management strategy of myasthenia gravis

1. Myasthenia Gravis

2. Introduction
• Myasthenia gravis (MG) is a neuromuscular
disease that leads to fluctuating muscle
weakness and fatigue
• Caused by a breakdown in the normal
communication between nerves and muscles
• There is no cure for myasthenia gravis, but
treatment can help relieve signs and
symptoms

3. Signs and symptoms
• Initial complaint is a specific muscle weakness
• Extraocular muscle weakness or ptosis
• Bulbar muscle weakness is also common,
along with weakness of head extension and
flexion
• Limb weakness may be more severe
proximally than distally
• Weakness is typically least severe in the
morning and worsens as the day progresses

4. • Weakness is increased by exertion and
alleviated by rest
• Weakness progresses from mild to more
severe over weeks or months, with
exacerbations and remissions
• About 87% of patients have generalized
disease within 13 months after onset
• Difficulty breathing, chewing, swallowing

6. • Factors that worsen MG symptoms :
– Fatigue
– Illness
– Stress
– Extreme heat
– Some medications (chloroquine, procaine, lithium,
phenytoin, beta-blockers, procainamide, statins)

7. Diagnosis
• Neurological examination
• Edrophonium test
• Ice pack test
• Blood analysis
• Repetitive nerve stimulation
• Single-fiber electromyography (EMG)
• Pulmonary function tests

8. Treatment
• Cholinesterase inhibitors
• Corticosteroids
• Immunosuppressant
• Plasmapheresis
• Intravenous immunoglobulin (IVIG)
• Surgery

9. Physical
Rehabilitation

10. Introduction
• MG symptoms tend to progress over time,
usually reaching their worst within a few years
after the onset of the disease
• Muscle weakness caused by MG worsens as
the affected muscles are used repeatedly,
therefore symptoms usually improve with rest

11. Factors limiting daily physical
function in stable MG
• Neuromuscular fatigue
• Low CV fitness levels (20% below normal)
• Diminished physiological fitness reserve (high
energy cost of walking at peak fitness level)
• Percent body fat 2-X normal (45%) and poor
fitness contribute to mobility disability

14. Potential benefits of physical
therapy in MG
• Weight reduction
• Decrease in risk of hypertension, diabetes,
cholesterol
• Decrease in risk of cardiac diseases
• Decrease in risk of osteoporosis
• Mood elevation ; improve cognitive function
• Enhance baseline functional capacity,
improved mechanical efficiency

15. Management Strategy
• There is a lot of variance between patients with
MG
• No one exercise program is same and treatment
strategies may vary
• Evaluation-
– Strength
– Flexibility
– Mobility
– Balance
– Gait

17. Exercise Goals
• Enhance ability to function daily
• Decrease risk of falling
• Completion of functional tasks and
maintenance of independence
• Smoothness and coordination of activities
• Once MG is stable, consistent exercise will
elevate baseline functional capacity which will
diminish the effect of MG exarcebation

18. Exercise Considerations
• The dollar per day rule
• Exercise at the best time of day
• Exercise at peak dose of medication
(pyridostigmine)
• Exercise large, proximal muscle groups for
short periods of time building up only to
moderate intensity
• Do not exceed moderate intensity exercise
level

19. Moderate Exercise Intensity
• HR should not elevate greater than 30 bpm from
resting baseline
• Patient should not become short of breath at
peak of exercising
• MG symptoms should not become worse during
exercise (drooping of eyes)
• Patient should not be tires after 2 hours of
exercise
• Patient should not have severe residual muscle
soreness the day post exercise

20. Types of Exercise used in MG
• Aerobic Exercises
• Strength exercises
• Swimming
• Postural exercise
• Breathing exercise

22. • Strength Exercise –
– Should be done progressively
– Range of motion (flexibility) to light resistance to
full resistance
– Start with lower prescription : 3 sets of 5 reps
– If significant weakness is present, active assist
exercises may be necessary (therapist help)
• The primary goal of therapy is to build the
individual's strength to facilitate return to
work and activities of daily living
• Do not overdo resistive training to the point of
fatigue

25. • Swimming
– Patients should swim in water where they can
touch the bottom
– Deep water is dangerous and may cause patient to
over exert

26. • Postural Exercises-
– Important in assisting with breathing, speaking
and swallowing
– Keeps bones and joints in the correct alignment so
that muscles are being used properly
– Prevents fatigue because muscles are being used
more efficiently, allowing the body to use less
energy

28. • Breathing exercises -
– Help improve lung function
– Include inspiratory muscle training
• Pursed lip breathing
• Diaphragmatic breathing
– These exercises can improve respiratory
endurance as many people with MG have affected
respiratory muscles

31. Reference
• http://www.myastheniagravis.org/
• Myasthenia Gravis foundation of America
http://www.myasthenia.org/
• http://www.mdguidelines.com/
• http://www.pivotalphysio.com/
• http://www.livestrong.com/