Myasthenia Gravis
A 3 year old male child with fever, cough and colds, came in for consultation.
During the course of the Physical examination and history taking, I noted that his both eyelids were drooping so the mother told me that it was evident since he was 1 year old and was diagnosed to have myasthenia gravis.
So, what is myasthenia gravis?
Myasthenia Gravis is a disorder of the neuromyal junction and will present as pathologic fatigability of the skeletal muscles.
An autoimmune theory maybe suggestive as the cause and it has high association with thyroid diseases, lupus erythematosus and other collagen vascular diseases.
Clinically, the affected individual will have pathologic fatigability of skeletal muscles. The muscle strength wanes with continued activity and recovers with rest.
They could present as:
A. Neonatal myasthenia gravis, the neonate will have weak cry, poor suck and in some cases will present with respiratory distress.
B. Congenital myasthenia gravis
– a rare disorder
– the child is born to a non-myasthenic mother and yet shows the classical symptoms of excessive fatigability of skeletal muscles
– prognosis is poor
C. Juvenile myasthenia
– most common type
– resembles the adult form of myasthenia gravis
– there maybe weakness of the muscles supplied by the cranial nerves, ptosis, diplopia, swallowing difficulties and facial weakness
The weakness becomes worse as the day progresses and the individual is stronger in the morning or after a nap.
When the disease progresses to respiratory distress and severe weakness, it becomes life- threatening and this is called as myasthenic crisis. So, it is but important to be examined by an expert if one has diplopia, ptosis, and diurnal fatigability to rule out myasthenia gravis.