Peripheral Neuropathy Flashcards
What 5 things should you always find out when trying to diagnose a peripheral neuropathy?
1 - Which nerves are damaged? 2 - Where are they damaged? 3 - How are the nerves damaged? 4 - Why are the nerves damaged? 5 - Can we stop the nerves from being damaged?
What is radiculopathy usually due to?
Intervertebral disc herniation
In peripheral nerve injury, what happens to reflexes?
Reflexes are reduced if there is damage to the afferent or efferent pathways
Peripheral neuropathy occurs due to a problem which affect the ________ _____?
PERIPHERAL NERVE
When there is damage to a large motor neurone, what symptoms are experienced?
- WEAKNESS
- Unsteadiness
- Wasting
When there is damage to a large motor neurone, what happens to the power?
REDUCED
When there is damage to a large motor neurone, what happens to the sensation?
NORMAL
When there is damage to a large motor neurone, what happens to reflexes?
ABSENT
When there is damage to large sensory fibres, what symptoms are experienced?
- NUMBNESS
- PARAESTHESIA
- Unsteadiness
When there is damage to large sensory fibres, what happens to the power?
NORMAL
When there is damage to large sensory fibres, what happens to the sensation?
Vibration and JPS are reduced
When there is damage to large sensory fibres, what happens to reflexes?
ABSENT
When there is damage to autonomic fibres, what symptoms are experienced?
- Dizziness (postural hypotension)
- Impotence
- Nausea and vomiting (gastroparesis
When there is damage to autonomic fibres, what happens to power?
NORMAL
When there is damage to autonomic fibres, what happens to sensation?
NORMAL
When there is damage to autonomic fibres, what happens to reflexes?
PRESENT
When there is damage to small fibres, what symptoms are experienced?
- Pain
* Dyesthesia
When there is damage to small fibres, what happens to power?
NORMAL
When there is damage to small fibres, what happens to reflexes?
PRESENT
When there is damage to small fibres, what happens to sensation?
Pin prick and temperature sensation are reduced
What is pseudoathetosis?
A problem with proprioception - there IS NOT a problem in the basal ganglia, but there is a problem in the peripheral nerve
Bilateral foot drop….
High stepping gait
Cant dorsiflex foot
Due to lesion in common perineal nerve
What would cause bilateral foot drop?
Lesion in common perineal nerve
Describe mononeuritis multiplex.
Subacute - occurring over weeks to months
What is mono neuritis multiplex usually driven by?
A nasty vasculitis
What is mono neuritis multiplex dependant on?
LENGTH
Describe the features of mono neuritis multiplex.
- VERY symmetrical
- Peripheral nerves die off from feet to wrists
- Usually caused by metabolic processes e.g diabetes
What causes mononeuritis multiplex often?
Diabetes
What could muscle wasting of the thenar eminence be due to?
- Carpal tunnel syndrome
- Median nerve compression at the elbow
- Plexopathy
- MND
Wrist drop
Radial nerve
Foot drop
Common peroneall nerve - unable to dorsiflex
What are the 3 major categories of nerve damage?
- Radiculopathy
- Plexopathy
- Peripheral neuropathy
What are the 2 main ways in which nerves can be damaged?
- Axonal loss
* Peripheral nerve demyelination
What test is done to find out which way nerves have been damaged?
Nerve Conduction Studies
Give an example of an acute demyelinating neuropathy which occurs over days to weeks
GBS
How does GBS often start?
TINGLING LIMBS
How quick is it before someone with GBS can become quadriplegic?
Over the course of 2 weeks
Give examples of chronic demyelinating neuropathies which occur over months to years.
- CIDP (chronic inflammatory demyelinating polyradiculopathy)
- Hereditary sensory motor neuropathy (formerly known as Charcot-Marie-Tooth disease)
What is the key feature of GBS?
Progressive paraplegia over days, up to 4 weeks
What precede the weakness in GBS?
Associated sensory symptoms
What is very common in GBS?
PAIN
When do peak symptoms occur in GBS?
10-14 days
Initially, how can a GBS exam be?
NORMAL
What does GBS have a possible association with?
Infection i.e campylobacter
What do 25% of people with GBS require?
Mechanical ventilation
How do 10% of people with GBS die?
From autonomic failure e.g cardiac arrhythmias
What is the treatment for GBS?
Immunoglobulin infusion OR plasma exchange
What are the different variants of hereditary neuropathy?
Pure motor, sensory, sensorimotor, small fibre (congenital insensitivity to pain syndrome) and autonomic variants
(also axonal and demyelinating variations)
Genetic testing is available for the most common mutation in hereditary neuropathy. What is this mutation?
CMT 1a
Give examples of CHRONIC causes of autonomic neuropathy.
- Diabetes (via gastroparesis)
- Amyloidosis
- Hereditary
Give examples of ACUTE causes of autonomic neuropathy.
- GBS
* Porphyria
If someone has a triad of:
- Acute psychosis
- Unexplained abdominal pain
- Peripheral neuropathy
What are they liked to have?
Autonomic neuropathy caused by PORPHYRIA
How are axonal peripheral neuropathies treated?
- Treat cause
* Symptomatic
Axonal peripheral neuropathies are REVERSIBLE
FALSE - IRREVERSIBLE
How are vasculitic axonal peripheral neuropathies treated?
With pulsed IV methylprednisolone + cyclophosphamide
How are demyelinating (inflammatory) peripheral neuropathies treated?
IV Ig (pooled immunoglobulin from donors).
Steroids.
Azathioprine, Mycophenalate, Cyclophosphamide.