9531 Lecture 12- Spinal Cord Injury

What is the organization of the spinal column and spinal cord?

• Segmentally organizes→ 31 segments and 31 cords exiting the spine 

  • Cervical 

    • 7 vertebrae, but 8 nerve roots

  • Thoracic 

  • Lumbar 

  • Sacral 

  • Coccygeal

What nerves exit above their corresponding vertebrae?

Cervical

What nerves exit below their corresponding vertebrae?

Thoracic, lumbar, sacral, coccygeal

Where is sensory information located?

dorsal horn

Where does motor information come from?

Ventral horn

UMN Basics/Review

• Cell Body originates in the brain

• The axons travel from the brain to the brain stem or the ventral (anterior) horn of the spinal cord

• Here they synapse with LMN

• 90% will cross over to the contralateral side at the brainstem, 10% will cross in the spinal cord at the level that they’re exiting

LMN Basics/Review

• The cell body od the LMN make up the ventral horn of the spinal cord

• Travels from the spinal cord to the muscle they will effect (Efferent fibers)

• Below L1, there are no UMN

• UMN injuries or lesions react differently than LMN lesions

Where do UMN cross?

• Cross over in the pyramidal tracts

• Our lateral tract is where our muscle fibres will cross at the brainstem (90%)

Where do motor neurons cross?

The midline at the level of the brainstem or the level of where they exit

Lateral Spinothalamic Tract

• Contains sensory neurons for pain and temperature

• Will enter and synapse at the same side that they’re sensing 

• Will cross at the same level and the goes up to the brain where it’s interpreted

Dorsal Column

• Fine touch and proprioception

• Travels up on the same side as the stimulus before crossing at the brainstem

What is the general motor control by nerve segments?

What is the general sensory area by nerve segments?

What is a complete SCI?

The absence of sensory and motor below the site of injury

What is an incomplete SCI?

Partial preservation of sensory and/or motor function below the site of injury

What is quadriplegia/tetraplegia?

Involves all four limbs and the trunk

What is paraplegia?

Affects the trunk and all or part of the legs

What is hemiplegia?

Affects one side of the body (left/Right)

What is a grade A SCI?

Complete- no sensory or motor function is preserved below the level of injury

What is a grade B SCI?

Sensory incomplete- Sensory but not motor function is preserved below the neurological level and no motor function is preserved more than three levels below the motor level on either side of the body

What is a grade C SCI?

Motor incomplete- motor function is preserved below the neurological level and more than half of key muscle functions below the neurological level of injury have a muscle grade less than 3

What is a grade D SCI?

Motor incomplete- motor function is preserved below the neurological level and at least half (half or more) of key muscle functions below the NLI have a muscle grade of equal or greater than 3

What is grade E SCI?

Normal- as per testing protocols

What are the grades of the MMT scale?

What do injuries above T12 present as?

UMN injuries (but not always)

What do injuries below the T12 tend to present as?

LMN injuries (but not always)

What are symptoms of an UMN vs LMN injury?

What are primary symptoms of an SCI?

• Loss of motor control or coordination

  • Mobility issues extremely common

    • Approx. 70% require manual wheeled mobility

    • Approx. 30% require powered wheeled mobility

• Loss of sensation

  • Depends on the level of the injury and which part of the spinal cord is injured 

What are secondary complications of SCI?

• Orthostasis (postural hypotension) 

• Autonomic dysreflexia 

• Bowel and Bladder dysfunction 

• Sexual dysfunction 

• Pressure Ulcers 

• DVT 

• Thermal Regulation 

• Pain 

• Spasticity & Heterotopic Ossification 

• Depression

What is orthostasis (postural hypotension)?

• Sudden drop in BP when body position changes from lying to sitting or standing. 

• Additional signs and symptoms 

  • Gray, nausea, dizziness, lightheaded, vision (tunnel/spots) 

What are common injuries that occur that cause orthostasis?

• More common with injuries above T6 and/or complete injuries

  • Not enough blood pressure that makes up the difference that occurs do to gravity

  • Don’t have enough musculature to compress to increase BP as artificial BP

  • Get someone horizontal to reestablish BP

What is autonomic dysreflexia?

• Medical Emergency!  

• Sudden increase in BP (↑ 20 mmHg SBP )  

• T6 level or above  

• Noxious stimulus below level of injury causes massive imbalance in sympathetic discharge.  

• Presents as sudden onset of:  

  • Throbbing Headache & feelings of anxiety  

  • Profuse sweating, flushing, piloerection

• Medical Emergency

  • Find and remove the cause

  • Use orthostasis to reduce BP, by sitting them up

  • Remove or reduce compression (socks, binders, etc.)

  • Can result in death if it keeps happening

• Can be a full bladder, pebble in their shoe, pressure from a wheelchair

  • Decrease BP by getting someone more upright

  • Can remove artificial compression aids to decrease BP

What are risks and signs of a deep vein thrombosis (DVT)?

• Risk due to: 

  • Reduced circulation caused by lack of muscle contraction 

  • Vascular damage due to low sensation, bumping into something while transferring for example 

  • Prolonged bed rest 

    • Can lead to a thrombotic stroke

• Signs: 

  • Swelling in the lower extremities 

  • Localized redness 

  • Low grade fever

What segments involve bowel and bladder injuries?

Sacral segments (S2-4)

What do UMN injuries result in, in terms of the bladder and bowel?

• Injuries above T12 (UMN injuries) results in a reflexive (spastic) bowel and bladder 

  • Urinary muscles may contract involuntarily causing “urge” incontinence

  • Reflexic bowel emptying

What do LMN injuries result in?

• Flaccid bladder and bowel 

  • Bladder doesn’t contract when full = difficulty annually emptying 

  • Bowel has loss of anal sphincter tightness 

  • A too full bladder will leak causing “overflow” incontinence

• Decrease circulation 

What is ranked as the top priority for those with paraplegia and #2 for those with quadriplegia?

• Difficulty with erection (ED) and ejaculation 

• Difficulty with vaginal lubrication

• Secondary posture and muscular function to engage in sexual intercourse

  • Can lead to impacts on mental health and self identity

What can spasticity lead to in those who suffer a SCI?

• Common following SCI 

• Triggers can include touch, infection and rapid movements 

• Can lead to contractures & decreased functional independence

  • Can develop random unwanted movements 

  • Can be used for purposeful functional movements→ ex. elicit movement from the stretch reflex

What are heterotopic ossifications?

• 15-20% of SCI cases 

• Calcification of connective tissue around joints (often shoulder/hip) 

  • Occurs when calcium gets into a tendon

• Results from immobility and decrease weight bearing, including passive

• Warm swollen joint with limited ROM

What is the impact of thermal regulation on those with SCI?

• Thermal regulation is another function ANS 

• Maintaining body temperature is often the problem for injuries above T6 

• Poikilothermia: The body will assume the temperature of the environment

  • Education on heat stroke or hypothermia

What are pressure ulcers in SCI?

• Most common over boney parts (heels, elbows, hips, base of spine) 

  • 90% of individuals, most or all are preventable

• Develop gradually over hours or days

  • From laying down or sitting for a prolonged period of time

  • Can be from sitting in a wheelchair for a long period of time

What are symptoms of pressure ulcers?

• Part of the skin becoming discoloured 

• Discoloured patches not turning white when pressed 

• A patch of skin that feels warm, spongy or hard 

• Pain or itchiness in the affected area

How do we monitor and prevent pressure sores from progressing?

• Daily skin checks

• Explore pressure relief methods

• Changing positions frequently, micro = every 15-20 minutes, macro = every 2-3 hours

• Pressure relieves cushions

• Postures that reduce pressures in certain areas

What is the impact of pain following an SCI?

• Pain is very common after a spinal cord injury 

  • Reported by 75% - 85% of people with a spinal cord injury

• Pain is an individual experience

• Absence as a signal can be interrupted by pain

• Areas of intact sensation

• Some can experience phantom limb pain

• Can feel muscle pull leading to pain

• Can experience pain due to lack of sensation, at or below the level of injury

  • Burning sensation or painful numbness and tingling, electrical shock

  • Normal touch can be experienced as pain

What are 2 types of pain we can experience?

• Nociceptive pain→ common pain that we experience in the body

• Neuropathic → our organs, can experience referred pain

What are respiratory complications in SCI and where do the occur on the spinal cord?

• Typically, no issues if the injury is below T12 

• Injuries above that level compromise the respiratory system to some degree

  • Diaphragm control → C4, technically C3-C5

  • Expansion and compression of the rib cage 

  • Postural control for breathing

What difficulties with depression do some individuals experience?

• Changes in sleep (too much or too little) 

• Feeling down or hopeless 

• Loss of interest or pleasure in activities 

• Changes in appetite 

• Diminished energy or activity 

• Difficulty concentrating or making decisions 

• Feelings of worthlessness or self-blame 

• Thoughts of death or suicide

What is anterior cord syndrome?

• All motor neurons are travelling mostly anteriorly in our lateral corticospinal tract

  • Motor paralysis below the level of the lesion and the loss of pain, temperature and deep sensation below the level of the lesion

  • Likely to still have light touch and proprioception awareness

What is Brown Sequard Syndrome?

• Damage to one half or one side of the spinal cord

  • Puncture wound

  • Ipsilateral or same side loss of motor function below the level of injury, reduction in deep touch and proprioception

  • Contralateral loss of pain, temperature and touch

    • Side with good or better motor control will have better sensation, and vice versa

What is posterior cord syndrome?

• Around the dorsal part

• Very rare, not many mechanisms that can result in this type of injury

• Loss of fine touch and proprioception below the level of lesion

• Motor control is likely relatively intact

What is central cord syndrome?

• More common forms of incomplete spinal cord injury

• From an extension injury of the cervical spine level

  • 90% or more will be at the cervical level

• Results in sensory loss below the site of the injury including bladder control

  • Tingling, burning or dull ache

  • Impairment in the arms, hands or lesser extent then in the legs

What is cauda equina syndrome?

• No Damage to the cord itself, but to the nerves that extend below it from L1/L2  

• Generally incomplete injuries since it isn’t one cord that can be injured 

• Symptoms:  

  • Loss of motor function and sensation below the level of injury  

  • Absence of reflex arc  

  • LMN type motor paralysis

    • Flaccid paralysis

Which complications of occur above neurological injury T6?

• Orthostasis (Postural Hypotension)

• Autonomic dysreflexia

• Temperature dysregulation