Peripheral Neuropathy Flashcards
What is the most common site of damage in the PNS?
Peripheral nerve
How is the integrity of the PNS tested?
By eliciting reflexes (reduced reflex = reduced PNS function)
What clinical signs and symptoms would we expect from a lesion to a large motor fibre?
Weakness (reduced power)
Unsteadiness
Muscle wasting
Absent reflexes
What clinical signs and symptoms would we expect from a lesion to a large sensory fibre?
Numbness Paraesthesia Unsteadiness Reduced vibration and proprioceptive sense Absent reflexes
What clinical signs and symptoms would we expect from a lesion to a small fibre?
Pain
Dyaesthesia (unpleasant sensation when touched)
Pin-prick and temperature sense reduced
What clinical signs and symptoms would we expect from a lesion to an autonomic fibre?
Dizziness (postural hypotension)
Impotence
Nausea/Vomiting (gastroparesis)
Small fibres are important for reflexes. True/ False?
False
Large fibres are the most important
What is ‘pseudoathetosis’?
Rare condition which involves loss of proprioception causing writhing movements
List the three classes of nerve damage, and what site in the PNS is damaged in each
Radiculopathy (root damage)
Plexopathy (plexus damage)
Peripheral neuropathy (peripheral nerve)
List the signs of C6 radiculopathy
Pain and/or weakness along the length of the arm, including the biceps (the muscles in front of the upper arms), wrist extensors, and the thumb and index finger.
Reduced biceps reflex
List the signs of C7 radiculopathy
Pain and/or weakness from the neck to the hand and can include the triceps (the muscles on the back of the upper arms), wrist flexors, finger extensors and the middle finger.
Reduced triceps reflex
What clinical symptom would suggest plexopathy?
Lots of pain and weakness in one area of the body
List the types of peripheral neuropathy
Length-dependant peripheral neuropathy
Mononeuropathy
Mononeuritis multiplex
What are the 4 main types of length-dependant peripheral neuropathy?
WEAKNESS AND/OR SENSORY LOSS Mild Moderate Severe Glove and stocking
Mononeuritis multiplex typically has a symmetrical/ asymmetrical pattern
Asymmetrical
Mononeuropathy is typically symmetrical
What is the most common cause of peripheral neuropathy?
Carpal tunnel syndrome
Longer nerves are more likely to be damaged in length-dependant peripheral neuropathy. True/ False?
True
What is the main diagnostic technique used to differentiate between axon loss and demyelination?
Nerve conduction studies
What result would we expect from a nerve conduction study of a patient with GBS?
Conduction block
What are the two main types of demyelinating mononeuropathy? Give an example for each
Acute (days-weeks) e.g. GBS
Chronic (months - years) e.g. heridatory sensory mononeuropathy, CIDP
Define Guillian Barre syndrome
Progressive paraplegia of up to 4 weeks (peak 10-14 days into onset)
What are the classical clinical features of GBS?
ASCENDING SENSORI-MOTOR WEAKNESS
Sensory symptoms (typically proceed weakness)
ALMOST ALWAYS PAIN
Areflexia
Guillian Barre syndrome is typically caused by…
An infectious illness e.g. lung or stomach infection
Which gut bacteria is commonly associated with GBS?
Camplyobacter
Outline the management for GBS
Immunoglobulin infusion
Plasma exchange
The 10% mortality rate of GBS is linked to…
Autonomic failure e.g. cardiac arrhythmias
What are the 5 main types of heridatory neuropathy?
Pure motor Pure sensory Sensorimotor Small fibre Autonomic
Congenital insensitivity to pain is associated with a lesion to what type of heridatory neuropathy?
Small fibre
List the two varieties of heridatory neuropathy
Demyelinating
Axonal
What is the main diagnostic technique for heridatory neuropathy?
Genetic testing
A mutation in which gene will cause ‘champagne bottle ‘legs in heridatory neuropathy?
HMSN1
List the aetiology of axonal neuropathies
Idiopathic (age-related)
Vasculitis (RA/ Sjogrens)
Paraneoplastic (myeloma, Ig mediated breast cancer SCLC)
Infections (HIV, sypillus ,lyme, Hep B/C)
Drugs/ toxins (Alcohol, amiodarone, phentoin, chemo)
Metabolic (DM, B12/ folate def., hypothyroidism, chronic uraemia, poprhyria)
List the aetiology of autonomic neuropathy
Acute illness (GBS, porphyria) Chronic illness (DM e.g. gastroparesis, amyloidosis, heridatory)
Mononeuritis multiplex is commonly caused by…
Vasculitis
Outline the management of axonal peripheral neuropathy
SYMPTOM CONTROL Physio Orthotics Neuronal pain relief Treat cause e.g. Hep C
Outline the management of VASCULITIC axonal peripheral neuropathy
Pulsatile IV methyprednisolone and cyclophosphamide
Outline the management of demyelinating inflammatory peripheral neuropathy
IV immunoglobulin Steroids Azathioprine Myclophenolate Cyclophosphamide
What two mechanisms lead to the damage of peripheral nerves?
Axon loss
Demyelination
GBS is common in…
Young adults
Which condition is the most common form of neuromuscular paralysis?
Guillian Barre Syndrome
Mononeuropathy occurs as a result of…
Nerve compression (Carpal/ cubital tunnel syndrome, ulnar/ radial neuropathy
Mononeuritis multiplex occurs as a result of…
Diabetes
Vasculitis
List investigations used to diagnose GBS
Neurophysiology (NCS, EMG)
CSF (high protein)
