Spinal Cord Injury (SCI)

SCI Epidemiology

• • • • • Incidence: 11,000 new cases per year. Prevalence: 225,000-296,000 persons in the USA living with SCI. Traumatic SCI is most common in people aged 16-30 (more than 50% of cases). Most common cause of traumatic SCI: • • • • • Motor vehicle accidents – 47% Falls – 23% Violence (esp. gunshot wounds) – 14% Sports accidents – 9% Other – 7% 78% male, 63% Caucasian.

• • • 48% paraplegic and 52% tetraplegic, 52% incomplete and 48% complete. Life expectancy for paraplegics (in those who live for one year) is near normal. Life expectancy for tetraplegics is reduced by ~10 years (reduced by ~20 years if ventilator dependent).

Spinal Cord Anatomy

Types of Injury

•

Upper motor neuron injury: injury to the neurons in the brain and/or spinal cord.

– Increased tone, brisk reflexes. – Involuntary spasms, preserved muscle bulk. – Occurs in brain injury and SCI down to the conus medularis – (So, fractures above L1 usually give upper motor neuron picture).

Types of Injury

•

Lower motor neuron injury: injury to the nerves after they synapse in the spinal cord.

– Decreased muscle tone – Areflexic – Muscle atrophy – Incontinent of bowel/bladder – 4% of patients with SCI above L1 are LMN injuries.

Spinal Cord Tracts

• • •

Corticospinal: descending tracts (also called the pyramidal tracts).

– Motor control.

Spinothalamic: Ascending tracts.

– Pain and temperature.

Dorsal columns: ascending (also called the posterior columns).

– Vibration, proprioception, and light touch. http://img.orthobullets.com/Spine/Introduction/Electrophysiologic%20Monitoring/Images/Pathways.jpg

•

Central Cord Syndrome-

– Occurs with cervical level injuries. – Typically results in greater weakness in upper limbs than lower. – Bowel/bladder usually preserved. •

Brown-Sequard Syndrome - Results from hemisection).

– Ipsilateral loss of motor function, light touch, vibration, and proprioception. – Contralateral loss of pain and temperature sense. http://img.tfd.com/mk/C/X2604-C-28.png

http://img.tfd.com/mk/B/X2604-B-40.png

•

Anterior cord syndrome – usually vascular cause from damage to the anterior spinal artery.

– Loss of motor function (with spasticity). – Loss of pain and temperature sense. – Some loss of light touch. – Vibration and proprioception are preserved. – Poor prognosis for motor recovery. http://img.tfd.com/mk/A/X2604-A-47.png

Blood Supply to Cord

•

Posterior Cord Syndrome columns. – damage to dorsal

– Loss of vibration and proprioception. – Can see spastic weakness and bladder dysfunction.

– Causes include trauma, B12 deficiency. http://www.stepahead.org.au/media/images/posterior-injury.jpg

• •

Conus medullaris: the end of the spinal cord, contains the sacral reflex center.

– Weakness in lower limbs.

– Areflexic bowel and bladder http://img.tfd.com/mk/C/X260 4-C-23.png

(sometimes with preserved reflexes)

Cauda Equina : “Horse’s Tail” lumbosacral nerve roots within the spinal canal.

– Areflexic bowel, bladder, and lower limbs.

– “Saddle Horse” Anesthesia http://www.aceproindia.com/ACE%20Sample%20Projects/ePUB/Examination%20and%20 Diagnosis%20of%20Musculoskeletal%20Disorders/OEBPS/images/9783131605818_c008 _f048.jpg

Acute Events s/p SCI

• First few hours patients experience neurogenic shock due to interruption of sympathetic nervous system to regions below the cord injury, and subsequent vasodilation •

Triad of:

bradycardia, hypotension, and hypothermia • ASIA Exam at this time is not prognostic due to other possible injuries present and neurogenic shock (must wait at least 72 hours to evaluate)

Transient Paralysis/Spinal Shock

• • • • • • Loss of all physiological functioning caudal to the cord injury Flaccid paralysis, anesthesia, absent bowel and bladder control, loss of reflexes Some males may experience priaprism after cervical injuries May last hours to weeks Early return of DTRs is associated with better prognosis Exact pathophysiology is not well understood, it is thought to be related to the release of K + by the injured cells in the cord leading to an accumulation of extracellular K + that eventually normalizes and results in resolution of the spinal shock As spinal shock resolves spasticity becomes evident

Medical Management

•

Cardiovascular

• Autonomic dysregulation results in

Triad

of: Hypotension, Bradycardia, and Hypothermia • Must maintain BP for adequate perfusion to the injured cord using fluids, pressors, and transfusions initially • Monitor electrolyte levels, urinary output, and fluid administration • Autonomic Dysreflexia (AD): usually occurs later • Headache, flushing, episodic paroxysmal HTN, bradycardia, and sweating • Pain is often the cause of this phenomenon

•

Pulmonary

• Initially High Risk of: PE, respiratory failure, pulmonary edema, pneumonia • • Highest incidence of the above with cervical lesions Decreased strength of diaphragm and chest wall muscles leads to difficulty of clearing secretions, ineffective cough, and hypoventilation • Frequent suctioning and chest physiotherapy should be implemented ASAP • In respiratory failure intubation and ventilation required • Pneumonia is the leading cause of death at any point s/p SCI

• • • • • • •

DVT/PE

• • • • Occurs in 50-100% of untreated patients Most common in first 72 hours to 14 days All pts should receive DVT prophylaxis Treatment of choice: Low-molecular-weight heparin with compression stockings • IVC filters required in patients when anticoagulation is contraindicated

Skin

Impaired autoregulation of skin capillaries and decreased sensation increases risk of skin breakdown Pressure sores develop quickly, especially on heels and buttocks Patients should be rolled q 2 hours Special rotating beds are also used for prevention Multipodus boots protect heels

•

Neurogenic Bladder

• Detrusor-sphincter dyssynergia (DSD) • Lack of sphincter relaxation during bladder contraction • Results in urinary retention and vesicoureteral reflux •

Treatment:

• Intermittent catheterization • • • • • Oral or intravesicular anticholinergics Alpha blockers Stent placement Sphincter botulinum injections neurostimulation

•

Neurogenic Bowel

• • Loss of bowel reflexive function results in ileus

Treatment:

• Stool softeners (Colace), rectal stimulant (Ducolax), and colonic stimulant (Senna) • Goal is to create a bowel regiment that allows for control of the timing of bowel emptying

•

Heterotropic Ossification

• Formation of bone in soft tissue adjacent to neurologically affected joints • • • • • Metaplasia of mesenchymal cells into osteoblasts More commonly seen near large joints Usually 1-4 months post injury Symps: swelling, decreased ROM, warmth, spasticity Plain X-ray or Triple-Phase Bone Scan used for diagnosis •

Treatment:

• joint rest, ice, gentle ROM exercises • • NSAIDS (indomethacine) Bisphosphonates • • Etidronate (also used preventatively) reduces osteoblast/clast activity and calcium phosphate precipitation • Surgical resection

Heterotropic Ossification

http://www.physio pedia.com/images/1/11/Ho1.jpg

•

Sexual Fuction/Fertility

• ED is more common acutely after SCI, but resolves with time. Many men are able to maintain an erection suitable for sexual activity • LMN injury – lack of erection • UMN injury – reflexogenic erection • Fertility may be reduced in males who have retrograde ejaculation or impaired spermatogenesis • Fertility in females is uncompromised, however, labor maybe difficult due to lack of voluntary muscle control • Uterine contractions are present

•

Glucocorticoids – Methylprednisolone

• Limited evidence (mainly animal studies) have shown that when given in first 8 hours after SCI, better outcomes are achieved • May reduce edema, intracellular K + depletion, and improve neurologic recovery • Timing is crucial: late administration may actually interfere with the initial healing process

ASIA Exam

http://www.emergency-medicine-tutorials.org/_/rsrc/1257199993383/Home/surgical/trauma/spinal/neuro-exam-chart/Spinal%20neuro%20exam%20chart.JPG

Level Terminology

• • • •

Neurological Level:

The unifying level to describe the overall fxn. It combines sensory and motor levels, based on the last level of the cord that is normal.

For C1-C4 and T2-L1 use the sensory level to define the neurological level

Complete Injury:

No sensory or motor fxn preserved below the neurological level

Incomplete Injury:

If any sensory fxn and/or motor fxn below the neurological level

ASIA Impairment Scale

• • • • •

ASIA A:

Complete (no motor or sensory)

ASIA B:

Incomplete sensory, but no motor fxn

ASIA C:

Motor and sensory fxn Incomplete, with strength of more than half of the key muscles below the level having a muscle grade < 3

ASIA D:

Motor and sensory fxn incomplete, with at least half of the key muscles below the level having a muscle grade > 3

ASIA E:

Normal motor and sensory fxn

• • ASIA Exam at 72 hours predicts short-term prognosis (2 3 months) ASIA Exam at 1 month predicts long-term prognosis (1 year) http://www.streetsie.com/wp-content/uploads/paralympic-games.jpg

• • • • •

Expected Functional Levels

C1-3:

Ventilator dependent

C5:

Can feed self with adaptive equipment

C6:

Highest level of complete injury consistent with independent living without aid. Tendonesis orthosis (aids in grasp) and short opponens orthosis with utensil slots. Can drive adaptive van.

C7/C8:

Completely independent from a wheelchair level

L2/L3:

Gait becomes functional http://www.healthmegamall.com/ProdImages/NCM-NC99485L_lg.jpg

Works Cited

• • • • Dawodu, S. T.

Spinal cord injury – definition, epidemiology, pathophysiology

. (2011, Nov 10) Medscape Reference. Retreived from http://emedicine.medscape.com/article/322480-overview#a30 Hansebout, R.R., Kachur, E. Acute Traumatic spinal cord injury. In: UpToDate, Aminoff, M.J., Marx, J.A.(Ed), UpToDate, Waltham, MA, 2012.

Ho, C.H., Wuermser, L., Priebe, M., Chiodo, A.E., Scelza, W.M., Kirshblum S.C.

Spinal Cord Injury Medicine. 1. Epidemiology and Classification

. Spinal Cord Injury Medicine, 2007; 88(3):S49-54.

Choi, H., Sugar, R., David, E.F., Shatzer, M., Krabak, B.(2003). Spinal Chord Injury (SCI). In R. Hurley, E. Wolfberg, C. Sahl (Eds.),

Physical Medicine and Rehabilitation Poketpedia

(pp. 97-102). Philadelphia; Lippincott Williams & Wilkins.

• • Kelbine, P., Lindsey, L. (2007, May). Spinal Cord Injury Information Network. Retrieved from http://www.spinalcord.uab.edu/show.asp?durki=22405 Stiens, S., Goldstein, B., Hammond, M., Little, J. (2008). Spinal Chord Injury Medicine: Acute Treatment, Rehabilitation, and Preventative Care. In J. Merritt, & S. Ward(Eds.),

Physical Medicine and Rehabilitation Secrets

(pp. 456-465). Philadelphia; Mosby Elsevier.