Download Muscular Dystrophy

Muscular Dystrophy
Definition
Refers to a group of hereditary progressive
diseases. Muscular Dystrophy affects muscular
strength and action, some of which first become
obvious in infancy, and others which develop in
adolescence or young adulthood. The syndromes are
marked by either generalized or localized muscle
weakness, difficulties with walking or maintaining
posture, muscle spasms, and in some instances,
neurological, behavioral, cardiac, or other functional
limitations.
Progressive Muscular Dystrophy
Type
Onset Age (years)
Clinical Features
Other organ systems involved
Duchenne
Before 5
1.Progressive weakness of
girdle muscles.
2.unable to walk after age 12
3.progressive kyphoscoliosis
4.Respiratory failure in 2dor 3d
decade.
Cardiomyopathy
Mental impairment
Becker
5-25yr
early childhood to adult
1.Progressive weakness of
girdle muscles
2. able to walk after
age
15.
1.3. respiratory failure may
develop by 4th grade
Cardiomyopathy
Emery-Dreifuss
Childhood to adult
Elbow contractures, humeral
and perineal weakness
Cardiomyopathy
Limb-Girdle
early childhood to adult
Slow progressive weakness of
shoulder and hip girdle muscles
Cardiomyopathy
Progressive Muscular Dystrophy
Type
Onset Age (years)
Clinical Features
Other organ systems involved
Congenital
At birth or within 1st
few months
.Hypotonia, contractures,
delayed milestones
Progression to respiratory
failure in some;
CNS and
Eye abnormalities
Facioscapulohumeral
Before age 20
Slowly progressive weakness
of face, shoulder girdle, and
foot dorsiflexion
Deafness
Coat’s (eye) disease
Oculopharyngeal
5th to 6th decade
Slowly progressive weakness
of extraocular, pharyngeal,
and limb muscles
______
Myotonic
Usually 2nd decade
May be infancy if
mother affected
Slowly progressive weakness
of face, shoulder girdle, and
foot dorsiflexion
Cardiac conduction defects
Mental impairment
Cataracts
Frontal baldness
Gonadal atrophy
Pathophysiologic
the exact mechanism is unknown, but there are 3 theories
• Vascular theory:
the lack of blood flow causes
the typical degeneration of muscle tissue.
• Neurogenic theory:
Disturbance in nerve-muscle
interaction.
• Membrane theory:
the cell membranes are
genetically altered, causing a compromise in cell
integrity. An increase in the activity of muscle proteolytic
enzymes may accompany the membrane alteration.
Leaving the muscle cell vulnerable to degeneration.
Symptoms
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Muscle weakness
Delayed development of muscle motor skills
Problems walking (delayed walking)
Difficulty using one or more muscle groups (depends on
the type of dystrophy)
Eyelid drooping (ptosis)
Drooling
Hypotonia
Mental retardation ( only present in some types of MD)
Joint contractures (clubfoot, clawhand or others)
Scoliosis
Signs and Tests
Examination and history help to distinguish the type of
MD. Specific muscle groups are affected by different
types of MD. Often, there is a loss of muscle mass
(wasting), which may be disguised in some types of
muscular dystrophy by an accumulation of fat and
connective tissuethat makes the muscle appear larger
(pseudohypertrophy).
Joint contractures are common. Shortening of the
muscle fibers, fibrosis of the connective tissue and
scarring slowly destroy muscle function. Some types of
MD involve the heart muscle, causing cardiomyopathy or
arrhythmias.
A muscle biopsy may be the primary test used to confirm
the diagnosis. In some cases a DNA test from the blood
may be sufficient.
Laboratory Test
Muscle biopsy: the primary test used to confirm the diagnosis.
DNA test
Serum CPK (creatine phosphokinase-an enzyme found in muscle) may be elevated.
EMG (electromyography) may confirm that weakness is caused by destruction of muscle tissue rather
than damage to nerves.
ECG (electrocardiography) to monitor changes in cardiac status.
Myoglobin - urine/ serum: When muscle is damaged, the myoglobin is released into the
bloodstream. It is filtered out of the bloodstream by the kidneys, and eliminated in urine. In
large quantities, myoglobin can damage the kidney and break down into toxic compounds,
causing kidney failure.
LDH: LDH is most often measured to evaluate the presence of tissue damage. The enzyme LDH is in
many body tissues, especially the heart, liver, kidney, skeletal muscle, brain, blood cells, and
lungs.
Creatinine : A normal (usual) value is 0.8 to 1.4 mg/dl. Creatinine is a breakdown product of creatine,
which is an important constituent of muscle. A serum creatinine test measures the amount of
creatinine in the blood. Greater-than-normal levels may indicate: Muscular dystrophy. Lowerthan-normal levels may indicate: Muscular dystrophy (late stage)
AST: The normal range is 10 to 34 IU/L. An increase has many indications, one of them being
progressive MD.
Aldolase: Why the test is performed? This test is indicator ofmuscle damage.
Nursing Diagnosis
Impaired mobility, activity intolerance, risk
for injury, risk for aspiration, risk for
impaired skin integrity, self-care deficit,
knowledge deficit, caregiver role strain,
low self-esteem, social isolation, disturbed
body image, and hopeless to name a few.
Nursing Implications and
interventions:
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Multidisciplinary. Care for these patients involves arranging for consultations
with physical therapy, occupational therapy, respiratory therapy, speech
therapy, psychosocial therapy, and dieticians.
Reinforce techniques learned in all of the above therapies.
Educate client and family members thoroughly about expected outcomes
and possible problems.
Encourage exercise while teaching s/s of exercise overload: feeling weaker
rather than stronger after exercise, excessive muscle soreness, severe
muscle cramping, heaviness of extremities, and prolonged shortness of
breath.
Ensure braces are a good fit to prevent pressure ulcers and promote
stability.
Have equipment (braces, wheelchairs) evaluated by PT, OT to ensure
proper fit.
Be sensitive to psychosocial needs and make appropriate referrals.
Refer to support groups and clinics.
Bibliography
• Cart, Greg. “Rehabilitation Management of
Neuromuscular Disease.”
http://www.emedicine.com/pmr/topic233.htm.
• Cox, Helen C., RN, C, EdD, FAAN. Clinical Applications
of Nursing Diagnosis. 4th
Edition. F.A. Davis
Company. Philadelphia, PA: 2002.
• Ignatavicius, Donna, MS, RN, CM. Medical-Surgical
Nursing. 4th Edition. W.B.
Saunders Company.
Philadelphia, PA: 2002.
• Muscular Dystrophy Association website:
http://www.mdausa.org.
• Harrison’s Principles of internal Medicine 15th edition,
McGraw-Hill Medical Publishing Division, New York.
2002.