Phys Neuro Testing Flashcards
Describe Mononeuropathy: Neuropraxia
Give example of diagnosis:
- Pressure, compression w/o Wallerian degeneration
- Carpal Tunnel
Acute NCV studies Mononeuropathy: Neuropraxia =
Prolonged =
Acute = Increase latency/decrease CV distally Chronic = Decrease amplitude of SNAP/CMAP
EMG Acute Mononeuropathy: Neuropraxia =
Prolonged =
Acute = Usually normal Chronic = signs of denervation
Describe Mononeuropathy: Axonotmesis
-Demyelination/axonal damage
+Wallerian Degeneration
NCV Mononeuropathy: Axonotmesis
Incomplete =
Complete =
Incomplete = Decrease amplitude SNAP/CMAP, increase distal segment latency Complete = Absence of CMAP/SNAP
EMG Mononeuropathy: Axonotmesis
- Prolonged insertional activity
- Fibrillation/+Sharp waves
- Polyphasic, initial reduced recruitment
Describe Mononeuropathy: Neurotmesis
-Complete disruption
NCV Mononeuropathy: Neurotmesis
Incomplete =
Complete =
Incomplete = Decrease amplitude SNAP/CMAP, increase distal segment latency Complete = Absence of CMAP/SNAP
EMG Mononeuropathy: Neurotmesis
- Prolonged insertional activity
- Abnormal activity at rest
- Fibrillations, sharp waves, fasciculations
- Polyphasic
- No voluntary activity
Polyneuropathy -
Diagnoses -
- Diabetes neuropathy (axonal damage)
1. Small nerve fibers
2. Sensory fibers
Polyneuropathy NCV
Decrease amplitude = decrease integrity
Polyneuropathy EMG
- Small nerve fibers 1st and EMG test big fibers
- Sensory 1st so won’t change EMG
Late stages:
-Fibrillations, + sharp waves LE>UE
-Increase amplitude and duration
Demyelination - Hereditary
Diagnosis -
-Charcot-Marie-tooth = muscles weakness (muscle and sensory)
Demyelination - Hereditary NCV
Increase latency and decrease CV
Demyelination - Hereditary EMG
Chronic
Acute- not helpful
Chronic - +fibrillations, +sharp waves
-Increase amplitude and duration
Demyelination - Acquired
Diagnosis
-Guillain-Barre = focal demylenation
Demyelination - Acquired
NCV:
Before and after conduction block
- Before conduction block - increase latency and decrease CV, decrease amplitude
- After conduction block no changes
Demyelination - Acquired
EMG
Not helpful acute stages
NMJ Disorders
Diagnosis -
Myasthenia Gravis = decrease AcH receptors ->decrease contractility with use
NMJ Disorders
NCV -
- Normal
- Use repetitive neuron stimulation = decrease amplitude over time
NMJ Disorders
EMG
Acute/chronic
-Acute - can be normal because small contractions = no change
-Chronic - Decrease MUAP amplitude/duration
Polyphasic
Myopathy
Diagnosis -
Muscular distrophy = decrease muscle mass
Myopathy: Muscular distrophy
NCV
NCV - usually normal
Myopathy: Muscular distrophy
EMG
Fibrillation, +sharp waves
Decrease amplitude
Decrease duration
Polyphasic
