The Differential Effects of Alzheimer's Disease and Lewy Body Pathology on Cognitive Performance: a Meta-analysis

Abstract

Differential diagnosis of Alzheimer's disease (AD) from normal aging and other dementia etiologies is imperative for disease specific treatment options and long-term care planning. Neuropathological confirmation is the gold standard for neurodegenerative disease diagnosis, yet most published studies examining the use of neuropsychological tests in the differential diagnosis of dementia rely upon clinical diagnostic outcomes. The present study undertook a meta-analytic review of the literature to identify cognitive tests and domains that allow for the differentiation of individuals with AD pathology from individuals with dementia with Lewy Bodies (DLB) pathology and pathology-free individuals. A comprehensive literature search yielded 14 studies that met the inclusion criteria for the present meta-analysis. Six studies comprised 222 decedents with AD compared to 433 normal controls, and eight studies comprised 431 cases of AD compared to 155 decedents with DLB. Results revealed that the effect of having neuropathologically confirmed AD versus DLB lowered performance in the memory domain, and having DLB decreased performance in the visuospatial domain. No single test differed significantly across the AD and DLB groups. For the AD and pathology free comparison, results indicated that that AD was associated with poorer performance on the memory and language domains. With respect to specific cognitive tests, AD produced lower scores on list learning tests, category fluency, and the Digit Symbol substitution test. The limited number of studies meeting inclusion criteria warrants formulation of guidelines for reporting in clinico-pathological studies; suggested guidelines are provided.

Cognition at Each Stage of Lewy Body Disease with Co-occurring Alzheimer’s Disease Pathology1

“…Interestingly, some patients with LBD exhibit a similar pattern of cognitive decline, which has been sugge-sted to occur, or is more pronounced, in the presence of co-morbid ADNC [ 13 ]. In contrast, most patients with LBD experience primary executive and visuospatial deficits, suggesting that these deficits are closely related to LBD neurodegenerative processes irrespective of ADNC [ 14 ]. However, it is unknown if the impact of ADNC on cognition is different at each pathologic stage of LBD (brainstem, limbic, and cerebral cortical).…”

Cognition among individuals along a spectrum of increased risk for Parkinson’s disease

“…The RBD cohort performed worse compared to all other cohorts in measures of processing speed/attention (SDMT) and visuospatial function (JOLO). This is of note considering that among individuals with RBD, abnormalities in tests of attention (as well as executive function) are predictive of future risk of DLB in RBD[ 26 ], and visuospatial dysfunction is a hallmark of DLB[ 27 ].…”

The Developing Infant Creates a Curriculum for Statistical Learning

“…These sensors are attached to the body and thus the sensory data for learning are determined by the disposition of the infant’s body in space [Box 1]. Advances in wearable sensors now provide researchers with the means to capture the learning environment from the perspective of the learner [8–11]. Accordingly, and in contrast to the usual focus on learning mechanisms, this review focuses on the data for statistical learning from the infant’s perspective.…”