Peripheral Nerve Flashcards
What separates bundles of nerve fibers? Epi or Peri NEURIUM
Perineurium
What structures are outside the pail membrane but are not member of the peripheral nervous system?
Optic nerves and olfactory bulbs
Wallerian or axonal degeneration? Dying backward in metabolic polyneuropathies.
Axonal
Wallerian or axonal degeneration? Dying forward in axonal damage
Wallerian
In wallerian degeneration and axonal degeneration give the histologic picture associated with the neuronal CELL BODY.
Chromatolysis: swelling of the cell cytoplasm and margnializaiton and dissolution of the Nissl substance
Match:
- GBS
- Polyarteritis nodosa
- Diptheric polyneuropathy
A. Endoneurial infiltrates of lymphocytes and other mononuclear cells in the nerves, roots and sensory and sympathetic ganglia
B. Demylinative changes around the roots and the sensory ganglia and a LACK OF INFLAMMATORY REACTION
C. Necrotizing panarteritis with thrombotic occlusion of vessels and focal infarction of peripheral nerves
1A
2C
3B
Most axonal polyneuropathies: nutritional, metabolic and toxic neuropathies assume a distal axonal pattern wherein the pathologic process begins in the largest and longest nerves, i.e. those of feet and legs EXCEPT FOR?
Porphyrias, mainly proximal weakness at first
Differentiate axonal polyneuropathies from demyelinating neuropathies in terms of pattern of weakness
Demyelinating: weakness of the proximal limb and facial muscles before or at the same time as the distal parts are affected
AP: Distal before proximal, feet before cranial nerves and arms
T or F, motor neuron or motor axon disease spare muscle bulk
F, demyelinating disease spare muscle bulk
What is the only CNS disease that will cause areflexia?
Spinal shock
What for of sensory loss usually predominates in axonal polyneuropathies?
Small afferent fibbers of pain and temperature
Which can cause burning type of pain in both feet? DM neuropathy or Partial nerve lesions?
BOTH
What kind of tremor arises from polyneuropathy?
Fast frequency action tremor much like cerebellar tremor. Look for other cerebellar signs such as nystagmus and scanning speech to differentiate
Give three diseases that causes ataxia without weakness.
- Tabes dorsalis
- DM polyneuropathy
- Fisher syndrome
- Cerebellar disease
In chronic polyneuropathies, tabes dorsalis and syringomyelia analgesic joints that are chronically traumatised become deformed then disintegrate, what is this process called?
Charcot arthropathy
Diabetic neuropathy with autonomic dysfunction usually manifests with which 2 symptoms?
Anhidrosis and orthostatic hypotension
Fasciculations cramps and spasms are prominent features of which kind of disease?
Anterior horn cell disease
What can be used to treat myokimia?
Carbamazepine or phenytoin
GBS– What is the most frequently identifiable antecedent infection to GBS?
C. jejuni. Also associated are Herpes family of viruses, and Hodgkin lymphoma
GBS– Which muscles are affected first? Proximal or distal?
BOTH affected at the same time BUT LE before UE
GBS– Describe the sensory involvement
Burning sensation may occur in feet and hands; Joint and position sense»_space;> pain and temperature
GBS- What symptoms are similar to a primary spinal cord disease?
- Back pain
- Motor and sensory problems
- Urinary retention occurs in 15 percent of patients needing catheterisation for a few days
GBS– Reflexes?
Reduced or absent
GBS– Autonomic dysfunction?
Facial flushing, labile BP, HR and sweat pattern
What variant of GBS?
- Abrupt and severe denervating paralysis, atrophy within weeks
- Complete ophthalmoplegia with ataxia and areflexia
- Severe axonal degeneration with minimal inflammatory changes
- Difficulty swallowing and proximal arm weakness occurring as presenting symptoms
- AMAN
- Fisher syndrome
- AMAN
- Pharyngeal-cervical-brachial muscle variant
Which GBS variant antibody?
- AMAN
- Fisher syndrome
- Antibodies to GM1 ganglioside
2. Anti-GQ1b
What comes first nerve conduction abnormalities or increase in CSF protein?
Nerve conduction abnormalities are early (within days of symptom onset) and dependable dxtic indicators of GBS. CSF protein normal in first few days and peaks at 4-6 weeks.
What are the EMG findings of GBS?
- Reduction in the amplitude of muscle action potentials
- Slowed conduction velocity
- Conduction block
- Absent F responses
- Prolonged distal latencies
- H reflex delayed or absent
GBS– Pathology
Endoneural perivenous lymphocytic infiltrates –> segmental demyelination –> PMNs arrive –> Axon degenerates
How to differentiate tick paralysis from GBS?
CSF protein normal and sensory loss is usually not a feature of tick paralyssi
How to differentiate polio from GBS?
- Fever
- Meningoencephalitic sxxs
- Asymmetrical areflexic paralysis
What electrolyte abnormality mimics GBS?
Hypophosphatemia of hyperalimentation
What characteristics differentiate carcinomatous meningitis from GBS?
- Weakness is mainly distal
- Absence of facial weakness
- Appearance of symptoms sequentially in one limb to another
- Spinal fluid with malignant cells
How does pupillary examination and reflexes differentiate
- GBS
- Brainstem infarction
- Botulism
GBS: Good pupillary response until very late in the disease + Areflexic
Botulism: Early pupillary paralysis + Poor reflexes
Brainstem infarction: Early pupillary paralysis + Lively reflexes
Being able to count to 20 means that once has a vital capacity of how much?
1.5L
What percentage of patient parlayed from GBS will develop hypotension from dysautonomia?
10%
What is the golden period for the treatment of GBS with plasma exchange?
2 weeks
What are the 2 most important predictors of responsiveness to plasma exchange treatment of GBS?
Young age and preservation of motor compound muscle action potential
What subset of patients should not be given IVIg 0.4g/kg for 5 consecutive days?
Those with congenital absence of IgA
What are adverse effects of IVIg?
Aseptic mengingitis, proteinuria, renal failure
After GBS residual deficits still present for ___ years will probably be permanent.
2
Critical illness polyneurpathy usually spares?
- Cranial nerves
2. Few or no dysautonomic symptoms
How can one distinguish paresis from critical illness polyneuropathy from GBS?
EMG findings are mostly axonal and CSF is normal in CIPN. Difficult to distinguish from acute axonal form of gbs