Mild cognitive impairment (MCI) due to Alzheimer's disease (AD), as an early stage of AD, is an important point for early warning of AD. Neuropathological studies have shown that AD pathology in pre-dementia patients involves the hippocampus and caudate nucleus, which are responsible for controlling cognitive mechanisms such as the spatial executive process (SEP). The aim of this study is to design a new method for early warning of MCI due to AD by dynamically evaluating SEP.

We designed fingertip interaction handwriting digital evaluation paradigms and analyzed the dynamic trajectory of fingertip interaction and image data during "clock drawing" and "repetitive writing" tasks. Extracted fingertip interaction digital biomarkers were used to assess participants' SEP disorders, ultimately enabling intelligent diagnosis of MCI due to AD. A cross-sectional study demonstrated the predictive performance of this new method.

We enrolled 30 normal cognitive (NC) elderly and 30 MCI due to AD patients, and clinical research results showed that there may be neurobehavioral differences between the two groups in digital biomarkers captured during SEP. The early warning performance for MCI due to AD of this new method (areas under the curve (AUC) = 0.880) is better than that of the Minimum Mental State Examination (MMSE) neuropsychological scale (AUC = 0.856) assessed by physicians.

Patients with MCI due to AD may have SEP disorders, and this new method based on dynamic evaluation of SEP will provide a novel human-computer interaction and intelligent early warning method for home and community screening of MCI due to AD.

Objective: Delirium is a common neurocognitive syndrome among hospitalised older adults. The clock drawing test (CDT) is a relatively simple bedside test of cognitive function. This systematic review and meta-analysis examine the accuracy of the CDT in identifying delirium in hospitalised older adults.Methods: PRISMA guidelines were used to report the identified studies. Pubmed, SCOPUS, and Ovid and EBSCO platforms (including MEDLINE ®, PsycINFO, PsycEXTRA, EMCARE, CINAHL and EMBASE databases) were searched. Studies were assessed for methodological quality using the Downs and Black Tool. Data were extracted regarding the number of delirious/not delirious, number with normal and abnormal CDT, age, and MMSE scores, and information regarding CDT scoring, criteria for diagnosis of delirium and setting of the study. Analysis was carried out with the "Mada" and "Metatron" packages of R software.Results: Fifteen studies were examined. The number of participants was 2199, of whom 597 (27.15%) were diagnosed with delirium. The overall sensitivity of CDT in the absence of any formal cognitive test was 0.76 (0.58-0.87) with specificity of 0.70 (0.51-0.83). When the MMSE was taken into account, the specificity and sensitivity reduced to 0.51. Diagnostic criteria for delirium, scoring method of CDT, age of participants and setting significantly (p < 0.05) affect the sensitivity and specificity of the CDT.Conclusion: Although, the CDT is generally considered to be a simple and easy to administer screening tool for cognitive impairment in older hospitalised adults, when a more formal cognitive test is used its sensitivity and specificity to detect delirium is low.

Efficient detection of delirium and comorbid delirium-dementia is a key diagnostic challenge. Development of new, efficient delirium-focused methods of cognitive assessment is a key challenge for improved detection of neurocognitive disorders in everyday clinical practice.

To compare the accuracy of two novel bedside tests of attention, vigilance and visuospatial function with conventional bedside cognitive tests in identifying delirium in older hospitalized patients.

180 consecutive elderly medical inpatients (mean age 79.6 ± 7.2; 51% female) referred to a psychiatry for later life consultation-liaison service with delirium, dementia, comorbid delirium-dementia and cognitively intact controls. Participants were assessed cross-sectionally with conventional bedside cognitive tests [WORLD, Months Backward test (MBT), Spatial span, Vigilance A and B, Clock Drawing test and Interlocking Pentagons test] and two novel cognitive tests [Lighthouse test, Letter and Shape Drawing test (LSD)-4].

Neurocognitive diagnoses were delirium (n = 44), dementia (n = 30), comorbid delirium-dementia (n = 60) and no neurocognitive disorder (n = 46). All conventional tests had sensitivity of > 70% for delirium, with best overall accuracy for the Vigilance-B (78.3%), Vigilance-A (77.8%) and MBT (76.7%) tests. The sustained attention component of the Lighthouse test was the most distinguishing of delirium (sensitivity 84.6%; overall accuracy 75.6%). The LSD-4 had sensitivity of 74.0% and overall accuracy 74.4% for delirium identification. Combining tests allowed for enhanced sensitivity (> 90%) and overall accuracy (≥ 75%) with the highest overall accuracy for the combination of MBT-Vigilance A and the combined Vigilance A and B tests (both 78.3%). When analyses were repeated for those with dementia, there were similar findings with the MBT-Vigilance A the most accurate overall combination (80.0%). Combining the Lighthouse-SA with the LSD-4, a fail in either test had sensitivity for delirium of 91.4 with overall accuracy of 74.4%.

Bedside tests of attention, vigilance and visuospatial ability can help to distinguish neurocognitive disorders, including delirium, from other presentations. The Lighthouse test and the LSD-4 are novel tests with high accuracy for detecting delirium.