Cognitive impairment associated with global sensory processing abnormalities

Recognition of the impact of primary sensory impairment on cognitive status and decline in the aging population has spurred research in this area. Most prior studies have focused on primary sensory function, with few studying the potential impact of central nervous system sensory processing and modulation in relation to cognitive status.This study sought to evaluate sensory processing abnormalities rather than primary sensory deficits in community-residing older adults through administration of the Adult Sensory Profile (ASP), a 60-item, norm-referenced assessment evaluating central nervous system sensory processing. The ASP items assess six sensory modalities: taste/smell, movement, visual, touch, auditory, and activity level. Participants ranked items based on their likelihood to engage in activities within each group. Responses were tabulated into four processing categories (sensation avoiding, sensory sensitivity, sensation seeking, and low registration) and compared with age-cohort normative data. Identification of more than one category outside of normative results was indicative of sensory processing abnormalities compared to same-aged peers. Participants were categorized based on the ASP as normal (<2 categories outside of normal range) or abnormal (2-4 categories outside of normal range). Chi-square tests compared cognitively normal participants to those with cognitive impairment.Seventeen participants completed the ASP. Eight were cognitively normal at the time of completion and nine were diagnosed with cognitive impairment. Of those with normal cognition, two were considered to have abnormal sensory processing (25%). Of those with cognitive impairment, seven were considered abnormal (78%), indicating a significant difference in global sensory processing between groups (x2 =4.73, p=0.029).Global sensory processing abnormalities were more frequent in those diagnosed with cognitive impairment compared to those that remained cognitively intact. It is likely that cortical neurodegeneration in sensory association areas is responsible for the increased prevalence of sensory processing abnormalities seen in the older adults with cognitive impairment in this study. Abnormal sensory processing abilities could contribute to increased behavioral and psychiatric symptoms, similar to that seen in children with severe sensory processing disorders. Larger studies are needed to confirm these results and investigate the relationship between impaired sensory processing and behavioral symptoms in dementia.