Spinal Cord Injuries
❖ Primary spinal cord injury: initial mechanical trauma and immediate tissue
destruction
➢ If not immediately mobilized
➢ Longitudinal stretch of cord
Injury Description
Cord concussion Results in temporary disruption of cord-mediated functions
Cord contusion Bruising of neural tissue causes swelling and temporary loss of cord-mediated
function
Cord compression Pressure on cord causes ischemia to tissues; must be decompressed to prevent
permanent damage to spinal cord
laceration Tearing of neural tissue of spinal cord; may be reversible if only slight damage
sustained by neural tissues; may result in permanent loss of cord-mediated
functions of spinal tracts are disrupted
Transection Severing of spinal cord causes permanent loss of function
Complete All tracts in spinal cord are completely disrupted; all cord-mediated functions below
transection are completely and permanently lost
incomplete Some tracts in spinal cord remain intact, together with functions mediated by these
tracts; has potential for recovery although function is temporarily lost
Hemorrhage Bleeding into neural tissue as a result of blood vessel damage; usually no major
loss of function
Damage or
obstruction of spinal
blood supply
Causes local ischemia
❖ Secondary spinal cord injury
➢ Cascade of vascular, cellular, and biochemical events beginning minutes
after injury and continuing for weeks
■ Hemorrhages- central gray matter
■ Inflammation
■ Edema-white matter impairs microcirculation of the cord
■ Ischemia
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➢ C1-C4
■ Swelling may be life-threatening because CV and respiratory
control functions can be lost
➢ Vertebral Injuries
■ Acceleration, deceleration, deformation forces occurring at impact
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Type of Injury Mechanism
Clinical findings : temporary loss of spinal cord functions below the lesion
★ Develop immediately after injury
❖ Spinal shock: temporary loss of spinal cord functions below the lesion
➢ Develops immediately after injury
➢ Caused by cord hemorrhage, edema, or anatomic transection
➢ Activity of cells AT and BELOW the level of injury cease
➢ Complete loss of reflex function, flaccid paralysis, absence of sensation, loss of
bladder and rectal control, drop in BP, bradycardia, poor circulation
➢ Damage to SNS results in loss of thermal control
■ Hypothalamus cannot regulate body heat through vasoconstriction
■ Assumes temp of air known as poikilothermia
■ Generally lasts 2-3 days
❖ Neurogenic shock/vasogenic shock
➢ Cervical or upper thoracic cord injury above T6
➢ Absence of sympathetic activity
➢ Symptoms
■ Vasodilation
■ Hypotension
■ Bradycardia
■ Failure of body temp regulation
➢ Paraplegia: paralysis of lower half of body
➢ Quadriplegia: paralysis of all extremities
■ Complete
● Level of injury is above C6
■ Incomplete
● Function at or above C6 preserved
◆ Shoulder, upper arm, some forearm muscle control intact
❖ Autonomic hyperreflexia: syndrome of sudden massive reflex sympathetic discharge
r/t spinal cord injury at level T6 or above
➢ Manifestations
■ Flexor spasms
■ Severe HTN
■ Pounding headache
■ Blurred vision
■ Profuse sweating
■ Nasal congestion
■ Nausea
■ Piloerection
■ Bradycardia
➢ Emergency medical management
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PRIMARY BRAIN INJURY
FOCAL BRAIN INJURY Localized injury from impact
CLOSED BRAIN INJURY Blunt trauma
Coup Injury is directly below site of forceful impact
Contrecoup Injury is on opposite side of brain from site of forceful impact
Epidural hematoma Vehicular accidents, minor falls, sporting accidents
Subdural hematoma Forceful impact: vehicular accidents or falls, especially in
elderly persons or persons with chronic alcohol abuse
Subarachnoid hemorrhage
*worst headache of my life
Bleeding caused by forceful impact, usually vehicular accidents
or long distance falls
OPEN INJURY Penetrating trauma: missiles, bullets, sharp objects i.e. knives,
ice picks
Compound fracture Objects strike head with great force or head strikes object
forcefully; temporal blows, occipital blows, upward impact of
cervical vertebrae
DIFFUSE AXONAL INJURY Traumatic shearing forces, tearing of axons from twisting and
rotational forces with injury over widespread brain areas;
moving head strikes hard, unyielding surface or moving object
strikes stationary head; torsional head motion without impact
SECONDARY BRAIN INJURY
SYSTEMIC PROCESSES Hypotension, hypoxia, anemia, hypercapnia, hypocapnia
INTRACEREBRAL PROCESSES Inflammation, cerebral edema, ICP, brain herniation, decreased
cerebral perfusion pressure; ischemia
Cellular processes Release of excitatory neurotransmitters (glutamate); failure of
cell ion pumps, mitochondrial failure, disruption of blood brain
barrier
➔ · Types of traumatic brain injury: alteration in brain function or other evidence of brain
pathology caused by an external force such as MVA or falls
◆ Primary: direct impact
● Focal Brain Injury 2/3rds head injury deaths
○ Observable bain lesion
○ Force of impact typically produces
◆ Contusions
◆ Subdural hematomas