Executive functioning of complicated-mild to moderate traumatic brain injury patients with frontal contusions.
Executive dysfunctions are among the most prevalent neurobehavioral sequelae of traumatic brain injuries (TBIs). Using culturally validated tests from the Delis-Kaplan Executive Function System (D-KEFS: Trail Making, Verbal Fluency, Design Fluency, Sorting, Twenty Questions, and Tower) and the Behavioural Assessment of the Dysexecutive Syndrome (BADS: Rule Shift Cards, Key Search, and Modified Six Elements), the current study was the first to examine executive functioning in a group of Iranian TBI patients with focal frontal contusions. Compared with a demographically matched normative sample, the frontal contusion patients showed substantial impairments, with very large effect sizes (p ≤ .003, 1.56 < d < 3.12), on all the executive measures. Controlling for respective lower-level/fundamental conditions, the differences on the highest-level executive (cognitive switching) conditions were still significant. The frontal patients also committed more errors. Patients with lateral prefrontal (LPFC) contusions were qualitatively worst. For example, only the LPFC patients committed perseverative repetition errors. Altogether, our results support the notion that the frontal lobes, specifically the lateral prefrontal regions, play a critical role in cognitive executive functioning, over and above the contributions of respective lower-level cognitive abilities. The results provide clinical evidence for validity of the cross-culturally adapted versions of the tests.
a Department of Psychology , University of Sistan and Baluchestan , Zahedan , Iran.
Heshmatollah
H
Ghawami
b Department of Neurosurgery , Zahedan University of Medical Sciences , Zahedan , Iran.
Sadegh
S
Sadeghi
a Department of Psychology , University of Sistan and Baluchestan , Zahedan , Iran.
Mahvash
M
Raghibi
c Department of Neurosurgery, Sina Trauma and Surgery Research Center , Tehran University of Medical Sciences , Tehran , Iran.
Vafa
V
Rahimi-Movaghar
D000293:Adolescent; D000328:Adult; D000070642:Brain Injuries, Traumatic / Q000150:complications / Q000523:psychology*; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000150:complications / Q000523:psychology*; D003288:Contusions / Q000150:complications / Q000523:psychology*; D056344:Executive Function; D005625:Frontal Lobe / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D055815:Young Adult
D-KEFS; dysexecutive syndrome; executive functions; frontal lobe; traumatic brain injury