It is an autoimmune disorder affecting the myoneural junction, is characterized by varying degrees of weakness of the voluntary muscles. A disorder of neuromuscular function thought to be due to the presence of antibodies to acetylcholine receptors at the neuromuscular junction (NMJ). this study comprises all basic facts about myasthenia gravis . please comment thank u

1. MYASTHENIA
GRAVIS
(Medical information)
PREPARED BY
MARTIN SHAJI
PHARM D

2. It is an autoimmune disorder affecting the myoneural junction, is
characterized by varying degrees of weakness of the voluntary
muscles.
A disorder of neuromuscular function thought to be due to the
presence of antibodies to acetylcholine receptors at the
neuromuscular junction (NMJ).
Myasthenia gravis

3. Incidence
• MG occurs in all ethnic groups and both genders.
• It most commonly affects young adult women (<40 years) &
older men (>60years), but it can occur at any age.

4. Prevalence
• Today there are an estimated 50,000cases ¡n the US.
• MG can be found in anyone, but ¡t is “most common in females
around the third decade of life.

5. • The Unknown cause.
• Defect ¡n the transmission of nerve impulses to muscles.
• Antibodies against acetyl choline receptor sat the NMJ.
• Thymic abnormalities.
ETIOLOGY

7. Pathophysiology
• Autoantibodies against acetylcholine receptor sites.
• Impaired transmission of impulses across the myoneural junction.
• Availability of fewer receptors for stimulation.
• Voluntary muscle weakness that scalates with continued activity.

9. Clinical Manifestations
• Ocular symptoms- Diplopia, ptosis.
• Bulbar symptoms- Weakness of the muscles of the face & throat,
and generalized weakness, and expressionless face.
• Weakness of the jaw muscles allows the mouth to open.
• Dysphonia.

10. ‘ The generalized weakness of all the extremities and the
intercostal muscles, resulting in decreasing vital capacity and
respiratory failure.
‘ Weakness of neck muscles may result in lolling of the head.
• Laryngeal involvement produces dysphonia and increases the
patients risk for choking, dysphagia and aspiration.

11. Diagnosis
• History
• Physical examination
• Anticholinesterase test
• Acetylcholine receptor antibody titers

12. Medical management
Anticholinesterase drugs. (pyridostigmine bromide)
Immunosuppressive therapy.(prednisolone)
Plasmapharesis.
Intravenous immunoglobulin (IVIG)therapy.
Thymectomy.

13. Complications
Myasthenia crisis
A myasthenia crisis is an exacerbation of the myasthenia gravis
process characterised by severe generalised muscle weakness
and respiratory and bulbar weakness that may result in
respiratory failure.

14. Treatment of myasthenic crisis
• Neostigmine methylsulfate -IM/IV
• Plasmapharesis and IVIG
• Endotracheal intubation and mechanical ventilation

15. Cholinergic crisis
Anticholinergic overmedication leads to cholinergic crisis. The
symptoms are similar to myasthenia crisis.
• Treatment- Withdraw the anticholinergic medication and
administer Atropine sulphate(antidote to anticholinesterase
drugs)
• Endotracheal intubation and mechanical ventilation