Abnormalities of CNS (exam 4)

damaged upper motor component of motor nervous system (injury or disease)

results in increased muscle tone in the limbs
-causes varying degrees of muscle spasticity

person experiences exaggerated spinal reflexes

individual will have a positive Babinski

damage to lower motor component of motor nervous system
(injury or disease)

no voluntary or reflex contraction of the muscles innervated

therefore loss of muscle tone and eventual atrophy

result of untreated syphilis-> Treponema pallidum (bacteria responsible)

chronic and progressice degeneration of posterior funiculi (columns) and dorsal roots of spinal nerves and dorsal root ganglia

have motor funtion but lose sensory input (proprioception) which is critical for coordinated voluntary muscle activity

therefore results in poor muscle coordination and muscle weakness including poor balance and posture.

viral caused

damages neurons in the anterior gray horn and motor nuclei of cranial nerves

results in motor paralysis with no sensory dysfunction

caused by patchy demyelination in many areas of CNS-> produces plaques associated with:
a. disappearance of oligodendrocytes and
b. proliferation of astrocytes

may be cyclic (symptoms, recovery, symptoms, recovery, etc)

some nerve fibers recover- with no permanent damage-> but damage is progressice with each recurring cycle

both motor and sensory dysfunction occur

this is one of the most common disorders of the CNS

more common in elderly

caused by diffuse inflammation of CNS accompanied by lack of dopamine

associated with degeneration of basal nuclei

results in rigidity and tremors-> especially extremities and face
--rigidity causes a mask-like face