A controlled historical cohort study on the post-concussion syndrome.

In Lithuania, expectation of chronic symptoms after minor head injury is less than in western countries and possibilities for monetary compensation are minimal. Therefore, an opportunity exists to study the post-concussion syndrome (PCS) without several confounding factors present in western societies. We sent questionnaires about symptoms attributed to PCS to 200 subjects who had a concussion with loss of consciousness between 35 and 22 months before the study. For each study subject, a sex- and age-matched control person with minor non-head injury was identified. These controls received similar questionnaires. All the responding post-concussion patients stated that they had had acute headache after the trauma but this headache had disappeared in 96% of cases within 1 month. Headache and dizziness at the time of the questioning were not significantly more prevalent in the patients with concussion than in the controls, and there was no significant difference concerning subjective cognitive dysfunction. Scores of visual analogue scales of symptoms attributed to PCS showed no significant differences except for depression, alcohol intolerance and worry about brain injury, which were more frequent in the concussion group. No specific effect of the head injury was detected when various definitions and different constellations of core symptoms of PCS were used. These findings question the validity of the PCS as a useful clinical entity.