Assessment of disparities in timely diagnosis and comprehensive workup of cognitive impairment between English and Spanish speakers.

BACKGROUND: Previous studies have examined disparities in dementia care that affect the U.S. Hispanic/Latino population, including clinician bias, lack of cultural responsiveness, and less access to health care. However, there is limited research that specifically investigates the impact of language barriers to health disparities in dementia diagnosis. METHODS: In this retrospective cross-sectional study, 12,080 English- or Spanish- speaking patients who received an initial diagnosis of mild cognitive impairment (MCI) or dementia between July 2017 and June 2019 were identified in the Yale New Haven Health (YNHH) electronic medical record. To evaluate the timeliness of diagnosis, an initial diagnosis of MCI was classified as "timely", while an initial diagnosis of dementia was considered "delayed." Comprehensiveness of diagnosis was assessed by measuring the presence of laboratory studies, neuroimaging, specialist evaluation, and advanced diagnostics six months before or after diagnosis. Binomial logistic regressions were calculated with and without adjustment for age, legal sex, ethnicity, neighborhood disadvantage, and medical comorbidities. RESULTS: Spanish speakers were less likely to receive a timely diagnosis when compared with English speakers both before (unadjusted OR, 0.65; 95% CI, 0.53-0.80, p <0.0001) and after adjusting for covariates (adjusted OR, 0.55; 95% CI, 0.40-0.75, p = 0.0001). Diagnostic services were provided equally between groups, except for referrals to geriatrics, which were more frequent among Spanish-speaking patients. A subgroup analysis revealed that Spanish-speaking Hispanic/Latino patients were less likely to receive a timely diagnosis compared to English-speaking Hispanic/Latino patients (adjusted OR, 0.53; 95% CI, 0.38-0.73, p = 0.0001). CONCLUSIONS: Non-English language preference is likely to be a contributing factor to timely diagnosis of cognitive impairment. In this study, Spanish language preference rather than Hispanic/Latino ethnicity was a significant predictor of a less timely diagnosis of cognitive impairment. Policy changes are needed to reduce barriers in cognitive disorders care for Spanish-speaking patients.

Assessment of Gray Matter Microstructure and Synaptic Density in Alzheimer's Disease: A Multimodal Imaging Study With DTI and SV2A PET.

OBJECTIVE: Multimodal imaging techniques have furthered our understanding of how different aspects of Alzheimer's disease (AD) pathology relate to one another. Diffusion tensor imaging (DTI) measures such as mean diffusivity (MD) may be a surrogate measure of the changes in gray matter structure associated with AD. Positron emission tomography (PET) imaging of synaptic vesicle glycoprotein 2A (SV2A) has been used to quantify synaptic loss, which is the major pathological correlate of cognitive impairment in AD. In this study, we investigated the relationship between gray matter microstructure and synaptic density. METHODS: DTI was used to measure MD and [11C]UCB-J PET to measure synaptic density in 33 amyloid-positive participants with AD and 17 amyloid-negative cognitively normal (CN) participants aged 50-83. Univariate regression analyses were used to assess the association between synaptic density and MD in both the AD and CN groups. RESULTS: Hippocampal MD was inversely associated with hippocampal synaptic density in participants with AD (r = -0.55, p <0.001, df = 31) but not CN (r = 0.13, p = 0.62, df = 15). Exploratory analyses across other regions known to be affected in AD suggested widespread inverse associations between synaptic density and MD in the AD group. CONCLUSION: In the setting of AD, an increase in gray matter MD is inversely associated with synaptic density. These co-occurring changes may suggest a link between synaptic loss and gray matter microstructural changes in AD. Imaging studies of gray matter microstructure and synaptic density may allow important insights into AD-related neuropathology.