Evaluate the neurological, neuopsychological and electroencephalogram (EEG) findings in a cohort of retired soccer players.

Chronic traumatic encephalopathy (CTE) is considered to be a consequence of exposure to repeated head traumas, but evidence suggests that a single moderate or severe traumatic brain injury can also induce progressive neuropathological changes.  

Prospective observational study that evaluated 26 retired soccer players and 14 controls. The retired athletes and controls were submitted to neurological evaluation, neuropsychological evaluation and EEG.

In general, the soccer players performed well in tests, within the normal range. 15 soccer players had a history of previous TBI/concussion. In the retired group the average age was 60,4 years (55,7 in the CG), average of 11.7 schooling years (13,7 in the CG). The average results in MMSE was 26.6 (29 in the CG), the average digit span in backwards was 3.1 (3.8 in the CG), the average verbal fluency for animals was 15.6 (24 in the CG) and the average clock-drawing test was 8.96 (9 in the CG). Visual EEG analysis showed a predominance of posterior alpha activity between 9.0 and 12.0 Hz (mean 10.3 Hz) in the soccer participants and 11 Hz in the control group (CG). The analysis wiht low resolution electromagnetic tomography (LORETA) showed that 11 soccer players had hippocampal asymmetry (5 had less activity in the right hippocampus and 6 had less activity in the left hippocampus).

Although the performance of the athletes in the tests was within the normal range, the means were always inferior to those of the controls. Almost half of the players presented asymmetry in the analysis by LORETA, although visual EEG analysis was normal. This may indicate that EEG changes may be earlier and more sensitive than clinical changes. These data are preliminary and further analysis are needed.