Diagnosis of Peripherl Neuropathy Flashcards
What is neuropathy?
disease or dysfunction of one or more peripheral nerves, typically causing numbness, pain or weakness.
Where will neuropathy typicall start?
distally
What is the pain describe like in neuropathy?
burning, shooting, electric. Allodynia
Is neuropathy length dependent?
yes
What should these make you think about?
Unsteadiness of gait. Multiple falls.
Unsteadiness typically worse when vision is taken away.
neuropathy
Is there vertio associated with neuropathy?
no
How can you distinguish between vertigo and unbalance?
you ask the patient if they feel the problem is in their legs or in their head
Neuropathy imbalance is due to (blank)
loss of proprioception
typically in neuropathy where do you get weakness? What will you lose the ability to do?
distally and you will lose ability to grip and execute fine motor tasks (i.e open jars), foot drop, dropping objects, problems with writing or typing
What are symptoms of bulbar/cranial nerve damage?
diplopia
ptosis
dysarthria/dysphagia
Why do you get diplopia?
cuz your extraocular muscles arent working right :(
What are the sensory features of bulbar/cranial nerve damage?
loss of pinprick sensation in distal extremities, mostly lower
loss of temp in distal extremities, mostly lower
proprioception testing/rhomberg test will let you know
What is the sign of the foot called when you have a high arch and hammer toes due to distal atrophy ?
charcot foot syndrome
What are the motor features of neuropathy?
distal atrophy with or without fasciculations
tremor
dimished/absent deep tendon reflexes
Pes cavus deformity of feet
steppage gait with foot drop or foot slap
What are the bulbar features of neuropathy?
diplopia or dysconjugate gaze ptosis facial assymetry tongue weakness/ atrophy pupillary abnormalities
How can you measure action potentials?
oscilloscope
reading electrode
reference electrode
motor unit potentials that are (blank) may be an indication of pathology
polyphasic
In a muscle wiht loss of nerve supply, what will the amplitudes look like of the muscle fibers?
super high because we have loss recruitment so the left over muscle fibers have to compensate
In muscle disease what will muscle fiber amplitudes look like?
you will get polyphasic spike but will be low amplitude and you will see increased recruitment
If it takes longer to transmit a single in the median nerve than the ulnar nerve what does this indicate?
carpal tunnel syndrome
decreased sensory or motor amplitudes may suggest (blanK)
axonal damage
Delayedor slowed distal latencies or slowed conduction velocities may be suggestive of (Blank) disease
conduction disease
Slowing of all latencies and conduction velocities can be seen if limb skin temp is too (blank)
cold
Abnormal temporal dispersion or conduction block may be suggestive of (blank) or (Blank)
demyelinating disease or focal nerve impingement
F-responses or H-reflexes; if delayed or absent, could be suggestive of (blank) or (blank) or (blank)
demylinating disease or radiculopathy or focal nerve compressoin
What exactly is temporal dispersion?
widening of peak as you move more proximal
In an EMG, what is increased insertional activity and muscle irritability a sign of?
neuropathy and myopathy
On an EMG, what will Fibs or P waves indicate?
acute, ongoing neuropathy or myopathy
On an EMG, what will complex repetitive discharges indicate?
chornic neuropathy; myotonic discharges in myotonic myopathies and other channelopathies
In denerevated muscle, motor units are (blank) amplitude, polyphasic with (blank) recruitment
high
recruitment
In myopathic muscle, motor units are (blank) amplitude, polyphasic with (blank) recruitment
low
increase
What do you use EMG for?
diagnosis and classification of peripheral neuropathy
diagnosis of major compressive mononeuropathies, especially CTS
diagnosis of Myopathy
diagnosis of severe radiculopathy when positiv
What is this:
Decreased or absent sensory and motor amplitudes on Nerve conduction study
axonal neuropathy
What is this:
increased insertional activity with fibs and p-waves and possibly CRDs as abnormal spontaneous activity
axonal neuropathy
What is this:
high-amplitude, polyphasic motor unit potentials with decreased recruitment on motor unit analysis
axonal neuropathy
What is this:
Nerve conduction study showing markedly delayed distal latencies and slow conduction velocities
demyelinating neuropathy
What is this:
abnormal temporal dispersion or conduction block
demyelinating neuropathy
What is this:
markedly delayed F-wave latencies or absent F-waves
demyelinating neuropathy
What is this:
A needle EMG shows increased insertional activity with p-waves, fibs as abnormal spontaneous activity
Demyelinating neuropathy
What is this:
high amplitude, polyphasic motor unit potentials with decreased recruitment
demyelinating neuropathy
What is this:
decreased sensory amplitudes or absent sensory responses
compressive neuropathies
What is this:
decreased or absent motor responses
compressive neuropathies
What is this:
EMG showing fibs, P-waves, fasciculations exclusively in muscles supplied by suspect nerve. Motor unit potentials of those muscles are large, polyphasic with decreased recruitment
compressive neuropathies
What is this:
normal sensory nerve conduction with normal or decreased motor amplitudes an delaed or absent F-responses
radiculopathies
What is tis:
EMG: fibs, p-waves, CRDs in appropriate myotome. In those muscles, motor unit potentials are large and polyphasic with decreased recruitment. Paraspinous muscles are most sensitive for these changes.
EMG/NCS can be normal in patients with a significant radiculopathy. Need to correlate with imaging.
radiculopathies
What is mononeuropathy?
only selective nerves are affected
(blank) is a condition due to a compressed nerve in the spine that can cause pain, numbness, tingling, or weakness along the course of the nerve.
Radiculopathy
What is the number one cause of neuropathy world wide?
leprosy
diabetes is number 1 in US
What are the four types of axonal neuropathy?
diabetic neuropathy
other metabolic neuropathies
vasculitic neuropathy
hereditary neuropathy
What are the mononeuropathy multiplex neuropathies?
vasculitic neuropathy
sarcoid neuropathy
cancer-related
What is this:
polyarteritis nodosa, Wegeners granulomatosis
causes of vasculitic neuropathy
What neuropathy is often associated with cranial neuropathy?
sarcoid neuropathy
What do you need to differentiate mononeuropathy multiplex from?
HNPP (hereditary neuropathy with liability to pressure palsy)
What are the four main demyleinating neuropathies?
guillain-barre syndrome
MGUS related neuropathies
selected toxic neuropathies-Toluene
hereditary demyelinating neuropathies- Charcot-Marie-Tooth Disease
How can you do a nerve biopsy?
take sural nerve and some muscle-> same day surgery
What will a nerve biopsy help you confirm especially?
vasculitic neuropathy
What will a nerve biopsy help you delinate between?
an axonal neuropathy and a demyelinating neuropathy
What is this:
Mostly a research tool at present
Quantitative method of estimating thresholds for various modalities of sensation
Limited availability: Mostly in academic centers
QSART
What is this:
Exclusively to confirm a small fiber neuropathy
May not have bearing on treatment
Skin Punch Biopsy
So summarize how you should figure out what type of neuropathy someone has
H and P-> use EMG-> look at clinical and physiological symptoms-> order bloodwork-> biopsy/generic testing (as needed)-> If not treatable go with supportive care. (i.e treatment of neuropathic pain)
