Cabs Unit 5 Spinal Cord

Front 1

Where do the LMN originate?

Back 1

Ventral horn

Front 2

Where do the fibers of the snsory neurons enter?

Back 2

Posterior horn

Front 3

How does the amount of white/grey matter change as you progress down the spine?

Back 3

At the level of the cervical spine- more white matter than grey. At the level of the sacral spine, more grey matter than white. Less white matter as you descend and more grey matter as you descend.

Front 4

What are the 3 major clinical motor tracts within the spinal cord?

Back 4

1) Lateral corticospinal tract 2) Corticospinal tract (motor tract) aka pyramidal tract 3) Anterior corticospinal tract: posture of trunk muscles/girdle muscles

Front 5

What are the two sensory tracts?

Back 5

Dorsal columns: two parts: medial gracile fasciculus and cuneate fasciculus (laterally), and the anterolateral system consisting of the lateral spinothalamic tract

Front 6

What sensations does the gracile fasciculus carry?

Back 6

Sensation from lower than T6 level of the cord (LE)

Front 7

What sensation does the cuneate fasciculus carry?

Back 7

Carries sensation from the upper extremities

Front 8

What sensations does the dorsal column carry?

Back 8

Vibration, position/proprioception and discrimitive touch (2-pt discrimination)

Front 9

What sensation does the lateral spinothalamic tract carry?

Back 9

Pain and temperature

Front 10

What is the order somatotopically for the spinothalamic and lateral corticospinal tracts?

Back 10

Cervical (medial) to sacral (lateral)

Front 11

What is the order somatotopically for the dorsal column?

Back 11

Sacral (medial) to cervical (lateral)

Front 12

What is spinal shock?

Back 12

acute stage of spinal cord injury: lose all sensory and motor below the lesion, lose all reflexes and sphincter control below the lesion (external urethral and anal)

Front 13

What is the difference between complete or incomplete spinal lesion?

Back 13

complete lesion: no sacral sparing, incomplete: will have sacral sparing; with sacral sparing, there is sensory and some motor function left in that sacral innervation which is S2,3,4,5 dermatomes for sensation. The bullseye around the anus – if they have sensation intact here it is sacral sparing and an incomplete lesion

Front 14

How do you assess motor function for sacral sparing?

Back 14

Rectal sphincter tone-> reflex will trigger this…it is the anal wink. Performed by either touching with a sharp to this region and sphincter contracts or tug on their catheter (lightly)- bulbocavernosus reflex

Front 15

How do you know when spinal shock is over?

Back 15

The first thing that happens is the return of the bulbocavernosus reflex; you can use this to assess if spinal shock is finished. At that point, if reflex returns, it is an incomplete lesion with sacral sparing

Front 16

What happens at the pyramidal decussation

Back 16

85% of nerve fibers become the lateral corticospinal tract; largest motor tract

Front 17

Where does the cell body originate and exit for neurons of the corticospinal tract?

Back 17

Cell body originates in the anterior horn and exit out via the ventral root and join together to form the spinal nerve to innervate muscles

Front 18

Which spinal tract is specific for hand and finger movement?

Back 18

Rubrospinal tract

Front 19

What are the 3 orders of sensory neurons?

Back 19

Those that originate in the periphery and synapse in the cord, those that ascend the cord to the thalamus where they synapse and those that synapse from the thalamus to the cortex

Front 20

Where does the ascending dorsal column decussate?

Back 20

At the medulla; where they synapse- called the nucelus gracilius and the nucleus cuneatus within the medulla. They cross over and then ascend to the thalamus

Front 21

What is the dorsal column called after the synapse at the medulla?

Back 21

Medial lemniscus after the medulla to the thalamus

Front 22

What is the function of the dorsal column?

Back 22

Sensory: vibration, proprioception/position and 2-pt discrimination

Front 23

What is the function of the spinothalamic tract?

Back 23

Pain and temperature

Front 24

Where does the spinothalamic tract decussate?

Back 24

Decussates within the spinal cord iteslf! It crosses either immediately or within 3 segments of the cord (does not decussate again within the medulla)

Front 25

If you have a lesion to the rt half of the spinal cord- how is sensation affected?

Back 25

Ipsilateral position/vibration sense; contralateral loss of pain and temperature

Front 26

What is the hallmark of a spinal cord lesion?

Back 26

Sensory band/tightness; loss of sensation in a "band" like distribution

Front 27

What is the difference between a deficit in the brain stem vs spinal cord in relation to motor/sensation?

Back 27

Brainstem: contralateral EVERYTHING!- pain/temp/proprioception/vibration/motor vs the Spinal Cord: contralateral pain/temp/motor and IPSILATERAL loss of fine touch, proprioception and vibration

Front 28

What are the symptoms of spinal shock?

Back 28

Flaccid paralysis, hyporeflexia, loss of sensation and motor (below level of lesion), DTR gone, superficial reflexes gone and autonomic reflexes (like bulbocavernosus and anal wink)- gone; loss of bowel/bladder- but not incontinence, but rather urinary retention!

Front 29

What happens if there is a spinal cord lesion above the level of T6?

Back 29

Can decrease sympathetic outflow --> produces a subtype of spinal shock known as neurogenic shock

Front 30

What are the characteristics of neurogenic shock?

Back 30

Characterized by hypotension, bradycardia and hypothermia

Front 31

What is the pathophysiology for neurogenic shock?

Back 31

with shock, typically response is to elevate pulse rate, but in this case there is an elimination of sympathetic outflow so instead of tachycardia, get BRADYCARDIA.

Front 32

How do you differentiate between neurogenic and hemorrhagic shock?

Back 32

Hemorrhagic: tachycardia; Neurogenic: Bradycardia

Front 33

When is neurogenic shock most common?

Back 33

With injury above T6

Front 34

What is subacute combined degeneration?

Back 34

A subtype of dorsal column lesion- caused from a vitamin B12 deficiency; symptoms more noticable at night; degeneration of the dorsal and lateral columns (lateral corticospinal tract); present with: loss of proprioception, vibration, 2-pt discrimination, atxia, muscle weakness, hyperactive DTR, spastic extremities, +Babinskis

Front 35

Symptoms of C3 level lesion:

Back 35

Total tetriplegia; requires respirator - cannot move diaphragm

Front 36

Symptoms of C4 level lesion:

Back 36

Shrug shoulders only; weak respirations; can live w/o respirator

Front 37

Symptoms of C5 level lesion:

Back 37

Move shoulder (deltoid is C5/C6); Flex elbow (C5/C6) weakly, can be independing with feeding, oral and facial hygeine

Front 38

Symptoms of C6 level lesion:

Back 38

Wrist extension (C5,6,7,8) weakly; able to grasp dress upper body and move wheelchair independently

Front 39

Symptoms of C7 level lesion:

Back 39

Elbow extension and weak hand grip; may be able to perform ADLs, transferes, bowel and bladder care, manual wheelchair

Front 40

Symptoms of C8 level lesion:

Back 40

Long finger flexors intact; intrinsic hand muscles weak; claw hand

Front 41

Symptoms of T1 level lesion

Back 41

Paraplegia, UE full intact; Independent w/ transfers, mobility and ADLs

Front 42

Where is the micturation control center?

Back 42

Frontal lobe

Front 43

What is the function of micturition control center?

Back 43

Becomes dominant at age 3. Sends inhibitory signal to the pontine micturition to inhibit voiding. When you get urge to go, this allows you to hold it; why some people with lesions in the frontal lobe may develop urge incontinence- known as detrussor hyperreflexia.

Front 44

What is the function of the pontine micturition enter?

Back 44

Coordinates urethral sphincter relaxation and detrussor muscle contraction; This is the SWITCH that turns things on and off

Front 45

What is the function of the sacral reflex center?

Back 45

Primitive voiding center triggers detrussor contraction; more typical of young infants when the pontine center is not fully developed; receives afferent signal from the wall of the bladder expanding; triggers reflexive contraction of the detrussor muscle

Front 46

How do sympathetic nerves assist with urination?

Back 46

Provide sympathetic, parasympathetic and pudenal nerve innervation; Sympathetic- from the lumbosacral splanchnic nerves; affects: relax detrussor and contract the internal urethral sphincter; bladder filling...Parasympathetic- bladder emptying- contraction of detrussor and relaxation of internal urethral sphincter; pelvic splanchnic nerves. Sympathetic: fight or flight and hold your pee in; Parasympathetic: rest and digest and pee.. Pudendal: External urethral sphincter contraction and relaxation

Front 47

What is neurogenic bladder?

Back 47

Any neurological dysfunction of bladder function - such as from the micturition control center, pontine control center, sacral reflex center or peripheral nerves (ANYWHERE along the chain!)

Front 48

What is detrussor hyperreflexia and where does it occur?

Back 48

Loss of voiding control; primitive voiding reflexes are intact; urge incontinence; Occurs in the: suprapontine UMN disorders such as CVA, brain tumor or parkinson's disease

Front 49

What is detrussor sphincter dyssynergia?

Back 49

Incoordination between the detrussor and the sphincter; acute: flacid bladder with urinary retention or chronic: hyperreflexic spastic bladder with urge incontinence; Both the detrussor and internal sphinter are contracting at the same time; Occurs: UMN lesion of the suprasacral spinal cord, but includes the pons; secondary to MS, MVA, diving accidents

Front 50

What is detrussor areflexia?

Back 50

Overflow incontinence; ureinary retention from inability of the bladder to empty; Cause: LMN lesion - no signal for contraction, just fills and fills! Seen with sacral cord tumors, herniated discs, pelvic crush, DIABETES, tabes dorsalis, polio and pernicious anemia

Front 51

What artery is of concern with a AAA surgery? (besides the obvious aorta)

Back 51

Artery of adamkowitz- results in paralysis as a complication