MS risk nearly double 15 years after concussion for teens
Congress of the European Committee for Treatment and Research in Multiple Sclerosis
Evidence was presented at the recent Congress of the European Committee for Treatment and Research in Multiple Sclerosis that for adolescents, the risk for MS (multiple sclerosis) emerging fifteen years after a concussion is almost double. MS is an autoimmune disease involving an inflammatory attack on myelin, the fatty 'insulation' around nerves in the brain and spinal cord necessary to normally conduct nerve impulses. In this age of increasing loss of immune tolerance, debris from even mild TBI (traumatic brain injury) presented to the immune system by cells involved in the clean-up process provides a chance for sensitization of the immune system to myelin.
Anti-Brain Antibodies Commonly Seen
If the microglia (immune cells in the brain) have already taken an abnormal interest in myelin due to earlier trauma or other factors promoting immune polarization with neurological autoimmunity, the brain can be primed for a more aggressive assault on subsequent exposure. In the young this includes infection, and in older adults age-associated priming and silent stroke can be contributors. Additionally, TBI can result in impaired vagus nerve activity expression in the gastrointestinal tract causing GI dysfunction, and other manifestations of dysautonomia that contribute to compromise of the blood-brain barrier and the promotion of neuroinflammation. At Lapis Light it's not unusual to find anti-neuronal antibodies, including anti-myelin antibodies, present with appropriate screening.
Replication of earlier study results for risk of multiple sclerosis
Concussion in adolescence and risk of multiple sclerosis
While the data presented at the 35th Congress showed risk mainly for males, a study published in the Annals of Neurology that assessed whether concussion in childhood or adolescence increased MS risk found similar effects without gender restriction. The authors examined data for 7,292 patients with MS who were matched individually with 10 people without MS by sex, year of birth, etc. comprising a study population of 80,212. In keeping with the principle of microglial priming, they additionally reported that a second TBI massively increased the risk.
Concussion in adolescence was associated with a raised risk of MS, producing adjusted odds ratios (95% confidence intervals) of 1.22 (1.05–1.42, p = 0.008) and 2.33 (1.35–4.04, p = 0.002) for 1 diagnosis of concussion and >1 diagnosis of concussion, respectively, compared with none.
That's more than double after a second concussion. This further emphasizes the importance prevention of mild TBI for children and adolescents, especially when there is a family history of autoimmunity or any functional manifestations of loss of tolerance or an autoimmune process that may be present prior to the appearance of symptoms as shown by predictive antibodies on lab testing. These authors conclude:
Head trauma in adolescence, particularly if repeated, is associated with a raised risk of future MS, possibly due to initiation of an autoimmune process in the central nervous system. This further emphasizes the importance of protecting young people from head injuries.
Medscape Medical News quotes the lead author of this study on the recent presentation at the Congress:
Olsson was coauthor of the 2017 study in Sweden that reported similar associations between adolescent concussion and risk of future MS. "Basically their findings replicate our own, which were published a couple of years ago. So I think all is fine with their data."
These findings argue in favor of screening for the presence of predictive anti-neuronal antibodies and other factors promoting neuroinflammation after even a mild TBI.