Sometimes, it can be difficult to diagnose amyotrophic lateral sclerosis (ALS), a progressive neurological disease which causes nerve cell (motor neuron) death in the brain, brain stem, and spinal cord. Currently, diagnosing ALS requires physician observation and other tests to rule out potential other conditions. Early diagnosis is crucial, as current treatments can slow disease progression and help improve outcomes. According to Medical XPress, researchers have begun searching for potential new diagnostic methods – like muscle biopsies – to improve the diagnostic process. 

A research team from Hiroshima University hypothesized that a protein called TDP-43 could be a potential biomarker for ALS. According to the researchers, TDP-43 is associated with motor neuron health. Too much TDP-43 building up in the muscles or nerve bundles, however, could signify a potential health issue. Therefore, researchers sought to evaluate this protein as an indicator of the early stages of ALS. 

First, the researchers sourced muscle tissue from 10 deceased individuals with ALS and 12 deceased individuals who did not have this disease. The researchers found high levels of TDP-43 in intramuscular nerve bundles for those with ALS, compared to no buildup in those without the condition. Then the researchers evaluated 114 patients who had undergo muscle biopsies and were, at the time of biopsy, not diagnosed with any condition. High TDP-43 accumulation was found in 29% of patients, who all – eventually during their lifetime – were given an ALS diagnosis. 

Therefore, researchers hypothesize that performing muscle biopsies to evaluate patients’ TDP-43 levels could indicate a future ALS diagnosis. However, more research is needed to confirm.

Interested in reading more about this study? Take a look at the research in JAMA Neurology.

What is Amyotrophic Lateral Sclerosis (ALS)? 

Also known as Lou Gehrig’s disease, amyotrophic lateral sclerosis (ALS) is a neurological disorder which causes muscle weakness and a loss of voluntary movement or control. As motor neurons die off, the communication between the brain and muscles is inhibited. ALS can be sporadic (in 90-95% of cases) or familial (in 5-10% of cases). Risk factors for developing ALS include being male, being over 60 years old, and being exposed to toxins. This condition is a variable disease, so symptoms and progression may differ from patient to patient. Potential symptoms can include:

• Frequent tripping and falling
• Slowed or slurred speech
• Difficulty performing everyday actions or small movements
• Muscle cramping and twitching
• Poor posture
• Anxiety, depression, or psychological stress
• Arm, hand, and leg weakness
• Difficulty speaking and swallowing
• Respiratory distress caused by respiratory muscle weakness