NMS
5/20/99

Pyramidal
•	pre-central gyrus of frontal lobe—motor cortex
•	goes down
•	decussates in medulla
•	to anterior horn to MN

Extrapyramidal
•	modulate the MN so it doesn't go crazy
•	goes to anterior horn

MN
•	goes through IVF
•	joins to form a mixed nerve
•	goes to a plexus
•	goes through a peripheral nerve
•	to a skeletal muscle
•	releases Ach causing muscle contraction

Golgi tendon organs
•	peripheral modulators
•	tension perception
•	send messages to the cord
•	inhibit contraction when there is too much tension

Disease in one or more of these pathways
•	spastic muscles around a joint rigid—extrapyramidal lesion—Parkinson's Disease
•	people are not paralyzed
•	most UMN lesions will not out both extra and pyramidal pathways—spastic and paralyzed
•	spastic paralysis, hyperreflexia
•	LMN lesion
•	cell body
•	nerve root
•	plexus
•	peripheral nerve
•	myoneuronal junction
•	are paralyzed b/c can't reach muscle
•	decreased tone
•	decreased reflexes
•	decreased strength

EMG
1.	Dx motor unit disease—what is a motor unit?
•	MNaxonmuscle cell (muscle fiber) (multinucleated)myofibrilsZ linessacromerefilaments of actin and myosinmyofibril junction w/nerve endingAchCalcium is released by sarcoplasmic reticulumaction potential
•	create only one action potential from on cell body no matter how many muscle cells it goes to 
•	MUAP—motor unit action potential
•	tall amplitude for a larger motor unit
•	results
•	neuropathy—loss innervation—can't contract, reacts to free floating Ach and contract—MS, carpal tunnel, myasthenia gravis—slightly—fibrillation—microscopic level or subclinical level
•	can't move the joint
•	can be felt
•	decentralization—Wallarian degeneration has occurred could come from pressure
•	fasciculations—can move the joint—can occur to overuse or fatigue
•	recruit—healthy nerves recruit the muscle fibers that do not have innervation
•	motor units are decreasing in number but increase in size
•	fibrillations at rest—nerve damage has occurred—also inflammatory muscle disease (myopathy)—muscular dystrophy
•	problem at the IVF (spur)—the myotome would help Dx
•	if nerve root—myotome of anterior primary ramus and myotome of posterior primary ramus
•	nonsegmental EMG abnormalities
•	NCU—nerve conduction
•	latency—slowing decrease of conduction—shows there's some type of neuropathy
•	double crush—ganglion-neuropathy—cervical adjust that helps w/ carpal tunnel
•	PND—persistent neurologic deficit
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