The Effects of Moderate-to-Severe Traumatic Brain Injury on Episodic Memory: a Meta-Analysis

Memory impairment following Traumatic Brain Injury (TBI) is among its most pronounced effects. The present meta-analysis focused only on studies of episodic memory (n = 73) conducted with adult patients with moderate-to-severe TBI. The results indicate that verbal Memory, and more specifically Verbal Recall, is most sensitive to the effects of moderate-to-severe TBI. Furthermore, verbal more than visual memory and recall more than recognition are sensitive to the effects of TBI. These effects are more pronounced in delayed than in immediate testing. Several moderating factors were found: age at testing - the younger the age, the greater the effect size of verbal recall. A greater effect size of delayed story recall was related to an older age of testing and longer time since the injury. The higher the educational level, the smaller is the effect size of visual recall. The clinical implications are discussed.