Right frontal stroke : extra-frontal lesions, executive functioning and impulsive behaviour

Abstract

The aim of this study was to evaluate executive functioning (EF) and impulsiveness in three groups of people aged 30 to 79 years: post-frontal stroke (n = 13) and post-extra-frontal chronic stroke of the right hemisphere (n = 31) and control (n = 38). The years of education varied between the groups was as follows, frontal lesion group: M = 12 (SD = 6.11); extra-frontal lesion group: M = 9.06 (SD = 4.94); and control: M = 9.61 (SD = 4.24) years. The following instruments were used: Behavioural Assessment Dysexecutive Syndrome, Wisconsin Card Sorting Test (WSCT), Barratt Impulsivity Scale, Impulsivity Evaluation Scale, Delay Descounting Task and Go/No-Go Task. We found differences in EF between the extra-frontal lesion group and the control group with respect to cognitive flexibility (p = .018); number of WCST trials (p = .018); WCST perseverative errors (p = .014) and omission by impulsivity errors on the go/no-go task for 250 ms (p = .008) and 1750 ms trials (p = .006). The frontal lesion group made more errors of omission than the control group in the 1750 ms go/no-go trials (p = .006). These results suggest that extra-frontal lesions impair EF by influencing attentional impulsivity.