A WIDE VIEW ABOUT NEURO-MUSCULAR JUNCTIONAL DISEASE

1. MYASTHENIA
GRAVIS
Presented by
INDRAJITTHAKUR
b.PHARM3RD YEAR

2. MYASTHENIA GRAVIS
Myasthenia -muscle illness , Gravis -grave or serious
First description in the 17th century by Sir Thomas Willis
“a woman who spoke freely and readily enough for a while, but after a
long period of speech was not able to speak a word for one or two hours”
Autoimmune Disorder- Autoantibody against Nicotinic Ach Muscarinic
receptor at muscle endplate .
Effect Skeletal muscle of body
Reduction in number of free acetylcholine to 1/3 of normal or less.
Purely motor disorder with no effect on sensation and co-ordination.

3. Nerve Terminal
Postsynaptic membrane
AChR
MuSK
AChase
ACh
Voltage-gated
Na+ channel
Voltage-gated
Ca+ channel
Ca++
Ca++
Na+
Mechanism of transmitter release

4. Increase in the
synaptic cleft
Decrease in
Ach receptor
Per Unit Area
Decrease
Membrane
Surface area

5. CAUSE
 In 85% of cases auto-antibodies are
produced against nicotinic
acetylcholine receptor at
neuromuscular junction and
In 15 % of cases auto- antibodies are
formed against muscle specific
tyrosine kinase(MuSK) receptor.

6. HALLMARKS OF MG
Eye lid drooping (ptosis)
Impaired speech (dysarthria)
Difficulty Swallowing(dysphagia)
Double Vision (diplopia)
Weakness of all extremities
Easily fatigued
 Waddling gait

7. TREATMENT
Acetylcholinesterase inhibitors- Pyridostigmine
Corticosteroids-
--Prednisolone, Cyclosporine
Plasma exchange
Intravenous immunoglobulin
Thymectomy

8. DIAGNOSTICMETHODS
AMELIORATIVE TEST:-
EDROPHONIUM i.v.
PROVOCATIVE TEST:- d-
tubocurarine
DEMONSTRATION OF ANTI-
NICOTINIC RECEPTOR
ANTIBODIES IN PLASMA

9. CONCLUSION
Myasthenia gravis (MG) is a rare, autoimmune
neuromuscular junction disorder. Contemporary
prevalence rates approach 1/5,000. MG presents
with painless, fluctuating, fatigable weakness
involving specific muscle groups.

10. REFERENCES
Tripathi., K.D., Essentials of Medical Pharmacology 7th
Edition (2013) Cholinergic System and Drugs
“Myasthenia gravis” 109-110
D. Grob, N. Brunner, T. Namba, and M. Pagala,
“Lifetime course of myasthenia gravis,” Muscle and
Nerve, vol. 37, no. 2, pp. 141–149, 2008.

12. DID YOU KNOW??