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Spasticity Mechanisms and Management

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SPASTICITY MECHANISMS AND MANAGEMENT Allison Oki, MD October 11, 2014 * Cortical neurons are responsible for the movement itself Pyramidal = direct Corticospinal (CS ... – PowerPoint PPT presentation

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Title: Spasticity Mechanisms and Management


1
SpasticityMechanisms and Management
  • Allison Oki, MD
  • October 11, 2014

2
Objectives
  • Video Development/Basic Mechanics of Gait
  • Overview Motor Disorders, Hypertonia, Spasticity
  • Pathophysiology
  • Cerebral Palsy
  • UMN syndrome - Consequences of Spasticity
  • Medical Management
  • Neurosurgical Interventions ITB and SDR

3
Development
  • Bipeds center of mass (COM) level of S2
  • Inherently unstable
  • Continual postural adjustment to maintain COM
    within base of support
  • Sit 6 mo
  • Crawl 9 mo
  • Independent walking 12 mo
  • Gait maturation at 6.5 years

4
Motor System
  • Motor system hierarchical
  • chain of command
  • extends from the cortical centers down to the
    nerves that innervate the muscles

5
Components of Motor System
  • Supplementary motor cortex
  • Cortical motor control centers
  • Basal Ganglia
  • Cerebellum
  • Brainstem Motor nuclei
  • Central pattern Generators

6
Motor Pyramid
7
Pyramidal and Extrapyramidal
  • Upper Motor Neurons
  • Pyramidal
  • direct corticospinal tract
  • Fine coordination motion
  • Extrapyramidal
  • indirect cortco-bulbo-spinal tracts (vestibular/
    reticular tracts)
  • Balance, posture, coordination

8
Central Pattern Generators
  • Located in the SC generate a consistent specific
    movement pattern
  • Analogy piano key and note, central pattern
    generator when stimulated produces the same
    movement pattern
  • Anterior horn of SC
  • Pyramidal lateral
  • Extrapyramidal - medial

9
Motor Disorders
  • Disorders of multiple neural components
  • basal ganglia
  • cerebellum
  • cerebral cortex
  • brainstem
  • descending spinal tracts
  • Hypertonia is a component of many motor disorders
  • Spasticity, dystonia and rigidity

10
Motor Disorders
  • Extra-pyramidal
  • Injury to BG, cerebellum or non-primary motor
    cortical areas
  • clinically abnormal motor control without
    weakness or changes in spinal reflexes
  • Pyramidal
  • cortical projections to the brainstem
    (corticobulbar)
  • SC (corticospinal)
  • clinically weakness and increased stretch
    reflexes
  • pyramidal
  • upper motor neuron
  • weakness

11
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12
What is spasticity?
  • Spasticity is a motor disorder characterized by
    a velocity dependent increase in tonic stretch
    reflexes, with exaggerated tendon jerks
    resulting from hyperexcitability of the stretch
    reflex, as one component of the upper motor
    neuron syndrome Lance 1980
  • Resistance to stretch increases with increasing
    speed and varies with the direction of the joint
    movement
  • Rapid rise in resistance to stretch above a
    threshold speed or joint angle
  • Sanger et al, Classification and Definition of
    Disorders Causing Hypertonia in Childhood,
    Pediatrics 2003

13
Hypothetical Mechanism
14
Pathophysiology of SpasticityTheories
  • Imbalance between excitatory and inhibitory
    impulses to the alpha motor neuron in the spinal
    cord
  • Due to a loss of descending inhibitory input to
    the alpha motor neuron due to injury to the
    cortical spinal tracts

15
Cerebral Palsy Definition
  • Primary abnormality of movement and posture
    secondary to a nonprogressive lesion of a
    developing brain
  • Represents a group of disorders rather than a
    single entity
  • Abnormal motor control and tone in the absence of
    underlying progressive disease

16
Epidemiology CP
  • Most common motor disorder of childhood
  • 3.6/1000 school age children
  • Higher survival rate of premature infants
  • Etiology majority of term infants do not have
    an identifiable cause
  • Causative factors
  • Prematurity
  • Infection
  • Inflammation
  • Coagulopathy
  • Greatest RF prematurity lt37wks
  • Incidence highest in the very premature

17
Pathology CP
  • gt80 abnormal neuroimaging
  • PVL white matter near the lateral ventricles
  • Premature 90 vs term 20
  • IVH
  • Corticospinal tract fibers to LE are medial to UE
    ? spastic diparesis

18
Common Gait Deviations CP
Location Impairment Potential Effects
Hip ? adductor tone Scissoring, difficulty advancing leg in swing
? iliopsoas tone Anterior pelvic tilt, lumbar lordosis, crouched gait
? femoral anteversion Intoeing, false genuvalgus, compensatory external tibial torsion
Abductor weakness Trendelenberg gait
Knee ? hamstring ROM Crouched gait
Hamstring/Quad co-contraction Stiff-kneed gait
Ankle ? gastroc tone/contracture Toe walking, genu recurvatum, difficulty clearing foot during swing
Internal tibial torsion Intoeing, ineffective toe-off
External tibial torsion Out-toeing, ineffective toe-off
Varus ? supination in stance or swing
Valgus ? pronation in stance or swing, midfoot breakdown
19
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20
Upper Motor Neuron Syndrome UMNS
  • Positive
  • Spasticity
  • Spastic Dystonia
  • Clonus/ hyper-reflexia
  • Reflex flexor and extensor spasms
  • Associated reactions
  • Negative
  • Weakness
  • Fatigue
  • Loss of selective motor control
  • Sensory deficits
  • Incoordination
  • Poor balance

Allison Brashear, Spasticity and Other Forms of
Muscle Overactivity in the Upper Motor Neuron
Syndrome, Nathaniel H. Mayer, Ch.1 Positive Signs
and Consequences of an Upper Motor Neuron
Syndrome, 2008
21
David Scrutton et al, Management of the Motor
Disorders of Children with Cerebral Palsy, H.
Kerr Graham, Ch.8 Mechanisms of Deformity
22
UMNS
  • UMNS disability
  • positive negative rheologic properties
  • Rheologic properties viscoelastic properties of
    the muscle and other soft tissues
  • Structural changes occur in the muscle cells
    causing intrinsic muscle stiffness (Olsen et al.
    2006)
  • Combined effects of all signs ? chronic
    unidirectional postures and movements that are
    generated by a net balance of muscle torques
    exerted across the involved joints

Allison Brashear, Spasticity and Other Forms of
Muscle Overactivity in the Upper Motor Neuron
Syndrome, Nathaniel H. Mayer, Ch.1 Positive Signs
and Consequences of an Upper Motor Neuron
Syndrome, 2008
23
UMNS
  • Torque force generated by muscle acting through
    a bony lever arm ?rotational movement
  • Normal movement is bi- or multi-directional,
    agonist and antagonist torques create motion
  • UMNS ? net unidirectional movements (positive
    signs) often persist as postures because
    voluntary bi- or multi-directional movement is
    impaired (negative signs) ? chronic effects on
    soft tissue, joint structures and bone

Allison Brashear, Spasticity and Other Forms of
Muscle Overactivity in the Upper Motor Neuron
Syndrome, Nathaniel H. Mayer, Ch.1 Positive Signs
and Consequences of an Upper Motor Neuron
Syndrome, 2008
24
Why is spasticity important?
  • Clinically diagnosed and treated
  • Musculoskeletal and neurologic exam
  • Tone, reflexes, strength, coordination
  • Spasticity ?
  • significant disability
  • ADLs
  • Seating
  • Comfort
  • Contracture
  • Loss of ROM
  • Negative impact on function
  • Bone deformity
  • Pain
  • Skin
  • Hygiene
  • Ability to provide cares

Allison Brashear, Elie Elovic, Spasticity
Diagnosis and Management, 2010, Ch 1.1 Why is
spasticity important?
25
Secondary effects of Spasticity
  • May effect function and long-term outcome
  • Persistent muscle imbalance ? muscle/tendon
    contractures ? joint or bone deformities
  • weak antagonists muscles ? require passive
    stretch for a minimum of 6 out of 24 hrs to
    maintain muscle length (Tardieu 1988) and to
    avoid development of a fixed contracture (Eames
    1999)
  • Abnormal forces across joints ? prolonged
    abnormal posture, increase energy expenditure,
    impair function, and negatively affect both the
    caregivers and patients QOL

L. Andrew Koman, MD et al, Botulinum Toxin Type A
in the Management of Cerebral Palsy, 2002, Wake
Forest University Press, p.40
26
Abnormal Forces across Joints
  • Ankle and subtalar ? fixed equinus, equinovarus
    or equinovalgus hindfoot deformities
  • Adductor and iliospoas spasticity ? hip
    subluxation and dislocation
  • Once a critical degree (50) of hip subluxation
    is present, dislocation is inevitable unless
    intervention occurs (Reimers 1987)
  • The resultant pelvic obliquity compromises
    sitting balance ? chronic pain
  • L. Andrew Koman, et al, Botulinum Toxin Type A in
    the Management of Cerebral Palsy, 2002, Wake
    Forest University Press

27
Bone Deformity
  • Abnormal muscle forces act on a growing skeleton
  • Hips and spine ? essential in weight bearing and
    positioning
  • Femur ? muscle and gravity loading forces during
    growth
  • Muscle forces in CP ? increased anteversion of
    femoral neck
  • hip flexion, adduction and internal rotation of
    the femur ? femoral head in a superoposterolateral
    direction, out of the acetabulum ? coxa valgus
    deformation of the femoral head and shallow
    acetabulum
  • Randall L. Braddom, Physical Medicine and
    Rehabilitation, 3rd Edition, Chapter 54 Cerebral
    Palsy, p.1249

28
Hip Dysplasia
29
Hip Subluxation
James R. Gage et al, The Identification and
Treatment of Gait Problems in Cerebral Palsy,
2009, Kevin Walker, Chapter 3.4 Radiographic
Evaluation of the Patient with Cerebral Palsy
30
Bone Deformity
  • Asymmetric muscle pull ? deformity of the spine
  • Kyphosis, scoliosis, rotational deformities
  • Comfort
  • Tone
  • Sitting
  • Standing alignment
  • Balance
  • Severe ? respiratory function compromise
  • Randall L. Braddom, Physical Medicine and
    Rehabilitation, 3rd Edition, Chapter 54 Cerebral
    Palsy, p.1249

31
Goals of Spasticity Management
  • Decrease spasticity
  • Improve functional ability and independence
  • Decrease pain associated with spasticity
  • Prevent or decrease incidence of contractures
  • Prevent bony deformity
  • Improve ambulation, mobility, function
  • Facilitate hygiene
  • Ease rehabilitation procedures
  • Improve ease of caregiving

32
Traditional Step-Ladder Approach to Management
of Spasticity

  • Neurosurgical procedures
  • Orthopedic
    procedures
  • Neurolysis
  • Oral medications
  • Rehabilitation Therapy
  • Remove noxious stimuli

33
Interdisciplinary team
  • Patient and family
  • Neurologist
  • Neurosurgeon
  • Occupational therapist
  • Physical Therapist
  • Physiatrist
  • Orthopedic Surgeon
  • Primary care physician

34
Rehabilitation Therapy
  • Stretching
  • Weight bearing
  • Inhibitory casting
  • Bracing
  • Strengthening
  • EMG biofeedback
  • Electrical stimulation
  • Positioning

35
Oral Pharmacologic Management
  • Baclofen
  • Diazepam
  • Clonidine
  • Tizanidine
  • Dantrolene Sodium

Allison Brashear, Elie Elovic, Spasticity
Diagnosis and Treatment, 2010, Ch.15
Pharmacologic Management of Spasticity Oral
Medications
36
Systemic medications limitations
  • Sedation
  • Hypotension
  • Confusion
  • Weakness
  • Nausea
  • For generalized rather than focal spasticity

37
Baclofen GABA analog
  • Binds to presynaptic GABA-B receptors in the
    brainstem, dorsal horn of SC and other CNS sites
  • Depresses both monosynaptic and polysynaptic
    reflexes by blocking the release of NTS
  • Inhibition of gamma motor neuron activity to the
    muscle spindle
  • Because these reflexes facilitate spastic
    hypertonia, inhibition reduces the overactive
    reflex response to muscle stretching or cutaneous
    stimulation

38
Baclofen
  • Dystonia
  • Baclofen some supraspinal activity that may
    contribute to clinical side effects
  • Orally relatively low concentrations in CSF
  • Side Effects
  • Central SE drowsiness, confusion, attentional
    disturbances
  • Others hallucinations, ataxia, lethargy,
    sedation and memory impairment
  • Lower seizure threshold
  • Sudden withdrawal ? seizures, hallucinations

39
Baclofen
  • Pharmokinetics
  • Relatively well absorbed, peak effect 2 hrs, t ½
    2.5-4 hours
  • Excreted unchanged by kidney, 6-15 metabolized
    in the liver
  • Schedule 3x a day due to short half life
  • Considerations
  • Cerebral lesions more prone to SE
  • DOC for spinal causes

40
Diazepam - Benzodiazepine
  • MOA does not directly bind to GABA receptors
  • Promotes the release of GABA from GABA-A neurons
  • Enhanced pre-synaptic inhibition, likely why
    useful in epilepsy
  • All CNS depressants
  • Anti-anxiety, hypnotic, anti-spasticity and
    anti-epileptic
  • Side Effects
  • Sedation and lethargy
  • Impair coordination and prolonged use can lead to
    physical/psych dependence
  • Effective doses vary considerably, upper doses
    primarily limited by SE
  • Rapid withdrawal ? irritability, tremors, nausea
    and seizures

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42
Neuromuscular Blockade
  • Goal Restore balance between agonist and
    antagonist muscles
  • Why is this important?
  • Shortened over contracted muscles ? decreased
    muscle growth despite linear bone growth ?
    antagonist muscles become over-lengthened ?
    weakness and imbalance
  • Contractures ? bone and joint deformity ?
    impaired function
  • Early intervention life long patterns of
    mobility
  • Blockade of agonist muscles ? improved stretch,
    ROM, increased resting length, antagonist muscles
    can continue activity and strengthening
  • Ann H. Tilton, Injectable Neuromuscular blockade
    in the treatment of Spasticity and Movement
    disorders, Journal of Child Neurology,
    200318S50-66

43
Botulinum Toxin A in the management of spasticity
related to CP
  • BTX-A is currently used for children of all ages
    with CP for spasticity management as determined
    by the practitioner
  • This use is off-label in the US
  • Dysport (British formulation), approved in UK and
    EU for treatment of dynamic equinus foot
    deformity due to spasticity in ambulant pediatric
    CP patients, two years of age or olderUE
    spasticity post-stroke, spasmodic torticollis,
    blepharospasm, and hemifacial spasm

L. Andrew Koman, MD et al, Botulinum Toxin Type A
in the Management of Cerebral Palsy, 2002, Wake
Forest University Press
44
Neuromuscular Junction
  • NMJ connection between the peripheral nerve and
    muscle fibers
  • Signals from the motor neuron are transmitted by
    the release of Ach from presynaptic vesicles
  • Ach crosses the synaptic cleft and attaches to
    post-synaptic receptors ? muscle contraction

L. Andrew Koman, MD et al, Botulinum Toxin Type A
in the Management of Cerebral Palsy, 2002, Wake
Forest University Press
45
Neuromuscular Junction
Chemodenervation, The Role of Chemodenervation in
the Management of Hyperkinetic Movement
Disorders, We Move 2007
46
Selected Literature Review
  • 1990 several studies supported the safety and
    efficacy of therapeutic BTX in children with CP
  • Goals decreasing spastic equinus, improving
    crouch knee gait, decreasing hip flexion,
    improving hand use
  • Studies demonstrated changes in muscle tone
    (reduction in spasticity scores), improvements in
    ROM, and kinematic changes in gait analysis
  • However, functional benefit was not demonstrated
    in blind, randomized controlled trials
  • 2013 Systematic review of interventions for
    children with CP state of the evidence BTX was
    recommended for spasticity reduction and improved
    walking

Iona Novak et Al, A systematic Review of
interventions for children with cerebral palsy
state of the evidence, Developmental Medicine
Child Neurology, 2013
47
Selected Literature Review
  • Why is it so difficult to show functional
    benefit?
  • Weakness and poor coordination co-exist in
    persons with spasticity, perhaps reducing muscle
    overactivity is not sufficient to see a
    functional change in the absence of a robust
    post-treatment program
  • Variability in injection protocols
  • patient selection
  • Insensitive outcome measures
  • Individualized treatment

Geoffrey L. Sheean, Botulinum treatment of
Spasticity Why is it so difficult to show a
functional benefit?, Current Opinion in
Neurology, 2001, 14 771-776
48
BoNT
  • Indications
  • Dynamic deformity function, pain, progressive
    deformity
  • Equinus, crouch gait, pelvic obliquity
  • UE
  • Focal dystonia
  • Muscle imbalance
  • Sialhorrhea
  • Contraindications
  • Allergic rxn to toxin or vehicle
  • Resistance to toxin effects
  • Significant muscle weakness
  • Failure to respond to injections
  • Fixed contracture

49
Side Effects
  • Most common weakness
  • Hoarseness or trouble talking
  • Dysarthria
  • Loss of bladder control
  • Trouble breathing
  • Trouble swallowing
  • FDA warning label and risk mitigation strategy
    2009
  • Advise patients to seek immediate medical
    attention if they develop any of these symptoms

50
Equinus
Gastrocnemius Soleus
Posterior tibialis
51
Phenol Injections
  • Injections of phenol were used for several
    decades prior to the advent of BoNT-A
  • Chemical neurolysis phenol injected onto a
    motor nerve denervating that particular muscle
  • EMG stimulus to localize the target nerve
  • Can be injected into
  • Motor points Motor neurons within a muscle
  • Motor nerves before they innervate a muscle

52
Phenol Injections
  • Localization of the motor neuron needs to be
    precise. Time required depends on which and how
    many nerves are injected
  • Typically requires multiple needle placements and
    burns with injection anesthesia in sensory
    aware/ cognitively aware child
  • Dosing guidelines not well established in peds
  • lt30mg/kg considered safe

53
Phenol Injections
  • Adverse Effects
  • Dysesthesias most common
  • Typically occur if phenol injected into a sensory
    nerve, can result in burning sensation or
    hypersensitivity to touch that can last for
    several weeks
  • Ibuprofen, gabapentin or carbamazapine

54
Phenol Injections
  • Duration of action
  • 3-12 months, can be longer than 1 yr
  • Increased duration typically occurs in muscles
    with more accessible nerves
  • Obturator - hip adductors
  • Musculocutaneous nerve - biceps
  • motor points within the medial hamstrings are
    more difficult to find

55
Discussion
  • Both BoNT and phenol cause selective and
    temporary muscular denervation
  • Treatment for focal spasticity
  • Different mechanisms of action
  • Phenol has proven effectiveness, immediate onset,
    low cost and potentially longer duration of
    effects, but generally less popular than BoNT
  • Technical challenges with administration,
    concerns for safety and adverse effects

56
Summary
  • Intramuscular injection of BTX-A well tolerated
    and efficacious - balance muscle forces across
    joints
  • Pre-defining injection goals, appropriate patient
    selection, and monitoring are essential
  • equinus deformity, managing selected upper limb
    deformities, adjunct in the global management of
    spasticity
  • Decrease pain related to spasticity, care-giver
    burden and enhance health-related quality of life
  • treatment philosophy includes early use in
    appropriate patients, to avoid contracture,
    delay/prevent bone and joint abnormalities, and
    avoid corrective surgery.

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Goals of ITB Therapy
  • Reduce spasticity
  • Decrease pain associated with spasticity
  • Improve function
  • Facilitate care

59
Intrathecal Baclofen vs Oral
  • ITB
  • CSF acts at GABAB receptor sites at spinal cord
  • Lower doses than required daily
  • Fewer side effects
  • Oral baclofen
  • Low blood/brain barrier penetration, high
    systemic absorption and low CNS absorption
  • Lack of preferential SC distribution
  • Unacceptable SE at effective doses

60
Plasma vs CSF drug levels
Plasma CSF
Plasma (est) CSF
Penn RD, Kroin JS. Intrathecal baclofen in the
long-term management of severe spasticity.
Neurosurg. 1989 4(2) 325-332.
61
Intrathecal Delivery
  • Advantages
  • Higher concentration of drug in CSF
  • Decreased SE
  • Titrateable
  • Disadvantages
  • Invasive
  • Risk of infection
  • Surgical risk
  • Devise risk
  • Maintenance
  • Cost

62
Intrathecal Baclofen Therapy
  • Baclofen directly to CSF target neurons in the SC
  • Externally programmable, surgically implanted
    pump, drug delivered at precise flow rates via
    catheter placed in the spinal canal
  • Decreases hypertonicity CP, SCI, MS, Strole
    trauma or hypoxia

63
Neurophysiologic effects
  • Dose dependent decrease in spinal reflex response
  • Disappearance of tendon taps and decrease in
    severity of spasms
  • Biomechanical and neurophysiologic studies
    evidence of decreased resistance to imposed
    stretch, decrease in EMG response
  • At neuronal level baclofen acts as potent
    GABA-B receptor agonist
  • GABA-B extensively distributed in SC
  • Baclofen directly administered to the
    subarachnoid space enhanced access to receptors
    ? greater reflex inhibition and tone reduction

64
Intrathecal Baclofen
65
Patient Selection
  • Grid illustration to compare various therapies
    for spasticity
  • ITB reversible (neural structures are not
    surgically altered, dose rate adjustable) and
    global
  • Pts with global or multifocal spasticity, who may
    benefit from adjustable (vs permanent) clinical
    effects are generally considered as better
    candidates

Grahm HK, Aoki KR, et al, Gait and Posture, vol
II, 200067-69
66
Components of ITB Therapy
  • Accessible drug reservoir
  • Catheter that connects drug reservoir to the CSF
  • Programmable adjustable for independent patient
    needs and response
  • External programming device

67
Synergistic Therapeutic effects
  • ITB combined with other modalities for synergist
    therapeutic effect
  • Rehabilitative therapies, oral pharmacotherapy,
    neurolytic procedures and muscle tendon
    lengthening
  • Combining ITB with neurolytic procedure focal
    dystonic features and global hypertonicity or
    residual UE hypertonia
  • Orthopedic procedures and ITB correction of
    fixed deformities in the setting of ongoing
    spastic hypertonia
  • Concomitant use in children with CP may reduce
    the need for subsequent orthopedic surgery

Gertzen et al, Intrathecal baclofen infusion and
subsequent orthopedic surgery in patients with
Cerebral Palsy. J Neurosurg 1998881009-13
68
Pump Placement
69
Ambulatory Function
  1. CNS injury or disease, will ITB administration
    permit ambulation or improve ambulation?
  2. Pts able to walk with assistance, will ITB
    improve their walking ability or allow them to
    walk independently
  3. For pts who are able to walk, will they
    experience decline of walking ability after ITB?
  • Isolated case reports of regained ability to walk
  • Prognosis for improving ambulatory function
    favors those with better baseline function
  • Most larger studies report mixed results, some
    pts improving, smaller percentage significantly
    worsening, with the largest subgroup
    non-significant changes overall

70
Withdrawal
  • Abrupt cessation ? withdrawal, serious and
    potentially fatal
  • itchy, twitchy, bitchy
  • Pruritus, seizures, hallucinations, autonomic
    dysreflexia
  • Exaggerated rebound spasticity, fever,
    hemodynamic instability and AMS
  • Can progress over 24-72 hrs to rhabdomyolysis (CK
    and phosphokinase), elevated transaminase levels,
    hepatic and renal failure and rarely death
  • Treatment
  • Supportive care
  • Observation and replacement of baclofen either
    enteral, or preferably through restoration of
    intrathecal delivery
  • Oral baclofen 10 -20 mg PO Q 4-6 hrs prn,
  • Tranxene 3.75 1-2 tabs mg Q4
  • Alternating every 2 hrs

71
ITB Therapy
  • ITB therapy has become a mainstay of long term
    spasticity management
  • Benefits include more potent effects, fewer
    systemic side effects, titratable
  • Disadvantages cost, maintenance, requires
    vigilance, risk of malfunction of catheter pump
    system, withdrawal and overdose, surgical risks
  • Appropriate patient selection and education are
    critical

72
SDR The Basics
  • First performed in 1913, but did not become
    popular until 1970s
  • Dorsal rhizotomy became selective and outcomes
    evaluated since 1987
  • SDR involves cutting sensory nerve roots that
    when stimulated, trigger exaggerated motor
    responses as measured by EMG intraoperatively

73
The Procedure
  • Multilevel laminectomy vs. minimally invasive
    approaches
  • L1 S1 sensory roots are identified and divided
    into 3-5 rootlets
  • Each rootlet is stimulated and responses are
    measured via EMG
  • Rootlets with the most abnormal signal are cut
  • Surgery takes about 4 hours

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Potential Complications
  • Paralysis of legs
  • Neurogenic bladder
  • Sensory loss or dysethesias
  • Wound infection
  • CSF leak

79
SDR Outcomes of Metanalysis
  • Children with diplegic CP (GMFCS II-III) received
    SDR PT, or PT w/o SDR.
  • Concluded that SDR PT is efficacious in
    reducing spasticity and has a small effect on
    gross motor function

McLaughlin J et al. Dev Med Child Neuro 2002,
44 17-25.
80
SDR versus ITB
  • 1-year outcomes of 71 children who underwent SDR
    before 1997 versus 71 children with ITB, matched
    by GMFCS and age
  • Both interventions significantly decreased
    Ashworth scores, increased PROM, improved
    function and resulted in high parental
    satisfaction
  • Compared with ITB
  • SDR provided greater improvements in muscle tone,
    PROM, and gross motor function
  • Fewer patients in the SDR group required
    subsequent orthopedic procedures
  • No difference between the degree of parents
    satisfaction

Kan P et al. Childs Nerv Syst. 2007 Sep 5.
81
Outcomes
  • Short and long term outcomes demonstrate
  • Decreased spasticity
  • Improved or unchanged strength
  • Improved gait pattern
  • Decreased oxygen cost
  • Improved overall function including decreased use
    of walking aids

82
Candidacy Determinations
  • Pre-term birth
  • Imaging consistent with PVL
  • Primarily spastic tone
  • Evidence of fair selective motor control
  • Demonstrated ability to cooperate and follow
    through with rehabilitation program
  • Patient selection

83
Candidacy Determinations
  • Red flags
  • Hyperextension at the knee in gait
  • Multiple orthopedic procedures
  • Generalized lower extremity/trunk weakness
  • Poor incorporation of trunk in gait
  • Poor isolated control of lower extremity movement
  • Poor rehab potential (behavior, sensory issues,
    cognition, social)

84
Summary
  • Spasticity Abnormal, velocity dependent increase
    in resistance to passive movement of peripheral
    joints due to increased muscle activity
  • Spasticity is a type of hypertonia that is a
    component of the UMNS
  • Due to a loss of presynaptic inhibition -
    modulation of the afferent stimulus by the
    descending tracts
  • Positive and negative signs of the UMNS
    collectively cause net unidirectional movements
    that often persist as postures ? chronic effects
    on soft tissue, joint structures and bone
  • Spasticity contributes to significant disability

85
Summary
  • CP spasticity is a common clinical feature
    associated with PVL
  • Traditional step ladder approach to management
    therapies, oral medications, injection therapies,
    orthopedic procedures, ITB or SDR, patient/family
    goals
  • Thank you

86
References
  • Sanger et al, Classification and Definition of
    Disorders Causing Hypertonia in Childhood,
    Pediatrics 2003
  • L. Andrew Koman, MD et al, Botulinum Toxin Type A
    in the Management of Cerebral Palsy, 2002, Wake
    Forest University Press
  • James R. Gage et al, The Identification and
    Treatment of Gait Problems in Cerebral Palsy,
    2009, Warwick J. Peacock, Chapter 2.2
    Pathophysiology of Spasticity
  • David Scrutton et al, Management of the Motor
    Disorders of Children with Cerebral Palsy, H.
    Kerr Graham, Ch.8 Mechanisms of Deformity
  • Allison Brashear, Spasticity and Other Forms of
    Muscle Overactivity in the Upper Motor Neuron
    Syndrome, Nathaniel H. Mayer, Ch.1 Positive Signs
    and Consequences of an Upper Motor Neuron
    Syndrome, 2008
  • Randall L. Braddom, Physical Medicine and
    Rehabilitation, 3rd Edition, Chapter 54 Cerebral
    Palsy, p.1249
  • James R. Gage et al, The Identification and
    Treatment of Gait Problems in Cerebral Palsy,
    2009, Kevin Walker, Chapter 3.4 Radiographic
    Evaluation of the Patient with Cerebral Palsy

87
References Continued
  • MC Olsen et al, Fiber type-specific increase in
    passive muscle tension in spinal cord injured
    subjects with spasticity, Journal of Physiology,
    577339-52, 2006
  • Allison Brashear, Elie Elovic, Spasticity
    Diagnosis and Management, 2010, Ch 1.1 Why is
    spasticity important?
  • Allison Brashear, Elie Elovic, Spasticity
    Diagnosis and Treatment, 2010, Ch.15
    Pharmacologic Management of Spasticity Oral
    Medications
  • R. Zafonte et al, Acute care management of
    post-TBI spasticity, Journal of Head trauma
    Rehabilitation 19(2)89-100

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89
Pathophysiology
  • Because spasticity depends on externally imposed
    velocity and joint angle changes ? suggests
    dependence on afferent feedback of proprioceptive
    information from muscle, joint and skin receptors
  • Spasticity is inherently dependent on afferent
    feedback from the muscle
  • presynaptic inhibition modulation of the
    afferent stimulus by the descending tracts
  • so any loss in these tracts will be reflected as
    a loss in presynaptic inhibition

90
Clinical Evaluation
91
Case
92
Stretch Reflex Pathway
  • Muscle spindle stretch receptor detects changes
    in muscle length
  • Myelinated sensory afferent neuron
  • The synapse
  • Homonymous motor neuron
  • Muscle innervated by the motor neuron

L. Andrew Koman, MD et al, Botulinum Toxin Type A
in the Management of Cerebral Palsy, 2002, Wake
Forest University Press
93
Stretch Reflex Pathway
  • Stretch detected by the muscle spindle ? CNS by
    Ia afferents through the dorsal root, connections
    in the SC
  • Homonymouos motor neuron monsynaptic excitatory
    connection with alpha motor neuron
  • Heteronymous motor neuron monosynaptic excitatory
    connections to synergist
  • Ia inhibitory interneuron projects to alpha
    motor neurons of antagonist muscles

L. Andrew Koman, MD et al, Botulinum Toxin Type A
in the Management of Cerebral Palsy, 2002, Wake
Forest University Press
94
Stretch Reflexes
  • Reciprocal inhibition normal pattern
    simultaneous excitation of agonist and inhibition
    of antagonist motor neuron
  • Co-contraction inappropriate activation of
    antagonist muscles during voluntary contraction
    of agonist muscles, superimposed stretch reflex
    activity stretching antagonists during movement
  • joint stability (ie eccentric contraction of the
    triceps during biceps activation to control
    flexion of the elbow)
  • Activated and deactivated at the cortical level
  • May represent an impairment of supraspinal
    control of reciprocal inhibition

L. Andrew Koman, MD et al, Botulinum Toxin Type A
in the Management of Cerebral Palsy, 2002, Wake
Forest University Press
95
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96
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98
Traditional Step-Ladder Approach to Management
of Spasticity

  • Neurosurgical procedures
  • Orthopedic
    procedures
  • Neurolysis/
    Chemodenervation
  • Oral medications
  • Rehabilitation Therapy
  • Remove noxious stimuli

99
Common Patterns of Motor Dysfunction in CP
  • Most common pattern of spasticity in CP
  • Upper Extremity
  • Internal rotation of shoulder
  • Elbow flexion
  • Forearm pronation
  • Wrist and finger flexion
  • Thumb in palm
  • Lower Extremity
  • Hip flexion and adduction
  • Knee flexion
  • Hindfoot valgus
  • Forefoot pronation
  • Spasticity Associated with CP in Children,
    Guidelines for the use of Botulinum Toxin A, L.
    Andrew Koman et al, Pediatric Drugs, 2003, 5 (1)
    p.11-23

100
Windswept Deformity
101
Possible Advantages of Spasticity
  • Maintains muscle tone
  • Helps support circulatory function
  • May prevent formation of deep vein thrombosis
  • May assist in function

102
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103
Diazepam - Benzodiazepine
  • MOA does not directly bind to GABA receptors
  • Promotes the release of GABA from GABA-A neurons
  • Enhanced pre-synaptic inhibition, likely why
    useful in epilepsy
  • All CNS depressants
  • Anti-anxiety, hypnotic, anti-spasticity and
    anti-epileptic
  • Side Effects
  • Sedation and lethargy
  • Impair coordination and prolonged use can lead to
    physical/psych dependence
  • Effective doses vary considerably, upper doses
    primarily limited by SE
  • Rapid withdrawal ? irritability, tremors, nausea
    and seizures

104
Clonidine Central Alpha Adrenergic Agent
  • Monoamines are widely distributed in CNS
  • Important role as modulators of spinal neuron
    excitability
  • Modulate sensory inputs via presynaptic
    inhibition of spinal afferent inputs
  • Also direct inhibitory effect on interneurons
  • When descending pathways from the brainstem to SC
    are disrupted, there is a reduction in the NE ?
    increased hypertonia

105
Clonidine Central Alpha Adrenergic Agent
  • Centrally acting apha-2 receptor agonist ?
    antispasticity effects
  • Also alpha-1 receptor agonist ? antihypertensive
    effects
  • profound nociceptive pain reliever
  • central sympatholytic effects on BP
  • Therefore little effect on the BP of persons with
    complete SCI, but can lower the BP for those with
    incomplete injuries
  • Side Effects
  • BP
  • Bradycardia, dry mouth, ankle edema, depression

106
Tizanidine Central Selective Alpha-2 adrenergic
agonist
  • Structurally related to clonidine
  • 1/10 to 1/15 the potency of clonidine in lowering
    BP or slowing HR
  • Preference for alpha-2 receptors
  • Active at both segmental spinal and supraspinal
    levels in both motor and sensory pathways
  • No effect on monosynaptic reflexes standard DTR
  • No activity at NMJ, no direct effect on skeletal
    muscle fibers, does not cause any muscle weakness
  • Extensive first pass metabolism

107
Tizanidine Central Selective Alpha-2 adrenergic
agonist
  • Side Effects
  • Sedation, asthenia, dizziness, dry mouth
  • Very little hypotension or bradycardia at
    clinically relevant doses, virtually none in the
    lower half of the dose range
  • Rebound HTN
  • Hallucinations and nightmares
  • GI - constipation
  • Precautions
  • Chronic use potential for hepatotoxicity
  • Liver enzymes should be periodically checked as
    dose is increased

108
Dantrolene Sodium Direct Acting Muscle Relaxant
  • No centrally acting SE
  • Acts peripherally by decreasing release of
    calcium from SR? uncoupling electrical excitation
    from contraction and decreasing the force of
    contraction
  • Affects intrafusal and extrafusal fibers,
    reducing spindle sensitivity
  • Action is specific for skeletal muscle and
    affects reflex contractions or spasticity more
    than voluntary contraction
  • Weakness -twice the voluntary effort is required
    to maintain a desired muscle tension

109
Dantrolene Sodium Direct Acting Muscle Relaxant
  • Because of propensity to cause weakness several
    reports advocate limiting use in CP, spasticity
    of spinal origin and MS pts
  • 1980 AMA Dantrolene should be used primarily in
    non-ambulatory pts and only if the resultant
    decrease in spasticity will not prevent the
    patient from functioning
  • Recent report has recommended as a first line
    agent in the treatment of spasticity after TBI,
    especially in the acute setting, as it exhibits
    minimal cognitive effects and may not interfere
    with neural recovery

R. Zafonte et al, Acute care management of
post-TBI spasticity, Journal of Head trauma
Rehabilitation 19(2)89-100
110
Dantrolene Sodium Direct Acting Muscle Relaxant
  • Risks
  • Significant increased risk of hepatotoxicity, 1
    overall, especially with doses over 400mg
  • Active hepatic diagnosis contraindication
  • RF female, gt35, polypharmacy
  • LFTs need to be monitored, lowest optimally
    effective dose should be prescribed

111
History of Botulinum Toxin A
  • 1875 Claude Bernard poisons can be employed
    as means for the destruction of life or as agents
    for the treatment of the sick
  • This concept was first used regarding CP in the
    20th century
  • Tardieu Alcohol as a muscular neurolytic agent,
    1970s
  • Carpenter (Richmond CP Hospital) 45 alcohol
    and bupivicaine
  • 1897 van Ermengem (Belgium) identifies
    Clostridium botulinum, obligate anaerobe bacillus
  • WWII - Schantz extensive research identifies
    the toxins produced by C. botulinum
  • 7 serotypes purified and identified (A-G)
  • Emphasis on type A, the most potent biologic
    toxin known
  • Techniques developed by Schantz and Lammana ?
    commercial preparations available today
  • Lamanna produced crystalline BTX-A, forerunner
    of Oculinum
  • British military ? British formulation BTX-A,
    Dysport

L. Andrew Koman, MD et al, Botulinum Toxin Type A
in the Management of Cerebral Palsy, 2002, Wake
Forest University Press
112
History of Botulinum Toxin A
  • 1960s Alan B. Scott, Opthalmologist in SF,
    toxin as therapeutic agent for strabismus
  • 1981 BTX-A in humans
  • dystonia and other movement disorders
  • Schantz type A toxin, Oculinum used in these
    protocols under the oversight of the FDA
  • 1988 Koman et al, first clinical trial for
    treatment of spasticity in CP
  • Oculinum, preliminary results 1993
  • Subsequent trials, including large multi-center
    placebo controlled trials ? efficacy of BTX-A for
    managing equinus foot deformity (Koman 2000)
  • Since then BoNT ? safe and effective for a
    large number of neurologic and non-neurologic
    diseases
  • regarding CP, additional studies confirmed
    indication for
  • UE CP (Corry 1997, Fehlings 2000)
  • Analgesia after hip surgery (Barwood 2000)
  • Crouched gait (Molanaers 1999)
  • Alternative to serial casting (Corry 1998)
  • Hamstring spasticity (Corry 1999)

L. Andrew Koman, MD et al, Botulinum Toxin Type A
in the Management of Cerebral Palsy, 2002, Wake
Forest University Press
113
History of Botulinum Toxin A
  • 1989 Allergan purchases the Oculinum in stock
    and the process to produce new bulk source of
    toxin from Dr. Scott
  • FDA approves BTX-A for strabismus, blepharospasm,
    and hemi-facial spasm (gt12)
  • 1992 registers tradename BOTOX
  • 2000 BTX-A and B (Myobloc/Neurobloc, Solstice)
    FDA approval for dystonia
  • 2002 FDA approval for cosmetic use
  • 2004 FDA approval for hyperhidrosis
  • 2010 approval for UE spasticity in Adults
  • Acceptance for treatment of spasticity is
    growing, with approvals in many European
    countries
  • Continued clinical trials for expanding
    indications

L. Andrew Koman, MD et al, Botulinum Toxin Type A
in the Management of Cerebral Palsy, 2002, Wake
Forest University Press
114
Summary
  • Intramuscular injection of BTX-A is well
    tolerated and efficacious if used to balance
    muscle forces across joints in the absence of
    fixed contractures
  • Pre-defining injection goals, appropriate patient
    selection, and monitoring are essential
  • It is well documented as a treatment option for
    equinus deformity, managing selected upper limb
    deformities, and is valuable as an adjunct in the
    global management of spasticity
  • It can diminish pain related to spasticity,
    decrease care-giver burden and enhance
    health-related quality of life
  • treatment philosophy includes early use in
    appropriate patients, to avoid contracture,
    delay/prevent bone and joint abnormalities, and
    avoid corrective surgery.
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