Citation

Stulemeijer M, Vos PE, Van der Werf SP, Van Dijk G, Rijpkema M, Fernández G. J. Neurotrauma 2010; 27(9): 1585-1595.

Affiliation

Radboud University Nijmegen Medical Centre, Medical Psychology, P.O. Box 9101, Nijmegen, Netherlands, 6500 HB, 31 24 3613608, 31 24 3613425; maja.stulemeijer@live.nl.

Copyright

(Copyright © 2010, Mary Ann Liebert Publishers)

DOI

10.1089/neu.2010.1298

PMID

20629484

Abstract

Memory deficits are among the most frequently reported sequelae of Mild Traumatic Brain injury (MTBI), especially early after injury. To date, these cognitive deficits remain poorly understood as in most patients, the brain is macroscopically intact. To identify the mechanism by which MTBI causes declarative memory impairments, we have probed the functionality of the medial temporal lobe (MTL) and the prefrontal cortex (PFC) within six weeks after injury in 43 patients from a consecutive cohort and matched healthy controls. In addition to neuropsychological measures of declarative memory and other cognitive domains, all subjects underwent functional Magnetic Resonance Imaging (fMRI). Behavioural results showed poorer declarative memory performance in patients than controls, and decreasing performance with increasing duration of post traumatic amnesia (a measure of injury severity). Task performance in the scanner was, as intended by the task and design, similar in patients and controls, and did not relate to injury severity. The task used activated reliably the MTL and PFC. Although we did not find significant differences in brain activity when comparing patients and controls, we revealed, closely in line with our neuropsychological findings, an inverse correlation between MTL activity and injury severity. In contrast, no difference in prefrontal activation was found between patients and controls, nor a relation with injury severity. On a behavioural level, injury severity was inversely related to declarative memory performance. In all, these findings suggest that reduced medial temporal functionality may contribute to poorer declarative memory performance in the post-acute stage of MTBI, especially in patients with longer posttraumatic amnesia.

Language: en