve syndrome affects?
Pure motor branch of median nerve
Causes weakness in flexors of interphalangeal joint of thumb (flexor pollicis longus)
Dip joints of index and middle fingers flexor digitorum profundus
Weakness of pronation
Ulnar palsy?
Ulnar claw present at wrist lesion, in upper limb lesion only flexion
Cyclists get ulnar nerve compressed at?
Guyons canal
Froments sign?
Ulnar nerve is needed for thumb abduction,
So taking piece of paper need to keep thumb striaght
So will pinch
C8 innervation?
All finger extensors by radial nerve
FDP of index and middle by median nerve
Saturday night palsy?
Radial nerve affecting extensors, not much sensory disturbance
If there is a lesion damaging axon then that affects?
Amplitude
