Duchenne Muscular Dystrophy Multidisciplinary Approach by nikeborome

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									Duchenne’s Muscular
    Dystrophy:
A Multidisciplinary Approach


By: Brittany Annis, Student PT
     Ithaca College 2010
                  Objectives
   Introduce background information on
    Duchenne’s Muscular Dystrophy
   Identify associated pathologies
   Identify and explain the benefits of the
    multidisciplinary team members
   Describe the goals and interventions of
    physical therapy for DMD
   Describe current evidence and
    recommendations for exercise and DMD
               Intro to DMD
   Most prevalent childhood muscular
    dystrophy, every 1 in 3000-6000 male births
   X-linked recessive disorder- gene deletion
   Deficiency of the muscle protein Dystrophin
   Progressive muscle weakness in skeletal,
    smooth, and cardiac muscle
   It has been observed that there is a greater
    number of Type II muscle fibers with
    degeneration compared to Type I.
                Dystrophin

   Provides mechanical
    reinforcement to the
    sarcolemmal
    membrane of muscle
    fibers; protects muscle
    fibers from being
    damaged while
    stressed during muscle
    contraction.
         Lifespan of DMD

 Shortened lifespan due to progressive
  muscle weakness and complications-
  mean age is 19 without intervention,
  mid-to-late twenties with proper care.
 Now, studies and research are showing
  that if properly diagnosed, individuals
  with DMD can have possible lifespan
  into their forties
             Signs and Symptoms
   Early signs between
    ages 3 and 5, when
    most commonly
    diagnosed
     Delayed walking
     Inability to run, jump,
      keep up with peers
     Difficulty climbing stairs
     Gower’s Sign
     Frequent falls
     Occasionally (30%)
      global developmental
      delay and delayed
      speech
Associated Pathologies:
      Weakness
             Progressive weakness of hip
              and shoulder girdle musculature
             Weakness in paraspinals make
              walking difficult
             Leads to:
               – Waddling gait
               – Lumbar lordosis
               – Forward thrusting of the
                  abdomen
               – Scapular winging
               – Anteroposterior scoliotic
                  curve
               – Joint contractures
               – Respiratory impairment
               – Weight gain
        Associated Pathologies:
          Joint Contractures
   Mainly found at hips,      Equinovarus:
    knees, ankles               – Ankle plantarflexion and
                                  supination
                                – Tight gastrocnemius
                                  mm/Achilles tendon
   Contractured Tensor
                                – Associated weakness of
    Fascia Latae:                 tibialis anterior and
    – Waddling gait               peroneal mms
    – Tightened IT Band        Complications include:
    – Resultant hip and            Difficulty wearing shoes
      knee                         Foot pain
      pain/deformities             Hypersensitivity
                                   Concern about foot’s
                                    appearance
     Associated Pathologies:
            Scoliosis
 Most commonly seen when non-
  ambulatory, due to increased amount of
  time spend seated in a wheelchair
 May require spinal fusion to promote
  better sitting and comfort, to prevent
  further deformity, avoid respiratory
  compromise
    The Multidisciplinary Team
 Can alter the natural     –   Rehabilitation
  progression of the        –   Orthopedics
  disease and improve
  function and quality of   –   Pharmocologics
  life.                     –   Psychosocial
 Comprehensive set of      –   Respiratory care
  recommendations to
  manage the wide           –   Cardiovascular care
  spectrum of               –   Pain
  complications             –   Gastroenterology/
 Includes:                     Nutrition
               Corticosteroids
   Currently the best treatment option available
   Improve muscle strength and function
   Significantly slow the progression of muscle
    weakness
   Prolong ambulation to mid-teens or later
   Delay the onset of respiratory and/or cardiac
    dysfunction
   [Use caution: complications include weight
    gain, vertebral fractures, failure to gain
    height, irritability]
Respiratory Management
   Patients with DMD are at increased risk of respiratory
    complications
   Because of progressive loss of muscle strength:
     – Cough may be ineffective
     – Nocturnal hypoventilation
     – Sleep-disordered breathing
   PT can assist with respiratory management by having patient
    breathe against a resistive load (water in pool), breath-holding,
    bubble-blowing, to improve ventilatory strength and endurance.
   Important to note signs and symptoms of hypoventilation to refer
    patient to respiratory physician.
     – Fatigue, dyspnea, tachycardia, morning/continuous
        headaches, sleep dysfunction, nightmares, difficulty
        concentrating
Cardiac Management
 Cardiomyopathy and/or cardiac arrhythmia
  are major sources of mortality in DMD
 The heart/myocardium have areas of
  hypertrophy, atrophy, and fibrosis
 Failure to see a cardiac specialist early in the
  disease process have led to late treatment
  and poor outcomes
 Higher levels of fitness are associated with
  better cardiac health
            Potential Surgeries
 Heelcord lengthening
 Hamstring lengthening
 ITB lengthening
 Cannot perform hip flexor lengthening
  (responds poorly, weakens muscles and
  cannot properly brace)
    – Hip deformities often correct themselves once
      knee and ankle malalignments have been altered.
   Surgery in the late ambulatory phase or after
    is usually not effective.
Other Important Teams:

 Nutritional, swallowing, gastrointestinal,
  speech and language, pain
  management, psychosocial,
  pharmacological
 All fields are continuously changing as
  the stages of the disease change
       Goals of Physical Therapy
   Prolong independent
    ambulation
   Maximize functional
    ability
   Prevent complications
    of inactivity
   Improve emotional well-
    being
Physical Therapy Interventions

 Stretching/Positionin      Objective measures
  g                           and testing to
 Management of               monitor progression
  contractures
 Assistive devices
 Exercise
               Objective Measures
   Strength testing- MMT to            ROM: goniometry to identify
    monitor disease progression          hypomobility, jt contractures
    and predict functional losses,       that may contribute to
    assess responses to                  functional deterioration or to
                                         musculoskeletal/integumenta
    treatment and monitor                ry complications, or to note
    muscle imbalances                    need of splinting/orthotics.
      – Test LEs every 6 months           – In ambulatory phase,
        when ambulatory; test                measure hips, knees,
        UE and LE every 6                    ankles (ITB, H/S,
        months when non-                     heelcords). In non-
        ambulatory                           ambulatory phase,
                                             measure UE as well as
                                             LE (elbows, wrists, finger
                                             flexors)
       Objective Measures, Con’t
   Timed Testing:                   ADLs: Assessment
    Standardized tests are            of impairment in
    responsive to change,
                                      home, school,
    easy to administer,
    relevant to function              community settings
    (when ambulatory only)            – Frequency of falls,
    – Timed 10 meter walk,              self-care skills
      timed Gower’s
      manuever, time to climb
      4 stairs, 6 min walk test
                 Stretching
                              Heelcords: Gastrocnemius/
 Combination of               Achilles Tendon lengthening
  AROM, AAROM,                 into dorsiflexion
  PROM, prolonged             Tensor Fascia Latae/Iliotibial
                               Band: stretch hip into
  elongation (splinting,       adduction, internal rotation,
                               and extension.
  positioning)
                              Other muscles throughout
 Minimum of 4-6               the hips, knees and ankles
  days per week, at           In non-ambulatory phase,
                               also focus on upper
  home/school and in           extremities: finger flexors,
                               wrist flexors, elbow and
  the clinic                   shoulder joints
        Assistive Devices: AFOs

 Custom-molded and comfortable for optimum
  foot and ankle alignment
 Throughout life: AFO’s are appropriate at
  night to prevent or minimize the progression
  of equinus contractures
 Late stages:
    – KAFOs for non-ambulatory boys to prevent
      contracture and deformity (not for use at night)
    – Resting hand splints for finger flexors
         Assistive Devices Con’t
   Wheelchair: Need                 Standing Frames: A few
    appropriate postural              hours per day, even
    positioning to prevent            with minimal weight
    scoliosis and back                bearing, to prevent and
    pain/aches                        reduce the severity of
    – Powered for more                contractures, decubitis
      involved patients.              ulcers, and scoliosis.
    – Manual Lightweight for          Also improves bone
      less involved patients so
      can self propel and             mineral density,
      increase independence,          circulation, and GI and
      as well as provide arm          respiratory functions.
      exercise
Exercise
   There is a high level of controversy concerning
    whether exercise is beneficial or harmful to patients
    with DMD
   Normal, dystrophic muscle (those without muscular
    dystrophy) can withstand mechanical forces during
    contraction.
   Those with muscular dystrophy are compromised due
    to weakened muscles, joints, tendons, and bones
    during muscle contractions and weight-bearing.
   But exercise is very important to avoid disuse atrophy
    and other secondary complications of inactivity
          Type I vs Type II Fibers
   Type I muscle fibers are            It is possible to switch Type
    slow twitch for slower               II muscle fibers to Type I with
    contractions, and fatigue-           exercise training, so with an
    resistant, so good for               increased number of Type I
    continuous contractions              fibers, the muscles are more
    (postural muscles)                   durable and more resistant
   Type II muscle fibers are fast       to degeneration.
    twitch for quick contractions,      But the form of exercise
    and are easily fatigued              needed to switch Type II
    (“sprinter” muscles). They           fibers to Type I is very
    are also less resistant to           specific
    mechanical stresses (more
    easily injured)
     Current Evidence Regarding
              Exercise
   In a mouse study, a          It has been observed
    greater percentage of         that Type II muscle
    Type I muscle fibers          fibers are subject to
    were observed after low       greater degeneration,
    intensity, long-term          and the majority of
    exercise                      research using animal
   Sedentary mice with           models and some
    DMD had a higher              human studies suggest
    percentage of Type I          that increasing activity
    fibers than sedentary         may actually slow the
    mice without DMD              degeneration in
                                  dystrophic muscle.
       Current Evidence, Con’t

   Further studies and information are
    needed for each subtype of muscular
    dystrophy to create subtype-specific
    recommendations, including specifics
    such as age, severity, rate of
    progression, and level of motivation.
         Recommended Exercise
              for DMD
   Low resistive and                  Long term, low-
    aerobic exercise are                intensity, preferably no
    justified to:                       load (or low-load)
    – Prevent deconditioning,
      decreased fitness, disuse
                                        weight-bearing activity
      atrophy and joint                 to reduce mechanical
      contractures                      stress on the muscle
    – Counteract secondary              – Increased Type I fibers,
      complications of inactivity         which are less vulnerable
      such as obesity,
                                          to degeneration
      Diabetes, osteoporosis
      and cardiovascular                – Will not promote
      diseases                            hypertrophy
         Recommended Exercise
            for DMD, Con’t
   Use caution to ensure       Aquatic Therapy!
    that cardiovascular or       Excellent for improving/
    muscular complications       maintaining mobility,
    do not develop               strength, flexibility, and
   High-resistance and          aerobic conditioning
    eccentric exercise is        and cardiopulmonary
    NOT recommended,
    although it has not          fitness
    actually been proven
    harmful for a DMD
    patient
                  Current Evidence
   Research and studies are being done with continuous
    advances and milestones in DMD research

   The severity of DMD can be determined by a positive
    correlation to the amount of dystrophin present in the
    muscle (the more dystrophin, the less severe the
    symptoms and progression)

   Corticosteroid prednisone was found effective in slowing
    the progression of DMD, and it also stimulates utrophin
    production ( a mm protein similar to dystrophin)

   Gene therapy clinical trials are underway and dystrophin
    gene injections are judged safe in clinical trial including 6
    boys with DMD; studies are being continued
                                Works Cited
Ansved, Tor. "Muscular Dystrophies: Influence of Physical Conditioning on Disease
    Evolution." Current Opinion in Clinical Nutrition and Metabolic Care 6 (2003): 435-39. Print.
Bushby, Katharine, Richard Finkel, and David Birnkrant. "Diagnosis and Management of
    Duchenne Muscular Dystrophy, Part 1: diagnosis, and pharmacological and psychosocial
    management." 30 Nov. 2009. Web. 1 Dec. 2009. <http://quest.mda.org/files/pdfs/Part_1-
    newDMD.pdf>.
Bushby, Katharine, Richard Finkel, and David Birnkrant. "Diagnosis and Management of
    Duchenne Muscular Dystrophy, Part 2: implementation of multidisciplinary care." 30 Nov.
    2009. Web. 1 Dec. 2009. <http://http://quest.mda.org/files/pdfs/Part_2-newDMD.pdf>.
Ciafaloni, MD, Emma, and Richard T. Moxley, MD. "Treatment Options for Duchenne Muscular
    Dystrophy." Current Treatment Options in Neurology 10.2 (2008): 86-93. Print.
Milestones in Duchenne's Muscular Dystrophy Research. MDA.org, Feb. 2009. Web. 1 Dec.
    2009. <http://www.mda.org/publications/milestones/dmd.html>.
Palmieri, B., V. Sblendorio, A. Ferrari, and A. Pietrobelli. "Duchenne Muscle Activity Evaluation
    and Muscle Function Preservation." Obesity Reviews 9 (2008): 121-39. Print.
Sayers, Stephen P. "The Role of Exercise as a Therapy for Children with Duchenne Muscular
    Dystrophy." Pediatric Exercise Science 12 (2000): 23-33. Print.

								
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