Neuropsychological Characteristics of the Confusional State Following Traumatic Brain Injury

Abstract

Objectives: Individuals with moderate-severe traumatic brain injury (TBI) experience a transitory state of impaired consciousness and confusion often called posttraumatic confusional state (PTCS). This study examined the neuropsychological profile of PTCS.

Methods: Neuropsychometric profiles of 349 individuals in the TBI Model Systems National Database were examined 4 weeks post-TBI (±2 weeks). The PTCS group was subdivided into Low (n=46) and High Performing PTCS (n=45) via median split on an orientation/amnesia measure, and compared to participants who had emerged from PTCS (n=258). Neuropsychological patterns were examined using multivariate analyses of variance and mixed model analyses of covariance.

Results: All groups were globally impaired, but severity differed across groups (F(40,506)=3.44; p<.001; ŋp 2 =.206). Rate of forgetting (memory consolidation) was impaired in all groups, but failed to differentiate them (F(4,684)=0.46; p=.762). In contrast, executive memory control was significantly more impaired in PTCS groups than the emerged group: Intrusion errors: F(2,343)=8.78; p<.001; ŋ p 2=.049; False positive recognition errors: F(2,343)=3.70; p<.05; ŋp 2=.021. However, non-memory executive control and other executive memory processes did not differentiate those in versus emerged from PTCS.

Conclusions: Executive memory control deficits in the context of globally impaired cognition characterize PTCS. This pattern differentiates individuals in and emerged from PTCS during the acute recovery period following TBI. (JINS, 2019, 25, 302-313).

Keywords: Cognition; Delirium; Executive functioning; Head injury; Memory; Posttraumatic amnesia.