The course of post-traumatic amnesia: three little words.

OBJECTIVE

To provide a simple means of "real time" recognition of emergence from post-traumatic amnesia (PTA).

METHODS

Ninety-one patients with traumatic brain injury (PBI); 53 minor (GCS 13-15), 19 moderate (GCS 9-12), 18 severe (GCS 3-8). Twenty-seven control subjects treated at two regional trauma units for their acute phase and followed in a hospital-based research institute were studied prospectively. Subjects were examined repeatedly following injury with the Galveston Orientation and Amnesia Test (GOAT) and tests of their ability to learn and retain new information. Word triplets balanced for concreteness and frequency were presented. Immediate and 24-hour recall were tested. If 24-hour recall was imperfect, recognition was tested by presenting the 3 target words and 6 distracters. The target words were then re-presented and recall was tested the next day. The time intervals to first perfect recognition and first free perfect recall were compared with the patients' first GOAT score of 75 or greater on 2 successive days. Simple line drawings of common objects were also presented to the subjects using an identical paradigm. The outcome measures were GOAT, 3-word recognition and recall, 3 picture recognition and recall.

RESULTS

For all categories of head injury severity, the median interval to perfect free recall of words followed the achievement GOAT criterion by a significant interval. The mean GOAT scores for perfect 3-word recall and recognition corresponding to minor, moderate and severe injuries were 97, 90 and 88, and 97, 76 and 68 respectively. The recognition and recall of pictures preceded the recognition and recall of words by approximately 1 day.

CONCLUSIONS

The orientation measures of the GOAT that contain material that the patient knew prior to injury obscure the determination of recovery of continuous memory and should be tested separately. Three-word recall which is simpler to administer than the GOAT is a more reliable measure of emergence from PTA. For patients who are dysphasic or who do not share a common language with the examiner, 3-picture recognition and recall may substitute for word recognition and recall.