Lecture 2-neuropathies/ALS Flashcards
Nerve causing foot drop
Perineal nerve
Nerve causing weakness of hand muscles
Ulnar nerve
Nerve causing wrist drop
Radial nerve
Mononeuropathy multiplex examples
DM(combo of individual nerves usu in stocking glove distribution) and thoracic neuropathy(ex of brachial plexus)
Poly neuropathic commonly seen in what nerve distribution?
Distal nerve distributions
Damage to the axons but NO nerve damage
Neuropraxia (ex: Saturday night palsy)
Causes of mechanical pathology
Direct trauma, neuropraxia, or entrapment
Ischemia of nerves
Vascular neuropathies
Examples of vascular neuropathies
DM, poly arthritis nodosa, and RA
Vascular neuropathies will be in ____(multiple or single) nerve distributions
Multiple
Most common atonal polyneuropathy
DM
Both motor and sensory deficits but SENSORY dominates
Axonal polyneuropathies
Diabetic polyneuropathy
- symmetric distal sensory loss in feet
- loss of thermal and vibratory sense first
- may complain of pain
- may see mononeuropathy a/w DM
Most common mononeuropathy a/w diabetes
3rd nerve palsy
Neuronal polyneuropathy
- ABSENCE of sensory involvement (Looks like pure motor)
- involves proximal and distal muscles
- fasciculations
Most common neuronal polyneuropathy
Amyotrophic lateral sclerosis (ALS)
Acute demyelination polyneuropathy
GBS
Chronic demyelinating polyneuropathy
Charcot-Marie-tooth
What will you see in CSF with all demyelinating polyneuropathies
Elevated protein in CSF
Most common mono neuropathy
Median nerve causing carpal tunnel syndrome
Guillian-barre pathology starts with
pins and needles in feet progression to weakness in legs and moves proximally; DTRs lost early in lower extremities
Guillian-barre can happen after infection 60% of the time with these etiologic agents
URI, campylobacter, mono, CMV, herpes
demyelinating disease seen in 2nd and 4th decade
charcot-marie-tooth (inherited)
see slowly evolving footdrop, on exam shows distal wasting of intrinsic muscles of feet; may have hx of ankle sprains
Charcot marie tooth
acute
onset in a few days; think trauma with compression
subacute
onset within 2-4wks
chronic
onset >1 month prior; think DM
most causes of peripheral neuropathy affect
BOTH MOTOR AND SENSORY
Motor symptoms
weakness, fatigue, cramps, muscle twitches
Sensory symptoms
numbness, pain (sharp, burning, stabbing, shooting), alteration in sensation, loss of coordination (sensory ataxia)
most UNCOMMON complaint in sensory symptoms
sensory ataxia
Motor signs we observe
weakness (usually focal; classify strength/compare sides), fatigue (myasthenia), cramps (must work muscles to see), fasciculations (easier to see in thin pts and more prominent in gastrocnemius)
Sensory signs we observe
sensory loss (loss of sharp/dull, light touch), sensory ataxia (may look cerebellar), hyporeflexia (loss of sensory feedback from muscles)
In polyneuropathies the deficit of sensory lost is seen in
distal areas (stocking glove)
Myopathy definition
inflammation or degeneration of skeletal muscles
Differences of myopathy and neuropathy:
myopathy has PROXIMAL motor weakness
neuropathies have DISTAL motor weakness if ANY sensory loss and or loss of reflexes think NEUROPATHY
Motor neuron disease findings
typically produce symptoms of upper and or lower motor neuron dysfunction WITHOUT sensory symptoms
B-12 Deficiency findings
symmetrical distal sensory involvement and symmetrical proximal motor involvement
two CLASSIC studies for neuropathies
EMG and nerve conduction studies
findings of slowing of nerve conduction velocity suggest
DEMYELINATING neuropathy (GB, CMT)
findings of denervation changes on EMG
AXONAL neuropathy
findings of segment of one nerve
MONONEUROPATHY
findings of slowing of nerve conduction velocity on multiple nerves
POLYNEUROPATHY
Nerve biopsy indication
if you think inflammatory
Muscle biopsy indication
if you think myopathy
Imaging indication
if you think TUMOR
DM Tx
control glucose; maybe try TCAs for neuropathic pain
Guillian-Barre Tx
supportive care, steroids DONT help
Carpul tunnel tx
cock-up splint or surgery
ALS tx
anticonvulsants for fasciculations
B-12 Tx
replace B-12 (duh)
Non-pharmacologic tx
PT, TENS, Magnets, relaxation techniques
idiopathic disease affecting both upper and lower motor neurons with NO ALTERATION in sensation
ALS
ALS accounts for what % of acquires motor neuron disease
80%
ALS weakness usually starts where
hands and arms and goes to legs later
commonly seen with ALS
muscle twitching and cramps
Signs and symptoms of ALS
PAINLESS progressive weakness of intrinsic muscles of the hand, may even see wasting of the msucles
Hallmark of ALS
presence of both upper and lower motor neuron signs in the same limb (spastic tone, hyperreflexia, fasciculations, wasting)
tongue fasciculations with limb weakness and upper motor neuron signs highly suggest:
ALS
How is ALS diagnosed?
clinically!!!; NCS normal, EMG shows widespread involvement of proximal and distal muscles, imaging is normal
ALS prognosis
mean duration of time between symptoms and death is 27-43months
