This is not only about memory: A systematic review on neuropsychological heterogeneity in Alzheimer’s disease.

Abstract

Alzheimer’s disease (AD) is the most prevalent cause of dementia and memory deficits are described as predominant in early AD. However, current knowledge demonstrated that the disorder may also manifest as non-amnestic phenotypes, which were referred to as “atypical”. Thus, the objective of this study is to analyze the neuropsychological heterogeneity of patients with AD. This study consists of a systematic review, as Prisma guideline. In this systematic review they fulfilled the eligibility criteria. In this systematic review they met the eligibility criteria. A clustering approach resulted in several cognitive phenotypes, showing “atypical” dementia subtypes of those described predominantly in the literature. Clustering subjects with AD associated cognitive profiles with different sociodemographic, genetic, clinical and neurobiological characteristics. Furthermore, patients with APOE e4 positive genotype were more often associated with membership of memory-impaired cluster.

Disentangling Heterogeneity in Alzheimer’s Disease and Related Dementias Using Data-Driven Methods

“…In addition to data-driven neuroimaging studies, considerable heterogeneity among AD dementia patients has also been revealed by applying clustering methods to comprehensive neuropsychological test data (reviewed in (49)). Across different studies, clustering approaches have identified two broad cognitive subtypes of AD dementia patients, corresponding to those with a typical memory-impaired cognitive profile and those with relatively spared memory compared to non-memory domains (50).…”

Diagnostic accuracy of early cognitive indicators in mild cognitive impairment

“…[32][33][34] Likewise, recent studies highlight the cognitive heterogeneity in AD, showing the importance of studying other cognitive aspects in addition to episodic memory. [35][36][37][38] Normal aging and some psychiatric disorders (such as MCI and AD) were associated with decline in PS. 39,40 PS involves several components of executive control, which vary according to age.…”

“… 32 – 34 Likewise, recent studies highlight the cognitive heterogeneity in AD, showing the importance of studying other cognitive aspects in addition to episodic memory. 35 – 38 …”

Robust Discovery of Mild Cognitive impairment subtypes and their Risk of Alzheimer’s Disease conversion using unsupervised machine learning and Gaussian Mixture Modeling

“…Furthermore, there is a wide variety of possible disease subtypes and each one is associated with the explicit clinical data type used to define it: Cognitive questionnaires, medical history, imaging features, laboratory tests, nutrition habits, genomics, proteomics, radiomics, and so forth [20]. Hence, reaching a consensus definition of clinically relevant disease subtypes at the prodromal stage is of paramount importance [21, 22].…”