Detection of Cognitive Impairment by Choice Auditory Reaction Time (ART) and Visual Reaction Time (VRT)s during Acute Mental Stress in Young Hypertensives: A Case Control Study

Background: Acute stress is known to be associated with both negative and positive influences on cognitive performance. Hypertension is one of the risk factors for lowered cognitive performance. Mental stress testing is easier to administer and can be regulated by the investigator. Mental arithmetic using serial subtraction is the most widely used method to administer stress. Reaction time (RT) is widely used to assess cognitive domains like attention, execution and psychomotor speed. Researchers have shown choice reaction times are delayed in hypertension. It is not known whether acute mental stress improves or deteriorates attention, execution and psychomotor speed in hypertension. We hypothesized in the present study that acute mental stress deteriorates cognitive function in hypertensives without overt cerebrovascular disease or other vascular risk factors. Methods: After getting medical ethical clearance from our institution, this case-control study was carried out over eight months (January 2017 to September 2017). 60 subjects between the age group of 35 to 55 years were included in the study. They were divided into 2 groups. Group 1 consisted of 30 diagnosed cases of hypertension at least two years of duration. Group 2 consisted of 30 sex and age-matched controls. MMSE was performed to assess the cognitive function in these groups. Simple (S) and choice (C) auditory reaction time (ART) and visual reaction time (VRT)s were measured at rest and acute mental stress in these groups to assess cognitive function. Predictive value of VRTC resting and VRTC during acute mental stress among hypertensives for cognitive dysfunction was calculated using the receiver operating characteristic (ROC) curve. Results: There was significant difference ART and VRT, both simple and choice, in hypertensive and nonhypertensive subjects and these reaction times further increased during mental stress (P<0.001). VRTC can be a predictor of cognitive dysfunction in hypertensives and during acute mental stress. Conclusion: A significant difference in cognitive functions in hypertensive and nonhypertensive subjects exists and this further deteriorates with acute mental stress.