The Progression of Dementia and Cognitive Decline in a Dutch 2-Year Cohort Study of People with Young-Onset Dementia.

Abstract

The progression of dementia in people with young-onset dementia (YOD) is relatively unknown. To investigate the progression of dementia and cognitive decline in the three most common subtypes in YOD and to explore which factors are associated with this course. The course of dementia was examined in 198 people with YOD. The primary outcomes were cognitive function, as assessed by the Mini-Mental State Examination (MMSE) and dementia severity, as assessed by the Global Deterioration Scale (GDS). Mixed-model analyses were used to explore factors associated with the course of dementia of the diagnostic sub-types. The mean overall two-year progression of dementia severity was 0.9 GDS points, this was a statistically significant change (p = 0.012) and was not significant different for the three dementia subtypes. The mean overall two-year decline in cognitive function was 1.6 points on the MMSE. The differences in cognitive decline were statistically significant (p = 0.046) among the three diagnosis groups, AD participants showed the greatest decline, of 2.3 points. In addition to lower education (p = 0.010), higher scores on the Neuropsychiatric Inventory (NPI) sub-syndromes psychosis (p < 0.001) and hyperactivity (p = 0.002) were associated with higher rates of cognitive decline. In contrast, higher scores on the NPI affect cluster were associated with lower levels of cognitive decline (p < 0.001). Different YOD subtypes show different rates of decline in cognitive functioning, and this decline seems less progressive compared to those observed in studies in late-onset AD. Further research is needed to evaluate whether managing neuropsychiatric symptoms can positively influence the decline of cognitive function.