Characteristics of myasthenia gravis

Myasthenia gravis (my-us-THEE-nee-uh GRAY-vis) is characterized by weakness and rapid fatigue of any of the muscles under your voluntary control. It’s caused by a breakdown in the normal communication between nerves and muscles.

The presentation of MG has the following characteristics: The clinical hallmark of MG is the presence of fluctuating fatigable muscle weakness that worsens with activity and improves on rest. 50% to 85% of patients with MG present with ocular symptoms with or without generalized weakness.

Myasthenia gravis most commonly affects muscles that control eye and eyelid movement, so the first symptoms you notice may be eyelid drooping and/or blurred or doubled vision. Most will go on to develop weakness in other muscle groups within one or two years.

“Myasthenia gravis” literally means “grave muscle weakness,” but many cases are mild, and life expectancy is normal. The muscles around the eyes tend to be affected first, causing the eyelids to droop.