A recent article from Healthline highlighted the similarities and differences between two neurological diseases, myasthenia gravis (MG) and multiple sclerosis (MS).
Deriving from the Greek and Latin words for “grave muscle weakness,” the very literally named myasthenia gravis is the most common autoimmune neuromuscular disorder. People with MG experience varying degrees of weakness and fatigue in voluntarily controlled muscles groups. The more active the individual is at any given time, the more their symptoms may worsen. Resting usually allows symptoms to improve again. Myasthenia gravis currently has no cure, and the symptoms are known to be progressive. However, the prognosis is far from “grave.” Only 10 percent of people with MG develop life-threatening respiratory complications. Instead, the majority of people not only live to an expected age, but treatment can drastically reduce MG’s impact on their daily lives. A subset of patients remains refractory to these traditional treatment options, which leads to refractory generalized myasthenia gravis (gMG). Myasthenia gravis impacts an estimated 20 per 100,000 individuals globally. The subdivisions of MG—including congenital myasthenia gravis, transient neonatal myasthenia gravis, and juvenile myasthenia gravis—occur more rarely.
Regardless of type, myasthenia gravis causes weakness and fatigue in skeletal muscles—any voluntarily controlled, skeletal muscle group. Most people notice it in the arm and leg muscles, as well as in the muscles around the eyes, mouth, and throat. Some manifestations include:
- Drooping eyelids
- Double vision
- Trouble swallowing or chewing (dysphagia)
- Slurred speech
- Changed gait
- Neck or limb weakness/fatigue
- A small percentage of people may also develop a weakness in the chest wall that could lead to life-threatening breathing difficulties.
Multiple Sclerosis (MS)
Multiple sclerosis is a neurological (brain-related) disease that affects the communication between the brain and the rest of the body. A person’s immune system attacks the protective covering of nerve cells known as the myelin sheath. In advanced cases, the nerves can be permanently damaged by the immune system’s attacks.
MS has two main types: relapsing and remitting or progressive. In relapsing and remitting MS, there are long periods of remission before episodes of intense symptoms. Progressive MS cases continues to progress without remission periods and may result in complete loss of daily life function. The course of the disease is unpredictable.
All parts of the body may be affected; in particular, muscles in the extremities and the eyes are most commonly involved.
Symptoms of MS present in a wide variety of ways. The first symptoms usually appear between the ages of 20 and 40. MS may cause weakness, numbness, loss of coordination, and balance. Problems with speech, vision, and bladder control are also hallmarks of the disease.
Myasthenia gravis is an autoimmune disorder, and multiple sclerosis (MS) is an immune-mediated condition with autoimmune features. In both diseases, the immune system is attacking the body mistakenly.
Furthermore, in patients with myasthenia gravis, the immune system targets and attacks the neuromuscular junction. This is what sends signals from the nerves in the body to the muscle fibers. In MS, the immune system attacks the central nervous system. This includes the protective myelin around the nerves, myelin-producing cells, and nerves.
The primary symptoms of myasthenia gravis is muscle weakness worsened by exertion. Other symptoms vary from patient to patient but can include blurry or double vision, facial paralysis, shortness of breath, speech impairment, etc. As for MS, the symptoms are mostly neurological. The other symptoms of MS include but are not limited to bladder dysfunction, bowel issues, fatigue, itching, trouble walking, etcetera.
Both diseases affect people of all races and ethnic groups. However, MS has shown to be most common amongst people who are white and of European descent.
Myasthenia gravis is prevalent equally among males and females, and most cases are diagnosed in people over the age of 40. It is extremely rare that infants are diagnosed with myasthenia gravis. On the other hand, MS is typically diagnosed between 20 and 50 years old, although people of all ages can be diagnosed. Plus, MS is three times more common in females compared to males.
Unfortunately, myasthenia gravis is misdiagnosed. It can be misdiagnosed with other neurological conditions with similar symptoms, such as MS or ALS. To diagnose myasthenia gravis, patients will undergo a physical exam, specialized tests (such as edrophonium test and single-fiber electromyography), blood tests (to look for specific antibodies), and imaging tests (CT and MRI scans) to check for tumors.
While there is no specific test for MS, diagnosis is usually determined by ruling out all other conditions. This is done through specialized tests (such as a lumbar puncture), blood tests, and imaging tests (MRI scans).
Currently, there is no cure for myasthenia gravis. However, there are treatment options for patients to help manage their long-term symptoms. Treatments include medication (immunosuppressants/corticosteroids), and procedures and surgeries (plasma exchange or intravenous immune globulin).
Similar to myasthenia gravis, MS does not have a cure as of right now. This disease also uses various treatment options to help improve a patient’s well-being. These treatment options include medications (disease-modifying therapies, antidepressants, corticosteroids, etc.), and lifestyle changes (getting adequate sleep, gentle exercise, and physiotherapy).
At initial glance myasthenia gravis and multiple sclerosis may appear similar. They are both immune-mediated conditions that entail an extensive range of neurological symptoms. However, these two diseases are distinctly different. It is important to recognize the differences between to two diseases, and if you’ve been diagnosed, it’s vitally important to obtain a proper diagnosis and appropriate treatment to improve your quality of life.