What is myasthenia gravis?

The neurological disease in which the body attacks its own muscle receptors is called myasthenia gravis. This disease affects the communication of the nerves and muscles and because of this poor communication, the symptoms are produced. Once diagnosed by Best Neurologist in Karachi myasthenia gravis can only be managed but not completely treated. Read on to know more about myasthenia gravis:

What is myasthenia gravis?

Myasthenia gravis is a condition of rapid fatigue of muscles due to antibodies produced against the muscle receptors. Consequently, this neuromuscular disorder impacts the ability of the body to control voluntary muscles. The patient experiences muscle fatigue and weakness with varying severity. As mentioned before, this is a lifelong disease in which the drugs can help relieve some symptoms but not achieve complete remission.

Myasthenia gravis occurs in 20 out of 100,000 people. Of these, the age group of the female patients is around 20 to 40 years, while men aged 50 to 80 get this disease. Although rare in the younger age group, about one in every 10 cases occur in teenagers, and this is called juvenile myasthenia gravis.

The risk of myasthenia gravis rises in people with:

  • History of other autoimmune disorders including rheumatoid arthritis and systemic lupus erythematosus (SLE).
  • History of surgical procedure
  • History of thyroid diseases
  • History of mediation for:
    • Cancer
    • Cardiac arrhythmias
    • Malaria
  • History of infectious diseases

What are the types of myasthenia gravis?

There are two types of myasthenia gravis:

  • Ocular: in this type of myasthenia gravis, there is involvement of the eyelids and the muscles that move the eyes. The patient complains of difficulty in keeping the eyes open, and drooping of eyelids. In fact, this may be the presenting complaint of the patient before diagnosis. About 50 percent of these patients go on to develop generalized form of myasthenia gravis.  
  • Generalized: apart from the eyes, myasthenia gravis can affect the muscles of the whole body. This is called generalized myasthenia gravis. The patient complains of difficulty in speaking, swallowing, walking and climbing. As the day progresses, the patient may also complain of difficulty in speaking.  

What are the symptoms of myasthenia gravis?

The symptoms of myasthenia gravis are:

  • Slurring of speech with the voice sounding nasal or soft
  • Doubling of vision
  • Drooping of eyelids
  • Weakness in arms, neck, legs
  • Difficulty in moving facial muscles
  • Difficulty in swallowing and chewing
  • Shortness of breath and trouble breathing

These symptoms get worse as the day progresses and the patient gets tired. Alternatively, the patient is better after sleep or the next day.

What causes myasthenia gravis?

Myasthenia gravis is an autoimmune disease. This means that the body’s own defense mechanism and antibodies are mistakenly attacking its own cells. In the case of myasthenia gravis, there are antibodies against the receptor of the neurotransmitter called acetylcholine. This neurotransmitter is responsible for transmitting the signal for movement at the receptor site of muscles.

Researchers believe that antibodies against myasthenia gravis are produced in the thymus gland. This gland is a part of the immune system, and is located in the chest just beneath the breast bone. In fact, many people with myasthenia gravis may also have tumors of thymus, known as thymomas.

Factors that make myasthenia gravis worse

The factors that make myasthenia gravis worse:

  • Stress
  • Surgery
  • Fatigue
  • Infection
  • Pregnancy
  • Menstruation
  • Medications like beta blockers

How is myasthenia gravis diagnosed?

The investigations that are recommended by experts like Dr. Khalid Jamil Akhtar to confirm the diagnosis of myasthenia gravis include:

  • Ice pack test: a bag of ice is placed on the eyelid of the patient for two minutes, and the eyelids are observed for signs of improvement.  
  • Repetitive nerve stimulation: nerve conduction studies are performed on the patient.  
  • Blood tests: antibodies are present in the blood of the patient
  • Imaging: CT and MRI of the chest are obtained to rule out thymus tumors
  • Single-fiber electromyography (EMG): to check the electrical activity between the brain and the muscles.