2. Chemodenervation: Basics and Practical Considerations Cynthia L. Comella, MD, FAAN Professor Rush University Medical Center Department of Neurological Sciences Barbara I. Karp, MD Combined NeuroScience Institutional Review Boards National Institute of Neurological Disorders and Stroke National Institutes of Health

3. “Sausage Poisoning” Justinius Kerner 1786-1862 Kerner’s second monograph on “fatty poison” (1822) Erbguth FJ. Mov Disord. 2004;(19 Suppl) 8:S2-S6.

4. Botulinum Toxin Seven distinct serotypes of toxin A, B, C, D, E, F, G Serotypes A and B available for human use Botulinum toxin complex Hemagglutinin and non-hemagglutinin proteins Neurotoxin

5. Botulinum Toxin Most potent neurotoxin known Nanogram amounts are sufficient to be lethal Listed among the 6 highest risk threat agents of bioterrorism by the Centers for Disease Control and Prevention (CDC)

6. Question Which of the following is the primary mechanism of action of botulinum toxin? A. Blocks acetylcholine receptors on muscles B. Inhibits calcium channels C. Cleaves SNAP proteins for vesicle fusion D. Weakens muscle by cleavage of actin SNAP = synaptosomal associated protein.

7. Botulinum Neurotoxin (BoNT) Heavy chain C terminus: acceptor binding site cholinergic neurons N terminus: translocation Light chain Zinc endopeptidase Cleaves specific proteins involved in membrane fusion (SNARE proteins) Department of Bacteriology. University of Wisconsin-Madison. Available at http://www.bact.wisc.edu/index.php. Accessed October 6, 2010. SNARE = soluble N-ethylmaleimide-sensitive factor attachment protein receptors.

8. Mauricio Montal Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, California 92093-0366; Botulinum Neurotoxin: A Marvel of Protein Design Montal M. Annu Rev Biochem. 2010;79:591-617.

9. BoNT Mechanism of Action Presumed to have local effects in muscle.

10. BoNT Mechanism of Action Presumed to have local effects in muscle.

11. BoNT Mechanism of Action Presumed to have local effects in muscle

12. Botulinum Toxin: Role of Heavy and Light Chains

13. Botulinum Toxin Serotypes: Cleavage of SNARE Proteins Type B Type A BTX = botulinum toxin; VAMP = vesicle-associated membrane protein.

14. Recovery Following Injection Clinical benefit wanes in approximately 3 to 6 months EMG evidence of denervation persists up to 1 year but completely resolves There is restoration of original neuromuscular junction EMG = electromyography.

15. Botulinum Toxins: Perspective on Therapeutic Development 1977 Used in humans (Allen Scott, MD, Smith- Kettlewell Institute) 1979 Edward Shantz produced 150 mg of BoNT-A licensed for all therapeutic uses from 1989 to 1998 1980s Oculinum ® used in patients with variety of neurological conditions Dysport ® (BoNT-A) used in Europe 1989 (FDA approved Botox  for strabismus, blepharospasm, and hemifacial spasm (lack class 1 evidence) 1990s SNARE complex described Mechanism of action of botulinum toxin described FDA = US Food and Drug Administration.

16. Botulinum Toxin: First Clinical Preparation 1979: Original batch BoNT-A (Oculinum  ) 150 mg was used for more than 250 000 injections in humans

17. 2000 to present Availability of new brands and serotypes Onabotulinum toxin (Botox ® [Type A]) Rimabotulinumtoxin (Myobloc ® [Type B]) Abobotulinumtoxin (Dysport ® [Type A]) IncobotulinumtoxinA (Xeomin ® [Type A]) Expanding list of possible uses Close to 100 uses described in all areas of medicine Only a few receiving approval of government agencies Botulinum Toxins: Perspective on Development

18. Toxin Brands Botox ® Onabotulinumtoxin A Serotype A Allergan Vacuum dried Refrigerate 50 Unit vial 100-U vial size Reconstitute with saline CD dose: 50 to 300 U Myobloc ® (NeuroBloc  ) RimabotulinumtoxinB Serotype B Solstice Liquid Refrigerate 2500 Unit vial 5000 Unit vial 10 000 Unit vial No reconstitution CD dose: 2 500 to 15 000 U

19. Dysport ® AbobotulinumtoxinA Serotype A Ipsen Freeze dried Refrigerate 250 Unit vial 500 Unit vial Reconstitute with saline CD dose: 250 to 1000 U Xeomin ® IncobotulinumtoxinA Serotype A Merz Powder Room temp 50 Unit vial 100 Unit vial Reconstitute with saline CD dose: 100 to 300 Toxin Brands

20. Know Your Botulinum Toxin! Be familiar with the brand of BoNT Storage, vial size, dosing, immunogenicity LABEL SYRINGE WITH TYPE AND CONCENTRATION

22. Evidence-Based Review: Focal Dystonia DisorderConclusionsRecommendLimitations Cervical dystonia Established safe and effective ANo effective alternative BlepharospasmProbably effective BLack of controlled studies Arm/hand dystonia Probably effective BNo effective alternative Leg/foot dystonia Data inadequateNoneNo effective alternative Spasmodic dysphonia Adductor Probably effective BNo effective alternative

23. Clinical Uses Proposed for BoNT Ophthalmologic Strabismus Nystagmus Apraxia of eyelid opening Protective ptosis Dystonia Blepharospasm Cervical dystonia (CD) Spasmodic dysphonia Oromandibular dystonia Limb dystonia Spasticity Arm/hand Leg Post-stroke Multiple sclerosis Cerebral palsy (CP) Spinal cord injury Other neurological disorders Hemifacial spasm Palatal myoclonus Tremor Tics Parkinson’s disease Tremor Freezing gait Clenched fist Pain Headache Migraine Tension headache Fibromyalgia Low back pain Painful muscle spasm Radiculopathy Gastrointestinal disorders Achalasia Anal sphincter spasm Constipation Urological Vaginismus Urinary sphincter spasm Spastic bladder Sialorrhea Stuttering Cosmetic uses Hyperhidrosis

24. FDA Approved Indications 1989 Blepharospasm/disorders of the VII nerve (onabotulinumtoxinA [Botox]) 2000 Cervical dystonia (onabotulinumtoxinA [Botox], rimabotulinumtoxinB [Myobloc]) 2002 Glabellar lines (onabotulinumtoxinA [Botox] cosmetic) 2004 Axillary hyperhidrosis (onabotulinumtoxinA [Botox]) 2009 Cervical dystonia and wrinkles (abobotulinumtoxinA [Dysport]) 2010 Cervical dystonia and blepharospasm (incobotulinumtoxinA [Xeomin]) Upper limb spasticity (onabotulinumtoxinA [Botox]) Chronic migraine (onabotulinumtoxinA [Botox])

25. Clinical Issues Methods for administration Safety Penetration into central nervous system (CNS) Brand and serotype equivalency Immunogenicity

26. Clinical Issues Methods for administration Safety Penetration into central nervous system (CNS) Brand and serotype equivalency Immunogenicity

27. Treatment Principles Establish treatment goals Understand functional neuroanatomy of area Select muscles based on observation, patient report, posture Adjust dosing for each muscle Target injection into intended muscles Follow up for benefit and side effects

28. Methods of Administration Number of injection sites into each muscle Use of electromyography Outcomes Clinically important measures Scales with demonstrated reliability, validity, and responsiveness

29. Question Should you utilize electromyography for injections of neck or limbs? Yes No

30. Is Electromyography Useful? Significantly increases the magnitude of improvement at the same dose of BoNT Used complementary to clinical examination Blinded evaluations show significance for both patient and physician assessments  Comella, 1992 Targeting muscle is not accurate without EMG guidance  Van Gerpen, 2000 Sternocleidomastoid “missed” in 20%; splenius capitis and deeper muscles missed up to 60% of the time without EMG guidance  Brans, 1996 Accuracy in forearm approximately 37% without EMG  Molloy, 2002

31. Methods of Administration Appropriate dilutions Dose into specific muscles Number of injection sites into each muscle Use of electromyography Outcomes Clinically important measures Scales with demonstrated reliability, validity, and responsiveness

32. Methods of Administration Outcomes Response assessed by patient Normalization of posture Functional improvement Relief of discomfort

33. Outcomes Response Assessed by Patient Visual Analog Scale No improvementComplete Improvement 0% 100% 0 = No benefit 1 = Minimal benefit (1–25%) 2 = Mild benefit (26–50%) 3 = Moderate benefit (51–75%) 4 = Excellent benefit (76–100%)

34. Outcomes Response Assessed by Examiner Scales with demonstrated reliability, validity, TWSTRs (CD) Blepharospasm rating scale Spasticity scales (modified Ashworth)

35. Clinical Issues Methods for administration Safety Penetration into CNS Brand and serotype equivalency Immunogenicity

36. Botulism Symmetric Cranial Neuropathies Diplopia/blurred vision Ptosis Dysphagia Dysarthria Dry mouth Mydriasis Flaccid paralysis Respiratory failure

37. Demonstration of Neuromuscular Junction Blockade by Repetitive Stimulation

38. November 2006 –100 micrograms pure BoNT- A, research grade (40,000 MU) –4 people get botulism from cosmetic injections 40 to 104 days in hospital Chertow DS, et al. JAMA. 2006;296:2476-2479. Safety

40. Evidence of Spread of Botulinum Toxins Beyond Local Injection Site Systemic spread Increased jitter in distant muscles Dysphagia following CD injections Dry mouth following injection of BoNT-B into limb muscles Direct or indirect central effects Altered plasticity

41. Safety Report from FDA’s Adverse Event Reporting System Figure 1. Serious adverse events and botulinum toxin type A sales figures (used with permission from M Brin, MD; Allergan, Inc), January 1989 to December 2002. Cote TR et al. J Am Acad Dermatol. 2005;53:407-415. In 217 serious AEs with therapeutic uses, there were 28 deaths. AE = adverse event.

42. Serious AEs More common with therapeutic than cosmetic use Not necessarily related to toxin (eg, MI, seizure) Probably related Weakness, dysphagia, flu-like syndromes, injection site trauma 28 deaths: 26 with underlying diseases Deaths from: MI, respiratory arrest, CVA, PE, pneumonia, other/unknown CVA = cardiovascular accident; MI = myocardial infarction; PE = pulmonary embolism.

43. Safety  FDA safety review in 2008  Deaths reported in children receiving high doses for CP; risk complicated by underlying disorders and use of anesthesia Black box warning required (April 2009) Risk of adverse events with toxin spread beyond injected site Developed generic names to emphasize difference between marketed products Risk Evaluation and Mitigation Strategy Information of risk for distant spread Medication guide

44. Black Box Warning The effects of (brand name) and all botulinum toxin products may spread from the area of injection to produce symptoms consistent with botulinum toxin effects. These symptoms have been reported hours to weeks after injection. Swallowing and breathing difficulties can be life threatening, and there have been reports of death. The risk of symptoms is probably greatest in children treated for spasticity, but symptoms can also occur in adults, particularly in those patients who have underlying conditions that would predispose them to these symptoms.

45. Safety Issues for CP Risk factors for adverse events in CP Dosing considerations (see review below) Gross motor function classification-V Nonambulatory Presence of comorbidities (neurological, physical) Presence of pseudobulbar palsy Method of sedation/anesthesia Graham K. Toxins. 2008. Heinen et al. Euro J Ped Neurol. 2006.

46. Clinical Issues Methods for administration Safety Penetration into CNS Brand and serotype equivalency Immunogenicity

47. Evidence of Central Effects Effects on spinal cord circuitry Reduced presynaptic inhibition between flexor and extensor forearm muscles following injection for limb dystonia/tremor Effects on brainstem Changes in abducens motoneurons with lateral rectus muscle injections No effects on blink reflex recovery, brainstem auditory evoked potentials Cortical effects Conflicting evidence of altered central plasticity and excitability following injections Caleo M et al. J Neurochem. 2009;109:15-24.

48. Botulinum Toxin: Physiologic Effects: H Reflex Before BTX: Loss of reciprocal inhibition 3 Weeks after BTX: Restoration of reciprocal inhibition Priori et al. Brain. 1995.;118 (Pt 3):801-107

49. Before1 mo p-BTX3 mos p-BTX Gilio et al. Ann Neurol. 2000;48:20-26. Botulinum Toxin: Physiologic Effects: H Reflex MO = month.

50. Retrograde Effects of BoNT-A Effects of BoNT-A (cleaved SNAP-25) observed: In retinal cells and visual cortex following superior colliculus injection In ipsilateral facial nucleus following injection into mouse whisker pad In contralateral hippocampus following unilateral injection Antonucci F, et al. J Neurosci. 2008;28:3689-3696. (BoNT-A cleaved SNAP-25 shown in red above)

51. Central Effects: Clinical Implications Central effects difficult to interpret clinically Primary clinical effect is denervation Altered central plasticity due to altered sensory input (Effects on gamma neurons?) Retrograde axonal transport with central BoNT activity “Lack of adverse central effects suggest that physicians can continue to use BoNT safely as therapy.” Curra A et al. Neurology. 2009;72:1095-1099.

52. Clinical Issues Methods for administration Safety Penetration into CNS Brand and serotype equivalency Immunogenicity

53. Question All brands and types of botulinum toxin can be used interchangeably. Yes No

54. Four brands of BoNT available for clinical use 3 are BoNT-A (Botox  [OnabotulinumtoxinA], Dysport  [AbobotulinumtoxinA], Xeomin  [IncobotulinumtoxinA]) 1 is BoNT-B (Myobloc  [RimabotulinumtoxinB]/NeuroBloc  [Botulinum Toxin Type B]) Each brand of BoNT except Xeomin ( IncobotulinumtoxinA) is a complex mixture of components with BoNT being the therapeutically active component, but… Each of these components influence therapeutic efficacy, adverse effects profile, and antigenicity. Comparative studies have not established simple dose equivalency calculations that can be utilized in a clinical setting. Clinicians should consider each brand and serotype individually. Can BoNT Brands and Serotypes Be Used Interchangeably?

55. Can BoNT Brands and Serotypes Be Used Interchangeably? No! When starting a new brand, base dosing on the package insert and studies of that brand Consider changing from one brand to another: If there is resistance to 1 serotype Based on patient need or insurance Avoid “rotating” brands and serotypes

56. Clinical Issues Methods for administration Safety Penetration into CNS Brand and serotype equivalency Immunogenicity

57. Question Which of the following is the most common reason for failure of efficacy following botulinum toxin injection? A. Immunoresistance B. Inactivated toxin C. Wrong muscles selected D. Previous tetanus inoculation

58. Failure to Benefit Rarely Due to Antibodies Common reasons for lack of efficacy Injection into the wrong muscles Inadequate dosing Unrealistic patient expectations Stress-induced exacerbation Uncommon reasons for lack of efficacy Change in dystonia Immunoresistance

59. Factors Associated With Immunoresistance ? Protein content of BoNT Complexing proteins Hemagglutinin and nonhemagglutinin More frequent injections Intervals less than 3 months “Booster” injections Large doses/cumulative doses Genetic predisposition

60. Pre-UBI Post-UBI Negative UBI Positive UBI Unilateral Brow Injection (UBI) for BoNT Resistance Injection of small amount of BoNT into corrugator on 1 side Re-evaluate at 4 weeks Assess symmetry of corrugator contraction by comparison of brow furrows UBI = unilateral brow injection.

61. Key Points Botulinum toxin works through reversible chemodenervation. Botulinum has a long history of efficacy and safety when used appropriately. Botulinum toxin used in practice requires careful explanation to patients of expectations, risks, and reporting of AE. The clinical importance of CNS penetration of BoNT requires further evaluation. Each BoNT brand and serotype should be considered a unique drug.