Myasthenia Gravis vs ALS: What are the Differences?

Table of ContentsView AllTable of ContentsSymptomsCausesDiagnosisTreatmentPreventionFAQs

Table of ContentsView All

View All

Table of Contents

Symptoms

Causes

Diagnosis

Treatment

Prevention

FAQs

Myasthenia gravis (MG)andamyotrophic lateral sclerosis (ALS)present with many of the same symptoms, such as difficulty swallowing and muscle weakness. However, the two are different conditions.

While MG affects how the neurons and muscles communicate with one another, ALS damages nerve cells that control muscle movement. This article discusses the similarities and differences in symptoms, causes, and treatment for both conditions.

The symptoms present in MG and ALS are similar because the communication pathway between the brain and the muscles is compromised in both conditions. However, not all symptoms that develop will do so in both MG and ALS.

Symptoms that are specific to each condition include:

MGMuscle weakness in the eyesEyelid droopingDouble or blurry visionChanges in facial expressionShortness of breathALSMuscle twitches and crampsMuscle atrophy, tightness, and stiffnessNasally speechDifficulty chewingDifficulty breathing

MGMuscle weakness in the eyesEyelid droopingDouble or blurry visionChanges in facial expressionShortness of breath

Muscle weakness in the eyes

Eyelid drooping

Double or blurry vision

Changes in facial expression

Shortness of breath

ALSMuscle twitches and crampsMuscle atrophy, tightness, and stiffnessNasally speechDifficulty chewingDifficulty breathing

Muscle twitches and cramps

Muscle atrophy, tightness, and stiffness

Nasally speech

Difficulty chewing

Difficulty breathing

Symptoms that are shared between the two conditions include:

The causes of MG and ALS differ.

Myasthenia Gravis

In people without MG, the brain and the muscles communicate via motor nerves, which send chemical messengers down the nerve so it can bind to a receptor. The binding passes along specific messages to the muscles in the body. This connection terminal is known as the neuromuscular junction.

When a person develops MG, immune proteins known as antibodies begin to block or destroy the receptors in the brain that receive a specific chemical messenger known asacetylcholine. When acetylcholine cannot bind to its receptor, the ability of the brain to communicate with the muscles becomes compromised.

It’s also thought that thethymus gland,which produces immune cells in childhood, plays a role in MG. The thymus gland is relatively large in childhood, but after puberty, it begins to shrink until most of it is replaced with fat. In people with MG, however, the thymus gland does not shrink as it should and remains large well into adulthood.

Because it is still present and producing immune cells, it’s thought that it malfunctions and relays the wrong message to the immune cells it continues to make, leading to them attacking bodily tissues instead of foreign bacteria, viruses, or other harmful substances.

Causes and Risk Factors of Myasthenia Gravis

ALS

ALS is aneurodegenerative disorder, and medical researchers are still trying to determine what causes it. Evidence suggests that a person’sgeneticsand environment may play a role.

From a genetic standpoint, it’s thought that over 20 different gene changes may lead to the development of the disorder. When genes mutate, the instructions they provide change along with them and can cause issues with how the entire system functions.

In ALS, specific genes known asC9orf72, SOD1, TARDBP, FUS, andTBK1, are thought to be the most common genetic culprits behind the disease.

Exposure to viruses, physical trauma, poor diet, and toxic or infectious agents may also lead to someone developing ALS. However, more research is needed to determine how these aspects affect the disease.

ALS and VirusesWhile medical researchers are weary of assigning any virus to the cause of ALS, some recent research in animal studies has found that some may be directly associated with a higher risk of the disease. They include:PolioCoxsackievirusEchovirusEnterovirus-A71Enterovirus-D68

ALS and Viruses

While medical researchers are weary of assigning any virus to the cause of ALS, some recent research in animal studies has found that some may be directly associated with a higher risk of the disease. They include:PolioCoxsackievirusEchovirusEnterovirus-A71Enterovirus-D68

While medical researchers are weary of assigning any virus to the cause of ALS, some recent research in animal studies has found that some may be directly associated with a higher risk of the disease. They include:

ALS Age of Onset, Risk Factors, and Early Signs

Since MG and ALS can present with the same symptoms, there is some overlap in the diagnostic process. Both conditions are examined first using a physical examination and health history collection. Other tests that may be used for both include:

That is where the similarities end when it comes to testing.

MG will also be diagnosedusing other tools, including anedrophonium test, which temporarily blocks the impairment or damage to acetylcholine so that levels can increase. The result allows healthcare providers to determine muscle weakness in the eyes.

While blood tests are used for both, a specific type is used for MG that looks for heightened levels of two different antibodies: acetylcholine receptor antibodies and the anti-MuSK antibody. Not everyone with the disease will have elevated levels of both, but the results can aid the diagnostic process.

To measure breathing in people with MG, pulmonary function testing will also be done to determine the strength of a person’s breath to see if they are at risk for a myasthenic crisis.

What is a Myasthenic Crisis?The muscles in people with MG can sometimes become so weak that they cannot breathe independently. If that happens, it is referred to as a myasthenic crisis, and it is life-threatening if not addressed quickly.

What is a Myasthenic Crisis?

The muscles in people with MG can sometimes become so weak that they cannot breathe independently. If that happens, it is referred to as a myasthenic crisis, and it is life-threatening if not addressed quickly.

While most of the diagnostic tools used to determine a case of MG are used in ALS, one such test is only used for ALS, and that is amuscle biopsy, which is when a piece of muscle is removed and sent to a lab for closer examination.

The results will help medical providers establish that the symptoms are not occurring because of a disease that directly affects the muscles.

Treatments for both MS and ALS vary, so getting a proper diagnosis is crucial before implementing a treatment plan.

Since the cause of MG is clear, viabletreatment optionshave been developed to significantly improve the quality of life for people with the disease. First-line therapy options for MG include:

What Is Myasthenia Gravis?

ALS is a fatal disease. There is no cure, and treatment interventions can only improve a person’s quality of life, reduce symptoms, and attempt to slow disease progression. Therapies for ALS include:

How Effective is Treatment for MG and ALS?As mentioned above, ALS treatment can only do so much. People with the disease can participate in many therapy methods only to improve their quality of life. However, a person with MG can go into remission with effective treatment and lead everyday, symptom-free lives.

How Effective is Treatment for MG and ALS?

As mentioned above, ALS treatment can only do so much. People with the disease can participate in many therapy methods only to improve their quality of life. However, a person with MG can go into remission with effective treatment and lead everyday, symptom-free lives.

Experimental ALS Drug Slows Disease Progression in Preliminary Study

Neither MG nor ALS can be prevented. Once someone is diagnosed with both diseases, they must undergo treatment to cope with symptoms.

Summary

While MG and ALS have some similar symptoms, the conditions are starkly different in many ways. MG is an autoimmune disorder that affects the neuromuscular junction, whereas ALS is a neurodegenerative disease.

Diagnostic tests such as an MRI, nerve studies, and blood tests will be a part of determining if someone has either MG or ALS, and these tests are vital so that the proper treatment can begin. Since ALS and MG have drastically different outcomes, a person must begin therapy as soon as possible.

A Word from Verywell

It can be difficult coping with symptoms when you don’t know where they’re coming from or what’s causing them. That is especially true if you’re experiencing symptoms that appear to be ALS.

See your medical provider as soon as you notice any symptoms that appear to be either ALS or MG. Since MG can be treated and a person can go into remission, but ALS is fatal and progressively worsens over time, getting the correct diagnosis as quickly as possible is the best thing you can do for yourself and your health.

Frequently Asked Questions

Both ALS and MG can present with similar symptoms, so they can suspected simultaneously. However, the two diseases are not one and the same. Because there are starkly different symptoms, after a thorough diagnostic process, the two are unlikely to be confused with one another.Learn MoreHow Common is Misdiagnosis of Missed Diagnosis?

Both ALS and MG can present with similar symptoms, so they can suspected simultaneously. However, the two diseases are not one and the same. Because there are starkly different symptoms, after a thorough diagnostic process, the two are unlikely to be confused with one another.

Learn MoreHow Common is Misdiagnosis of Missed Diagnosis?

ALS and MG develop when the communication pathway between the brain and the muscles is compromised. However, the cause is not the same. In MG, the immune system is to blame for the damage. In ALS, genetics plays a role, but it is not yet clear what causes the injury to occur.Learn MoreImmune System Disorders: Types and Triggers

ALS and MG develop when the communication pathway between the brain and the muscles is compromised. However, the cause is not the same. In MG, the immune system is to blame for the damage. In ALS, genetics plays a role, but it is not yet clear what causes the injury to occur.

Learn MoreImmune System Disorders: Types and Triggers

Learn More7 Steps for Disease Prevention and Healthy Living

6 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Institute of Neurological Disorders and Stroke.Myasthenia gravis.National Institute of Neurological Disorders and Stroke.Amyotrophic lateral sclerosis (ALS).Dresser L, Wlodarski R, Rezania K, Soliven B.Myasthenia gravis: Epidemiology, pathophysiology and clinical manifestations.J Clin Med.2021;10(11):2235. doi:10.3390/jcm10112235Masrori P, Van Damme P.Amyotrophic lateral sclerosis: A clinical review.Eur J Neurol.2020;27(10):1918-1929. doi:10.1111/ene.14393Xue YC, Feuer R, Cashman N, Luo H.Enteroviral infection: The forgotten link to amyotrophic lateral sclerosis?Front Mol Neurosci.2018;11:63. doi:10.3389/fnmol.2018.00063Farmakidis C, Pasnoor M, Dimachkie MM, Barohn RJ.Treatment of myasthenia gravis.Neurol Clin.2018;36(2):311-337. doi:10.1016/j.ncl.2018.01.011

6 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Institute of Neurological Disorders and Stroke.Myasthenia gravis.National Institute of Neurological Disorders and Stroke.Amyotrophic lateral sclerosis (ALS).Dresser L, Wlodarski R, Rezania K, Soliven B.Myasthenia gravis: Epidemiology, pathophysiology and clinical manifestations.J Clin Med.2021;10(11):2235. doi:10.3390/jcm10112235Masrori P, Van Damme P.Amyotrophic lateral sclerosis: A clinical review.Eur J Neurol.2020;27(10):1918-1929. doi:10.1111/ene.14393Xue YC, Feuer R, Cashman N, Luo H.Enteroviral infection: The forgotten link to amyotrophic lateral sclerosis?Front Mol Neurosci.2018;11:63. doi:10.3389/fnmol.2018.00063Farmakidis C, Pasnoor M, Dimachkie MM, Barohn RJ.Treatment of myasthenia gravis.Neurol Clin.2018;36(2):311-337. doi:10.1016/j.ncl.2018.01.011

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

National Institute of Neurological Disorders and Stroke.Myasthenia gravis.National Institute of Neurological Disorders and Stroke.Amyotrophic lateral sclerosis (ALS).Dresser L, Wlodarski R, Rezania K, Soliven B.Myasthenia gravis: Epidemiology, pathophysiology and clinical manifestations.J Clin Med.2021;10(11):2235. doi:10.3390/jcm10112235Masrori P, Van Damme P.Amyotrophic lateral sclerosis: A clinical review.Eur J Neurol.2020;27(10):1918-1929. doi:10.1111/ene.14393Xue YC, Feuer R, Cashman N, Luo H.Enteroviral infection: The forgotten link to amyotrophic lateral sclerosis?Front Mol Neurosci.2018;11:63. doi:10.3389/fnmol.2018.00063Farmakidis C, Pasnoor M, Dimachkie MM, Barohn RJ.Treatment of myasthenia gravis.Neurol Clin.2018;36(2):311-337. doi:10.1016/j.ncl.2018.01.011

National Institute of Neurological Disorders and Stroke.Myasthenia gravis.

National Institute of Neurological Disorders and Stroke.Amyotrophic lateral sclerosis (ALS).

Dresser L, Wlodarski R, Rezania K, Soliven B.Myasthenia gravis: Epidemiology, pathophysiology and clinical manifestations.J Clin Med.2021;10(11):2235. doi:10.3390/jcm10112235

Masrori P, Van Damme P.Amyotrophic lateral sclerosis: A clinical review.Eur J Neurol.2020;27(10):1918-1929. doi:10.1111/ene.14393

Xue YC, Feuer R, Cashman N, Luo H.Enteroviral infection: The forgotten link to amyotrophic lateral sclerosis?Front Mol Neurosci.2018;11:63. doi:10.3389/fnmol.2018.00063

Farmakidis C, Pasnoor M, Dimachkie MM, Barohn RJ.Treatment of myasthenia gravis.Neurol Clin.2018;36(2):311-337. doi:10.1016/j.ncl.2018.01.011

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