Single Traumatic Brain Injury Not a Contributing Factor for ALS Onset

In a new study entitled “Acute traumatic brain injury does not exacerbate ALS in the SOD1 model” researchers report that a one-time traumatic injury to the brain is not an accelerating factor for amyotrophic lateral sclerosis progression. The study was published in the eNeuro journal.

Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, is a rapidly progressive neurodegenerative disease, eventually culminating in patients’ death. The disease is characterized by death of motor neurons localized in the brain and the spinal cord, which are responsible for controlling voluntary muscles. With time, disease progression leads to a complete loss of control of muscle movement, culminating in paralysis and death.

While the majority of ALS cases have no known genetic factor, it was previously suggested that trauma to the brain increases ALS risk. These reports, however, were based on epidemiological studies and so there was a necessity to perform a controlled study to assess the impact of brain injury in ALS progression.

Here, a team of researchers at the Cedars-Sinai Medical Center, Los Angeles, CA investigated in a rat model for ALS (these rats carry a mutation in the SOD1 gene, which is proposed to cause ALS) whether a traumatic brain injury contributed to early ALS onset and rats’ shortened lifespan. They observed that one-time brain injury did not affect disease onset or rats’ survival.

These findings suggest that contrary to what has been postulated, a one-time traumatic brain injury does not promote ALS disease onset. This prompts researchers to focus on other potential injuries to the central nervous system that may contribute to ALS onset and/or progression, such as repetitive traumatic brain injury or diffuse axonal injury (one of the most common and deadly type of injuries to the brain characterized by extensive lesions in white matter over a widespread area).

Lucie Bruijn, Ph.D., M.B.A., Chief Scientist for The ALS Association commented, “This study provides evidence that a single head injury is unlikely to play a role in development of ALS. The possibility remains that multiple traumas to the central nervous system may be a risk factor for the disease, a possibility that will need to be explored through further experiments.”