Spinal Cord Injury Flashcards
Definition of Spinal Cord Dysfunction
It relates to SCI or Spina Bifida (SB)
Depending on neurological level and severity of lesion, SCI results in tetraplegia/-paresis [also know as quadriplegic/-paresis] or paraplegia/-paresis
Paralysis or weakness of all four limbs or lower extremities, respectively.
SCI, usually from trauma, results like in compression, contusion or severance of SC or arteries causing cord necrosis and Dysfunction
SB is a congenital neural tube defect; posterior arch of spine fails to close during first month of pregnancy.
Epidemiology & Pathophysiology of SCI:
Most SCI caused by trauma, approx. 10 000 per/year in U.S.
Greatest in 16-30 age group [median age 26 year], and 80% are male
Largely caused by motor vehicle accidents [44%], violence [24%], falls [22%], and sports [8%]
SB has rate of ~0.6 births per 1000, but rate is falling.
Name the 2 types of SCI:
Complete = no function below the level of injury [no sensation or voluntary movement]
Or
Incomplete = some function below level of injury e.g. Able to feel parts of body they can’t move, or able to move one limb more than the other.
The level of SCI and what is affected:
C4 - level may require a ventilator to breathe
C5 - often allow shoulder [deltoid] and biceps control, but no control at the wrist or hand.
C6 - injuries allow wrist control [wrist extensors], but no finger hand function.
C7 & T1 - injured can straighten their arms [triceps] but may have dexterity problems with hand and fingers. Injuries at and below the thoracic level results in paraplegia, with the hands not affected.
At T1-T8 - there is most often control of the hands, but poor trunk control due to lack of abdominal muscle control.
T9-T12 - allow trunk and abdominal muscle control. Sitting balance is very good.
Lumbar and Sacral injuries decrease control of the hip flexors and legs, and bladder/bowel/sexual function.
Pathophysiology of SCI: What Secondary damage occurs? [name 5]
- Reduced blood flow to site [largely affects grey matter], and blood vessels leak and cells lining blood vessels in spinal cord swell, causes further flow reduction and cell death.
- Excessive release of NT [esp. glutamate] causes excitotoxicity, kills neurones and oligodendrocytes.
- Blood-brain barrier broken by damage allows immune cells into SC tissue and causes cytokines release that may damage cord further; microglia and astrocytes also start to produce cytokines, which may form scar tissue.
- Immune response accelerates free radical production which damages cells.
- Apoptosis [programmed cell death] of oligodendrocytes days to weeks after injury, so myelination affected.
What factors affect functional improvement in SCI?
Intact vs. partially/completely severed SC [complete severe highly unusual]
Extent of initial spinal cord compression
Stability of surgical fixation - is it contributing to cord and/or spinal canal compromise?
Extent of SC degeneration
Obstruction of cerebral spinal fluid [CSF]
Secondary infections & systemic disorders - use of specific antibiotic treatments and immune stimulation
Smoking- reduces small blood vessels in SC = further constriction & cord ischemia
What are the Secondary Conditions and Consequences in SCI?
- Chronic pain, spasticity, depression, obesity, urinary tract infections and pressure sores
- Dependence on upper extremities [wheelchair/crutches] predisposes overuse injuries, joint degeneration and tendon pathology
- Severe spasticity reduces ROM, may affect breathing
- Standard health issues with inactivity
- Inability to perform large muscle group ex exacerbates problems
What are the Secondary Conditions and Consequences in SCI: During Exercise ?
- Inability to stimulate autonomic/cardiovascular systems: lack of adrenaline, venous pump problems, thermoregulation difficulties
- Limited positive cardiac chronotropy [HR problems], and inotropy [SV problems]
- Exercise hypotension
- Exercise intolerance
- Autonomic dysreflexia - mass activation of autonomic reflexes causing extreme hypertension [>300/200mmHg], headache, flushing, goosepimples, sweating/shivering, nasal congestion.
What are the Secondary Conditions and Consequences in SCI:
Explain Autonomic Dysreflexia:
- Life threatening reflex action mostly affecting patients with neck and upper back lesions
- Occurs with pain, irritation or stimulus to the nervous system below level of lesion: urge to urinate, pressure sores, cuts, burns, bruises, sunburn, etc.
- Irritation causes signal, but cant get to brain so lack of regulation causes hyper response in vascular and organ systems controlled by sympathetic nervous system.
- Must stop irritation immediately, including emptying bladder, removing or loosening right clothing or changing position
Describe Cauda equine syndrom [CES]
- It’s a serious neurologic condition in which damage to the cauda equina causes loss of function of the lumbar plexus [nerve roots] of the SC
- Below the termination [conus medullaris] of SC, i.e. Lower motor neurone lesion
- Occurs with trauma, surgery and other issues
- Causes severe back pain, ‘saddle anaesthesia’, sexual dysfunction, loss of lower reflexes.
- Often requires surgery, and ex and bowel/bladder retraining strategies.
What are the Secondary Conditions and Consequences of SB?
- About 80% of SB affects lumbosacral nerve roots, so sensorimotor and autonomic impairment to legs and/or pelvic organs [bladder, bowels, sex organs]
- hydrocephalus in 90% of individuals due to poor absorption and drainage of CSF - brain compression= should have shunt (drains to chest/abdomen) from ventricles of brain.
-Close monitoring required for changes in muscle tone or strength, rapidly progressing scoliosis or changes in bowel/bladder behaviour
=hydromyelia - fluid cavity in central canal of SC, requires surgery
=tethered cord - stretching of SC with movement/exercise, surgical correction needed.
What are the Secondary Conditions and Consequences of SB?
- SB is a life-long disease, so usually have stress strain on joints, scoliosis, hip sub/dislocation, muscle imbalances, Achilles’ tendon rupture.
- Overuse injuries [carpal tunnel, tendinosus, arthritis] and osteoporosis common
- Skin care, hygiene and protection important - prevent pressure sores
- Lifestyle diseases typical of non-exercises
- 30% may have mild-moderate cognitive or learning disabilities
- Low self esteem, immature social skills, depression
~70% of SB patients have allergic hypersensitivity to latex [natural rubber]
~ Shouldn’t touch= exercise, clinical or research equipment with latex
=causes allergic symptoms, including wheezing, itching, hives and life-threatening anaphylaxis
Medical/surgical treatments
Methylprednisolone reduces damage to nerve cells if given early after damage - no effect on ex after cessation; other drugs may be used to stop inflammation, apoptosis, etc.
Surgery after SCI, may require bone screws, splints, plating, spinal fusion or external spinal orthopedist such as halo
Learning bowl, bladder hygiene
May have implanted devices: cardiac pacemakers, intrathecal pumps [delivers drugs to SC- CSF], functional electrical stimulation [FES] devices, need to check for functional status and ensure they don’t prelude exercise interventions.
What is Prednisone/prednisolone?
Synthetic corticosteroid used to reduce inflammation/suppress the immune system
Used for some allergies, cancer treatments, and to minimise symptoms of MS, Duchenne’s muscular dystrophy and others
During use has many side effects - high blood glucose, fluid retention, anxiety, problematic emotional control, depression and mania, confusion, fatigue/weakness, ulcers, and other issues
Long term osteoporosis and many other issues.
Pharmacology : What are the 3 classes of drugs?
- Spasmolytics/antipasticity [baclofen/diazepam]
- side effects include tachycardia, hypotension, CNS/CV depression, sedation/weakness - Antithromboics/anticoagulants [warfarin]
- side effects include haemorrhage, increased bruising - antibiotics [Bactrim]
- no important side effects
Neurogenic bladder treatment may require alpha blockers - hypotension
