Myasthenia Gravis
Myasthenia Gravis is a disorder of the neuromyal junction and this presents as a pathologic fatigability of the skeletal muscles.
In the pediatric age group, females are affected 2-6 times more than the males. It has high association with thyroid diseases, lupus erythematosus and other collagen-vascular diseases thus suggesting of an autoimmune problem.
Clinically, the patient will manifest changes in muscle strength that wanes with continued activity and recovers with rest. There are different types of myasthenia gravis and they are as follows:
1. Neonatal myasthenia
– this occurs in babies born to a myasthenic mothers in 16% of cases
– transitory and recovery is the rule in 3-4 weeks
– babies will have a weak cry, poor suck and in extreme cases will have respiratory distress that may result to death if untreated
2. Congenital myasthenia
– a rare disorder
– a baby is born to a nonmyasthenic mother and exhibits the classical symptoms of excessive fatigability of skeletal muscles – poor prognosis
3. Juvenile myasthenia
– this is the most common type and closely resembles the adult form of myasthenia gravis
– the patient will show weakness of the muscles supplied by the cranial nerves
– there will be ptosis, diplopia, swallowing problems and facial weakness
– the patient is stronger in the morning or after nap and the weakness becomes worse as the day progresses
In some cases, the disease progresses to respiratory distress and severe weakness that it becomes life-threatening and this is called Myasthenia Crisis.
This condition may be provoked by infections and other stress factors.