In this study, funded in part by an unrestricted gift from the National Football League (NFL) to the CSTE, McKee found that when they died, all 12 athletes showed neuropathological evidence of chronic traumatic encephalopathy (CTE), a progressive degenerative brain disease characterized by deposits of an abnormal form of tau protein and believed to be caused by repetitive head trauma. In the three athletes with motor neuron disease, abnormal tau protein deposits were not only found throughout the brain, but also in the spinal cord.
CSTE researchers also discovered that 10 of 12 CTE victims had a second abnormal protein, TDP-43, in their brains. Of those 10, only three had TDP-43 in the brain and the spinal cord, and those were the three athletes diagnosed with motor neuron disease. TDP-43 is also found in individuals with sporadic ALS although in the athletes with repetitive brain trauma, the TDP-43 pathology was more severe than found in sporadic ALS and was accompanied by extensive tau pathology. The brains and spinal cords of normal individuals show no TDP-43 or tau deposition.
These new findings suggest that the motor neuron disease that affected the three athletes is similar to, but distinct from sporadic ALS and represents a disease never described previously in the medical literature. This new disease, referred to as chronic traumatic encephalomyopathy (CTEM) by McKee and colleagues is likely caused by the repetitive head trauma experienced by athletes in contact sports.
The association between head trauma and ALS is supported by the medical literature, in which the risk of ALS has been reported to be higher among contact sport athletes and veterans. A study of professional soccer players in Italy found that the incidence rate of ALS was 6.5 times higher than in the general population. An increased incidence of ALS has also been reported in American football players, in
|Contact: Gina DiGravio|
Boston University Medical Center