Former tennis star Monica Seles has revealed she has been diagnosed with myasthenia gravis , a rare autoimmune condition that affects how the muscles work. The multiple Grand Slam champion says she was actually diagnosed three years ago after experiencing trouble with her vision and weakness in her arms and legs.
Author
- Adam Taylor
Professor of Anatomy, Lancaster University
It is estimated that myasthenia gravis affects between three and 12 in every 100,000 people and occurs when the body attacks the neuromuscular junction - a specialised connection between the muscles and the body's neurons (nerve cells). This reduces the ability to transmit neurotransmitters (chemical messengers) across the junction, affecting the way the muscles contract and function.
The most common signs of the condition are weakness of the muscles that move the eyes , drooping of one or both eyelids and blurred or double vision . Less common ocular symptoms include dry eyes, pain and tearing .
Cardiac changes are also commonly seen and arrhythmia (abnormal heart beat) is also common. The condition also weakens the facial muscles , making it more difficult to physically express emotions .
Other voluntary movements can be affected, too - particularly when moving the arms and legs . This weakness can make regular daily tasks more difficult. This symptom often worsens the more activity you do , while improving with rest .
Myasthenia gravis can affect people of any age, though in women it tends to emerge between the ages of 20 and 40 . In men it tends to occur over the age of 60 . It's not considered an inherited condition, so it can occur even in people with no family history of the condition.
The condition is extremely rare in infants, though there's a form of the myasthenia gravis that can be passed from the mother to her foetus. This causes the unborn child to acquire antibodies across the placenta, which can temporarily lead to symptoms for a few months after birth. It affects up to 30% of children whose mothers have myasthenia gravis.
Symptoms occur between three and 72 hours after birth and can include poor sucking , respiratory difficulty , facial muscle weakness or paralysis and weak muscle tone .
In the past 20 years, there has been a rise in the incidence of myasthenia gravis - particularly in over 65s. It's unclear what factors are driving this increase. It could be due to improved diagnostics, longer life expectancy and the natural deterioration of the immune system that occurs with ageing.
While most people with myasthenia gravis have a near normal lifespan, some research suggests the condition may lead to premature death - potentially due to the effect that the condition has on the muscles needed for breathing and swallowing.
It is estimated that 20% of people with myasthenia gravis will experience a respiratory crisis. This typically happens within the first two years of diagnosis.
Managing muscle symptoms
It isn't entirely clear what causes myasthenia gravis, but the thymus gland, located in the chest, is believed to be involved in the condition. This gland is largest in childhood, as it plays a role in forming new immune cells, but shrinks with age.
The thymus gland is believed to produce the antibodies which attack the neuromuscular junction - leading to myasthenia gravis. Adding strength to this theory are findings that patient with myasthenia gravis have better health outcomes and lower risk of premature death after having their thymus removed.
There's currently no cure for the myasthenia gravis. Available treatments focus on reducing muscle weakness which can help to improve quality of life - particularly when symptoms worsen.
Pyridostigmine is often the first-line treatment. This medication improves communication between the nerves and the muscles by preventing the breakdown of the neurotransmitter acetylcholine that is found in the neuromuscular junction.
Corticosteroids , such as prednisolone, are also often used when pyridostigmine doesn't work or when symptoms worsen. These steroids reduce inflammation and lower the immune system's ability to damage the body's tissues. Only low doses of these types of drugs are used as long-term use can have side-effects such as bone thinning (osteoporosis) , increased blood sugar levels and fatigue .
Immunosuppressants can also be beneficial as they decrease the body's attacks on its tissues and reduce symptoms.
During symptom flare-ups, treatments such as monoclonal antibodies or complement inhibitors can help, by reducing the body's natural processes for fighting infections. In autoimmune diseases this process is overactive, leading to inflammation and tissue damage.
This is one reason why these treatments don't come without risks. For instance, complement inhibitors can increase the risk of certain bacterial infections such as Neisseria meningitidis, which can result in meningitis.
Therapeutic plasma exchange has also been shown to reduce the number of harmful antibodies circulating in the blood. This treatment works by removing the plasma from a sample of a person's blood using a machine, and replacing it with donated plasma or sterile fluid. This has a significant and positive impact on the severity of symptoms.
Seles isn't the first famous person to talk about her diagnosis in the hope of educating people about the disease. Actors Sir Laurence Olivier and Suzanne Rogers, US Olympian James Carter and Christopher Milne - son of Winnie the Pooh author AA Milne - were all diagnosed with the condition. Walt Disney apparently also based Sleepy , one of the seven dwarves, on his friend who suffered from the condition.
With increasing awareness and better diagnostics, treatment options for myasthenia gravis are improving, making it easier for people who suffer with this incurable condition to lead full and active lives.
Adam Taylor does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
