Long-term recovery of visual reaction time after closed head injury.

A follow-up study covering two years after a closed head injury was carried out on a group of 57 young males. Their reaction time was tested on both a simple and a four choice visual reaction task. The group was divided into three subgroups according to length of unconsciousness after the injury. Reaction time discriminated between subgroups, and a highly significant improvement during follow-up was shown. Choice reaction time discriminated better and continued to do so throughout the whole period of follow-up. Some relations of reaction time with clinical variables and outcome are discussed. The choice reaction in particular seems to have some value for monitoring recovery and predicting final outcome.