Spasticity and the Use of the Baclofen Pump for the SCI Patient From Hospital to Home: The Continum of Care after SCI

1. Spasticity and the Use of the Baclofen Pump for the SCI PatientFrom Hospital to Home: The Continum of Care after SCI University Health Network – Intrathecal Baclofen Pump Program Dr. Anthony S. Burns (presenter), Co-director, Toronto Rehabilitation Institute Dr. Mojgan Hodaie, Co-director, Toronto Western Hospital January 23, 2014

2. Objectives • Identify candidates for intrathecal baclofen (ITB) • Appreciate the basic principles of ITB management • Understand the advantages of ITB versus other treatments

3. Intrathecal baclofen is the gold standard treatment for severe, refractory spasticity

4. What is Spasticity? • Pandyan and colleagues defined spasticity as ”disordered sensori-motor control, resulting from an UMN lesion, presenting as intermittent or sustained involuntary activation of muscle.” (Pandyan AD, et al. Disability & Rehabilitation 2005; 27: 2-6)

5. Signs & Symptoms of Spasticity Velocity-dependent increased resistance to passive stretch Exaggerated deep tendon reflexes Clonus (rhythmic alternating contractions) Involuntary spasms (random muscles contractions) Presence of UMN signs (Babinski, Hoffman’s)

6. Ankle Clonus

7. Involuntary Lower Extremity Spasms

8. What Causes Spasticity? Basic Theory Loss of descending inhibition to the motor neurons in spinal cord:

9. What Causes Spasticity? Basic Theory Loss of descending inhibition to the motor neurons in spinal cord: Spasticity of cerebral origin results from lack of descending inhibitory input due to injury to the brain

10. What Causes Spasticity? Basic Theory Loss of descending inhibition to the motor neurons in spinal cord: Spasticity of cerebral origin results from lack of descending inhibitory input due to injury to the brain Spasticity of spinal origin results from interruption of descending tracts that inhibit or modulate alpha and gamma motor neurons

11. Loss of Inhibitory Input DescendingInhibition DescendingInhibition SensoryExcitation SensoryExcitation Normal Muscle Tone Loss of Descending Inhibitory Input

12. Common Etiologies (Causes) Spasticity of Spinal Origin Spinal Cord Injury Multiple Sclerosis Spasticity of Cerebral Origin Stroke Brain Injury Cerebral Palsy

13. Some Implications of Spasticity Muscle Stiffness FixedContracture • Unpredictable jerking of extremities, • Pain & fatigue, • Inability to bend joints & permanent loss of range of motion (contractures), • Inability to bend or pull the legs apart for ADLs (e.g., grooming, hygiene, etc.) • Arching of the back/pelvis & inability to maintain proper seating position, • Impaired mobility (ambulation & transfers), • Interrupted sleep FunctionalTask Care/Comfort Spasticity/ Neural SelectiveMotor Control/Dexterity Strength

14. Spasticity Treatment Options

15. Baclofen • Oral drug most frequently prescribed for spasticity of CNS etiology. • GABA agonist that binds to GABA-b (inhibitory) receptors in the CNS. • Oral baclofen has supraspinal activity that contributes to side effects. • sedation, excessive weakness, dizziness, mental confusion, and somnolence. • Reported incidence of adverse effects has ranged from 10% to 75%. (Dario A, Tomei G. Drug Safety 2004; 27: 799-818) • ~25-30% of SCI & MS patients fail to respond to oral baclofen. (Lewis KS, Mueller WM. Annals of Pharmacotherapy 1993; 27: 767-774)

16. Intrathecal Baclofen (ITB) Therapy Programmable pump is surgically placed in the abdomen and connected to a catheter placed in the intrathecal space Baclofen is delivered directly to the cerebrospinal fluid surrounding the spinal cord

17. The baclofen is implanted under the skin of the abdomen. • The catheter is tunneled under the skin to the back. • The catheter tip is inserted into the intrathecal space around the spinal cord.

18. Advantages of ITB Therapy? • Delivers drug directly to the site of action (spinal cord) • Minimize central side effects (brain) such as drowsiness or confusion • Can attain higher baclofen concentrations (CSF) than those attainable via the oral route. • Pump can be non-invasively programmed to deliver a range of infusion rates in customized dosing patterns • Reversible

19. Patient Selection & Screening

20. Basic criteria for ITB therapy • Conservative management not effective or poorly tolerated (e.g., side effects). • Identified, agreed upon goals for ITB therapy. • Positive response to intrathecal test dose trial. • Able to comply with follow-up requirements – refills q3-6 months.

21. Goals of ITB Therapy? Examples: • Improve activities of daily living (ADLs) and decrease caregiver burden (dressing, bathing, etc.) • Improve sleep • Decrease pain (related to spasticity/spasms) • Prevent contractures • Improve mobility/transfers • Improve wheelchair sitting • Improve gait (ambulatory patients)

22. 1. Patient selectionPatient perceptions of ITB Therapy®

23. Test Dose Trial

24. Test Dose TrialBaclofen injection – bolus via lumbar puncture Recommended concentration for screening test 50 microgram (mg)/ml Screening test may be repeated at increased doses if patient does not have positive response to first dose

25. Test Dose TrialUnderstanding patient’s response • Intrathecal bolus injection: • ‘Light switch’ that turns spasticity off • Long-term ITB Therapy® with Implanted Pump: • ‘Dimmer switch’ that allows dose to be adjusted precisely • Some patients can retain some functional spasticity while muscle strength and control are developed

26. Spasticity of Cerebral Origin • 86% of patients with spasticity of cerebral origin demonstrate a positive response to the screening test (Gilmartin R, Bruce D, Storrs BB, et al. J Child Neurol. 2000;15:71-77)

27. Spasticity of Spinal Origin • 97% of patients with spasticity of spinal origin demonstrate a positive response to the screening test (Penn RD. J Neurosurg. 1992;77:236-240)

28. Intrathecal Baclofen Trial

29. Pump Implantation

30. Surgical implantation

31. Titration & Ongoing Management

32. Initial dosing and titration • Key tasks: • Postoperative assessment • Titration of ITB dose • Wean oral medications (e.g. oral baclofen) • Monitoring of patients for side effects, overdose, underdose/withdrawal • Goals of dose titration: • Maintain muscle tone as close to normal as possible • Reduce frequency and severity of spasms • Use lowest dose required to achieve optimal response

33. Initial dosing and titration (continued…) • Dose requires frequent adjustments during first months • some patients do not make gains until several months after implant • Final dose is individualized • factors such as diagnosis, function and severity of symptoms influence dose • Programmability of ITB pump allows individual tailoring • Refills generally required every 3-6 months

34. Pump Refill

35. Summary of ITB Therapy Patient Care Pathway Patient Selection—Essential to therapeutic success Screening Test—Trial dose of intrathecal baclofen injection via lumbar injection Pump Placement—If screening test yields positive results, a Medtronic SynchroMed® II Drug Infusion System is implanted Rehabilitation and Titration—Dosetitration, which may be accompanied by inpatient and/or outpatient rehabilitation Management—Outpatient follow-up for pump refills

36. Complications & ITB Withdrawal

37. ITB Therapy Underdose/Withdrawal Signs of Underdose Causes of Underdose Programming error Empty drug reservoir (e.g. from missed refill appointment) Pump reached end of service Catheter complications (e.g. kink, occlusion, disconnection, migration, tear, fracture) Pump malfunction • Exaggerated rebound spasticity and muscle rigidity • Pruritus without rash • Hypotension • Paresthesias • Altered mental state • Seizure • Rhabdomyolysis • Condition may resemble autonomic dysreflexia, sepsis, malignant hyperthermia, neuroleptic malignant syndrome

38. Management of ITB Withdrawal Admit to monitored setting ↓ Start high dose oral baclofen ↓ Add additional GABA agonists (e.g., benzodiazepines) & titrate to control symptoms ↓ Consider dantrolene if hyperthermia & rhabdomyolysis present ↓ Interrogate & troubleshoot pump system

39. ITB Overdose Signs of Overdose Causes of Overdose Dosing error Programming error Injecting catheter access port during refill Use of concomitant drugs, e.g. oral Baclofen • Drowsiness • Lightheadedness • Dizziness • Somnolence • Respiratory depression • Seizures • Excessive muscular hypotonia • Loss of consciousness progressing to coma

40. Management of ITB overdose Admit to monitored setting ↓ Consider intubation to protect airway ↓ Interrogate and trouble shoot pump ↓ Continue to monitor until drug clears (< 24 hrs)

41. Case Reports

42. Satisfaction with ITB Therapy • More than 94% of caregivers are satisfied with ITB Therapy1 • 82% of subjects/caregivers indicated they would repeat the decision to receive the treatment2 • Most successful with goals that are: • Specific • Realistic • Set jointly by patient in collaboration with health care team • Documented prior to initiation of treatment 1. Campbell WM, Ferrel A, McLaughlin JF, et al. Long-term safety and efficacy of continuous intrathecal baclofen. Dev Med Child Neurol. 2002;44(10):660-665. 2. Krach LE, Nettleton A, Klempka B. Satisfaction of individuals treated long-term with continuous infusion of intrathecal baclofen by implanted programmable pump. Pediatr Rehabil. 2006 Jul-Sep;9(3):210-218.

43. UHN ITB Program Toronto Rehab Lyndhurst Centre Toronto Western Hospital Neurosurgery – Dr. Mojgan Hodaie Program Coordinator – Filomena Mazzella, RN Physiotherapy Anesthesiology – Dr. Philip Peng, Dr. Anuj Bhatia PACU, 5A Unit for post-op care ER staff & Neurology on call for after hours emergencies & admissions (as needed) • Physiatry – Dr. Anthony Burns • Program Coordinator – Filomena Mazzella, RN • Physiotherapy • Social Work • On-call Brain & Spinal Cord Rehab Program Physicians for after hours calls • In-patient rehab unit for select patients)

44. Questions? anthony.burns@uhn.ca