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Upper Motor Neurons
Originate in the cerebral cortex
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Lower Motor Neurons
Originates in the brain stem
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White Matter Region
Three Major Tracts
- Corticospinal tract
- -Transmits motor activity
- Spinothalamic Tract
- -Transmits pain and temperator
- Posterior Column (Dorsal ) tract
- -Carries sensations of vibrations, propriception, touch, fine touch, pressure and texture.
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Complete Spinal Cord Injury
- Complete spinal cord transection
- -lack of sensory and motor function below the level of injury
- Tetraplegia (Quadraplegia)
- -Complete severing of the spinal cord between C1 and T1
- Loss of motor and sensory function of the arms, trunk, legs and pelvic organs
- Probably no bowel or bladder function
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Paraplegia
- Complete severing of the spinal cord between T2 and L1
- Loss of motor and sensory function of the lower extremities
- Will have upper extremity function
- Possible bowel and bladder training
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Incomplete Spinal Cord Injury
- Injury did not completely sever the spinal cord
- Preservation of some sensory and or some motor function below the level of injury
- Could have altered sensory and or motor function
- Symptoms of injury depends on which area the spinalcord was injured
- This is where the tracts matter
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Incomplete Spinal cord injury
- If the incomplee injury occurs at T12 and above- it will be an upper motor neuron injury
- Manifestations:-spasticity of muscles-Exaggerated tendon reflexes-Spastic neurogenic bladder-anal sphincter will respond
- If the incomplete injury occurs below T12 - it will be a lwer motor neuron injury
- Manifestations: -Hypotonation - Hyporeflexia -Flaccidity - Acontractile bladder and bowel
- Cannot have bowel and bladder training
- There will no control , no contraction to push stool out
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Cervical Injuries
- Complete = will be ventilator dependant
- Cervical vertabrae are the most vulnerable
- C1-C3 can be fatal-loss of phrenic nerve=ventilator dependant
- C4-C5 most common driving injuries
- C7-T1 - Coup -Contrecoup Shearing force mechanism of injury
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Thoracic and lumbar injuries
- T12-L1 most common site of thoracic spinal cord injury
- Usually occur from a fall onto upper back
- a fall onto buttock
- Calcaneous fractures
- Lumbar usually occur from only wearing a lap belt in a MVC
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Primary Injury
- Occurs at the Moment of Impact
- Mechanism of Injury:-Hyperflexion
- Hyperextention
- Flexion -rotation
- Compression
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Secondary Injury
- Occurs within minutes of the primary injury
- Is vascular injury to spinal cord
- Can last days to weeks
- Manifestations:Ischemis, Elevated intracellur calcium, Inflammatory process
- Secondary - everybody gets all three
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Reflex activity Assessment
Perineal Reflexes
- Assess for presence of perineal reflexes
- If present - indicates a feasibility of bowel and bladder training
- Indicates a upper motor neuron injury
- Perineal reflexes included:
- Anal wink -eleicted when the rectal sphincter contracts
- Bulbocavernosus - elicted when the rectal sphincter contracts to tugging on the foley catherer
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Shock States
- Results of autonomic nervous system dysfunction-dysfunction of homeostasis in the body
- The higher the spinal cord injury is, the greater the dysfunction will be.
- Two major types of shock states in SCI
- Spinal shock and Neurogenic shock
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Facts about Spinal Shock
- Why? Results of autonomic nervous system dysfuncion
- When? Occurs within 30-60 minutes after spinal cord injury
- Resolves? Can last weeks or months and can be transient
- How do you know the patient is in spinal shock?
- Temporarily causes: Absence of all reflex activity- Flaccidity -Loss of all neurologic activity below the level of injury
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Neurongenic Shock
- Occurs in SCI that are at or above T6 within 30 minutes of SCI
- Due to sudden loss of sympathetic stimulation to the blood vessels-bradycarida
- Massive relaxation and vasodialtion of vessels -severe hypotention
- Loss of vasconstrictive effects - pooling of blood
- Unable to regulate temperature -poikilothermia
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Neurogenic Shock
- Manifestations:
- Severe atrerial hypotension in the presence of bradycardia is the classis indicator of shock
- Treatment:
- Fluid resuscitation (0.9% NSS), vasopressor (neo-synephrine - Phenylelphrine, Atropine
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Hypovolemic shock
Atrerial hypotension with tachycardia
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Steroid Therapy for SCI
- Methylprednisolone (MPSS)
- Steroids used to minimize inflammation from secondary injury
- Given as a 24 hour infusion within 3-8 hours of the SCI
- Discontinued if neurological sypmtoms resolve
- Can cause increased incidence to: Pneumonia, sepsis, GI Bleed, electrolyte imbalance, and delayed healing.
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Autonomic Dysreflexia (AD)
- Life-threatening medical emergency affecting SCI
- Occurs in patients with spinal cord injuries at or above T6 level
- Its an amplified response by the autonomic nervous system to being overstimulated
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AD triggers
- Bladder distention/spasms
- bowel imacation
- Stimulation of the anal reflex
- pain
- temperature change
- ingrown tonails
- tight, irritation cloths
- urinary tract infections
- uterine contractions
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AD Manifestations
- Hypertension-40mm over baseline, suspect AD
- Profuse sweating
- Goose bumps(known as piloerection)
- Sudden headache
- Blurred vision
- Anziety and feeling of doom
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AD Treatment
- First Priority is to lower the BP
- elevate HOB to 90 degrees to cause orthostatic hypotention
- Lossen any binding or restrictive cloths
- relieve and bladder distention
- implement measures to facilitate defecation
- eliminate any irritant below the level of SCI
- pain medication if pain is the irritant
- anti hypertensive medications
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