Myasthenia Gravis (Grave Muscle Weakness) Symptoms: Droopy Eyelid, Double Vision & More
Myasthenia Gravis begins with droopy eyelids, and can progress to weakness in voluntary muscles elsewhere in the body. The Department of Neurology at National Neuroscience Institute shares its symptoms.
Myasthenia Gravis is a little-known disease that can be serious, but can be treated effectively if diagnosed correctly.
Myasthenia Gravis, translated, means grave muscle weakness, and that is exactly what it is. It begins with droopy eyelids, and can progress to weakness in voluntary muscles (not involuntary muscles such as those in organs) elsewhere in the body.
An acquired autoimmune disorder, the disease can be triggered by an infection or inflammation, or develop gradually without any trigger. It cannot be cured or prevented, but there is effective treatment. Patients can even go into remission, though relapses may occur, caused by stress, infection, pregnancy, extreme heat, and certain types of medication, among other factors.
Dr Kamal Verma, Senior Consultant, Department of Neurology,
National Neuroscience Institute (NNI), a member of the
SingHealth group, said that the disease can be serious, but fortunately, most sufferers have less dire symptoms, and with treatment, can lead normal lives. He said it occurs when nerves stop “talking” to muscles. Ordinarily, nerve impulses in the brain send signals through nerves to muscles by releasing the chemical acetylcholine. This chemical binds with receptors on muscle cell membranes at neuromuscular junctions. If the body produces antibodies which destroy these receptors, less acetylcholine will get through, causing signal failure and then muscle weakness.
What are the symptoms of Myasthenia Gravis (Grave Muscle Weakness)?
For most patients, the disease starts with droopy eyelids, and sometimes also double vision. In some cases, only the eyes will be affected, but for the majority, symptoms become generalised within two years. “Symptoms can progress to involve other parts of the body. Patients may develop weakness in swallowing, or speech – they may slur or become very soft after speaking for some time. They may also develop fatiguable weakness – which fluctuates – in their legs and arms. They feel worse in the evening, because as the day progresses, they get more tired, with less acetylcholine reaching the muscle membranes,” said Dr Kamal.
The disorder can strike people at any age and even those in the pink of health. It is more common in women in their 20s and 30s and men over 50. In the United States, it affects 20 out of 100,000 people. Dr Kamal himself sees about 30 to 35 patients on regular follow-up a month, and NNI ’s neuromuscular clinic sees about two to four new cases a month.
The 5 grades of Myasthenia Gravis
- Ocular myasthenia: One or both eyes are affected
- Mild generalized myasthenia: Fatigue sets in only on sustained exertion
- Moderate myasthenia: The patient starts to feel tired with a minimal amount of movement or action.
- Severe myasthenia: The patient starts to feel tired even at rest, or has symptoms all the time.
- Myasthenia crisis: Respiratory muscles have weakened so much that the patient is unable to breathe, putting his life at risk. He will need to be intubated and put on a ventilator in the intensive care unit.
See next page for the diagnosis and treatment options for myasthenia gravis.