P2‐459: EXECUTIVE CONTROL DEFICITS AS AN EARLY DIAGNOSTIC TO DEMENTIA OF ALZHEIMER'S TYPE

Abstract

Dementia of Alzheimer's type (DAT) is marked by executive control deficit which allows monitoring and resolution of conflict between different stimuli and responses. The possible underlying cause of executive control deficit may be the dysfunction of inhibitory mechanisms due to the reduced availability of attentional resources early in the course of the disease. Literature have evidenced of deficit in executive control as an early diagnosis to DAT before memory impairment which indicate that as the disease progresses early onset of executive deficit may lead to conversion of patient with amnestic mild cognitive impairment (aMCI) to DAT. The early diagnosis of DAT may reduce its devastating effects. The current research converging on executive control function as an earlier indicator of DAT in patients with mild cognitive impairment (MCI) at preclinical stage. The present study examined the executive control in attentional function among people with aMCI, mild and moderate levels of DAT compared with age-matched healthy controls (HC) by using the attentional network paradigm. The flanker paradigm of Attentional Network Task (ANT) was used to assess executive control effect. The reaction time and performance accuracy of the participants were recorded. The result showed that the inhibitory control function was less efficient in DAT as compared to HC. The aMCI group differed to mild and moderate DAT in response time measure. Further, the post-hoc analysis showed significantly slower performance of aMCI and mild DAT with HC group, the performance of patients with mild DAT was also significantly faster than moderate DAT, however, it was seen that aMCI group showed a non-significant difference with mild DAT group on executive control performance. This non-significant result suggests that the few patients with aMCI who performed significantly different at congruent and incongruent condition may progresses to DAT in comparison to those who don't face difficulty in resolving conflict among responses. The impairment in executive control network in aMCI revealed by difference in performance of response inhibition task could be proven as an early diagnostic to DAT which could further delay the onset of symptoms.