Myasthenia gravis


Legs | Rheumatology | Myasthenia gravis (Disease)


Description

Myasthenia gravis is characterized by weakness and rapid fatigue of any of the muscles under your voluntary control. The cause of myasthenia gravis is a breakdown in the normal communication between nerves and muscles.

The hallmark of myasthenia gravis is muscle weakness that increases during periods of activity and improves after periods of rest. Certain muscles such as those that control eye and eyelid movement, facial expression, chewing, talking, and swallowing are often, but not always, involved in the disorder. The muscles that control breathing and neck and limb movements may also be affected.

Causes and Risk factors

Myasthenia gravis is caused by a defect in the transmission of nerve impulses to muscles. It occurs when normal communication between the nerve and muscle is interrupted at the neuromuscular junction—the place where nerve cells connect with the muscles they control. Normally when impulses travel down the nerve, the nerve endings release a neurotransmitter substance called acetylcholine. Acetylcholine travels from the neuromuscular junction and binds to acetylcholine receptors which are activated and generate a muscle contraction.

While myasthenia gravis can affect people of any age, its more common in women younger than 40 and in men older than 60.

Diagnosis and Treatment

A special blood test can detect the presence of immune molecules or acetylcholine receptor antibodies. Most patients with myasthenia gravis have abnormally elevated levels of these antibodies

There is no cure for myasthenia gravis, but treatment can help relieve signs and symptoms - such as weakness of arm or leg muscles, double vision, drooping eyelids, and difficulties with speech, chewing, swallowing and breathing. ...