Target phenotypic dimensions
Papers investigating psychometric properties of recommend tools
Episodic memory abilities
For each test proposed for clinical use we should know the sensitivity and specificity for AD and other NDD. Other issues to consider include: age effects, practice effects, ceiling and floor effects, repeatability, ease of administration, and correlation with biomarkers.
Among extant tools, the FCRST and the Visual Short-Term Memory Binding Test are good candidates to discriminate between AD-related memory deficits and memory disorders occurring in other NDD.
Good specificity for AD
The extent of language assessment should be closely linked to the aim of the investigation. A consensus on a high-quality cross-language naming task is heavily needed. Lack of standardised tools to differentiate dementias that are not primarily characterised by language disorders
In most settings, picture naming is the test of choice (e.g. Boston Naming Test). In investigations of progressive language disorders, a more comprehensive evaluation including an analysis of extended speech production as well as sentence-level tasks is recommended. Communication abilities should be assessed also as a key component of the functional profile
Picture naming tests are sensitive but not specific for dementia, as a naming disorder is a pervasive aspect of many NDD
Many tests to examine executive function of shifting, inhibition, and updating have unknown ecological validity. Few validated tools are currently available for the assessment of emotional processing and social cognition. There is no convergent agreement on the modular organisation of executive domain.
Executive functions: at a screening level at least two tests investigating two sub-components of the executive domain should be used. The following individual tests can be used: Stroop test, Trail Making Test, Wisconsin Card Sorting Test, Verbal Fluency, Emotional processes and social cognition: the Social and Emotional Assessment battery can be applied to assess emotion recognition and social cognition
Inhibition tests (e.g. Stroop test) are the most sensitive to AD. The Social and Emotional Assessment battery shows good sensitivity to FTD-behavioural symptoms In general, executive tests show low test–retest reliability and low ecological validity.
A main issue is represented by the relatively low specificity of the available tools. Low specificity is attributable to the difficulty in differentiating between basic visual processes alterations and proper spatial disorders.
Useful tools for the global assessment of visual-spatial abilities are the VOSP and the BORB batteries that allow the examination of multiple visual-spatial components. For a short screening, the Rey-Osterrieth figure and Benton Judgement of Line Orientation could be administered.
The VOSP has good sensitivity to AD. The contribution of Rey-Osterrieth complex figure test to differential diagnosis is controversial. The Benton Judgement of Line Orientation test can differentiate patients with DLB with psychotic symptoms from both patients with DLB with parkinsonian symptoms and patients with AD.
Available tools have low specificity hampering the possibility to differentiate between different NDD
The choice of the best tool to assess BPSD in dementia should be guided by a syndromic approach. The Neuropsychiatric Inventory (NPI) is a reliable scale for the assessment of a wide range of BPSD in dementia.
The NPI has good specificity for DLB compared to AD. The Neuropsychiatric Inventory-Clinician rating scale (NPI-C) has good inter-rater reliability.
Lack of validated tools to assess motor symptoms specific to the different NDD
The use of the following disease-specific tools with good validity is recommended: UPDRS; UHDRS PSPRS; UMSARS; Clinical examination according to El Escorial criteria for ALS. For the assessment of ideomotor apraxia, the Dementia Apraxia Test (DATE) can be applied.
The DATE shows a good capacity to discriminate between individuals with AD and individuals with FTD-behavioural variant
Some currently used IADL tools have relatively low evidence of validity. Lack of tools for the assessment of functional abilities in very early stages of dementia (i.e. mild cognitive impairment)
Although further research is needed to investigate quality aspects of IADL instruments, promising results have been found for several questionnaires, including the Everyday Cognition (ECog), the Cognitive Function Instrument (CFI), and the Amsterdam IADL questionnaire.
The Lawton IADL has good reliability. Some everyday cognition (ECog) sub-items (i.e. language sub-items) allow us to differentiate between MCI and dementia. The Amsterdam IADL questionnaire has good sensitivity to dementia-related changes over time