Cognitive impairment and postural control in elderly

Background: a correct postural control stems by central nervous system-cortical and subcortical- and the peripheral one. With aging, the highprevalence of polimorbidity undermines these mechanisms determining agrowth of risk to falls. Some evidence has showed that an interpolatedcognitive task increases, even in healthy subjects, postural imbalance.At the moment, just a little has known about the relationship betweenmild-moderate dementia and postural control. Objective: to investigate1. possible differences in postural sways between controls and dementedsubjects at quiet standing and with an interpolated cognitive task; 2. die roteof frontal functions in the integration of postural and cognitive performance,requiring spatial or verbal skills. Materials and methods: we have chosen34 subjects: M = 14 and F = 20, aged between 65 and 85, 10 controls and24 demented patients with MMSE score ranging from 21 to 26. Ancillarytests were applied to exclude visual, hearing, vestibular and proprioceptivedisabling deficits, muscle strength deficits, high level of co-morbidity.Tinetti's scale was applied to check balance and gait, while three indices ofthe CAMDEX (CAMCOG, Depress and Organicity) were used to evaluatethe cognitive level, depressive symptoms and functional abilities. Both DualTask test and verbal fluency were used to assess frontal functions. Twocomputerized indices of postural control were obtained by a static forceplatform (Kistler type 9284) allowing to measure the postural sway, in arepeated 20" trials protocol, in two different experimental conditions: 1. atquiet standing condition, with subsequently open and closed eyes sessions2. at interference condition, with the performance of an interpolated verbal(counting back) or spatial (a plane rotation pictures paradigm) cognitivetask, administrated to each subject in a random sequence. Conclusions:the results show that any significant difference could be detected betweengroups at basal evaluation, while sways significantly increase in dementiapatients at interference trials, namely during verbal cognitive task. Moreovera significant relationship could be detected between the increase of posturalsways during verbal task and frontal impaired performance in dementedsubjects.