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NS Exam 4: Diseases of Peripheral Nerves

Terms in this set (18)

What are the three ways that peripheral nerves get damaged?
1)Wallerian degeneration
2) segmental dymyelination
3) axonal degeneration
What disease is the most commonest cause of neuropathic acute/ subacute generalized paralysis?
* Guillan Barre Syndrome
* Affects all ages, both sexes, all parts of the world, all seasons
*preceded 1-3 weeks by a mild respiratory or GI infection immunization in 60%
*identified pathogens
-campylobacter jejuni
-viral exanthems and other viral illnesses (CMV, EBV, HIV).
-other bacterial infections (mycoplasma, lyme borreliosis)
-lymphoma
- A/ New Jersey (swine) influenza vaccine (? H1N1).
What is the incidence of Guillian Barre?
* Incidence= 2/10^5
* non seasonal, non epidemic
*most frequent age=50-75 years
Symptoms of Guillian Barre?
* Numbness/paresthesias of toes and fingers
*Symmetric weakness
-evolving over days to a few weeks
-proximal/distal, lower before upper limbs
*total paralysis/respiratory in 5%
*pain/aching in > 50%
*sensory loss variable (may have vibration loss, DCML)
* Loss of DTRs
*facial diplegia > 50%
* autonomic dysfunction
-cardiac, facial flushing, urinary retention (15%)
variants
* fisher syndrome
*cervico-brachial-pharyngeal
*oculopharyngeal
*predominant paraparesis
*bilateral facial or abducens weakness with distal paresthesias
*pure opthalmoplegia (GQ1 b autoantibodies)- no eye movement
*axonal form- worse form, axon damage instead of myelin sheath damage, associated with camplyobacter jejuni infection.
*Chronic Guillain-Barre syndrome (CIDP)
What are some of the characteristics axonal form of Guillian Barre Syndrome?
* Widespread, severe denervation (on EMG whereas with other forms tend to see muscle weakness)
*rapidly evolving, poor recovery
*minimal demyelination, minimal inflammation, severe axonal degeneration
* role of anti-myelin antibodies (anti-GM1)
Laboratory results of Guillan Barre?
*CSF analysis (can only use if the person has had the disease for over a week). Otherwise CSF will appear normal prior to that even if the disease is present.
* high protein content
*glucose is normal
*EMG/NCS
-decreased muscle action potentials
-decreased conduction velocities
- conduction block in the motor nerves
-prolonged/absent late responses (F waves, H reflex)
* MRI- can view lumbosacral spine for signs of inflammation
->demyelination or dennervation better ways to Dx than CSF.
Pathology of Guillan Barre?
*perivascular lymphocytic infiltrates
*segmental demyelination and variable wallerian degeneration involving the entire course of the cranial/peripheral nerve
Pathogenesis of Guillan Barre?
*cell-mediated immune response
*experimental allergic neuritis (EAN)
- T cell mediated
-Target antigen
*Role of antimyelin antibodies
-anti-GQ1 B
-anti-GM1(axonal form with jejuni)
*role of preceding infection/vaccination
-molecular mimicry
-host factors: could be genetic factors
Differential Diagnosis: common diseases that can be confused with Gullian Barre Disease?
*Acute spinal cord disease-reflexive paralysis from the neck down, sensory loss with acute spinal cord disease, usually not with Guillan Barre Disease.
* Poliomyelitis/West Nile virus- S/S include fever, headache, malaise, stiff neck, onset nearly immediate.
*myasthenia gravis- end plate is destroyed, where ACH receptors
*botulism
*tick paralysis- usually affects children, kids can get tick from a dog, once tick removed, paralysis goes away.
*ciguatoxin
*toxic neuropathy (e.g. thallium)
What are some common treatments for Guillain Barre?
*general care
-assisted ventilation (25%)
*measurements of expiratory vital capacity
- cardiovascular monitoring
-prevention of complications (DVT, aspiration, pressure sores, pressure palsies, etc.)
-plasma exchange
-intravenous gammaglobulin (IVIg)
-corticosteroids
Prognosis of GB?
*mortality= 3-5 %
-cardiac arrest, adult respiratory distress syndrome (ARDS)
*significant disability=10%
*duration of hospitalization= 50 days
*speed of recovery
*recurrent relapses= 5-10%
Syndrome of Subacute Sensorimotor Polyneuropathy
*symmetrical polyneuropathies
-deficiency states
* berberi, pellagra, vitamin B12, vitamin B6, chronic GI disease
-Poisoning with heavy metals and solvents
* arsenic, lead, mercury, thallium, n-hexane, acrylamide
-drug toxicity
*isoniazid, nitrofuratoin, vinicristine, cisplatin, phenytoin, vitamin B 6, amiodirione
-uremic polyneuropathy

*asymmetrical polyneuropathy
-diabetes
-polyarteritis nodosa
-sjogren-sicca syndrome
-sarcoidosis
-ischemic neuropathy
-lyme disease
Syndrome of Subacute Sensorimotor Polyneuropathy
*berberi (alcoholic), pellagra
-distal weakness, parasthesias, pain
- decreased distal DTRs, distal weakness, stocking glove distribution, decrease in sensation
- B Vitamin supplements, treatment of neuropathic pain
*Lead
- radial neuropathy (wrist drop)
*polarteritis nodosa
-abdominal pain, hematuria, fever, eosinophilia, increased blood pressure, asthma
-mononeuropathy multiplex
Syndrome of Chronic Sensorimotor Polneuropathy: Which diseases are acquired types and which is inherited?
*acquired
-diabetes
-paraneoplastic (occasionally subacute)
-paraproteinemias
-connective tissue diseases (SLE, RA)
-Berberi (usually subacute)
-leprosy
-amyloidosis
*inherited
-Charcot-Marie-Tooth disease
What are the five types of diabetic neuropathy?
1. Cranial neuropathy
-oculomotor neuropathy
2. Distal sensorimotor polyneuropathy
-most common polyneuropathy
-trophic changes (Charcot joints (swollen joints), foot ulcers)
3. Acute mononeuropathy
-any peripheral nerve (femoral, sciatic, peroneal)
4. Multiple mononeuropathies, radiculopathies
-painful asymmetric LE weakness, often in early DM in older diabetics
-painful thoracoabdominal radiculopathy in long standing DM
5. Autonomic neuropathy
- decreased pupillary reflexes, xerophthalmia. anhydrosis, orthostasis, nocturnal diarrhea, impotence, bladder atony.
Syndrome of Chronic Sensorimotor Poly Neuropathy
*paraproteinemias
-monoclonal gammopathy (non neoplastic)
* IgM> IgG > IgA: kappa > lambda
* middle aged males
* usually demyelinating or mixed
* IVIG or plasmaperesis
*Leprosy
-infectious neuropathy
* tuberculoid versus lepromatous
*Charcot Marie Tooth disease
-autosomal dominant beginning in 1st or 2nd decade
-distal wasting and weakness, sensory ataxia
Mononeuropathy and Plexopathy
*entrapment neuropathy
-carpal tunnel syndrome (median nerve)
-meralgia paresthetica (lateral cutaneous nerve of the thigh)
*traumatic neuropathy
-ulnar, radial, axillary, sciatic, peroneal
*brachial plexopathy
-pancoast tumor: lung cancer @ apex of the lung, affect medial cord and can present with Horner's Syndrome (ptosis)
-Radiation induced: can be associated with those treated for breast cancer
-post infectious, vaccination
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