Neuropathic Disease Flashcards
What is the most common inherited motor-sensory neuropathy?
Where geographically is it common?
Which is more common– acquired or inherited neuropathies?
Charcot-Marie-Tooth Disease
- Common in rural WV
- Acquired neuropathies are more common
Demyelinating CMT-1: Inheritance pattern? Which gene/ protein is mutated? What is the problem? What is are two distinct clinical features associated with the disease?
Describe the findings on a nerve biopsy?
AD, mutant peripheral myelin protein 22 (PMP22) gene–> demyelination and remyelination of large axonal segments
**Patients have high arches and hammer toes
Nerve biopsy will reveal “onion bulbing”
Which age group gets demyelinating CMT-1?
How does the weakness and wasting present? (2)
Do patients typically have sensory symptoms?
- Presents in teenagers/ adults
Clinical presentation:
- Distal –> proximal muscle wasting + weakness
- Eventually wheelchair bound
- Typically no numbness; patients may simply never have had sensation to lose
Axonal CMT-2:
Inheritance pattern?
What is the problem?
How does it differ from CMT-1?
AD, axonal damage
- Slower to progress than CMT 1 (patients ambulate with orthotics)
- Otherwise similar in clinical manifestations
Dejerine-Sottas Diasease (CMT-3):
Inheritance pattern?
Problem?
Clinical manifestations and age of onset?
- AR, demyelinating neuropathy
- Presents in infants and toddlers with delayed / absent motor milestones
What does the diagnostic workup entail for the CMT diseases? (3)
- What history should be asked?
- What is seen on neuro PE?
- What testing should be done?
- Good genetic hx.
- Good neuro PE: will see absent reflexes due to demyelination/ axonal injury
- Nerve conduction study (differentiate etiology)
What will you seen on the nerve conduction study for a patient with demyelinating CMT?(3)–which of the findings determines severity of disease?
- # 1 Decreased velocity**
- Increased latency (determines SEVERITY)
- Marginally decreased amplitude
What will you see on the nerve conduction study for a patient with axonal CMT?
- # 1 Decreased amplitude**
How do we treat CMT?
Surgery for scoliosis, tendon lengthening, damage due to muscle atrophy
**There are no preventative or disease suppressing treatments
What is the most common nerve entrapment syndrome?
Describe the clinical presentation (2).
How is it diagnosed (2 clinical tests + 1 additional finding)?
Carpel Tunnel Syndrome
- Numbness, pain over palm digits 1-3
- Weakness in advanced disease
Diagnosed Clinically or NCS:
- Phalen’s, Tinnels
- Weakness in abductor pollicis brevis, Opponens pollicis (gripping)
How do we treat carpel tunnel syndrome? (3 conservative, 2 aggressive)
What is the only definitive treatment?
Treat conservatively w braces, rest, NSAIDS
Treat aggressively with corticosteroid injections or ligament release surgery (only definitive cure)
What causes CTS?
Repeated gripping
What is the leading cause of neuropathy in US and Europe?
What was the former leading cause?
How does the neuropathy present?
How is it diagnosed?
Diabetes (60-70% DM patients have neuropathy)–formerly leprosy
- Presents with stocking-glove sensory loss, burning–> evolves to weakness
- Diagnosed CLINICALLY or w/ NCS (rarely)
How do we treat DM neuropathy? (1 lifestyle, 3 drugs)
1 Glycemic control (prevent further damage)
- TCAs treat sx.
- Gabapentin + other AEDs
- Topical capscaisin
Describe the pathophysiology of GBS:
- Problem?
- Timeline?
- Which areas are damaged first?
Autoimmune demyelinating disease +/- secondary axonal loss
- Progresses within days to weeks (2-4 weeks to plateau)
- Proximal–> distal demyelination
What causes the axonal damage associated with GBS?
MQs scavenging damaged areas after myelin is destroyed
Describe how GBS is considered to be a parainfectious disease.
With which vaccine was it most heavily associated?
Which infection?
- 75% cases preceded by infection, immunization, or surgery
- 1970s swine flu vaccine
- # 1 Campylobacter jejuni
- EBV, CMV, Lyme, HIV, Hepatitis
Describe the clinical presentation of GBS (5):
- RAPIDLY ASCENDING PARALYSIS feet–> torso
- Absent DTRs
- Mid-lower back pain/ paresthesia
- ANS instability (KILLS**)
- Respiratory failure
Describe 3 severe complications associated with GBS related ANS instability
- Thyroid storm
- Rapidly undulating BP
- Respiratory failure
What is the prognosis for GBS?
80-90% patients return to their previous baseline
5-10% die–respiratory failure
How do we treat GBS (3)?
Which is more dangerous?
Most effective = Combined:
- IVIG for 10 days
- PLEX: 5 treatments, every other day
- Monitor in ICU for change; may need ventilation
PLEX is more dangerous bc ANS instability and severe HypoTN may result
What will you find on the nerve conduction study for a patient w GBS?
NORMAL FINDINGS–Wallariean degeneration takes longer to occur, therefore the study will be worthless most of the time…
Describe the pathophysiology of CIDP:
Abs + T cells + MQs invade interstitial/ perivascular endoneurium–>
SEGMENTAL DEMYELINATION of peripheral nerves
Describe the clinical findings associated with CIDP:
- Time course of disease?
- Type of Deficits (2)?
- CSF findings?
- EMG/NCS findings?
- Insidious and slowly progressive; may relapse/ remit
- Sensory + Motor deficits
- ANS dysfunction: orthostasis, incontinence, arrythmias
- CSF = ^ protein
- EMG/ NCS shows demyelination (decreased velocity)
What is seen on nerve biopsy of patient with CIDP?
Onion bulbing due to continuous demyelination and demyelination
How do we treat CIDP?
Immunosuppression/modulation
- Steroids, Azathioprine, Mycophenolate, Cytoxan
- PLEX and/ or IVIG for unresponsive cases
Amyotrophic Lateral Sclerosis:
- What is the problem here?
- When is the peak age onset?
- Which gene is associated with the familial variant? Inheritance pattern?
- Neurodegeneration of anterior motor neurons
- Peak onset 65-70 yoa
- AD inheritance, mutant SOD gene
Describe the clinical presentation of a patient with ALS:
- Sensory exam?
- Motor sx (2)
- Bulbar involvement?
- Time course?
- NORMAL sensory exam
- Upper + Lower motor neuron signs w asymmetric onset
- Bulbar involvement
- Ventilatory failure + frontotemporal dementia 3 yrs following onset
How do we dx ALS?
Clinical and EMG findings to rule out c-spine injury/ reversible cause
What is the treatment for ALS– which is FDA approved (2)?
- Riluzole (Rilutek) only FDA approved treatment, ^ life by 3 mos
- Supportive care, i.e. PEG tube, vent, etc.
List 3 hereditary neuropathies:
- CMT
- Amyloidosis
- Mitochondrial disease
List 5 potential causes of autoimmune neuropathy:
- MGUS
- Sjogrens
- Sarcoidosis
- RA
- Vasculitis
Two causes of infectious neuropathy?
- HIV
- Lyme (BL Bells palsy)
3 nutritional/ metabolic causes of neuropathy?
- B12 deficiency (subacute combined degeneration)
- B6 excess (sensory neuropathy)
- ETOH abuse
4 industrial exposures that can cause neuropathy?
- arsenic
- mercury
- lead
- organophosphates
Drugs that can cause neuropathy (6):
- colchicine
- paclitaxel
- vincristine
- metronidazole
- hydrazine
- NO
What is the Miller Fischer Variant of GBS– How does it present?
Anti GQ1B antibodies present in most cases– Presents with:
- facial weakness
- dysarthria
- areflexia
Describe the clinical presentation of B12 deficiency:
- Age/ circumstance (4)
- clinical sx (3)
- Dx workup (2)
- 60+ yoa, pernicious anemia, gastric bypass, NO abuse
- Numbness, neuropathic pain, gait disturbance
- Check serum B12 (LOW), methylmalonic acid (HIGH)
