lecture 4c-spinal cord lesions Flashcards Preview

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Flashcards in lecture 4c-spinal cord lesions Deck (10)
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what is a myotome

the skeletal musculature innervated by motor axons in a given spinal root


what is a dermatone

the sensory component of each spinal nerve is distributed to a dermatome, a well defined segmental portion of the skin. conditions that affect the dorsal roots or dorsal root ganglia produce sensory alterations in the distribution of skin segments supplied by that


what happens when you have total destruction to the cord at a certain level?

pts eventually lose all somatic sensations below the level of the lesion, and they also lose all voluntary motor control below the level of the lesion
-don't lose involuntary


what accounts for the paralysis everywerhe below the level of the lesion

UMN-corticospinal tract
-spastic paralysis: lose voluntary motor activity below the lesion, you don't lose involuntary activity


what spinal shock

happens right after the injury, early on
-the spinal cord shuts down for a few days-weeks
-during this time, you lose all motor-voluntary AND involuntary, so no reflexes, no muscle tone, no voluntary strength.

-AFTER THIS acute phase of spinal shock do the segmental reflexes and muscle tone return


what happens above the level of the lesion?
at the level of the lesion?
below the level?


-motor: segmental LMN signs (ventral horns/verntral roots)-flaccid paralysis, fasciculations, atrophy, areflexia
-sensory: segmental loss of pain and temp (ventral white commissure) 1-2 lvls below

-motor: UMN signs (spastic paralysis, babinski, etc); paraplegia or tetraplegia
-sensory: no sensations


what happens if you have a C1-C4 injury
injuries above C7?
injuries sparing of C7?
thoracolumbar injuries?

-rarely survive w/o immediate ventilatory support
-dependent on others for care
-retain elbow and wrist extension allowing independent ability to transfer to wheelchair
-have arm strength but require wheelchair


what is brown-sequared syndrome aka hemicord syndrome or cord hemisection

lesion one half of the spinal cord at a certain level


what happens to the white matter sections in cord hemisectoin

dorsal column: loss of proprioception, 2 point tactile, pressure, and vibratory sense. ipsilateral loss and below the level of the lesion

lateral corticospinal tract: UMN signs, ip loss, below level of lesion

spinothalamic tract: loss of pain and temp. contralateral loss. starting 1-2 segments below lvl of lesion


what are the affects to the gray horn segments in a a hemisection

ventral horn gray: ipsi LMN signs. only at the level of the lesion (segmental loss)

dorsal horn gray: ipsi loss of pain and temp due ot damage to afferent fibers that have entered but not crossed. (no cell bodies for lissaurer's to synapse on so can't cross into ventral white comm)
-at segments located 1-2 lvls below (seg loss)