1. Neurological Complications following SCI William McKinley MD Director, SCI Rehabilitation Medicine Associate Professor PM&R VCU / 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. Symptoms of Spasticity NEGATIVE SX’s Weakness Function Sleep Pain Skin, hygiene Social, Sexuality contractures USEFUL SX’s Stability Function Circulation Muscle “bulk”

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. Spasticity Scales 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

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

41. THE END