How is Myasthenia Gravis (gra​ve muscle weakness) diagnosed?

Neurologists diagnose the disease by checking​ for droopy eyelids, other areas for fatiguable weakness, and antiacetylcholine receptor (AChR) antibodies in the blood. These are present in 85 per cent of patients with generalised symptoms. Those who do not have these antibodies undergo more tests, including repetitive nerve stimulation, single fibre EMG, and other blood tests.

How is Myasthenia G​ravis treated?

Treatment depends on a patient’s condition. Those with only eye symptoms and no antibodies are likely to remain as is for many years, and can be treated with drugs for symptomatic relief. Others, especially those who are antibody positive and have generalised symptoms, may be given an immunosuppressant that suppresses mostly the “bad” immunity, along with the “good”.

“The benefit outweighs the risk,” said Dr Kamal, Senior Consultant, at the Department of Neurology​, National ​Neuroscience Institute​, a member of the SingHealth​ group​, citing studies which show that early treatment with these drugs can sometimes prevent the disease from spreading. Dosages are reduced when symptoms ease, or if a patient goes into remission. During such periods, patients needs close monitoring. Another option is removing the thymus gland (thymectomy) because data suggests it may trigger or maintain the production of AChR antibodies. “We generally advise all our young patients to do it because the beneficial effects of the surgery are not seen until later. Patients i​n the older age group are also so advised, only if a tumour is found within the thymus gland,” said Dr Kamal.

Patients with weakened lung muscles who have difficulty breathing may need to be intubated in an emergency. Here, additionally, a plasma exchange can clean the blood of the offending antibodies, much like dialysis. Another rescue treatment is IVIG – giving a patient immunoglobulins intravenously to modulate the body’s immunity.

Not a case for plastic surgery

Some patients with droopy eyes may mistakenly think it is age-related and undergo surgery to lift their eyelids at an eye clinic. “The diagnosis can be missed if only the eye muscles are affected, especially in the older population,” said Dr Kamal, stressing that because it is a treatable illness, it is important not to ignore symptoms and get referred to a neurologist for an accurate diagnosis. “Symptoms can be reversed with proper treatment. That’s why awareness is so important.” His advice to patients who have difficulty seeing, speaking, swallowing, breathing, biting, chewing, or with fluctuating tiredness in their limbs, especially late in the day is: “See a doctor!”

See previous page ​for the symptoms of myasthenia gravis​.

Ref: O17