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Muscle Biopsy and ALS: What's the Connection?

When we hear the word ‘muscle,’ our brain immediately visualizes an image of a bodybuilder– or perhaps flexed biceps, to be specific. It is known to most people what the function of muscles are: movement and support. Yet, we underestimate the importance muscles have- whether that is in terms of body stability or the ability muscles have to aid in the diagnosis of crucial ailments at an early stage.

How does ALS involve muscles?

Amyotrophic lateral sclerosis (ALS) is a disease which causes the malfunction of the nervous system, causing motor neurons to degenerate which primarily affects muscle function and the ability to function physically. Although the disease is categorized as rare (<20,000 cases annually), patients who are affected with this disease usually do not survive. This disease can be passed down genetically, but familial ALS (which is passed down genetically) only accounts for 5-10% of all known cases. Symptoms of ALS include weakness in limbs, difficulty walking, slurred speech, and muscle cramps. ALS has no cure to it yet, but medication like Riluzole, Nuedexta, and Radicava, along with therapy, can ease pain and discomfort while slowing down the effects of the disease. Diagnosis for this disease can be done by MRI scans, blood and urine tests, and even muscle biopsies.

Muscle Biopsy

This technology is used to examine musculoskeletal health and abnormalities as well as diagnose many neuromuscular diseases, such as muscular dystrophy, a disease which can cause loss of muscle mass. Doctors usually perform this test on patients to diagnose various muscular diseases such as ALS, polymyositis, and muscular dystrophy. The process is usually performed by inserting a needle into the concerned area of the body to remove a piece of muscle tissue, which will be assessed for diseases and overall health. This procedure is also usually done after an overall health checkup and routine blood tests/ lab tests. There are four different types of biopsy methods, some of which include: core needle biopsy, fine needle biopsy, image guided biopsy, and vacuum assisted biopsy. Core needle biopsy uses a medium-sized needle to take tissue samples, while fine needle uses a thinner needle attached to a syringe. Image guided and vacuum biopsy, however, use x-ray machines, CT scans, or a ‘vacuum’ to collect more cells to look for any signs of disease. Risks of muscle biopsy testing can include: bruising, discomfort, bleeding, and infected biopsy site.

Muscle Biopsies and ALS

New studies have found that muscle biopsy testing can help diagnose ALS at a rather earlier stage. According to a professor and doctor at Hiroshima University, Mr. Hirofumi Maruyama, the buildup of a protein called TDP-43, usually found in nerves of muscles, can be used to detect ALS. The muscle biopsy test is performed, in which doctors look for abnormal clusters of the protein. This protein is specifically found to cause ALS- associated degeneration of the body. Multiple studies were done to help prove this finding, and in all studies, TDP-43 was found in clusters in people that had symptoms possibly indicating ALS. This finding has potentially opened a door for us to be able to diagnose ALS at a much earlier stage and potentially, finding some sort of treatment for it!

Thanks for reading the last article in our All about Muscles series! We hope you learned a bit about ALS, and about new discoveries for treatment options for ALS patients.

If you enjoyed reading this article, check out Nihitha's article on toxic masculinity, linked here.

Thanks for reading, and see you soon!


Harshita and the Writing Committee :)


Wexler, Marisa. “Locating TDP-43 Clumps in Muscle Biopsies May Speed ALS Diagnosis.” ALS News Today, 29 June 2022,

“Muscle Biopsy.” ALS News Today,

“Muscle biopsy test for biomarker could lead to earlier diagnosis of ALS.” ScienceDaily, 21 June 2022,

“Muscle Biopsy Could Prove Effective as Early ALS Diagnosis.” Technology Networks, 22 June 2022,

“Muscle biopsy test for biomarker could lead to earlier diagnosis of ALS.” EurekAlert!, 21 June 2022,

“Muscle Biopsy: Purpose, Procedure, and Risks.” Healthline,

“What is ALS? - Amyotrophic Lateral Sclerosis | The ALS Association.” ALS Association,

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1 Comment

Aug 03, 2022

A fascinating analysis between muscle biopsy and ALS. Great job, Harshita.

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