Peripheral neuropathies Flashcards
List four examples of peripheral neuropathies
Bell's palsy GBS Charcot marie tooth syndrome Carpal tunnel syndrome Ulnar nerve palsy Peroneal nerve palsy
What are the symptoms of peroneal palsy?
foot drop- can’t walk on heels
Which spinal nerves form the common peroneal nerve?
L4-S1
What are the features of ulnar palsy?
ulnar claw/sign of benediction
parasthesia
Which tests are positive in carpal tunnel syndrome?
tinel’s and phalen’s
Which nerve is damaged in carpal tunnel syndrome?
median nerve
List two causes of sensory neuropathy
alcohol
B12
DM
Every vasculitis!!!
List two causes of motor neuropathy
GBS
lead poisoning
paraneoplastic
Two causes of autonomic neuropathy?
DM
HIV
SLE
GBS
List three features of autonomic neuropathy
Postural hypotension ED, ejaculatory failure ↓ sweating Constipation / Nocturnal diarrhoea Urinary retention Horner’s
List two classic motor signs in charcot marie tooth?
symmetrical muscle atrophy
- champagne bottle- peronal muscles
- hand and arm- claw hand
Which nerve is predominantly affected in charcot marie tooth?
peroneal nerve
What are the types of peripheral neuropathies?
motor, sensor, autonomic
What is the clinical presentation of large sensory nerve fibres?
sensory ataxia, loss of vibration sense, numbness tingling
Clinical presention for small sensory fibres?
impaired pin prick, temp, painful burning, numbness and tingling
What is the function of large myelinated fibres?
involved in proprioception, vibration and light touch
What is the function of thinly myelinated and small nerve fibres?
light touch, pain, temp
What is the most common of polyneuropathy?
length dependent axonal neuropathy
What are the features of length dependent axonal neuropathy?
symmetrical, starts in toes, slowly progressive, mild weakness, diffuse
What are the causes of length dependent axonal neuropathy?
diabetes, alcohol, nutritional, immune, renal failure, drugs, infections, inherited, myeloma, critical illness-bed bound
What are examples of nutritional causes of length…neuropathy?
folate B12 thiamine B6
Immune causes of length dependent axonal neuropathy?
RA, lupus, vasculitis
Infections?
HIV, hep B and C
What causes GBS to arise?
post infection e.g. campylobacter, EBV, CMV
How are neuropathies diagnosed?
nerve conduction studies
How can you distinguish between axonal or demyelinating causes of polyneuropathy?
in axonal degeneration- the amplitude of the response would be lessened but the time would be the same compared to normal, however the opposite is the case in demyelinating, where the amplitude remains the same but is slower to manifest= conduction delay
Which 5 sites are most commonly affected in mononeuritis multiplex?
radial, common peroneal, axillary, median, sciatic
If the common peroneal nerve is affected, what would be the clinical presentation?
weak ankle dorsiflexion, sensory disturbance of lateral aspect of calf and foot
Axillary?
weakness of shoulder abduction, ‘badge’ of sensory disturbance inf deltoid region
Femoral?
weak hip flexion and knee extension, sensory disturbance lat calf and dorsum of foot
Median?
LOAF weakness, sensory disturbance
Radial nerve?
wrist/finger drop, sensory disturbance of dorsum of hand
Which cancer can result in mononeuropathy?
lymphoma
What are causes of mononeuropathies?
diabetes, vasculitis, RA, lupus, sarcoidosis, lymphoma, infective
