Effectiveness of a mobile application for independent computerized cognitive training in patients with mild cognitive impairment: study protocol for the NeNaE Study, a randomized controlled trial

BACKGROUND

Mild cognitive impairment (MCI) involves cognitive decline beyond typical age-related changes, but without significant daily activity disruption. It can encompass various cognitive domains as the causes of MCI are diverse. MCI as well as frequent comorbid neuropsychiatric conditions like depression and anxiety affect individuals' quality of life. Early interventions are essential, and computerized cognitive training (cCT) is an established treatment method. This paper presents the protocol for the NeuroNation MED Effectiveness Study, evaluating the self-administered mobile cCT intervention ("NeuroNation MED") in individuals with MCI to assess training effects on cognitive domains, health competence, neuropsychiatric symptoms, psychological well-being, and the general application usability.

METHODS

This study protocol presents a single-blinded multicenter randomized controlled trial that will be carried out in six study centers in Germany and Luxembourg. We included adults with MCI (existing F06.7 ICD-10-GM diagnosis and TICS ≥ 21 and ≤ 32). The intervention group will use a mobile, multi-domain cCT ("NeuroNation MED") for 12 weeks. Meanwhile, the wait list control group will receive standard medical care or no care. The eligibility of volunteers will be determined through a telephone screening. After completion of the baseline examination, patients will be randomly assigned to one of the experimental conditions in a 2:1 ratio. In total, 286 participants will be included in this study. The primary outcome is the change of cognitive performance measured by the index score of the screening module of the Neuropsychological Assessment Battery. Secondary outcomes are changes in the Cognitive Failures Questionnaire, Hospital Anxiety and Depression Scale, Health-49, Health Literacy Questionnaire, among others. All of the primary and secondary outcomes will be assessed at baseline and after the 12-week post-allocation period. Furthermore, the intervention group will undergo an assessment of the System Usability Scale, and the training data of the NeuroNation MED application will be analyzed.

DISCUSSION

This study aims to assess the effectiveness of a mobile self-administered cCT in enhancing cognitive abilities among individuals diagnosed with MCI. Should the findings confirm the effectiveness of the NeuroNation MED app, it may confer possible benefits for the care management of patients with MCI, owing to the accessibility, cost-effectiveness, and home-based setting it provides. Specifically, the cCT program could provide patients with personalized cognitive training, educational resources, and relaxation techniques, enabling participants to independently engage in cognitive training sessions at home without further supervision.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00025133. Registered on November 5, 2021.

The neuropsychological assessment battery (NAB) is a valuable tool for evaluating neuropsychological outcome after aneurysmatic subarachnoid hemorrhage

Background

Detecting and treating neuropsychological deficits after aneurysmatic subarachnoid hemorrhage (aSAH) play a key role in regaining independence; however, detecting deficits relevant to social and professional reintegration has been difficult and optimal timing of assessments remains unclear. Therefore, we evaluated the feasibility of administering the Neuropsychological Assessment Battery screening module (NAB-S) to patients with aSAH, assessed its value in predicting the ability to return to work and characterized clinical as well as neuropsychological recovery over the period of 24 months.

Methods

A total of 104 consecutive patients treated for aSAH were recruited. After acute treatment, follow up visits were conducted at 3, 12 and 24 months after the hemorrhage. NAB-S, Montreal Cognitive Assessment (MoCA) and physical examination were performed at each follow up visit.

Results

The NAB-S could be administered to 64.9, 75.9 and 88.9% of the patients at 3, 12 and 24 months, respectively. Moderate impairment of two or more neuropsychological domains (e.g speech, executive function, etc.) significantly correlated with inability to return to work at 12 and 24 months as well as poor outcome assessed by the extended Glasgow Outcome Scale (GOSE) at 3, 12 and 24 months. The number of patients with favorable outcomes significantly increased from 25.5% at discharge to 56.5 and 57.1% at 3 and 12 months, respectively, and further increased to 74.1% after 24 months.

Conclusion

The NAB-S can be administered to the majority of patients with aSAH and can effectively detect clinically relevant neuropsychological deficits. Clinical recovery after aSAH continues for at least 24 months after the hemorrhage which should be considered in the design of future clinical trials.

Executive functions and intelligence from the CHC theory perspective: Investigating the correspondence between the WAIS-IV and the NAB Executive Functions Module

Substantial overlap between executive functions (EFs) and intelligence has been reported. Yet further research is required with respect to how the specific components of the two constructs are interrelated. The present study was aimed at exploring the relationship between EFs and intelligence by examining the latent structure of the Wechsler Adult Intelligence Scale (WAIS-IV) and the Executive Functions Module from the Neuropsychological Assessment Battery (NAB). The aim was also to test the correspondence of the two measures to the Cattell-Horn-Carroll (CHC) theory. 205 healthy participants, aged 18-89 years, were administered the NAB and WAIS-IV. Confirmatory factor analysis (CFA) was employed to explore the latent constructs underlying the two test batteries. Models based on the current WAIS-IV index structure showed worse model fit than models based on the CHC theory. In particular, factors representing broad CHC abilities comprehension knowledge (Gc), fluid reasoning (Gf), visual processing (Gv), processing speed (Gs), and working memory capacity (Gwm) proved model fit improvement. The best model fit, however, provided a five-factor model combining the Gf and Gwm abilities into one factor and additionally including a retrieval fluency (Gr) factor. The results demonstrate strong relationships between the WAIS-IV and the NAB Executive Functions Module and suggest substantial overlap between EFs and intelligence within the CHC framework. Nevertheless, according to the recent update of the CHC theory, the NAB fluency tasks may represent a distinct EF factor comprising Gr abilities independent from the WAIS-IV.

Intraindividual Variability in Executive Function Performance in Healthy Adults: Cross-Sectional Analysis of the NAB Executive Functions Module

The current study was aimed at investigating across-tasks intraindividual variability, also termed dispersion, in EF performance. The German adaptation of the Neuropsychological Assessment Battery (NAB) was used as a measure of EFs. Data of 444 participants aged 18-99 from six NAB Executive Functions Module subtests (i.e., Planning, Mazes, Letter Fluency, Judgment, Categories, and Word Generation) along with the NAB Total Index score as a measure of overall cognitive ability were analyzed. Maximum discrepancy (MD) was applied as a measure of dispersion. MD values ranged from 0.47 to 5.20 indicating substantial across-tasks dispersion in EF performance. Furthermore, dispersion moderately decreased with advancing age. Taking overall cognitive ability into account revealed that dispersion might be lower at older ages; especially, when associated with low overall ability levels. The dedifferentiation hypothesis offers a plausible explanation for these findings. That is, the cognitive profiles of older people might be less heterogenous than that of younger people, which may be due to age-related central nervous system constraints.

Subjektive Einschätzung und objektive kognitive Leistung bei psychisch Gesunden

Zusammenfassung. Neuropsychologische Untersuchungen verweisen auf uneinheitliche Zusammenhänge zwischen der subjektiven und objektiven kognitiven Leistungsbeurteilung. Bei 286 psychisch Gesunden wurden objektive kognitive Leistungswerte in der deutschen Adaptation der Neuropsychological Assessment Battery (NAB) sowie der Fragebogen zur subjektiven Einschätzung der geistigen Leistungsfähigkeit (FLei) erhoben. Trotz sehr guter Reliabilitäten des FLei limitierten Bodeneffekte die Aufdeckung richtungskonformer Zusammenhänge mit objektiven Leistungswerten in den Bereichen Aufmerksamkeit, Gedächtnis und exekutiven Funktionen. Dennoch erwies sich die Gedächtnisleistung als sensitivste Einzeldomäne für einen positiven Zusammenhang zwischen subjektiver und objektiver Leistungseinschätzung. Dabei moderierte das subjektive Wohlbefinden (WHO-5-Index) den Zusammenhang beider (subjektiver/objektiver) Ebenen im Gedächtnisbereich und in der kognitiven Gesamtleistung. Vor dem Hintergrund dieses Ergebnismusters sollten zukünftige Zusammenhangsanalysen insbesondere bei Personen mit psychischen Belastungen zu weiteren klinisch relevanten Befunden führen.

Age-related differences in the predictive ability of executive functions for intelligence

Abstract. The Executive Functions Module of the Neuropsychological Assessment Battery (NAB) and the Wechsler Adult Intelligence Scale – Fourth Edition (WAIS-IV) were used to investigate age-related differences in the predictability of intelligence with executive functions. The NAB subtests age and sex better predicted the WAIS-IV index scales and the Full Scale IQ in the older than in the younger age group, with total variance explained up to 75 % in 60- to 88-year-olds and up to 46 % in 18- to 59-year-olds. The NAB subtests Categories and Word Generation were most frequently included, whereas Letter Fluency was least frequently included in the best-fitting models of WAIS-IV prediction. Mazes predicted better in the younger age group, whereas Judgment predicted better in the older age group.