Nerve palsies Flashcards
Which nerves are commonly affected following fractures and soft tissue injuries
Elbow injuries → median nerve
Iatrogenic e.g. pinning fractures → ulnar nerve
What are the birth related palsies in children
Brachial nerve palsy
Phrenic nerve
Facial nerve
Spinal
Describe brachial nerve palsies
Traction to the brachial plexus nerve roots
Affected arm = straight, limp, hand pronated, fingers flexed (waiter’s tip)
RF: breech, shoulder dystocia
What is erb’s palsy
Type of brachial nerve palsy
Affects the upper nerve root (C5 and C6)
Resolves completely by 2 years
Refer to orthopaedic or plastic surgeon if not resolved by 2-3 months
Describe phrenic nerve palsies
Elevated diapghragm
Describe facial nerv palsies
compression of the facial nerve against the mother’s ischial spine or pressure from forceps
Unilateral, facial weakness on crying
Eye remains open
Transient, but methylcellullose drops may be needed for the eye
Describe spinal palsies
Damage to the cervical spine, where there is a lack of movement below the level of lesions
What is the aetiology of Charcot-Marie-Tooth disease
hereditary motor sensory neuropathy, multiple forms
Mutation in the myelin genes:
- CMT1A (70-80%)
- Autosomal dominant (2/3) or de novo (1/3)
What are the signs and symptoms of Charcot-Marie-Tooth disease
Symmetrical, slowly progressive, distal muscular wasting
Preschool: tripping from bilateral foot drop
Examination: loss of ankle reflexes progressing to loss of knee reflexes
Pes cavus may be present (Lower limbs affected > upper limbs)
What investigations should be done for Charcot-Marie-Tooth disease
Nerve conduction studies: motor and sensory neuropathy
- Affected nerves may be hypertonic due to demyelination followed by attempts at remyelination
Nerve biopsy: onion bulb formation (due to demyelination and remyelination attempts)
What is the aetiology of Guillain barre syndrome
Acute post-infectious polyneuropathy
2-3 weeks after an URTI or campylobacter gastroenteritis
What are the signs and symptoms of guillain barre syndrome
Ascending, progressive, symmetrical weakness over a few days to 2 weeks
2-3 weeks after an URTI or campylobacter gastroenteritis
Sensory symptoms (usually distal limbs or trunk) are less striking than the weakness but may be unpleasant
Bulbar muscle involvement → difficulty with chewing and swallowing → aspiration
Examination: Loss of tendon reflexes and autonomic involvement | Bilateral facial weakness
Dysautonomia (70%) = tachycardia | bradycardia | arrhythmias | hypertension | orthostatic hypotension | urinary retention | ileus | loss of sweating
What investigations are done for guillain barre syndrome
MRI spinal cord ± brain: identify a spinal cord lesion e.g. bleed, tumour, inflammatory transverse myelitis
LP: Protein markedly raised, WCC normal (not seen until the second week)
Nerve conduction studies: reduced velocity (not seen until the second week)
What is the management for guillain barre syndrome
Supportive, respiratory support
IvIG infusion or plasma exchange
What is the prognosis for guillain barre syndrome
full recovery can be expected in 90% of cases, but this may take up to 2 years
