Memory function after closed head injury: a review of the quantitative research.

Studies which provide quantitative analyses of memory function following closed head injury were reviewed. Specific issues covered include criteria for assessing post-traumatic amnesia (PTA), PTA duration, relation of PTA duration to later memory impairment, memory functions within PTA, and comparisons between PTA and other amnesic conditions. Issues associated with the assessment of retrograde amnesia were also reviewed. With regard to memory function after PTA has terminated, we described and discussed normative data, the time course of recovery, and issues related to the nature of the later memory impairment. Directions for future work which seem particularly useful from a practical and theoretical viewpoint were also considered.