Bilingualism and Its Implications for Neuropsychological Evaluation

A scoping review of neuropsychological assessment for Asian Indians in the United States - research and clinical recommendations

Objective: There is an increasing focus on understanding health disparities among various cultural groups in the United States. The need for heterogeneity in norms and test stimuli across ethnically diverse individuals are being increasingly recognized. However, to date it remains unknown whether and to what extent differences in cognitive norms and tests exist in Asian Indians, a fast-growing population in the U.S. It is essential to understand these differences to improve diagnostic accuracy and provide timely and appropriate clinical care. Method: In this study, we conducted a scoping review of available cognitive tests that were normed, developed, or adapted for Asian Indians living in the U.S. Results: The results suggested a paucity of norms and tests specifically examining cognition in this community. Conclusions: Based on the findings, we provide suggestions for research directions focusing on the development of culturally sensitive neuropsychological tools, normative data representative of this demographic, and interventions addressing healthcare access barriers. Overall, this review provides readers with relevant clinical information to immediately enhance patient care as well as provide actionable items in research to improve the future utility of neuropsychology for Asian Indians in the United States.

Protective effect of bilingualism on aging, MCI, and dementia: A community-based study

INTRODUCTION

Lifelong bilingualism is associated with a delayed age at onset of dementia, but evidence from community-based studies is limited. We investigated the relationship between bilingualism and the prevalence of cognitive impairment in a linguistically diverse community.

METHODS

A door-to-door community study was conducted from January to December 2021 in urban Bengaluru, India. 1234 individuals aged ≥60 years participated in the study. Participants were diagnosed with no cognitive impairment (NCI), mild cognitive impairment (MCI), or dementia using established diagnostic criteria.

RESULTS

Dementia prevalence was higher in monolinguals (4.9%) than bilinguals (0.4%) (P = .001). The prevalence of MCI was also higher in monolinguals (8.5%) than bilinguals (5.3%) (P = .001). The study also revealed better cognitive function in bilinguals than monolinguals with NCI, after controlling for confounding variables.

DISCUSSION

The current study provides significant support for the protective effect of bilingualism on cognitive impairment in an urban community with extensive bilingual interactional contexts in everyday life.

HIGHLIGHTS

Bilingualism has been demonstrated to protect against dementia and mild cognitive impairment in a linguistically diverse community with extensive code-switching contexts. Bilingual older individuals had superior baseline cognitive performance compared to monolingual older individuals. Bilingualism was found to have an independent effect on general cognition after adjusting for major social determinants of health in the group without cognitive impairment.

Picture naming test through the prism of cognitive neuroscience and linguistics: adapting the test for cerebellar tumor survivors-or pouring new wine in old sacks?

A picture naming test (PNT) has long been regarded as an integral part of neuropsychological assessment. In current research and clinical practice, it serves a variety of purposes. PNTs are used to assess the severity of speech impairment in aphasia, monitor possible cognitive decline in aging patients with or without age-related neurodegenerative disorders, track language development in children and map eloquent brain areas to be spared during surgery. In research settings, picture naming tests provide an insight into the process of lexical retrieval in monolingual and bilingual speakers. However, while numerous advances have occurred in linguistics and neuroscience since the classic, most widespread PNTs were developed, few of them have found their way into test design. Consequently, despite the popularity of PNTs in clinical and research practice, their relevance and objectivity remain questionable. The present study provides an overview of literature where relevant criticisms and concerns have been expressed over the recent decades. It aims to determine whether there is a significant gap between conventional test design and the current understanding of the mechanisms underlying lexical retrieval by focusing on the parameters that have been experimentally proven to influence picture naming. We discuss here the implications of these findings for improving and facilitating test design within the picture naming paradigm. Subsequently, we highlight the importance of designing specialized tests with a particular target group in mind, so that test variables could be selected for cerebellar tumor survivors.

Evaluation of Vascular Cognitive Impairment Using the ICMR-Neuro Cognitive Tool Box (ICMR-NCTB) in a Stroke Cohort from India

Background and Purpose

Vascular cognitive impairment (VCI) presents with a spectrum of cognitive impairment due to stroke and poses a huge socioeconomic burden especially in low middle-income countries. There is a critical need for early recognition and identification of VCI patients. Therefore, we developed and validated culturally appropriate neuropsychological instruments, the ICMR-Neuro Cognitive Tool-Box (ICMR-NCTB) and Montreal Cognitive Assessment (MoCA) to diagnose vascular MCI and dementia in the Indian context.

Methods

A total of 181 participants: 59 normal cognition, 25 stroke with normal cognition, 46 vascular MCI (VaMCI) and 51 vascular dementia (VaD) were recruited for the study. The ICMR-NCTB and MoCA were administered to patients with VCI and major cognitive domains were evaluated.

Results

The ICMR-NCTB was found to have good internal reliability in VaMCI and VaD. The sensitivity of the ICMR-NCTB to detect VaMCI and VaD ranged from 70.8% to 72.9% and 75.9% to 79.7%, respectively, and the specificity for VaMCI and VaD ranged from 84.8% to 86.1% and 82.5% to 85.2%, respectively. The MoCA had excellent sensitivity and specificity to detect VaMCI and VaD at ideal cut-off scores.

Conclusion

The ICMR-NCTB is a valid neuropsychological toolbox that can be used for comprehensive cognitive assessment and diagnosis of VCI in India. In addition, the Indian version of MoCA is more adept as a screening instrument to detect VCI due to its high sensitivity. The ICMR-NCTB will aid in early detection and management of many patients, thereby reducing the burden of vascular MCI and dementia in India.