Apolipoprotein E and Subjective Symptomatology Following Brain Injury Rehabilitation

Abstract

The Apolipoprotein E (APOE) allele ∊4 has been repeatedly demonstrated to be related to the development of Alzheimer's disease. We have investigated its potential significance in stroke and traumatic brain injury as reflected in outcome following neuropsychological rehabilitation of 39 brain injured adults (mean age at injury 33.3 years, range 16–56). Outcome was evaluated by rating scales derived from a questionnaire completed by each brain injured subject and by a close relative. The questionnaire scales covered physical, cognitive, emotional, and social functioning. Ten of the subjects were found to carry the APOE-epsilon4 gene and the remaining 29 did not. There were no differences between these two groups on the questionnaire scales at the time of entry into the rehabilitation programme. At follow-up, however, on average more than 1 year after completing the rehabilitation programme, scale scores for the APOE-non epsilon4 group showed significant improvements in functioning whereas the APOE-∊4 showed deterioration, the two groups differing on a global scale by 0.87 standard deviations. A battery of attention and memory tests, administered and readministered over a shorter test-retest interval, showed no such deterioration. Within the constraints of the time interval and small sample sizes involved, these findings would suggest that the presence of the APOE-epsilon4 may be associated with poorer outcome following neuropsychological rehabilitation.