Spinal Cord Injury Study GuideThe Spinal Cord The spinal cord is a part of the central nervous system. Bundle of spinal nerve fibers that carry messages between the brain and different parts of the body. Other nerve fibers send and receive messages of feeling or sensation back to the brain from the body, such as heat, cold, or pain. Autonomic nervous system It controls the involuntary activities of the body; such as blood pressure, body temperature, and sweating. The spinal cord extends from the base of the brain (medulla oblongata) and leaves the cranium through the foramen magnum into the spinal canal. The spinal cord travels down the middle of the back, to about L2. The spinal cord is surrounded and protected by bones called vertebrae. The vertebral column is the number one support for the body. The spinal cord runs through the middle of the vertebraeSpinal Nerve Dorsal Ramus Motor and sensory Innervates the muscles and skin of the back Ventral Ramus Motor and sensory Innervates the ventrolateral part of the body wall and all limbs31 Spinal Nerves 8 cervical spinal nerve pairs (C1-C8) C1 goes above the C1 vertebra C8 goes below C7 vertebra 12 thoracic pairs (T1-T12) 5 lumbar pairs (L1-L5) 5 sacral pairs (S1-S5) 1 coccygeal pairVertebral Column 33 Vertebrae 7 Cervical Vertebrae 12 Thoracic Vertebrae 5 Lumbar Vertebrae 5 Fused Sacrum 4 Fused CoccyxLong Tracts of the Spinal Cord Bundles of axons in the white columns Relay certain type of information in same direction

** In Image, Blue is Ascending tracts, Red is Descending tracts, and Purple is Bidirectional tracts.Descending Pathways Carry motor commands to spinal cord Corticospinal Tract: motor pathways Destruction of this tract results in upper motoneuron syndrome Hypertonicity, Hyperreflexia and Babinski signsAscending Pathways Carry information to brain Spinothalamic tract: pain and temperature and crude touch Dorsal Columns: proprioception/vibration and discriminative touch Spinocerebellar Tract: Unconscious proprioception Muscular position and toneEpidemiology Traumatic SCI Incidence: 12,000 new injuries/year Prevalence: >250,000 in US Ratio 4(male):1 (female) Male between 16-30 years old Etiology of SCI Motor Vehicle Accidents 47% Falls 24% Sports 9% Violence 14% Other 7% C5 is the most common level T12 is the most common para level Weekends and summer months are the most frequent time periods for injury Incomplete tetraplegia (38.3%) Complete paraplegia (22.9%) Incomplete paraplegia (21.5%) Complete tetraplegia (16.9%)Nontraumatic SCI Spinal stenosis with myelopathy Cancer Transverse Myelitis Radiation Myelopathy Motor neuron disease Vascular ischemia Multiple Sclerosis Vit B 12 Deficiency Infectious abscess SyringomyeliaPathophysiology of Spinal Cord Injury Changes in Ionic Concentration at site of injury Influx on Calcium resulting in increase concentration of Phospholipase C and A 2 Increase in extracellular Potassium resulting in depolarization of cells Free radicals and excitatory amino acids (glutamate and aspartate) Damage to the spinal cord can occur from either a traumatic injury or from a disease to the vertebral column Ischemia (decreased blood flow) EdemaAfter Spinal Cord Injury From the point of injury and below, the spinal cord nerves cannot send messages between the brain and parts of the body like they did before the injury. Motor deficit Sensory deficit Bladder and bowel dysfunction Respiratory difficulties Sexual Dysfunction Each spinal cord injury is different. A person's injury is described by its level and type. Tetraplegia Refers to impairment or loss of motor and/or sensory function in the cervical segments of the spinal cord Impairment of function in the arms as well as in the trunk, legs and pelvic organsParaplegia Refers to impairment or loss of motor and/or sensory function in the thoracic, lumbar, or sacral segments of the spinal cord Depending on the level of injury, the trunk, legs and pelvic organs may be involvedClassification by ASIA Score ASIA stands for American Spinal Injury Association which developed standards for classification. These standards are now international. Scored from A-E. International Standards for Neurological Classification of Spinal Cord InjuryWhy do we perform ASIA testing? Diagnose Spinal cord injury Monitor Neurological Status Develop rehab program Prognostication ResearchDermatomes Region of skin that is innervated by a given spinal nerve Assess 28 dermatomes T4- Nipple line T6- Xiphisternum T10- UmbilicusMyotomes The collection of muscle fibers innervated by the motor axons within each segmental nerve rootLevel of Injury Neurological Level Refers to the most caudal segment of the spinal cord with normal sensory and motor function on both sides of the body Sensory Level Refers to the most caudal segment of the spinal cord with normal sensory function on both sides of the body Motor Level Similarly defined (to sensory) with respect to motor functionNeurological Category Incomplete injury Partial preservation of sensory and/or motor functions below the neurological level and includes the lowest sacral segment Complete injury There is an absence of sensory and motor function in the lowest sacral segmentMotor Exam: Required Elements The required portion of the motor examination is completed through the testing of key muscles (one on the right and one on the left side of the body) in the 10 paired myotomes Anal sphincter exam Each key muscle should be examined in a rostral-caudal sequence Strength graded on 6 point scale (0-5) 0 = total paralysis. **Involuntary spasms = 0 1 = palpable or visible contraction 2 = active movement, gravity eliminated, full range A 2 minus means active movement no quite full ROM 3 = active movement, against gravity, full ROM 3 minus given to less than full ROM against gravity, no ctx 4 = active movement, against some resistance 5 = active movement, against full resistance NT = not testable (halo, burn area, external fixator) Examine and grade bilaterally C5-T1 & L2-S1 C5 Elbow Flexors (biceps, brachialis) C6 Wrist Extensors (extensor carpi radialis longus) C7 Elbow Extensors (triceps) C8 Finger Flexors (flexor digitorum profundus)middle finger T1 Small Finger Abductors (abductor digiti minimi) L2 Hip Flexors (iliopsoas) L3 Knee Extensors (quadriceps) L4 Ankle Dorsiflexors (tibialis anterior) L5 Long Toe Extensor (extensor hallucis longus) S1 Ankle Plantarflexors (gastrocnemius,soleus) Limiting factors such as pain and deconditioning may be pesent such that the patient only grades a 4/5 In these situations, the muscles should be graded as a 5 with (*) to indicate that inhibiting factors were presentPin Sensory Examination Clean safety pin Must be able to distinguish between the pin( sharp) and dull edge Scoring Absent ( 0) Impaired (1) Normal (2)Light Touch Sensory A cotton tip applicator Stroke across the skin moving over a distance not to exceed 1 cm For dematomes C6-C8, the dorsal surface of the proximal phalanx is tested For LT, you do not have to distinguish b/w dull and sharp to get a 1Sensory Testing The S4-5 dermatome tested for both pin and light touch; represents the most caudal aspect of the spinal cord Deep anal sensation: on rectal digital exam the patient is asked to report any sensory awareness. Recorded as either present or absentSensory Level Last intact level on both sides of the body for both Pin and light touchASIA Impairment Scale A = Complete no sensory or motor function is preserved in the sacral segments S4 5 B = Incomplete sensory but no motor function is preserved below the neurological level and includes one of the following: any pinprick or light touch sensation in S45 or any deep anal sensation. Must have sacral sparing C = Incomplete - motor function is preserved below the neurological level, and less than 50% of the muscles below the neural level of injury are less than grade 3 (grade 0-2) D = Incomplete - motor function is preserved below the neurological level, and at least 50% of the muscles below the neurological level have a muscle grade greater than or equal to 3 (Grade 3,4,or 5) E = Normal sensory and motor function are normal, but elements or spasticity or SCI type pain may remain. Not truly neuro intactMedical Complications following Spinal Cory Injury Cardiovascular Hypotension Bradycardia Thermoregulatory problems (lesion above T8) Orthostasis Venous thromboembolism Autonomic DysreflexiaBradycardia Sinus bradycardia is exacerbated by Tracheal suctioning Consider Atropine 0.1-1 mg IV 10-15 min prior to suctioning Defecation Belching HR < 60 almost universal in acute SCI due to unopposed effects of Vagus Nerve. Rarely need pacemaker Up to 100% of tetraplegics will have bradyarrhythmias. Cardiac arrest due to these are rare Bradycardia resolves as spinal shock gradually resolves. Most pronounced at weeks 2-3 and typically resolves by week 6Thermoregulation Body temperature is normally regulated by hypothalamus Increase body temp Shivering (vasoconstriction) Decrease body temp Sweating (vasodilatation)SCI Thermo(dys)regulation SCI decreases ability of the hypothalamus to direct the periphery SCI patients are at times poikilothermic Adapt to the temp of the environment Patient able to shiver only above the level of injury Fever of unknown origin may be due to warm environment quad fever diagnosis of exclusionHypotension Neurosurgical guidelines MAP 85-90 mmHg the 1st week after injury Improve Spinal cord perfusionOrthostatic Hypotension Fall in blood pressures resulting from change in body position toward upright posture Symptoms Lightheadedness Dizziness Syncope Pallor Normal physiology Decreased BP from tilting toward upright is sensed in aortic and carotid baroreceptors Baroreceptors result in sympathetic outflow resulting in tachycardia and vasoconstriction SCI physiology Efferent pathway is interrupted No increase in sympathetic outflow No increase in epinephrine and norepinephrine Venous pooling limits venous return, reducing cardiac output More likely to occur in higher injury levels Less likely with incomplete injury or injury below T6 Improves with repeated postural challenges and the development of postural reflexes Spasticity may also lessen pooling Treatment Abdominal Binders Elastic compression stockings Adequate Hydration Gradual change toward upright posture Reclining wheelchair Daily tilting sessions Medications Pseudoephedrine, midodrine, Fludrocortisone, Salt tablets Caution in patients prone to autonomic dysreflexia Can cause supine hypertensionVenous Thromboembolism Incidence in SCI unknown Report of 47%-100% Most frequently in the first 2 weeks Virchows triad Venous stasis Intimal injury Hypercoagulability Other Risk Factors for DVT Extreme vasodilation while in spinal shock Concomitant long bone fxs with SCI Obesity, DM, PVD, malignancy Advanced age History of prior thrombosis Venous Thromboembolism Clinical Practice Guidelines Pneumatic compressive devices are recommended for the first 2 weeks Level 1 Scientific Evidence Anticoagulant within 72 hours for no evidence of bleeding, head injury, or coagulopathy Level 2; Strong panel opinion Most SCI centers use LMWH Prophylaxis LMWH Motor incomplete ASIA D should continue while in the hospital and up to 8 weeks for ASIA C Motor complete (ASIA A OR B) for 8-12 weeks depending on other risk factors Chronic SCI individuals who are hospitalized are also recommended to receive prophylaxis Vena cava filters are recommended to patients who Failed anticoag prophylaxis Contraindication to prophylaxis High level motor complete tetraplegia with poor cardiopulmonary reserve Level IV, C, Panel Opinion-Mod ***IVC filters are not substitutes to anticoagulation Diagnosed DVT now what? Therapeutic LMWH, warfarin LMWH is continued until INR is therapeutic for at least 24 hours Length if treatment is at least 3 months for DVT and 6 months for PTE, although some prefer longer treatment in SCI population.Autonomic Nervous System Autonomic Dysreflexia Massively imbalanced sympathetic discharge occurring in patients with SCI above the splanchnic outflow (T5-6) Incidence generally reported at 48-85% of all individuals with T6 or higher injury Causes GU Bladder distention Infection, Stones GI Impaction, abdominal emergencies Pressure ulcers PTE Ingrown toenails Fractures Body positioning Tight clothing Labor and Delivery Sexual Intercourse Menstruation Excessive Alcohol intake Symptoms Headaches Sweating above the level of lesion Flushing above level of lesion Nasal congestion Anxiety Complications Retinal hemorrhage Subarachnoid hemorrhage Intracerebral hemorrhage Myocardial infarction Seizures Death Treatment Early recognition!!! Elevate head Removal of precipitating stimulus Vasodilating meds Nitroglycerin (sublingual or paste) nifedipine bite and chew, not SL Hydralazine