Presentation on theme: "Robert J. Coni, DO Neurology – Grand Strand Regional Medical Center"— Presentation transcript:
1 Robert J. Coni, DO Neurology – Grand Strand Regional Medical Center The upper motor neuron syndrome and spasticity: Pathophysiology and ManagementRobert J. Coni, DONeurology – Grand Strand Regional Medical Center
2 Learning ObjectivesAfter this discussion, the participant should be able to:Define and differentiate spasticity from other neurological conditions associated with increased tone and be able to articulate the intricacies of various treatment options available.Relate the various presentations and be able to outline appropriate treatment measures depending on the presentation.Define and appreciate the full range of treatment options available.Appreciate the natural history and progression of spasticity including the causes, consequences of the insult and the added effects of disuse of the affected region.Understand the various modalities of chemodenervation and where, when they are applied.Appreciate the pharmacology of applicable oral agents including; indications, side effects and use of these agents.
3 Epidemiology and prevalence of Spasticity Spasticity affects > 12 Million people worldwide.Prevalence estimates vary and are specific to the associated conditions and/or etiology.19% of persons 3 months after a stroke.17% of persons 1 year after a stroke.4% with disabling spasticity.38% of persons 1 year after a stroke.Arms and legs affected.42% of persons 1 year after a stroke.Usually multiple joints affected.
4 Pathophysiology of Spasticity One of several components of the Upper Motor Syndrome.Causes:StrokeBrain or Spinal Cord InjuryCerebral PalsyMultiple Sclerosis
5 Features of Spasticity and spastic paresis Spasticity is one type of “muscle overactivity” which needs to be distinguished from other components of the syndrome including dystonia and rigidity.Muscle overactivity, soft tissue shortening and paresis are the 3 major disabling factors in spastic paresis of the UMN syndrome.Spasticity and muscle overactivity cause disability, interfere with ADLs and may cause pain and immobility.
7 Natural History of Spastic Paresis ACUTEDelayedCNS DamageParalysisImmobilized and shortened
8 Factors in the pathophysiology of spastic overactivity SpinalEnhanced excitability of monosynaptic pathways caused by multiple changes in reflex activity. Increased muscle spindle stimulation in stiffer muscles; α motor neuron excitability; presynaptic inhibition on group Ia afferents, group Ib inhibition, group II pathways, Renshaw cells and reciprocal group Ia inhibition.SUPRASPINALRelease of activity in excitatory brainstem descending pathwayscausing dystonic posturing.A hemiplegic posture develops, where antigravity musclesin particular are stimulated by motor neurons which developoveractivity.
9 Post Immobilization Joint ROM Limitation Immobilization in the shortened position results in less longitudinal tension (unopposed) producing contracture.Muscle contracture – results inAtrophyLoss of sarcomeres (shortening)Accumulation of connective tissueIncrease in spindle responsiveness
10 Natural History of Spastic Paresis DelayedACUTECNS Plastic Rearrangements*Spinal*SupraspinalCNS DamageParalysisDisuseMuscle OveractivitySpasticitySpastic contractionDystoniaOthersImmobilized and shortenedSoft Tissue Plastic RearrangementsCONTRACTURE
11 Common types of muscle overactivity in Umn syndrome SpasticityVelocity dependent increase in response to phasic stretch in absence of volitional command (ie., at rest).Clasped knife responseSPASTIC DYSTONIAStretch sensitive tonic muscle contraction in absence of volitional command (ie., at rest), including command to neighboring or distant muscles, and in the absence of phasic stretch of that affected muscle.SPASTIC CO-CONTRACTIONInappropriate antagonist recruitment triggered by volitional command during effort of an agonist in absence of phasic stretch.
14 Signs of the UMN syndrome Positive SignsNegative SignsSPASTICITY (Increased muscle stretch reflexes)SPASTIC DYSTONIASPASTIC CO-CONTRACTIONRELEASED FLEXOR REFLEXESASSOCIATED REACTIONS (SYNKINESIS)RHEOLOGIC CHANGES: INCREASED MUSCLE STIFFNESS AND CONTRACTUREMOTOR WEAKNESSMuscle fatigueLoss of selective control of specific muscles
15 FORCES that generate umn syndrome patterns ExtensorsFlexorsA combination of positive and negativesigns and rheologic changes in muscleproduce the common patterns ofUMN dysfunctionExtensorsSpastic and/orContracted Flexors
16 UMN Patterns generated by dynamic and static forces Upper LimbLower limbAdducted, internally rotated at shoulderFlexed elbowPronated forearmFlexed wristClenched fistThumb-in-palmFlexed hipAdducted thighsFlexed kneeStiff kneeEquinovarus or equinus footHyperextened hallusFlexed toes
17 Adverse effects of muscle overactivity Slow voluntary movements due to spasticityImpaired coordinationSkin sheer and breakdownRisk of contracturesPoor bed and wheelchair posturesImpaired standing balanceImpaired gaitImpaired sleepImpaired perineal hygiene and sexual functionDifficulty dressingpain
18 Clinical manifestations of the UMN syndrome SYMPTOMATIC COMPLAINTSPROBLEMS OF PASSIVE FUNCTIONPersonal carePositioningPROBLEMS OF ACTIVE FUNCTIONLimb useMobility
19 Consequences of Spasticity Possible medical complicationsContracture, Fibrosis, Muscle atrophyNEGATIVE IMPACT ON PATIENTS AND CAREGIVERSReduces mobility and impedes activities of daily livingOFTEN POORLY TREATED AND MISMANAGEDInadequate assessment guidelinesLack of specialized spasticity managementTreatment not individualizedInappropriate treatment selectionInsufficient follow-up
20 Assessment algorithm for muscle overactivity Patient presents with muscle overactivityEVALUATE PATIENTDoes the muscle overactivity significantly interfere with function or will it lead to musculoskeletal deformitiesNOYESPatient and Caregiver objectivesFunctional objectivesTechnical objectivesInitiate comprehensive treatment program
21 Assessment of spasticity Instrument MeasuredClinician reportedPatient/Caregiver Reported3D Gait analysisGoniometric ROMFunctional measuresFIMBarthel indexDisability scalesMuscle tone (modified Ashworth scale and Tardieu)Physician gait ratingsROM of jointsQOLGlobal outcome measuresSatisfaction/preferenceParticipation/impairmentsDependenceFunctional status
22 Clear outcomes measures needed No general consensusSystematic review of botulinum toxin use in patients with cerebral palsy demonstrated that outcomes tend to focus on spasticity or ROM and not activity or function.There have been conflicting reports of use of the modified Ashworth scale to assess lower limb spasticity.Inter rater reliability and longitudinal rating reliability are poor.Thus, Ashworth scale lacks validity and reliability to measure spasticity.
23 Importance of spasticity treatment When Untreated or inadequately treated, there can be long term health consequencesPainBladder and bowel dysfunctionDeformityContractureCompromised cognitive function due to fatigueNONPHARMACOLOGIC OPTIONS TO TREAT MUSCLE OVERACTIVITYPhysical and Occupational therapySurgical interventions
24 Objectives in treating muscle overactivity in Umn syndrome Improve quality of lifeRelieve symptoms and reduce disfigurementEase personal care and positioning (passive function)Improve limb function and mobility (active function)Enable activities of daily livingReduce burden of care
26 Nonpharmacologic treatment options for spasticity Surgical optionsPhysical or occupational TherapyStretchingOrthoticsCasting, splinting, positioningThermal or electrical modalitiesBiofeedbackSelective dorsal rhizotomyTendon Lengthening or transfersSpinal cord stimulator
27 Commonly used oral medications for spasticity treatment AdvantagesDisadvantagesDecreases frequency and severity of painful spasmsImproves ROMDecrease clonus, hyperreflexia, muscle stiffness and crampingReduces muscle toneReduces frequency of spasmsReduces muscle spasmsReduces spasticity without altering muscle powerSedation, weakness, nausea, dizzinessHallucinations due to sudden withdrawalDrowsiness, diarrhea, malaise, weaknessHepatotoxicWeakness, sedationDependence with long useWeakness, sedation, drowsiness, dry mouth, dizzinessBACLOFENDANTROLENEDiazepamTizanidine
28 Intrathecal agents: advantages and Disadvantages medicationadvantagesDisadvantagesIntrathecal baclofen (pump implantation)Other drugs (eg. Morphine)Direct administration of baclofen into spinal canal allows continuous supply of baclofen to site of action.Useful for severe or generalized cases of spasticity that do not respond to other less invasive treatments.Less CNS affects compared with oral baclofen because of the reduced dose required.Reduced painful spasmsReduces muscle tone and frequency of spasms while increasing ROMSurgical technique to implant reservoir and catheter to thecal sca.Risk of complications due to catheter or pump failure and infection.DrowsinessHeadacheWeaknessRisk of drug withdrawalHigh upfront cost
29 Commonly used nerve and muscle injectable medications for spasticity management AdvantagesDisadvantagesAlcoholPhenolBotulinum toxinQuick onset of actionReduces tone, increased passive ROMReduces temporary nerve block lasting up to several monthsHelps control muscle spasticityCauses localized decrease in symptomsReduces spasticity related painReversibleAssociated pain, skin irritation, muscle discomfortHighly variable duration of action, pain, muscle necrosis, dysesthesiaTransient muscle weaknessTolerance can develop
30 Neurolytic agents: mechanism of action MedicationMechanism of actionAlcohol, phenolPrimary mechanism involves denaturing proteins and tissue destruction. Lower concentrations result in decreased conductance of potassium and sodium while high concentrations result in effects on proteins. Behaves as a local anesthetic Onset of actions < 1hr duration approximately 2-12 wks Provides focal neuromuscular blockade Complications include transient pain Perineural blocks can be used for proximal muscles or when multiple muscles need to be injected (risk of long lasting dysesthesia)
31 Chemodenervation agents: mechanism of action medicationMechanism of actionsBotulinum toxinInhibition of acetylcholine in neuromuscular junction that leads to reduction in muscle activity. Onset of action, within 7 days; duration, approximately several months. Provides improvement in pain symptoms Can result in weakness in non-target muscles
32 Surgical options May reduce spasticity for some patients Combining orthopedic surgery and neurosurgery, with subsequent rehabilitation, helps normalize biomechanics of the spine and extremities and manage tone.Selective dorsal rhizotomy, in combination with physiotherapy, has been shown to be safe and effective for reducing spasticity.
33 Botulinum toxin serotypes Serotypes and preparationsA, B, C1, D, E, F, GDiffer in complex size and compositionexcipients, serotype manufacture processes and testing methods.Dosing and pharmacology cannot be generalized across serotypes and brands/products.Duration of effect will vary widely among serotypes.Mechanism of actions will vary by serotype.
34 Botulinum toxin target proteins Action/target proteinserotypeSelective cleavage of SNAP-25Leads to inhibition of acetylcholine releaseCLEAVAGE OF VAMP, OTHERWISE KNOWN AS SYNAPTOBREVININHIBITION OF SUBSTANCE P, CGRP, AND GLUTAMATE RELEASEA, C1, E B, d, f, g a
36 Botulinum Toxin: properties and actions Focal intramuscular injection therapyPhysiologic actionReversibleTitratable to the patient’s needsReduces muscle overactivityImproves passive /active functionFacilitates ease of careIncreases comfortPrevents or delays musculoskeletal complicationsLessens disfigurement
37 Proprietary botulinum toxins available Abobotulinumtoxin A Serotype A DysportIncobotulinumtoxin A Serotype A XeominOnabotulinumtoxin A Serotype A BotoxRimabotulinumtoxin B Serotype B Myobloc
38 Indications for the different Botulinum toxins DysportXeominBotoxMyoblocBlepherospasm and strabismus√Cervical dystoniaGlabellar linesAxillary hyperhydrosisUpper limb spasticityMany of these have been tested for the other indications listed above with literature reports available
39 Black Box warningThe effects of all botulinum toxin treatments may spread from the injection site to other areas, causing symptoms similar to botulinum toxin effects.Unexpected muscle weakness or loss of strength, hoarseness or trouble speaking, difficulty saying words clearly, loss of bladder control, double vision, blurred vision, drooping eyelids, and difficulty breathing or swallowing which can be life threatening. There have been deaths reported.Symptoms reported hours to weeks after injection
40 Onabotulinumtoxin A - Botox Serotype AIndications and usage:Cervical dystonia, primary axillary hyperhidrosis, blepherospasm, strabismus and chronic migraine.Also approved for upper extremity spasticity in adults.Decreases severity of increased muscle tome in elbow flexors (biceps). Wrist flexors (FCR and FCU), and finger flexors (FDP and FDS).Important limitationsSafety and efficacy not established of other upper ext muscle groups or lower limb spasticity.Not demonstrated to improve function or ROM when joint is affected by fixed contracture.Does not replace usual standard of care rehabilitation therapies.
41 Dosing Considerations The Pharmacology of the botulinum toxin preparations cannot be compared to each other or exchanged.Variability exists with toxin preparation, injection techniques, injection site, severity of spasticity and other confounding dosing issues which must be considered.Awareness of the wide range of dosing schedules and understanding of how to incorporate this expertise into clinical setting are important to achieving optimal treatment results.Duration of effect will vary with different preparations.In addition, even the dose units of different serotype A toxins are not interchangeable and there are no dose conversion factors that are reliable.
42 Botulinum toxin injection technique Generally, the dose is based on the size of the muscle and motor unit.The smallest dose is generally used to start but may be based on the degree of spasticity.Distribution of the injection doseSmaller muscles may only require one injection site., usually mid-belly.Larger or wider muscles may require injections in more than one site.The needle is Teflon coated and will allow EMG to be performed or electrical stimulation in only a small number of motor units.Both techniques can be used to localize.Deeper muscles require longer needles.Ultrasound guidance can be used to direct the needle into the muscle for added specificity and accuracy.To evaluate for fixed contracture, a diagnostic nerve block can be performed with lidocaine or bupivacaine.
43 Increasing Effectiveness of Botulinum toxin injections Target the motor end plate region.Perform active and passive stretching of injected muscles (with or without electrical stimulation).Nerve stimulation may boost botulinum toxin action.Studied in Gastroc/Soleus/Tib posterior.Botulinum toxin plus E-stim gave a better response to control group.Felt to help target muscle fascicules with a high density of NMJ.Increase the dilution of the toxin to allow greater spread.Theoretical concerns include spread out of the injected muscle and systemically.
44 Example: treatment of adducted, internally rotated shoulder with botulinum toxin Inject pectoralis major and minorPalpate the muscles to minimize the risk of pneumothorax.Distribute dose among several sitesLat dorsi and teres major may causeshoulder adduction and are accessiblebelow the post axillary fold.Increase accuracy with EMG,Ultrasound and or E-Stim.
45 Example: Treatment of Wrist Flexion with Botulinum toxin Inject flexor carpi ulnaris and flexor carpi radialis.May need to inject finger flexors tooFDS for proximal interphalangeal joint flexion.FDP for distal interphalangeal joint flexion.Inject 2 sites per muscle
46 ConclusionsSpasticity is one type of “muscle overactivity.” Other visible components include spastic dystonia and spastic co-contraction.These can be managed effectively with a combination of modalities, including but not limited to: PT/OT physical interventions, and medications given orally, intrathecally or directly into tissues in the form of neurolysis.Injury to the CNS leads to muscle over activity which leads to immobilization, shortening of tissues, contracture, disuse and then poor function, hygiene and discomfort.Management is dependent on the presentation but also on the desired effect and function and usually requires a comprehensive approach with good follow-up.Both medication management and neurolytic injections have advantages and disadvantages and often are used in combination depending on the outcome desired.More research is needed to define criteria for therapies, follow the effects of treatments in order to make definitive recommendations.