Combining visual rating scales to identify prodromal Alzheimer's disease and Alzheimer's disease dementia in a population from a low and middle-income country

Abstract

BackgroundMany low- and middle-income countries, including Latin America, lack access to biomarkers for the diagnosis of prodromal Alzheimer's Disease (AD; mild cognitive impairment due to AD) and AD dementia. MRI visual rating scales may serve as an ancillary diagnostic tool for identifying prodromal AD or AD in Latin America. We investigated the ability of brain MRI visual rating scales to distinguish between cognitively healthy controls, prodromal AD and AD.MethodsA cross-sectional study was conducted from a multidisciplinary neurology clinic in Lima, Peru using neuropsychological assessments, brain MRI and cerebrospinal fluid amyloid and tau levels. Medial temporal lobe atrophy (MTA), posterior atrophy (PA), white matter hyperintensity (WMH), and MTA+PA composite MRI scores were compared. Sensitivity, specificity, and area under the curve (AUC) were determined.ResultsFifty-three patients with prodromal AD, 69 with AD, and 63 cognitively healthy elderly individuals were enrolled. The median age was 75 (8) and 42.7% were men. Neither sex, mean age, nor years of education were significantly different between groups. The MTA was higher in patients with AD (p < 0.0001) compared with prodromal AD and controls, and MTA scores adjusted by age range (p < 0.0001) and PA scores (p < 0.0001) were each significantly associated with AD diagnosis (p < 0.0001) but not the WMH score (p=0.426). The MTA had better performance among ages <75 years (AUC 0.90 [0.85–0.95]), while adjusted MTA+PA scores performed better among ages>75 years (AUC 0.85 [0.79–0.92]). For AD diagnosis, MTA+PA had the best performance (AUC 1.00) for all age groups.ConclusionsCombining MTA and PA scores demonstrates greater discriminative ability to differentiate controls from prodromal AD and AD, highlighting the diagnostic value of visual rating scales in daily clinical practice, particularly in Latin America where access to advanced neuroimaging and CSF biomarkers is limited in the clinical setting.

The Memory Alteration Test Is Correlated with Clinical, Cerebrospinal Fluid, and Brain Imaging Markers of Alzheimer Disease in Lima, Peru

“…This is a secondary analysis from a previously reported case-control study of healthy and cognitively impaired participants [7]. Briefly, for this study, we included 63 cognitively healthy participants, 53 participants with aMCI, and 69 participants with dementia due to AD.…”

Diagnóstico de la variante conductual de demencia frontotemporal basado en estadios clínicos adaptado para países con baja educación: el caso de Perú

“…En las imágenes por resonancia magnética (IRM) cerebral se observa un incremento de surcos y fisuras en regiones frontotemporales, particularmente en el cíngulo anterior y corteza orbitofrontal (36) . En algunos casos, el hipocampo, también puede mostrar atrofia (37) de manera similar a la observada en EA (38) . Ciertos patrones de atrofia pueden sugerir DFT asociada a mutaciones genéticas, por ejemplo, una pronunciada atrofia bitemporal ocurre en pacientes con mutación de la MAPT; una marca marcada atrofia frontotemporal asimétrica es común en pacientes con mutación GRN en quienes también se puede observar extensas lesiones de sustancia blanca (LSB).…”

Galvas smadzeņu kvalitatīvu un kvantitatīvu radioloģisko biomarķieru izmaiņu saistība ar kognitīvo funkciju izmaiņām un demenci. Promocijas darbs

“…Tomēr ikdienas magnētiskās rezonanses attēlu izvērtēšana un attēlu iegūšanas metodes lielākoties balstās uz kvalitatīvu galvas smadzeņu struktūras vai funkcijas novērtējumu, kas nereti nenodrošina pietiekamu jutīgumu un specifiskumu agrīnu izmaiņu noteikšanā (Custodio et al, 2022;Harper et al, 2016;Yuan et al, 2019). Šobrīd kvantitatīvo MR biomarķieru izmantošana ir ienākusi klīniskajā praksē un nodrošina precīzākus un objektīvākus smadzeņu struktūru mērījumus (Pemberton et al, 2021).…”