Role of mild cognitive impairment in postural control of older adults

This thesis primarily focuses on studying the effects of dual tasks on the postural control in older adults with Mild Cognitive Impairment (MCI). The study tries to answer the following questions: Is there any difference in postural control between individuals with MCI and older adults? Will there be any difference in performance of a secondary task in individuals with MCI to that of older adults without impaired cognition? Will the dual task effect the postural control in the individuals with MCI? Will the complexity of the dual task affect postural control in individuals with MCI to a larger degree compared to healthy older adults? The first chapter of the thesis provides information about the present statistics on population at falls risk. It then provides information about Mild Cognitive Impairment (MCI) and describes the neuropathology basis of MCI as what changes occurs within the MCI and its progression. The chapter also introduces information related to the importance of study of postural balance in MCI and older adults and describes the previous research methods to study postural control. Than a statement of aims of the study is provided. Then information is provided about how participants were chosen for the study, the inclusion and exclusion criteria, IRB (International Review Board) approval obtained for the study, and the clinical assessment measures performed within the study to provide descriptive information about the study participants. The second chapter describes the results of the study of the effect of a cognitive task and light finger touch on standing balance in healthy adults. As previous studies have reported the individual effects of cognitive task and light finger touch, this study is the first to determine the concurrent effect of the cognitive task and finger touch on static balance in young healthy adults. This study involving healthy individuals provides a foundation for the study of the effect of a cognitive task and finger touch in balance control of older adults and individuals with cognitive impairment. The third chapter includes 3 studies investigating dual task effect on static and dynamic balance in individuals with MCI as compared to healthy older adults. Part 1 of the third chapter is in line with the second chapter involving investigation of the concurrent effect of cognitive task and light finger touch on standing balance in the individuals with MCI as compared to older adults. Part 2 of the third chapter focuses on the study of the effect of manual and cognitive secondary task on spatio-temporal gait variables in older adults with Mild Cognitive Impairment. Gait variables reported were gait velocity, cadence, step length and stride length that provides definite measures of gait cycle. Part 3 is devoted to the study of the effect of dual task on performance of clinical test of mobility and balance. In particular, we investigated how individuals with MCI perform Timed Up and Go (TUG) test in 3 experimental conditions involving concurrent secondary task performance. The TUG test is frequently used as a clinical tool in determining individuals with MCI at falls risk. Chapter four is devoted to conclusion and clinical implications from the findings of the studies included in the thesis.