Spinal Cord Injury: Epidemiology, Pathophysiology, & Treatment, Slides of Orthopedics

Download Spinal Cord Injury: Epidemiology, Pathophysiology, & Treatment and more Slides Orthopedics in PDF only on Docsity! Spinal Cord Injury Docsity.com Overview • Epidemiology • Pathophysiology • Classification of SCI’s & descriptive terms • Natural History & functional prognosis • Treatment Strategies Docsity.com Spinal Cord Injury pathophysiology Secondary injury • Biochemical cascade • Cellular processes Most acute therapies aim to limit secondary injury cascade Docsity.com Secondary Injury theories • 1970’s: free radicals • 1980’s: Ca, opiate receptors lipid peroxidation • 1990/2000’s: apoptosis intracellular protein synthesis glutaminergic mechanisms Docsity.com Definitions • Neurologic level most caudal segment w/ normal sensory & motor function on both sides of the body • Motor level most caudal segment w/ normal motor function on both sides of the body (motor grade ≥ 3) Docsity.com Classification incomplete SCI syndromes Central Cord Syndrome • Motor loss UE>LE • Hands usu affected • Common in elderly w/ pre-exist spondylosis/stenosis • Substantial recovery Docsity.com Classification incomplete SCI syndromes Brown Sequard • Ipsilat motor, proprioception loss • Contralat pain, temp loss • Penetrating injuries • Good prognosis for ambulation Docsity.com Classification incomplete SCI syndromes Anterior Cord Syndrome • Motor loss • Vibration/position spared • Flexion injuries • Poor prognosis for recovery Docsity.com Expected Neurorecovery complete tetraplegia • 70-85% chance of gaining at least one additional level • Motor grade 2/5 for a given level @1 week, all gained functional strength at next level Ditunno, Arch Phys Med Rehabil, 2000 Docsity.com Expected Neurorecovery incomplete tetraplegia • >90% gain at least one UE motor level • If pinprick spared in same dermatome, 92% chance of recovery to ≥ 3/5 motor strength Poynton, JBJS-Br, 1997 Ditunno, Arch Phys Med Rehabil, 2000 Docsity.com Expected Neurorecovery incomplete tetraplegia • Majority of improvemen t in first 6-9 mos Waters, J Spinal Cord Med, 1998 Docsity.com Functional Capacity C1-C4 • Dependent in self-care and transfers • motorized wheelchair w/ special controls - mouthsticks (C3-C4) - infrared - sip-and-puff Docsity.com Functional Capacity C5 • Active elbow flexion present • Capable of some simple ADL’s w/ setup - may eat w/ balanced forearm orthosis - may write/type w/ opponens splint • Still dependent for transfers/ bed positioning Docsity.com Functional Capacity C6 • Added shoulder stability due to rotator cuff innervation • Active wrist extension (extensor carpi radialis) • Tenodesis grip: passive finger flexion and thumb opposition w/ wrist extension • Tenodesis grip strengthened w/ flexor-hinge orthosis Docsity.com Functional Capacity C8-T1 • Intrinsic hand function • improved grasp/ dexterity • independent bed mobility & transfers • independent ADL’s Docsity.com Functional Capacity thoracic paraplegia • Abdominal strength beginning @ T6 • sitting balance improved • bipedal ambulation w/ KAFO’s & walker (swing-to gait pattern) • energy consuming, difficult for community use Docsity.com Ambulation after SCI motor requirements • Grade ≥ 3/5 strength in hip flexors on one side • Grade ≥ 3/5 strength in quadriceps on other side Docsity.com Steroids methylprednisolone sodium succinate • Large body of animal studies • Various neuroprotective mechanisms postulated Docsity.com Neuroprotection w/ MPSS Inhibition of Lipid Peroxidation Preservation of Spinal Cord Blood Flow Preservation of Aerobic Metabolism Attenuation of delayed Glutamate release Preservation of Na, K Homeostasis Inhibition of Calpain-mediated Cytoskeletal damage Preservation of Calcium Homeostasis Docsity.com MPSS The standard of care? Docsity.com NASCIS III • 16 hospitals, 499 patients • 3 treatment arms (all got MPSS bolus) MPSS 5.4 mg/kg for 24 hrs MPSS 5.4 mg/kg for 48 hrs Tirilazad 2.5 mg/kg Q6 hr for 48 hrs Bracken, JAMA, 1997 Bracken, J Neurosurg, 1998 Docsity.com NASCIS III • 48 hr protocol better than 24 hr protocol (if treated between 3 and 8 hours) • 2x incidence of pneumonia, sepsis in 48 hr group (NS) Bracken, JAMA, 1997 Bracken, J Neurosurg, 1998 Docsity.com Criticism of NASCIS II • All primary outcomes (-) (no diff in neuro improvement between grps) • (+) findings only in post-hoc analyses (arbitrary stratification to before or after 8hrs) • Only 38% of original enrollment included • <8 hr control group poor results Docsity.com Criticism of NASCIS III • Primary outcomes negative (no diff in treatment among groups) • all positive findings in post hoc analyses (when arbitrarily divided into <3hr/ >3 hr) Docsity.com Criticism of NASCIS III • Treatment effects small • Effect NS @ 1yr • ? Inappropriate statistics Docsity.com Methylprednisolone • Routine use currently not uniformly accepted • Several professional associations have issued position statements that MPSS should not be considered “standard of care” • Medico-legal concerns remain Docsity.com SYGEN® clinical trials • Single center trial, 37 pts: promising • Multicenter trial, 800 pts: disappointing Geisler, N Engl J Med, 1991 Geisler, Spine, 2001 Docsity.com Augmentation of Regenerative Ability of CNS Neurons Neurotrophic Factors • Epidermal growth factor • Fibroblast growth factor 2 • BDGF: brain derived growth factor • Cyclic AMP Kojima, J Neurotrauma, 2002 Docsity.com Inhibitors of Neurite Outgrowth • ECM molecules in CNS myelin • Glial scar/ cystic cavity that forms at injury site Jones, J Neuroscience, 2002 Docsity.com