Neurological Complications following SCI William McKinley MD Director, SCI Rehabilitation Medicine Associate Professor

1. Neurological Complications following SCIWilliam McKinley MDDirector, SCI Rehabilitation Medicine Associate Professor PM&RVCU / MCV

2. Overview of Spinal Cord Function / Injury • Movement (Weakness) • Sensation (Sensory loss, Pain) • Muscle tone (Spasticity) • Bladder/bowel (Neurogenic B/B) • Sexuality (Sexual dysfunction)

3. Neurological Complications Following SCI • Syringomyelia • Pain • Spasticity

4. Syringomyelia • Syrinx = fluid filled cavity (cyst) within the spinal cord • Syringomyelia = neurological symptoms due to syrinx • incidence - 3-10% • etiology - trauma, tumor, congenital • area of tissue damage / inflammation • can expand, elongate, cause pressure

5. Syringomyelia: symptoms • Pain (radicular) • Sensory loss • weakness • Spasticity • Hyperhydrosis • Bladder / bowel

6. Syringomyelia Diagnosis / Treatment • Dx: • clinical findings / suspicion, physical exam • MRI (CT/myelogram, U/S) • Rx • surgical shunt / drainage to “low” pressure points • syrigopleural, syringoperitoneal) • pain management

7. SCI PAIN • Challenging issue • Physiologically & psychologically • Incidence 15 - 85 % • Etiology • Spinal cord pain • Radicular • Muscuoskelletal

8. Factors associated with SCI Pain • Level of Injury (LOI) • Complete vs Incomplete • Time since injury • Type of injury (GSW, trauma) • Psychological factors

9. Classification of SCI PAIN • Central Pain • Central Pain - below LOI, symmetrical (burning, tingling) • Radicular Pain • At the LOI, asymmetrical (aching, stabbing) • Musculoskelletal Pain • localized MS structures (aching, tender)

10. Mechanism of Neurogenic SCI Pain • largely unknown • Irritation / abnormal firing of damaged nerve axons or roots • Loss of descending inhibition

11. management of SCI Pain • Pharmacological - neuropathic pain meds • Surgery • Adjunctive treatments • Psychological Rx

12. Neuropathic meds • Anticonvulsants (nerve membrane stabilization) • Neurontin, Tegretol, Dilantin • Antidepressants (increase Seritonin levels) • Elavil, Trazadone • Others : Mexiletine • Epidural agents • Morphine, Clonidine, baclofen

13. Non-pharmacologic Rx • Spinal cord stimulation • ? effectiveness • Surface TENS • best with radicular pain incomplete injuries • Surgery • Dorsal Root Entry Zone (DREZ)

14. Spasticity • Definition: “Abnormal, velocity-dependent increase in resistance to passive movement of peripheral joints due to increased muscle activity”

15. Spasticity: Etiology (Diagnosis) • Spinal Cord Injury • Traumatic Brain Injury • Stroke • Multiple Sclerosis • Cerebral Palsy

16. Pathophysiology • Intrinsic hyperexcitability of alpha motor neurons within the spinal cord secondary to damage to descending pathways • cortico, vestibulo, reticulospinal • CNS modification • neuronal sprouting • denervation hypersensitivity

17. NEGATIVE SX’s Weakness Function Sleep Pain Skin, hygiene Social, Sexuality contractures USEFUL SX’s Stability Function Circulation Muscle “bulk” Symptoms of Spasticity

18. Spasticity: Treatment Decisions • Is Spasticity: • Preventing function?, Painful? • A result of underlying treatable stimulus • A set-up for further complications? • What Rx has been tried? • Limitations and SE’s of Rx… • Therapeutic goals

19. Goals of Therapy • Ease function (ambulation, ADL) • Decrease Pain, contracture • Facilitate ROM, hygiene

20. Ashworth Scale 1= no increased tone 2= slight “catch” in ROM 3= moderate tone, easy ROM 4= marked tone, difficult ROM 5= Rigid in flexion or extension Spasm Frequency Scale 0= none 1= mild 2= infrequent 3=> 1 per hour 4= > 10 per hour Spasticity Scales

21. Rehab Evaluation (con’t) • Gait patterns • Transfer abilities • Resting positioning • Balance • Endurance

22. Management Options • Physical interventions • systemic medications • chemical denervation • Intrathecal agents • orthopedic interventions • neurosurgical interventions

23. Rehabilitation Interventions • Positioning (bed, wheelchair) • Modalities • heat (relaxation) • cold (inhibition) • Therapeutic Exercise • inhibitory to spastic muscles • facilatory to opposing muscles • Orthotics

24. Non-Conservative Treatment Options • Oral Medications • Injections (Phenol , Botox) • ITB (Intra-Thecal Baclofen) • Surgical (nerve, root, SC) • Spinal Cord Stimulator

25. Oral Antispasticity Medications • Baclofen • Dantrium • Diazepam • Clonidine • Tizanidine • (limitations: non-selective, side effects)

26. Baclofen (Lioresal) • GABA-B analogue; binds to receptors • inhibits release of excitatory neurotransmitters (spasticity control) • Ca++ (pre-synaptic inhibition) • K+ (post-synaptic inhibition) • may also decrease release of substance P (pain control)

27. Dantrium • Inhibits Ca++ release at muscle level • Preferred : TBI, CVA, CP • SE’s - weakness, GI • Hepatotoxicity (<1%)

28. Diazepam • GABA “potentiation” • Usage : SCI, MS • SE’s - CNS depression, dependence,

29. Clonidine • Alpha-2 receptor blockage • Usage : SCI • Max dose - .4mg/d (oral & patch) • SE’s - OH, syncope, drowsiness

30. Tizanidine (Zanaflex) • 1996 - Approved for SCI, MS, CVA • Alpha-2 agonist (pre-synaptic inhibition) • 1/10 potency of Clonidine In lowering BP • Dose: T1/2: 2-5hr, begin 4 mg qhs (max 36 mg) • SE’s - Sedation, nausea, LFT’s

31. Chemical Neurolysis • Phenol 5-7%- Motor Point/Nerve block • Non-selective destruction of axons/myelin • Inds: Local (not general) spasticity • Duration: 3-6 months • SE’s - dysesthetic pain

32. Botulinum Toxin • 1989 FDA approved for strabismus & blepherospasm • Botox-A inhibits Ach Release at NMJ • Dose: 300-400u total (50-200/muscle) • Onset: 2-4 hours, Peak : 2-4 weeks • Duration: 3-6 months • ? Immunoresistance w/repeated inj’s

33. Spasticity: Surgical Management • Rhizotomy (posterior) • Cordotomy • Tendon Release • (limitations: invasive, bowel/bladder changes, irreversible, effectiveness varies)

34. Intrathecal Baclofen and Spasticity • Intrathecal delivery of baclofen via an inplantable pump is a safe and effective therapy for the management of spasticity !

35. Intrathecal Baclofen • Indicated for patients unresponsive to oral meds or with SE’s • Delivered directly to intrathecal space affording much higher drug concentration • Implantable system allows non-invasive monitoring & adjustments

36. ITB: Successful Outcomes • Study results since 1984 demonstrate reduction of Ashworth spasticity scores and spasm scales • Other results include improvements in: • pain • bladder function • chronic drug side effects • quality of life for patient & caregiver

37. ITB • 1992 - FDA Approved ITB for spinal Spasticity • 1996 - FDA Approved for Cerebral Etiologies (BI and CP)

38. ITB: Pharmacokinetics • Baclofen: GABA-b agonist; inhibits neuronal firing • ITB (Lioresal) • preservative-free; stable for 90 days • half-life 1.5 hours • typical dose: 1/100 of oral dose • average daily dose: 300-800ug • lumbar/cervical ratio 4:1

39. Decision to Treat w/ ITB • Have oral antispasticity meds truly failed? • Are their SE’s too great? • Can a single definitive surgical procedure accomplish similar goals? • Is precise control necessary for functional gains? • Does gain in function / comfort justify invasive procedure & maintenance?

40. Other Considerations ITB • Test dosing / trial dose via intrathecal lumbar puncture • Pump re-programming via radio-telemetry and computer • Maintenance follow-up: Q 4-12 weeks

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