Lecture 4: Spinal cord injury (minus first 12 slides)

Question 1

Pathogensis of SCI:

Blood flow changes
* Ischemia releated to reduced blood flow, damage to blood vessels and microhemorrages, hypoxia

Inflamamtion:
* Positive and negative effects

Demyelination
* Reduced rate of axonal firing, maturation of a scar around the lesion (positive and negative effects) - if a scar forms and becomes rigid, mobility can suffer around that area (can also be protective and sealing)

Grey Matter
* Loss, fluid-filled cyst (syrinx) forms or cord collapses

Dural scarring
* Causes permanent connection of cord to dura, no longer freely mobile

Neural function
* Impacted below injury level
* If its at C6 they’ll have C6 abilities

Neuropraxia
* Athletic injury, PNS nerve damage

Syringomyelia
* Can appear over time, cyst activation and gliosis of SC, syrinx forms, cyst cavity
* can cause pressure in areas we dont want

Question 2

Fluid filled aera
* can cause area of pain and numbness and tingling

Answer 2

Question 3

Think bruising of SC
* can lead to cell death
* Sensory/motor problems
* necrossis / hemorrhage

Question 4

Syringomyelia

Answer 4

Neurologic disorder in which a fluid filled cyst (syrinx) forms within the SC

Question 5

What does dural scaring do to the SC?

Answer 5

Makes it less mobile

Question 6

Spinal cord is impacted will they be okay at the level of the lesion

Answer 6

Yes, if C6 is impacted you will be okay at the level of C6, its just everything below that thats the issue

Question 7

Neuropraxia

Answer 7

Neuropraxia is a type of nerve injury characterized by a temporary loss of function in a nerve due to compression or stretching. This condition often results in symptoms like weakness, numbness, or tingling in the affected area. Neuropraxia typically involves no structural damage to the nerve itself, and recovery usually occurs within a few hours to weeks, depending on the severity and cause of the injury.

Question 8

Trauma happens
* Arteries / veins are affected (blood supply)
* Cells are affected
* Impared breathing
* Vasodilation impared inotropy

All the leads to ischemia

Question 9

Notice what happens to the vertebral artery when vertebrae are affected.
* so everything below this area will be affected

Question 10

What makes the cord less mobile?

Answer 10

Dural scaring

Question 11

SCI’s are classified according to if the are complete or incomplete.

SCI’s are classified by the neurologic level of injury
* Named by most caudal level with normal sensory and motor function bilatearlly

Question 12

SCI injury that has lack of sensory and motor function in the lowest sacral segment

Answer 12

Complete injury

Question 13

SCI that has preservation of sensory and/or motor function in the lowest sacral segment

Answer 13

Incomplete injury

Question 14

How are SCI’s names?

Answer 14

Named by most caudal level with normal sensory and motor function bilatearlly

Question 15

What are the two ways SCI’s are classified

Answer 15

1) Compleite or incomplete
2) Neurologic lvl of injury

Question 16

Neurologic Level of Injury - NLI
* SCI named for neurologic level of injury - NLI
* American spinal injury association distributes and maintains the international standards of neurlogical classification of SCI

Identifies sensory and motor levels indiciative of the most rostrual spinal levels demonstrating unimpared function
* Rostral levels are unimpared (toward the head)
* Named by most caudal level bilatearlly that is unimpared

28 dermatomes are assessed bulatearlly using pinprick and light touch sensation, and 10 key muscles are assessed bulatearlly w/ MMT
* Results are summed to produce overall sensory and motor scores and are used in combination w/ evaluationof anal sensory and motor function as a basis for the deternubatuib if AIS ckassufucatuib

So you’re naming it based on the most caudal thats unimpaired bilatearlly, but testing the ones above to make sure they’re uninpaired

Question 17

NLI extended

A clinical examination is conducted to rate sensation as follows
* 0 = absent
* 1 = impaired
* 2 = normal

Muscle function is rated from 0 (total paralysis) to 5 (normal-active movement, full ROM against significant resistance)

The presence of anal sensation and voluntary anal contraction area ssessed as Y/N
* So thats either yes or no because they either can or cannot do it

Bilatearl motor and sensory levels and the AIS are based on the results of these examinations

AIS (5 pound ordinal scale) classifies individuals from A (complete SCI) to E (normal sensory and motor function)
* NOTE: these are reserved for people that have had a SCI wouldnt rate eachother

Preservation of function in the sacral segments (S4-S5) is key for determining the AIS score

Question 18

Knowledge check: No sensory function under level os SCI =

Answer 18

complete

Question 19

Complete loss of sensory and motor function below the level of the lesion

Answer 19

Complete

Complete lesions are a result of spinal cord transection, severe compression or continusion, or extensive vascular dysfunction

Question 19

Partial loss of sensory and mot function below the level of the injury
* The resulting motor or sensory function is called

Answer 19

Incomplete

Incomplete lesions often occur when there is a contusion produced by bone framents, soft tissue, or edema within the spinal canal

The resulting motor or sensory function is also called sparing
* Know that sparing is associated w/ incomplete lesions

Question 20

ASIA SCALE

A = complete
B = Sensory incomplete (you have sensory but no motor below the NLI (neurologic level of injury)
C = Motor incomplete
* Less than half of key muscles below the level of NLI have a muscle grade >/3
D = Motor incomplete
* More than half of key muscles below the level of NLI have a muclge grade >/3
E = Normal - but they had to have prior deficits

So E is the best w/ A being the worst

ASIA (AIS) scale

Question 21

ASIA Scale

The circled muscles are the 10 key muscles for testing motor function

ASIA SCALE

Answer 21

Asia Scale sensory testing

The dots on the person are where you’re going to be sensory testing

We have a C6 sensory and motor because that is the last spot on our scale where the person got a 5 bilatearlly
* and the last time they got normal sensory as well
* C6 is the last time they got a 2 for sensory bilatearlly and a 5 for motor bilatearlly

2 = max for sensory

This is an incomplete injury

Question 22

Half of the key muscles are 3/5 or greater

Answer 22

D

Question 23

Collection of signs and symptoms that do not indicate a specific cause, resulting from tumors or truma

Answer 23

Syndromes

Question 24

Which syndrome

Answer 24

Anterior cord syndrome

Question 25

Which syndrome

Answer 25

Central cord syndrome

Question 26

Which syndrome?

Answer 26

Brown sequard syndrome

Question 27

Which syndrome?

Answer 27

Cauda equina syndrome

Question 28

Make sure you at least know the 3 main tracts

Question 29

Anterior cord syndrome * What kind of injuries (flxn or extension)? * Interfers w/ what 3 things? * What is it typically caused by * This ischemia damages which portion of the cord. * Are problems at, below, or above the level of the lesion * Is it bilatearl or unilatearl? * Why is conscious proprioception and light touch information spared?

Answer 29

**Flexion injuries** **Interferes w/ pain and temperature sensation and motor control** Typically caused by a disruption of blood flow in the anterior spinal artery Ischemia damages the anterior 2/3 of the spinal cord (because thats what the anterior spinal artery supplies) * affects the ascending spinothalamic tract and descending upper motor neurons * Will also damage somas of lower motor neurons Anterior cord syndrome interfers with nociceptive (pain) temperature sensation and with motor control **below the level of the lesion** - bilateraly (because the artery supplies the entire front of the cord) NOTE: Because tracts that convey conscious proprioception and light touh information are located in the posterior cord, these functions are spared (DCML)

Question 30

Central Cord Syndrome * what kind of injuries (flxn or extension) * At what level do they typically result, as a cause of what * In small lesionswhat do you lose and why * In larger lesions what do you lose * Is it more sevre in UE or LE?

Answer 30

Hyperextension injuries Usually occurs at the cervical level as a result of trauma **if the lesion is small, loss of nociceptive (pain) and temperature information occurs at the level of the lesion because spinothalamic fibers crossing the midline are interrupted** Larger lesions additionally impair upper limb motor function due to the medial location of upper limb fibers in the latearl corticospinal tracts - at/below level of lesion in UE * More severe in UE than LE, variable degree of impairement in trunk/LE's due to integrity of SC She said to know: small lesion = problems at level of lesion, large lesion = upper body all together is impared * Its going to be more severe impairement in upper body, but you're going to see some degree of problems in LE as well

Question 31

Brown Sequard Syndrome * Disruption of what part of cord? * Segmental losses are ipsilatearl or contralataeral? * Below the level of sensation what is lost ipsilatearlly * Below level of lesion what is lost contralaterally

Answer 31

Disruption to hemisection of the cord Results from a hemisection of the cord Segmental (spinal segment) losses are ipsilateral and include loss of lower motor enurons and all sensations **Below th elevel of the lesion, voluntary motor contorl (corticospinal), conscious proprioceptions, and light touch (DCML) are lost ipsilatearlly; nociceptive (pain) and temperature (spinothalamic) sensation is lost contralaterally**

Question 32

Cauda Equina Syndrome - also called medullaris syndrome * what muscles are affected * Why does spasticity and hyperreflexia occur? * Are they common?

Answer 32

Indicates damage to the lumbar and/or sacral spinal roots, causing **sensory impairment and flaccid paresis or paralysis of lower limb msucles, bladder and bowl** Spasticity and hyperreflexia do not occur because cauda equina lesions are below the spinal cord proper and thus upper motor neurons are intact Complete cauda equina lesions are rare

Question 33

This syndrome causes low back and lower limb pain and difficulty walking, execessive lordosos, scoliosis, problems with bowel and/or bladder contorl and foot deformities * What can it be associated w/?

Answer 33

Tethered cord syndrome Associated w/ spina bifida

Question 34

KNOW: A good way to dilinate tethered cord from cauda equina is that tethered cord is onset as a child, that cord is thetehred to vertebral column area = low back pain, difficulty walking etc * **During development the vertebral column grows longer than the SC** * Infrequiently the SC becomes attached to surrounding structures during early development when its still growing down * This tethering of the SC becomes stretched which damages the cord and the cauda equina Lower motor signs (weakness, flaccidity) occur if the anterior cauda equina (because its the spinal nerves which are lower motor neurons?) is stretched. Upper motor neuron signs (abnormal reflex, paresis and changes in skeletal muscles) occur if the SC is excessively stretched

Question 35

Posterior cord syndrome * Common or rare? * There is loss of what that leads to what? * Which tract is affected?

Answer 35

Rare Preservation of motr function, pain. There is loss of light touch and proprioception below the level of the lesion leading to severe gait deviations? DCML affected (this is light touch, proprioception, and vibration)

Question 36

Look at the right side of this picture

Question 37

Knowledge check: Which syndrome has bilateral loss of pain, temp and motor control loss below the level of the lesion

Answer 37

Anterior cord syndrome (remember often caused by flexion injuries)

Question 38

Immediately after traumatic injury to SC, cord functions below the lesion are depressed or lost

Answer 38

Spinal shock Due to the interruption of descending tracts that supply tonic faciliation to the spinal cord neurons

Question 39

During spinal shock these are impaired - note this happens right after the injury to the cord - everythign becomes flacid and no more * Somatic reflex, including stretch reflexes, withdrawl reflexes and crossed extension reflexes * Autonomic reflexes, including smooth muscle tone and reflexive emptying of the bladder and bowel * Autonomic regulation of BP, resulting in hypotension * Control of sweating and piloerection is lost

Question 40

During Spinal shock what happens to arterial BP? * This indicates that the output of the sympathetic NS is _

Answer 40

Arterial BP drops significaintly Sympathetic NS comlpetely interrupted

Question 41

During Spinal shock what are skeletal muscle reflexes like? How many months may it take to regain normal relexive activity after spinal shock?

Answer 41

Non functional Takes several months to return to normal

Question 42

In spinal shock if the transection is incomplete and some of the descending pathways remain intact what happens to some reflexes?

Answer 42

They may become hyperactive

Question 43

KNOW: For spinal shock sacral autonomic reflexes that regulate bladder and bowel function may be suppressed for several weeks

Question 44

NOTE: In an upper motor neuron injury like SCI hypertonicity is normally present. However, in spinal shock (which is right after the injury) is the opposite. Its flacid. Later on they may get some of hypertonicity

Question 45

NOTE: if its an incomplete spinal cord injury that causes that shock they will initially be completely flacid then that hypertonicity will return below that level of the lesion. However, if its a complete dissecution of the SC than there will not be any tone that returns below the lvl of the lesion

Question 46

Changes that we see post SCI

Question 47

**Lesion above _ result in paralysis of the diaphram and generally necessitate artifical ventilation because of loss of phrenic nerve innervation**

Answer 47

C4 Just take C3,C4,C5 and go to the middle

Question 48

Pulmonary complications with lesions at C5 through T12 arise as a result of loss of innervation to these two muscles

Answer 48

Abdominal Intercostal muscles Because these both help w/ expiration/inspiration

Question 49

Progressive paralytic scoliosis in a chronic SC patient. Happens due to lack of muscle tone and contorl following a SCI. Through being sedintary / sitting the SC goes into some curves they shouldnt go into * This can impaire respiration if its severe (notice the 110 cobb angle)

Question 50

**Knowledge check: Lesion above which neurlogic level of injury will paralize the diaphragm?**

Answer 50

C4 obvisouly a C3 would do this as well and anything above it

Question 51

Issue that is characterized by an overactive autonomic NS response due to stimuli below the level of injury * Happens particullary with injrues at or above the _ level * What percent of patients exerpience this when they have a lesion at or above the level above?

Answer 51

Autonomic dysreflexia At or above T6 90% pts

Question 52

What happens to the sympathetic NS in autonomic dysreflexia? Increases the risk of _ What happens to BP What do you see above the neurologic level of injury? What happens below it? **What will patient report when this happens?** What happens to vision? Are they coherent?

Answer 52

Uncrolled sympthatic response * Increased risk of stroke * Elevated BP * Flushing and sweating above neurologic level of injury, pallor below * **Report a severe HA** * Blurring of loss of vision * Incoherent (could be) - there will at least be a change or an episode of something happening

Question 53

**A person has an episode of autonomic dysreflexia. What is it most likely releated to?**

Answer 53

Always releated to some noxious stimulus below the neurlogic level of injury However, 85% is urological * think catheter backing up * NOTE: We actaully lose the sense of the need to void w/ this kind of SCI, so thats why it backs up This puts them at an increased risk of stroke so ints dangerous (because BP gets so high)

Question 54

How much does autonomic dysreflexia increase BP?

Answer 54

Increased systolic BP by 40 mmHg or above baseline (>150 mmHg)

Question 55

Can autonomic dysrelfexia while current spinal shock is happening?

Answer 55

Will happen after spinal shock has disapated can begin any time within the first year

Question 56

KNOW: In autonomic dysreflexia some noxious stimuli (think urinary) triggerys sympathetic reflex to the intermediolatearl grey columns Lack of compensatory descending medullary parasympathetic response (vagal nerve) generalized vasoconstriction * Parasympathetic response occurs above the NLI (bradycardia and vasodilation) * Sympathetic response continues below NLI So they're essentially getting both a sympathetic and parasympathetic response going on at the same time

Question 57

4 steps of what to do w/ a pt with autonomic dysreflexia?

Answer 57

1) Sit the pt up 2) Remove restrictive clothing 3) Find the trigger (think urinary catehter back up - however, even tight clothing can cause it) 4) If it doesnt clear than cause 911

Question 58

**What is the center for urination in the spine?** * What level is it?

Answer 58

Conus medullaris * Upper vertebrae (L1/L2)

Question 59

Primary reflex of bowl, bladder, and sexual stuff originates from what area of the spine?

Answer 59

Originiates in the sacral segment

Question 60

What happens to the bladder in spinal shock?

Answer 60

Becomes flacid, with absence of musle tone and bladder reflexes (makes sense, you've got nothing spinal shock)

Question 61

Lesions above the conus medullaris (spinal center for urination) will cause reflexive neurogenic bladder demonstrated by _ (what happens?) * What does this lead to in regaurds to voiding

Answer 61

Leads to spasticity of the bladder (makes sense, conus medularis is part of the spine so an injury here can lead to that spasticity) Leads to voiding difficulities (cant really fill correct) Detrusor muscle hypertrophy and urethral reflux NOTE: UTI's are common

Question 62

What does the conus medullaris turn into?

Answer 62

Caudea equina * While the conus medullaris is considered upper motor neuron, the caudea equina are spinal nerves are considered lower motor neurons NOTE: Spastic bladder is different than a flacid one. A spastic bladder makes you hold in urine and unable to void (due to that UMN lesion = spasticity). However, if its in those LMN they'll release the bladder and can't hold it in because its flacid)

Question 63

NOTE: sexual response is directly releated to the level and completeness of injury Sexual function relies on pathways similar to those of the bladder and bowel

Question 64

When talking about sexual function men with higher level lesion can often do what?

Answer 64

Achieve erection (this that spasticity) but they cannot ejaculate

Question 65

What happens to erection and ejaculation w/ caudea equina lesion?

Answer 65

Not usually possibile * This is considered LMN so they dont get that spastistic boner (only flacidity)

Question 66

How long are menses typically interupted following a SCI? What happens to fertility and pregnancy?

Answer 66

3-6 months Not interupted

Question 67

Knowledge check: What is the first step in managing autonomic dysreflexia?

Answer 67

Sitting the pt up * were trying to change BP response

Question 68

KNOW: Prognosis for SCI depends on the level of injury, muscle strength, and ASIA at the initial injury. remember ASIA scale can change over time, but the inital is what were looking at here

Question 69

Who recovers better from SCI young or old?

Answer 69

Young

Question 70

During what timeframe does most motor recovery occur following a SCI?

Answer 70

6 months The muscles graded 1 to 3 in the zone of partial preservation have potential for recovery of motor function; **however, less than 50% of the most cephalad muscle grade 0/5 at initial testing regained strength at 1 year** NOTE: more than one half of the SCI population will have return of some neurlogic function

Question 71

**When do neurlogic recovery happen the most following a stroke 3 months** quiz

Question 72

**What kind of fx have the most favoriable prognosis for return to function in SCI?** * What about the worst?

Answer 72

Compression = best Crush (think burst) = worst Preservation of axonal integrity and regrowth of neural tissue are anticipated to have a significant effect on the recovery and mobility after SCI * So if these happen you'll get better

Question 73

**Individuals who score _ or better on the ASIA scale ahve higher life expectancies compared with idnividuals with ASIA scores of _** - quiz question here

Answer 73

If you score D or better than you have a higher life expectancy than those of A, B, C. Just know things like "A complete A has a worse life expectancy than an incomplete D". Or a cervical injury is going to have a worse prognosis than lumbar (might need a ventilator)

Question 74

Who lives longer those w/ paraplegic injuries or those w/ low cervical and higher cervical level injuries in SC?

Answer 74

Paraplegic (meaning lumbar/thoracic levels)

Question 75

What kind of SCI pts have the lowest life expectancy?

Answer 75

**Those who depend on ventilators**

Question 76

NOTE: Long term urinary tract infections continues to be a large cause of death in SCI pts, but cnontrol of sepsis has improved Another common cause of death is respiratory diseasem specifically atelectasis and penumonia

Question 77

**What is the leading cause of death among SCI w/ high cervical injury?**

Answer 77

Remember, C4 is what innervates the diaphragm. So its Pneumonia because they can't properly clear the lungs

Question 78

**Knowledge check: Which pt has the best prognosis for recovery** - probs something like this one quiz * It was the one with the compression fx instead of the crush * Younger pt better than older * D on asia scale opposed to A

Question 79

What spinal level is quadriplegia?

Answer 79

C1-C8

Question 80

C1-C5 SCI injuries (note most of these injuries are complete instead of incomplete) Dressing: dependent in all dressing activities Bathing: dependent in all bathing activities Independent with assistive devices for verbal communication (c1-3) * meaning they can't communicate w/o assistive devices Assistive devices necessary for keyboarding, writing, page turning, and use of telephone

Question 81

Independent verbal communication w/ what kind of cervical fx

Answer 81

C4-C5 = independent verbal communcation * However, if you're C1-C3 you'll need assistive device for verbal communication

Question 82

Question 83

**A quadriplegia pt is able to undress in wheelchar and be independent w/ assitive devices is what level?**

Answer 83

C8 Makes sense because they get finger contorl at this point

Question 84

What does C8 do?

Answer 84

Finger flexion

Question 85

What level is paraplegia?

Answer 85

T1 and below

Question 86

**NOTE: level of lesion insdicates the caudal most intact spinal segment that is the nurlogic level, not the vertebral level**

Question 87

Question 88

If someone is a C6 will they have wrist extensors?

Answer 88

C6 = wrist extension myotome * They will have it because SCi injuries named for the last level of bilateral ability * But they wouldnt have C7 (finger flexors)

Question 89

Pharmacotherapy muscle relaxants

Answer 89

1) **Diazempam (Valium)** 2) **Tizanidine (Zanaflex)** 3) Chlorzoxaone (Parafon Forte), **Cycolbenzaprine (flexeril)**, carisoprodol (soma), methocarbamol (robaxin), and orphenadrine (norflex) 4) **Baclofen (Lioresal)** 5) **Dantrolene (Dantrium)** (but has some side effects)

Question 90

NOTE: in SCI pts muscle relaxants are often used to manage tone (however, they also have other uses) * can be used as a general relaxant

Question 91

Which muscle relaxant acts centrally in supraspinal centers and spinal neurons * Used to treat? * Side effects (2)

Answer 91

Diazepam (Valium) Used to treat muscle spasm (doesnt necessarily mean its actually treating spasticity) - could have chronic spasms (MS) and not have spasticity **Side effects** * Drowsiness can be serious - can prevent people from driving / being independent * Abuse can lead to withdrawl symptoms NOTE: Drug interactions with cimetidine (tagamet, anticulare and anti stomach acid), viracept and norvir (antiviral agents), and some AIDS medications that can inhibit enzymes that metabolze diazepam. The result could be increased blood levels of diazepam.

Question 92

What muscle relaxor acts on the cord as an adrenergic agonist * what is it used to reat * Side effect (1)

Answer 92

Tizanidine (Zanaflex) **used to treat spasiticity (not spasm)** **Side effect is hypotension**

Question 93

What muscle relaxor acts at the level of the brain stem or SC? * sued to treat * side effects (4)

Answer 93

Chlorzocaone (Parafon Forte), **cyclobenzaprine (Flexeril)**, Carisoprodol (Soma), methocarbamol (Robaxin), and orphenadrine (Norflex) Used for temporary relief of local, acute **muscle spasm** Side effects * Similar to antidepressents such as sinequam and elavil * All of these can interact with monoamine oxidase inhibitors such as nardil and parnate to potenally cause a **hypertensive crisis** * Flexeril can also cause **tachycardia, blurry vision, and dry mouth** Basically side effects seem like a sympathetic response

Question 94

Which muscle relaxant inhibits release of neurotransmitters in the brain and spinal cord, especially substance P. This can reduce inflammation and pain * How is it taken * Used to treat * Side effects (2)

Answer 94

Baclofen (Lioresal) Taken orally and also intrathecal Used to treat **spasticiity** or reduce painful flexor or extensor **spasm** * So used to treat both Side effects * Drowsiness * Increased seizures if patient has epilepsy

Question 95

which muscle relaxant acts locally on muscle fibers to block release of calcium

Answer 95

Dantrium Used for **chronic spasticity** Side effects: * **Dizziness * Drowsiness * Diarrhea * Photosensitivity** * Adverse effects can include toxic hapatitis (potentially fatal), seizures, tachycardia, and muscle weakness. Should not be used w/ cardiac and respiratory dysfunction because od decreased m strength

Question 96

Knowledge check: Which muscle relaxants side effect is hypotension?

Answer 96

Tizanidine (Zanaflex)