Alzheimer´s Disease initial cognitive profile in an Argentinian cohort of individuals with Down Syndrome

Abstract

AbstractBackgroundDown Syndrome [DS] is the most frequent cause of genetic developmental and intellectual disability. The lifetime risk of Alzheimer’s Disease [AD] in people with DS is more than 90%, with an earlier age of onset than the general population. There is ongoing debate whether there are significant differences in dementia presentation in the specific context of DS, with some studies suggesting a predominantly frontal phenotype with behavioural symptoms and others suggesting a more frequent amnestic presentation.The aim of this study was to characterize the initial cognitive profile of AD in a cohort of Argentinian adults with DS.MethodAdults with DS and prodromal or established AD dementia who were part of the IASDA (Argentinian initiative for the study of DS and AD) cohort or spontaneusly attended our Memory Clinic were included. Initial cognitive profile was determined by a semi‐structured interview conducted by a cognitive neurologist with the subject, their family and caregivers.ResultSixteen adults with DS were included. Fifty‐six percent (n = 9) were males. Mean age was 51 yo (42‐59 yo). Sixty‐two percent (n = 10) had premorbid moderate intellectual disability [DI], 25% (n = 4) had severe DI and 13% (n = 2) had mild DI.Fifty‐six percent (n = 9) had a clinical diagnosis of prodromal AD, and the remaining individuals had clinically established AD dementia. Fifty percent (n = 8) had positive amiloid biomarkers (determined by cerebral PiB‐PET or cerebrospinal fluid levels of Aβ42, phosphorylated‐tau and total‐tau), while the remaining subjects did not undergo amiloid biomarker assessment. Due to cognitive impairment, premorbid language impairment and/or premorbid severe DI, only 25% (n = 4) of individuals completed neuropsychological testing (CAMDEX‐DS, Cued Recall Task).Initial cognitive profile was charactirized as amnestic (single‐domain amnestic or multiple‐domain amnestic) in 81% percent (n = 13) of the cohort. Only 13% (n = 2) of the subjects had initial non‐amnestic syndromes, and in one case (6%) the initial cognitive syndrome was uncertain.ConclusionAmnestic cognitive impariment was the most frequent presentation of AD in this small cohort of Latin American adults with DS.