I have been asked by patients if their prior history of trauma brought on their MS. It was interesting to read this article on childhood head trauma and risk of subsequent diagnosis of multiple sclerosis
In this study, the authors systematically analyzed longitudinally collected data from the national Swedish registry to look for a possible association between head trauma in childhood and adolescence and risk of subsequent multiple sclerosis. This is the largest study yet that examined concussion before the age of 20 years and the risk of MS. The study found that concussion in adolescence (age 11- 20 yrs) was associated with a statistically significant risk of a subsequent diagnosis of MS and there was a dose dependent increase in the risk. The authors found no association between childhood (birth to 10 years of age) concussion and risk of MS.
Possible explanations for why there might be an increased risk of MS associated with trauma are, among others, release of myelin specific antigens due to the injury which elicits an immune response that might be directly toxic to oligodendrocytes, and neuro-inflammation that remains sustained long after the injury.
The study however also has its limitations, ie a diagnosis of concussion could have resulted in increased vigilance that lead to a diagnosis of MS, confounding factors such as a low level of education which might be a risk for both MS and trauma. A diagnosis of concussion alone was used in ascertaining a history of head trauma, so other forms of head injury were excluded in the analysis. The difference in the risks between adolescence and childhood could be due to the small number of cases of childhood trauma that were included in the study, but it could also mean that time of exposure to trauma as the immune system undergoes changes through adolescence might play a more pivotal role in initiation of inflammation that leads to MS. This observation of increased risk when exposure happens during adolescence was also seen in studies investigating the risk of infections like EBV and subsequent diagnosis of MS.
This study found a significant association between concussion during adolescence and subsequent risk of MS. The risk was higher when there was a history of multiple episodes of concussion. This is yet another reason to drive home the importance of protecting the brain from any kind of trauma including from sports and emphasize wearing of protective gear when indicated. This study shows enough evidence for further research.
Montgomery et al. Concussion in Adolescence and Risk of Multiple Sclerosis. Ann Neurol. 2017 Oct;82(4):554-561
Jai S Perumal, MD