Symptoms of Myasthenia Gravis
People with myasthenia gravis generally experience specific muscle weakness (such as in the eye), especially with repeated use of the muscles. This weakness often has a characteristic pattern; ie, face and head muscles are involved early in the disease. Drooping eyelids and double vision are the most common early complaints (Kasper 2005). People afflicted may also have difficulty chewing, facial weakness that affects their smile, and a nasal quality to their voice due weakness in the palate.
Progression of the disease is variable, with periods of remission followed by exacerbation(s). In about 85 percent of cases, the weakness will progress to a generalized weakness affecting large muscle groups.
At some point in the illness (usually within two to three years after diagnosis), 12 to 16 percent of myasthenia gravis patients will experience a crisis episode, in which the weakness becomes so severe that breathing is compromised and respiratory assistance is required (Berrouschot 1997; Cohen 1981). This eventuality is most likely in people with tongue and mouth weakness or a thymoma (Berrouschot 1997; Cohen 1981; Thomas 1997).
Myasthenia gravis is distinguishable from congenital myasthenic syndromes. These syndromes are caused by genetic defects in the acetylcholine receptor and other components of the neuromuscular junction. Although they share symptoms, the illnesses respond differently to treatment(s).