Myasthenia Gravis Involves Nerves, Muscles
Dr. Paul Donohue, St Louis Post-Dispatch (MO)
Dear Dr. Donohue: What can you tell us about myasthenia? Our niece told us recently that she has it. We are crushed. We feel extra close to this young woman, having raised her since her childhood, when her parents were killed in a terrible accident. She is 22 and in college now.
First of all, I want you to write the Myasthenia Gravis Foundation, 53 W. Jackson Blvd., Suite 660, Chicago, IL 60604. The people there can answer your questions and suggest how you can help your niece.
Myasthenia gravis affects the body's neuromuscular receptors. The cause is a misdirected attack on those structures by the body's normally protective immune system.
Let me back up: For a muscle to contract, its nerves must first emit a chemical - acetylcholine - at matching muscle receptor points. Many receptors have to take part in many such tiny chemical reactions in order for the slightest muscle contraction to take place.
In myasthenia, many receptors have been destroyed, producing muscle weakness. An eyelid might droop, or chewing might be difficult, as might swallowing if those muscles are involved. Arm and leg muscles may tire easily. In extreme cases, respiratory muscles are affected, causing great breathing difficulty.
With today's medicines and other therapies, most myasthenia patients can lead normal lives. You should adopt an upbeat attitude toward the problem and encourage your niece.
Myasthenia's sex predominance differs with age. The kind that occurs in the 20s or 30s favors women. The later-onset kind strikes mostly men in their 60s and 70s. …