spinal cord injury Flashcards
statistics/risks for SCI
a. Catastrophic crisis but fairly stable incidence. 10,000new injuries per year.
b. 80% affected are male. 60% of SCIs in persons 16-30 years old.
c. 55% from motor vehicle accidents, 23% from falls, 16% from penetration injuries. Also, can result from occupational & sports injuries.
d. Commonly affects motorcyclists, sky divers, football players, police, divers and military personnel.
e. Alcohol and/or drugs may be present with the injuries.
f. Falls are more common in the elderly.
g. Slightly more than 50% of new SCIs involve the cervical spine.
etiology of SCI
Injuries result most commonly from excessive flexion, hyperextension, compression & rotation on the spinal cord.
a. Events that cause abrupt, forceful acceleration & deceleration are common initiating factors.
Persons with chronic arthritis, stenosis, or osteoporosis are at high risk for injury.
classification of SCI
Level as in the cervical, thoracic, or lumbar spine.
Extent of injury:
a. Can affect vertebrae, spinal column. Can be a fracture or a dislocation.
b. Can affect anterior or posterior ligament causing compression on the spinal cord.
c. May be concussion, contusion, compression or laceration or a penetrating missile to the spinal cord.
mechanism of injury SCI
Mechanism of injury:
a. Hyperflexion
b. Hyperextension c. Compression injuries d. Rotational injuries e. Penetrating wounds
hyperflexion SCI
Usually result of sudden deceleration like a head-on collision or from severe blow to the back of the head.
Head and neck are forcibly hyperflexed and then snapped backward into forced hyperextension.
Typically involves C5 & C6. May cause fracture of the vertebra, dislocation and/or tearing of the posterior ligaments.
Hyperextension SCI
Usually result from acceleration as seen in rear-end collisions or as a result of falls where the chin is forcefully struck.
Tends to cause significant damage because of the head’s downward & back arc being so great.
C4 & C5 area of the spine is most often affected.
compression injuries SCI
Cause the vertebra to squash or burst. Usually involves high velocity and can affect any part of the vertebra.
Blows to the top of the head and forcible landing on the feet or buttocks can result in a compression injury.
Can result from an axial loading force exerted straight up or down the spinal column as in a diving accident.
rotational injuries SCI
Caused by extreme lateral flexion or twisting of the head or neck. The tearing of ligaments can easily result in dislocation as well as fracture.
Soft tissue damage frequently complicates the primary injury.
Can result in a highly unstable spinal injury involving more than one directional force.
Penetrating Injuries can result from knives, bullets that penetrate the spinal column.
cord concussion SCI
. Cord is severely jarred or squeezed as in sports injuries. No pathological changes are detectable in the cord but there is a temporary loss of motor and/or sensory function. Usually resolves in 24 to 48 hours.
cord contusion SCI
a. Frequently caused by compression. Causes bleeding into the cord resulting in bruising and edema.
b. Extent of damage reflects adequacy of overall perfusion to the cord and the severity of the inflammatory response.
cord laceration SCI
a. Is an actual tear in the cord. Results in permanent damage since the neurons do not regenerate.
b. Contusion, edema, and compression may also be present complicating the injury.
Cord transection SCI
Complete transection is rare because of the strong, protective layers of the cord.
b. When complete, there is a total loss of motor & sensory function below the level of injury. c. Is more common in the thoracic area because the cord is more narrow in this region.
pathology of a cord transection
Spinal Shock:
a. Entire cord below the level of the lesion fails to function resulting in spinal shock.
b. Symptoms seen are:
1. Hypotension, bradycardia
2. Flaccid paralysis below the level of the injury
3. Lack of temperature control in affected parts
4. Absence of reflexes below the level of injury
5. Retention of urine and feces
6. Loss of sympathetic innervation causes
peripheral vasodilation, venous pooling and
a decrease in cardiac output.
Effects generally seen with cervical and high thoracic injuries.
Generally lasts 7 to 10 days after injury but can last longer.
Indications that it has ended include spasticity, reflex emptying of the bladder and hyper-reflexia.
Active rehabilitation may begin in the presence of spinal shock.
clinical manifestations of SCI
Vary. A person with an incomplete lesion may have a mixture of symptoms. The higher the injury, the more serious the symptoms because of the nearness of the cervical spine to the medulla & brainstem.
Quadriplegia occurs with injuries to C1 to C8. All four extremities are paralyzed. Respiratory paralysis occurs in lesions above C4 due to the lack of innervation to the diaphragm.
Paraplegia occurs with injuries from T1 to L4 causing paralysis of the lower half of the body involving both legs.
Trauma can also result in many other injuries like a head injury.
Respiratory complications of SCI
Injuries above C4 may need mechanical ventilation. Below C4 may result in diaphragmatic breathing if the phrenic nerve is functioning but edema & hemorrhage can affect its functioning.
Hypoventilation usually occurs with diaphragmatic breathing because there is a decrease in vital capacity & tidal volume.
Cervical injuries can cause paralysis of the abdominal musculature and frequently the intercostal musculature. The patient cannot cough effectively to remove secretions. Can lead to atelectasis and pneumonia. Need good pulmonary toileting.
