Neuromuscular Autoimmune Disorders

Tuesday 24 November 2020
Autoimmune Disorders

Table of Contents


I. What is the Neuromuscular System?

II. Multiple Sclerosis

a. Symptoms of Multiple Sclerosis

III. Myasthenia Gravis

a. Symptoms of Myasthenia Gravis

IV. Myositis

a. Symptoms of Myositis

V. Treatments


What is the Neuromuscular System?

Autoimmune disorders can affect every aspect of the body. When the neuromuscular system is affected, the communication between the brain and muscles is disrupted. The neuromuscular system includes all the muscles in the body and the nerves that serve them. These nerves communicate with the brain and make movement and articulation possible.

Neurons (nerve cells) carry messages to the brain through the spinal cord. These messenger cells are called motor neurons. Motor neurons sit close to muscle fibers in a neuromuscular junction. Motor neurons release a chemical that is picked up by muscle fibers and tells the muscle to contract, creating movement. [1]

Neuromuscular autoimmune disorders occur when the immune system causes your body to attack nerve cells, hampering communication between motor neurons and the brain. When the immune system attacks these cells, it can lead to several disorders, including multiple sclerosis, Myasthenia gravis, and myositis. Several prescription medications are available to help with symptoms of these diseases, like Gilenya and Mestinon (pyridostigmine). [2]

a fake skeleton with the nerves displayed in blue

Multiple Sclerosis

It is estimated that over one million people in the United States have multiple sclerosis (MS). It is the most prevalent neurological condition that affects young adults in the world. People can develop MS at any age, but it is most common in those between the ages of 20 and 50. Interestingly, researchers have found that multiple sclerosis rates are higher further from the equator and colder climates. [3] 

When someone develops MS, the immune system attacks the myelin sheath that protects the nerve fibers and helps communication between the brain and the body. If this disease is left untreated, MS can be disabling to the brain and spinal cord. The nerves can become severely damaged and deteriorate over time. Those with severe MS may lose the ability to walk, but others may only experience MS symptoms periodically and have long remission periods. [4] 

a. Symptoms of Multiple Sclerosis 

MS does not have a cure, but modern medical care has made it possible for MS patients to live a full life and have an average lifespan. MS affects many aspects of the body so that symptoms can affect vision, movement, and other bodily functions.

Symptoms that affect movement:

  • Numbness or weakness in one or more limbs
  • Electric shock sensations in the neck and when bending the neck
  • Tremors
  • Lack of coordination
  • Unsteady gait

Symptoms that affect vision:

  • Blurry vision
  • Partial or complete vision loss
  • Prolonged double vision

Other symptoms:

  • Dizziness
  • Fatigue
  • Slurred speech
  • Sexual problems
  • Bowel and bladder function problems [4]

a woman laying her head down on a table

Myasthenia Gravis

Myasthenia gravis is a condition that causes weakness and fatigue of muscles under voluntary control. In myasthenia gravis, the immune system produces antibodies that block muscles’ receptor sites (acetylcholine), which prevent proper communication between nerve cells and the brain. Due to a lack of nerve signals, the muscles become weaker over time.

A malfunctioning thymus gland can also result in myasthenia gravis. This gland is responsible for the production of acetylcholine. If the gland becomes large and develops tumors, it can lead to myasthenia gravis and possibly cancer. Your risk factors for myasthenia gravis may be increased if you have a close family member with the disease, are experiencing stress or fatigue, or take beta-blockers.

Those with myasthenia gravis are more likely to develop if you have another autoimmune condition. You may also experience underactive or overactive thyroid if you live with myasthenia gravis. In severe cases, you may experience a myasthenic crisis. This is a life-threatening condition that affects the muscles that control breathing. If these muscles become weak, breathing may be severely affected and potentially deadly. [5]

a. Symptoms of Myasthenia Gravis 

This chronic condition tends to have more severe symptoms after periods of heavy activity. The symptoms may improve after periods of rest, so many people do not know they are experiencing myasthenia gravis. The severity of myasthenia gravis can vary significantly, but those with myasthenia gravis often have a normal life span. Symptoms of this condition can include:

  • Weakness of eye muscles
  • Drooping of one or both eyelids
  • Difficulty swallowing
  • Shortness of breath
  • Impaired speech
  • Weakness in the fingers, hands, legs, and necks
  • Changes in facial expression [6]

Myositis

Myositis is a generally uncommon autoimmune disorder that causes inflammation of the muscles in the body. An injury or infection may also cause this condition. The two types of myositis include polymyositis and dermatomyositis. Polymyositis leads to muscle weakness in the body's trunk, and dermatomyositis leads to muscle weakness and skin rash. [7]

Muscle inflammation occurs when the immune system attacks muscles within the body. Many people do not know they are experiencing myositis at first. They may get an unexplained rash or trip more frequently, but attribute it to old age. If you do have myositis, it is a serious condition that requires treatment. It can be difficult to diagnose and often requires extensive testing and a muscle and skin biopsy. [8]

a person walking on a plateau with a backdrop of a purple sky

a. Symptoms of Myositis 

Common symptoms of myositis can include:

  • Trouble swallowing
  • Muscle pain and soreness that does not go away
  • An elevation in muscles enzymes
  • Difficulty climbing stairs
  • Difficulty lifting arms
  • Trouble rising from a chair
  • Tired feeling after standing or walking [9]

Treatments

Those with autoimmune neuromuscular disorders can often maintain their symptoms and live a long and healthy life. Initially, the hardest part of these conditions is receiving the proper diagnosis. When diagnosed, your doctor will provide the proper medications for your treatment. In the case of myositis, lifestyle management changes are recommended and common corticosteroid medications like prednisone, which helps reduce inflammation of muscles. [9]

Gilenya is a medication used to treat symptoms of multiple sclerosis. It is a class of drug called a sphingosine 1-phosphate receptor modulator. These drugs prevent the entry of white blood cells into the central nervous system, causing inflammatory damage to nerve cells. This drug has been shown to decrease the number of MS episodes and prevent or delay disability. [10] Mestinon (pyridostigmine) is used to treat myasthenia gravis and improve muscle strength. It also helps prevent the breakdown of acetylcholine, which improves normal muscle function. Your doctor will provide the best treatment plan for you. [11]

The content in this article is intended for informational purposes only. This website does not provide medical advice. In all circumstances, you should always seek the advice of your physician and/or other qualified health professionals(s) for drug, medical condition, or treatment advice. The content provided on this website is not a substitute for professional medical advice, diagnosis, or treatment.