MYASTHENIA GRAVIS CAUSES | SYMPTOMS | DIAGNOSIS | TREATMENT
Introduction to Myasthenia Gravis
Myasthenia Gravis
is
a
neuromuscular disorder
primarily characterized by muscle weakness and muscle fatigue. Although the disorder usually becomes apparent during adulthood, symptom onset may occur at any age. The condition may be restricted to certain muscle groups, particularly those of the eyes (ocular myasthenia gravis), or may become more generalized (generalized myasthenia gravis), involving multiple muscle groups. Most individuals with myasthenia gravis develop weakness and drooping of the eyelids (ptosis) weakness of eye muscles, resulting in double vision (diplopia) and excessive muscle fatigue following activity.
Causes of Myasthenia Gravis
Myasthenia Gravis is a neuromuscular disorder that is usually caused by an autoimmune problem. Autoimmune disorders occur when the immune system mistakenly attacks healthy tissue. In this condition, antibodies (proteins which normally attack foreign, harmful substances in the body) attack the neurotransmitter substance called acetylcholine, which is a crucial substance for nerve cell and muscle communication. This results in the muscle weakness that characterizes the condition. The exact cause of this autoimmune reaction is unclear to the doctors.
Symptoms of Myasthenia Gravis Symptoms may include: Trouble talking Problems walking up stairs or lifting objects Facial paralysis
Difficulty breathing because of muscle weakness Difficulty swallowing or chewing Fatigue Hoarse voice Drooping of eyelid Double vision
Diagnosis of Myasthenia Gravis Your doctor will perform a complete physical exam, as well as take a detailed history of symptoms. He or she will also do a neurological exam. This may consist of: Checking your reflexes
Looking for muscle weakness Checking for muscle tone Making certain your eyes move properly Testing sensation in different areas of your body Seeing if you can perform certain movements, like touching your finger to your nose
Diagnosis Continue… Other tests that can help your doctor diagnose the condition include: Repetitive nerve stimulation test
Blood testing for antibodies associated with Myasthenia
Gravis Edrophonium (Tensilon) test: a drug called Tensilon (or a
placebo) is injected, and the patient is asked to perform muscle movements under doctor observation Imaging of the chest, using CT scans or MRI, to rule out a tumour
Treatments of Myasthenia Gravis Common treatments for myasthenia gravis include: Medications such as Mestinon (pyridostigmine bromide)
and Prostigmin (neostigmine bromide) Corticosteroid medications such as prednisone Medications that suppress the immune system, such as Imuran (azathioprine) and cyclosporine Removal of the thymus gland (thymectomy), the main
gland in the immune system Plasma exchange (plasmapheresis), in which the person's
blood plasma containing the abnormal antibodies is removed and fresh plasma is put back
Preventions of Myasthenia Gravis Myasthenia gravis cannot be prevented, but avoiding the following triggers may help patients prevent exacerbation: Emotional stress Exposure to extreme temperatures Fever
Illness
(e.g.,
respiratory
infection,
pneumonia,
tooth abscess)
Low levels of potassium in the blood (hypokalemia; caused by diuretics, frequent vomiting) Medications (e.g., muscle relaxants, anticonvulsants, certain antibiotics) Overexertion