Studied by 0 peopleUpper Motor Neuron Tracts
Which part of the Motor System delivers signals to spinal interneurons and LMNs?
Lower Motor Neurons
Which part of the Motor system delivers signals directly to the skeletal muscles and elicits contraction of muscle fibers?
Top down ( Brain to Muscle)
Voluntary movements are controlled from _____ to _____ .
Axial and Proximal muscles
The Medial aspect of the anterior horn controls …
Distal Muscles
The Lateral aspect of the anterior horn controls…
Extensor Muscles
The Anterior aspect of the anterior horn controls…
Flexor Muscles
The Posterior aspect of the anterior horn controls…
ALS (amyotrophic lateral sclerosis)
Which disorder affects the upper motor neurons that arises from the cortex and brainstem as well as cranial/spinal lower motor neurons?
Lower Motor Neuron Disease
The following clinical findings are consistent with
weakness
flaccid paralysis of involved muscles
muscle atrophy
degeneration of muscle fibers over time
histological-reaction (degeneration 10-14 days of injury)
reflexes of the involved muscles are diminished/absent
No abnormal reflexes are obtainable
It is when the distal portion of the nerve and the mylin following a lesion is reabsorbed.
What is Wallerian Degeneration?
The time it takes to build enough ACH to send an AP
What is distal latency on an EMG?
Onset Latency and Peak Latency
What are the 2 ways that latency is measured (Sensory Nerve AP)?
The time measured from the stimulus to the initial deflection from baseline
What is Onset Latency?
The time measured from the stimulus to the peak of the spike
What is Peak Latency?
It will appear normal b/c you are still testing the healthy portion of the axon ( normal DL and CV)
If the conduction block is proximal to both simulation sites what do you expect to see in the CMAPs?
Barely any signal will go through due to the “break” in the pathway so DL will be increased and CMAP amplitude will decrease
If the conduction block is distal to both simulation sites what do you expect to see in the CMAPs?
The DL and distal CMAP will be normal but the proximal CMAP will show decreased amplitude
If the conduction block is between both simulation sites what do you expect to see in the CAMPs?
Slows down the time as well as possibly no recovery
Once the protective layer of the nerve (endoneurium and perineurium) is damaged how does it affect the level of recovery?
Decreased amplitude of both distal and proximal CMAP
When it comes to pure Axonal Loss, what would we see in the EMG?
Increased distal latency and slow conduction velocity
When it comes to pure Demyelination, what would we see in the EMG?
If the nerve is viable or not
What is one guiding factor we can determine looking at an EMG?
Stretch Injury, Lacerations, Compression and Repetitive stress injury
What are some of the major causes of (local)Peripheral Neuropathies?
Cancers, Infections, Inherited Neuropathies (Guillain-Barre), Diabetes (2), Kidney disorders (high levels of ammonia), Autoimmune diseases, Vascular disease, Vitamin Deficiencies and Alcoholism
What are some of the major causes of (systemic )Peripheral Neuropathies?
UMN injury
If you see signs of hyper-reflexive that usually correlates to UMN or LMN injury
LMN injury
If you see signs of hypo-reflexive that usually correlates to UMN or LMN injury
Note
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