Polyneuropathy Flashcards
what are the three types of polyneuropathy?
- Axonopathy
- Myelinopathy
- Neuronopathy
What is the temporal profile that you can learn from EMG (3)
Acute 21 days 5 months
Subacute 6-11 months
Chronic 12-18 months
What are the 4 predominant pathologies in peripheral neuropathy?
A. Axonal
B. Uniform demyelinating (usually hereditary)
C. Segmental demyelinating (usually acquired)
D. Axonal & Demyelinating (classic example is diabetes)
What three things about polyneuropathy must you know to correctly diagnose?
- generalized process
- symmetric vs asymmetric
- multifocal (spotty distribution)
During polyneuropathy protocol:
1. Test ____ site
2. Start with _____ study
3. If abnormal –> ____
4. If no response –> ____
- most involved site when mild-to-moderate. Least involved if severe.
- a. Peroneal motor (EDB) - stim at ankle and knee. record F response latency. If no response or abnormal response move to 3 or 4.
b. Sural sensory
c. Median sensory or ulnar (since high incidence of median pathology) - tibial motor (abd hall) stim at ankle and knee; record F response latency
- peroneal motor (anterior tibial) stim at fibula and knee.
ulnar motor (hypothenar) stim at elbow and wrist
measure F response latency
Median motor (thenar) stim at elbow and wrist
measure F response latency
If prominent CN involvement, stim at facial motor and blink reflex.
Needle exam
- anterior tib
- medial gastroc
- first DI
- lumbar paraspinals
(if normal, intrinsic foot muscles should be tested.
Nickerson protocol for polyneuropathy:
Lower ext sensory:
Upper ext sensory:
Lower ext motor:
Upper ext motor:
plus?
EMG:
Usually do longest sensory
Sural bilat - if can’t get, do superficial peroneal (peroneal commonly used as can get prox and distal stim)
ulnar - bc median pathology is common
peroneal and tibial
ulnar - F wave
do long loop (H waves and F reflexes)
EMG: sample lower extremity first. If abnormal do contralateral muscle
radic screen: atleast 5.
Tib ant, med gastroc, FDI
Upper, FDI and biceps (something distal and something proximal)
In axonopathy, will have ____ phenomenon
_____ nerves and ____ fibers are affected first
___ is spared
___ is preserved if corrected
Overall, will see ____ and ___ on NCS
Prognosis:
dying back (not exclusive)
longest/largest
myelin sheath
endoneurium
decreased amplitude and area under the curve
slow re-growth and return of function over months to years.
incomplete recovery.
Myelinopathy spares ____ but affects ______.
subsequent ____ loss occurs
______focal
distal or proximal?
Prognosis:
Recovery:
schwan cell, myeline sheath.
axonal loss (slight amount of axonal injury)
multifocal/segmental demyelination - doesn’t strip entire nerve.
- affects node of ranvier (multisites)
- proximal before distal
- uniform or segmental
prog: weeks to months
Functional recovery better than axonopathy
incomplete recovery
In acquired, will have excessive temperal dispersion (spread out, extra bumps), not in hereditary.
Name the two most common uniform demyelinating mixed sensorimotor peripheral neruopathies
- HMSN I, II, IV
- Krabbe Leukodystrophy
Name the three most common segmental demyelinating motor>sensory peripheral neuropathies
Other 6?
- AIDP
- CIDP
- MGUS
- Arsenic
- Toxins
- Diptheria
- AIDS
- Leprosy
- Lyme disease
Name the 4 most common axon loss motor > sensory peripheral neuropathies
other 3?
- Porphyria
- Vincristing
- Axonal GBS
- HMSN II, V
- Dapsone
- AIDP
- Lead
Name the 3 most common axonal loss sensory neuronopathy
Other 3
- HSN I-V
- Friedreich’s ataxia
- cisplatinum
- Sjogren’s syndrome
- Pyridoxine
- Crohn’s disease
Name the three most common axon loss mixed sensorimotor peripheral neuropathies
other 9?
- Critical illness polyneuropathy
- ETOH
- Toxic
- Amyloidosis
- Vit B12
- Folate
- Gold
- Mercury
- Paraneoplastic syndrome
- Sarcoidosis
- Lyme disease
- HIV related
Name the 2 most common mixed axonal and demyelinating sensorimotor peripheral neuropathies
DM
uremia
_____ is a condition that affects the cell body (DRG or anterior horn cell)
Neuronopathy
sensory neuronopathies fit in this category as well.
If a myelin problem, will get what 3 things on NCS?
onset or peak latency delay
CV decreased
temporal dispersion
Is this physiologic or pathologic temporal dispersion?
stimulate proximally you get amplitude x, stimulate distally and get slightly lower amplitude; this will happen with all nerves (this happens because longer length, some axons get there at the same time, there is phase cancellation, and the amplitude is decreased) The area under the curve will remain constant
Physiologic
Is this physiologic or pathologic temporal dispersion?
stimulate proximally you get amplitude x, stimulate distally and you get an amplitude more than 20% less than x (less than 15% change in negative duration of wave). Overall curve is shortened (amplitude) and more spread out (duration). The area under the curve stays similar.
pathologic
____ will be decrease in amplitude without increase in duration of the wave. Can be confused with_____
partial conduction block
pathologic temporal dispersion.
What will be seen on axonal process for EMG
increased insertional activity
abnormal spontaneous activity - fibs/PSW
- reinnervation potentials (polyphasics, serrations, increased amplitudes, CRD if chronic)
- wont see abnormal spontaneous activity in demyelinating
wont see _____ on EMG in demyelinating process
abnormal spontaneous activity
Distal latency:
Early demyelinating:
Chronic demyelinating:
Acute axonal:
Chronic axonal:
increased
increased
normal or slightly increased
normal or slightly increased
Nerve conduction velocity
Early demyelinating:
Chronic demyelinating:
Acute axonal:
Chronic axonal:
decreased
decreased
normal or slightly decreased
normal or slightly decreased
F-latency
Early demyelinating:
Chronic demyelinating:
Acute axonal:
Chronic axonal:
increased or absent
increased or absent
normal or absent
normal or absent
H-reflex
Early demyelinating:
Chronic demyelinating:
Acute axonal:
Chronic axonal:
increased latency or absent
increased latency or absent
absent
absent
SNAP amplitude
Early demyelinating:
Chronic demyelinating:
Acute axonal:
Chronic axonal:
Decreased or absent
decreased or absent
decreased or absent
decreased or absent
CMAP amplitude
Early demyelinating:
Chronic demyelinating:
Acute axonal:
Chronic axonal:
normal or decreased
normal or decreased
decreased
decreased
MUAP duration
Early demyelinating:
Chronic demyelinating:
Acute axonal:
Chronic axonal:
normal
normal or increased
normal
increased
MUAP amplitude
Early demyelinating:
Chronic demyelinating:
Acute axonal:
Chronic axonal:
normal
normal or increased
normal
increased
polyphasics (subacute 3-6 months)
Early demyelinating:
Chronic demyelinating:
Acute axonal:
Chronic axonal:
normal
increased
normal
increased
Recruitment
Early demyelinating:
Chronic demyelinating:
Acute axonal:
Chronic axonal:
normal or decreased
decreased, rapid
decreased, rapid
decreased, rapid
abnormal spontaneous activity
Early demyelinating:
Chronic demyelinating:
Acute axonal:
Chronic axonal:
none
none or fibs, PSW, CRD
Fib/PSW, CRD
none or fibs/PSW, CRDs
Uniform demyelinating mixed sensory-motor polyneuropathy is (inherited/acquired)?
affects _____ fibers
inherited
sensory and motor
What are the NCS findings for Uniform demyelinating mixed sensory motor polyneuropathy?
(6)
1 prolonged latency
2. slow conduction velocity <60–80 (85?)% than normal
3. Morphology from proximal and distal stimulations are similar
4. prolonged F
5. minimal/no temporal dispersion, no conduction block
6. decreased amplitudes (low normal)
HSMN I is also known as ______.
Nerve biopsy looks like _____. due to?
Present in _____ yoa
Charcomarie tooth (different types IA, IB, IC)
onion bulb formation, due to demyelination and remyelination process
20-30 yoa
Pathology?
patient presents in 20-30s with clumsiness, multiple sprained ankles, pes cavus deformity, hammer toes, halux valgus, enlarged nerves, scoliosis, absent reflexes, decreased vibration/position sense
what if essential tremor is involved?
HMSN I - CMT
roussy levy syndrome
can sometimes palpate sural nerve bc it is enlarged and has demyelination and remyelination.
CMT is inherited how?
Decreased CV is averaged to be _____m/s or ____% below normal.
autosomal dominant
15-25m/s
60-80%
HMSN III is also known as _______.
This is the ____ form.
_____ inheritence.
Presents in _____
Dejerene Sottas Syndrome
severe
autosomal recessive
infancy
pathology?
neurogenic kyphoscoliosis, pes cavus as babies, ataxia, areflexia, enlarged nerves (greater aricular, sural - can palpate)
HMSN III - Dejerene Sottas Syndrome
What is the difference between acquired and hereditary demyelinating sensorimotor peripheral neuropathies?
partial conduction block
HMSN IV is also known as _____.
due to ______.
Associated with ___ eye disorder
Inheritence:
Increased _____ protein
Refsum’s disease
lipid metabolism abnormality (phytanic acid oxidation deficiency) - failure of phytanic acid to undergo alpha oxidation
retinitis pigmentosa (night blindness) — also cerebellar dysfunction/ataxia.
AR
CSF protein
What is the uniform demyelinating mixed sensorimotor peripheral neuropathy that shows cognitive issues, seen in infancy secondary to a metabolic disorder?
Krabbe Leukodystrophy
EMG/NCS findings:
1. CV slow to 30s
2. varying degrees of conduction block (amplitude drop by 20% with no change in negative spike duration)
3. Pathologic temporal dispersion
4. increased phases when compare distal to proximal
5. increased peak and onset latency
6. prolonged or absent F wave
7. patchy sensory studies
acquired segmental demyelinization motor > sensory
What pathology?
1. ascending symmetrical weakness
2. distal > proximal
3. legs > arms
4. 70% after viral illness (gastroenteritis, URI)
5. spares occular (no diplopia) and sphincter muscles
6. Areflexic
7. positives seen on long loops (f waves)
AIDP - Guillain Barre
what pathology
1. symmetric onset
2. proximal > distal
3. three different types.
4. areflexic
5. varying courses.
CIDP
CIDP has varying courses
_____% can have 1 episode then done
____% have slow decline
___% have slow stepwise decline
_____% have rapid stepwise
40
15
15
30
types:
slow monophasic (does not progress)
chronic relapsing
slow progressing stepwise
pathology
-asymmetrical weakness, arms > legs
-conduction block (loss of 20-25% amplitude from proximal to distal) in multiple nerves.
-Fasciculatios seen
-no sensory problems
-antiglycolipid antibodies (anti GM1 antibodies) seen in this autoimmune disorder
multifocal motor neuronopathy with partial conduction block (MMNPCB)
in differential with ALS
what is the pathology behind multifocal motor neuronopathy with partial conduction block?
which category of peripheral neuropathy is it
anti-GM 1 antibodies - antiglycolipid antibodies
segmental demyelinating motor>sensory peripheral neuropathy
Monoclonal gamopathy of undetermined significance (MGUS) is associated with ______ .
Polyneuropathy starts ______ before they develop this.
Check ____ (lab)
colon cancer
3-4 years before they develop cancer
check CMP total protein will be high. Then get serum protein electrophoresis. They will have a spike of gamma portion of SPEP.
EMG/NCS findings for axonal loss motor>sensory
- small amplitudes - the one that is proximal is just as small as the stimulation that is distal (50% of expected value)
- No pathological temporal dispersion (small amount of physiologic temporal dispersion)
- No conduction block
- slightly increased latencies
- slightly decreased CV (bc loose the fastest firing fibers due to axonal damage)
- EMG: fibs/PSWs
Pathology?
Autosomal dominant inheritance
incomplete penetrance (can have gene but not disease)
classic triumvirate: psychosis, abd pain, polyneuropathy
porphyria
HSMN II also known as _____
presents in ____ decade
inheritence?
____ amplitude, _____ CV
Neuronal CMT
3rd and 4th decade
AD
small, preserved CV (mid-upper 30s)
will see pes cavus, hammer toes, leg muscle atrophy
name the three types of AiDP
- demyelinating - segmental
- axonal (fibs/PSW)
- miller fischer varient
HSMN II belongs to which category of peripheral neuropathy
axonal loss motor > sensory
What is the classic triad of porphyria
psychosis, abd pain, polyneuropathy
Vincristine neuropathy shows what kind of peripheral neuropathy?
axonal loss motor > sensory
months to years later.
Axonal loss sensory neuropathy and neuronopathy affects the _____
dorsal root ganglion (PURE SENSORY)
EMG/NCS findings for axonal loss sensory neuropathy: (5)
- only sensory nerve affected
- decreased amplitudes (proximal and distal waves)
- normal motor NCS
- slightly decreased CV (lose `fastest firing fibers)
- EMG will be normal b/c EMG assesses motor
Friedreichs ataxia is what form of peripheral neuropathy?
inheritance?
axonal loss pure sensory
pathology?
cerebellar degeneration, areflexia, ataxia, scoliosis, pes cavus, nystagmus, upgoing toes (UMN); posterior column loss, vibration sense, position sense and 2 pt discrimination affected
freidreichs ataxia
pathology?
areflexia, ataxia, diplopia, and ophthalmoplegia. increased CSF proeint. Associated with Gq1B antibody
miller fischer variant
cisplatinum belongs to which peripheral neuropathy
sensory axonal loss
alcohol, pharmaceuticals, neutritional deficits, toxic neuropathies (CO2, organophosphates), CIP are all belonging to which peripheral neuropathy
axonal loss sensorimotor
Pathology?
- slowed CV in upper extremity limit of normal 32
- slowed CV in lower extremity lower limit of normal 28
- no temporal dispersion (differentiates from axonal demyelinating sensorymotor polyneuropathy) - prox and distal stim are the same.
- prolonged latencies (onset and peak)
- small amplitudes
- EMG with fibs/PSWs
axonal loss mixed sensorimotor
pathology
1. pathological temporal dispersion
2. slowed CV
3. decreased amplitudes
4. prolonged latencies
5. axonal timeline on EMG
axonal demyelinating mixed sensorimotor polyneuropathy (acquired)
what are the 6 different ways someone can have diabetic polyneuropathy?
1.Sensory
2. Sensorimotor
3. Autonomic (gastroporesis)
- presents as orthostasis, neurogenic B/B, abnormal sweating)
4. Diabetic amyotrophy
-focal lumbar polyneuropathy radiculopathy (multiple roots)
5. Mononeuritis multiplex
-polyneuropathy of blood supply to nerve (vaso nevorum)
-one nerve in multiple spots along that nerve
6. Cranial nerve involvement
uremia belongs to which peripheral neuropathy
axonal demyelinating sensorimotor polyneuropathy (acquired)
will continue to have neuropathy after kidney transplant
which diabetic peripheral neuropathy presents with gastroparesis, orthostasis, neurogenic b/b, and abnormal sweating?
DM autonomic polyneuropathy
pathology
- inflamed nerve
- injured blood supply to the nerve
- axonal abnormalities
- asymmetric
- patchy
- vasculitis and DM associated (poorly controlled)
mononeuritis multiplex
