Combination of white matter hyperintensities and Aß burden is related to cognitive composites domain scores in subjective cognitive decline: the FACEHBI cohort.

BACKGROUND: To explore whether the combination of white matter hyperintensities (WMHs) and amyloid-beta (Aß) deposition is associated with worse cognitive performance on cognitive composites (CCs) domain scores in individuals with subjective cognitive decline (SCD). METHODS: Two hundred participants from the FACEHBI cohort underwent structural magnetic resonance imaging (MRI), 18F-florbetaben positron emission tomography (FBB-PET), and neuropsychological assessment. WMHs were addressed through the Fazekas scale, the Age-Related White Matter Changes (ARWMC) scale, and the FreeSurfer pipeline. Eight CCs domain scores were created using the principal component analysis (PCA). Age, sex, education, and apolipoprotein E (APOE) were used as adjusting variables. RESULTS: Adjusted multiple linear regression models showed that FreeSurfer (B - .245; 95% CI - .1.676, - .393, p = .016) and ß burden (SUVR) (B - .180; 95% CI - 2.140, - .292; p = .070) were associated with face-name associative memory CCs domain score, although the latest one was not statistically significant after correction for multiple testing (p = .070). There was non-significant interaction of these two factors on this same CCs domain score (p = .54). However, its cumulative effects on face-name associative performance indicated that those individuals with either higher WMH load or higher Aß burden showed the worst performance on the face-name associative memory CCs domain score. CONCLUSIONS: Our results suggest that increased WMH load and increased Aß are independently associated with poorer episodic memory performance in SCD individuals, indicating a cumulative effect of the combination of these two pathological conditions in promoting lower cognitive performance, an aspect that could help in terms of treatment and prevention.

Correlations between plasma and PET beta-amyloid levels in individuals with subjective cognitive decline: the Fundació ACE Healthy Brain Initiative (FACEHBI).

BACKGROUND: Peripheral biomarkers that identify individuals at risk of developing Alzheimer's disease (AD) or predicting high amyloid beta (Aß) brain burden would be highly valuable. To facilitate clinical trials of disease-modifying therapies, plasma concentrations of Aß species are good candidates for peripheral AD biomarkers, but studies to date have generated conflicting results. METHODS: The Fundació ACE Healthy Brain Initiative (FACEHBI) study uses a convenience sample of 200 individuals diagnosed with subjective cognitive decline (SCD) at the Fundació ACE (Barcelona, Spain) who underwent amyloid florbetaben(18F) (FBB) positron emission tomography (PET) brain imaging. Baseline plasma samples from FACEHBI subjects (aged 65.9 ± 7.2 years) were analyzed using the ABtest (Araclon Biotech). This test directly determines the free plasma (FP) and total plasma (TP) levels of Aß40 and Aß42 peptides. The association between Aß40 and Aß42 plasma levels and FBB-PET global standardized uptake value ratio (SUVR) was determined using correlations and linear regression-based methods. The effect of the APOE genotype on plasma Aß levels and FBB-PET was also assessed. Finally, various models including different combinations of demographics, genetics, and Aß plasma levels were constructed using logistic regression and area under the receiver operating characteristic curve (AUROC) analyses to evaluate their ability for discriminating which subjects presented brain amyloidosis. RESULTS: FBB-PET global SUVR correlated weakly but significantly with Aß42/40 plasma ratios. For TP42/40, this observation persisted after controlling for age and APOE ε4 allele carrier status (R2 = 0.193, p = 1.01E-09). The ROC curve demonstrated that plasma Aß measurements are not superior to APOE and age in combination in predicting brain amyloidosis. It is noteworthy that using a simple preselection tool (the TP42/40 ratio with an empirical cut-off value of 0.08) optimizes the sensitivity and reduces the number of individuals subjected to Aß FBB-PET scanners to 52.8%. No significant dependency was observed between APOE genotype and plasma Aß measurements (p value for interaction = 0.105). CONCLUSION: Brain and plasma Aß levels are partially correlated in individuals diagnosed with SCD. Aß plasma measurements, particularly the TP42/40 ratio, could generate a new recruitment strategy independent of the APOE genotype that would improve identification of SCD subjects with brain amyloidosis and reduce the rate of screening failures in preclinical AD studies. Independent replication of these findings is warranted.

FACEHBI: A Prospective Study of Risk Factors, Biomarkers and Cognition in a Cohort of Individuals with Subjective Cognitive Decline. Study Rationale and Research Protocols.

BACKGROUND: Long-term longitudinal studies with multimodal biomarkers are needed to delve into the knowledge of preclinical AD. Subjective cognitive decline has been proposed as a risk factor for the development of cognitive impairment. Thus, including individuals with SCD in observational studies may be a cost-effective strategy to increase the prevalence of preclinical AD in the sample. OBJECTIVES: To describe the rationale, research protocols and baseline characteristics of participants in the Fundació ACE Healthy Brain Initiative (FACEHBI). DESIGN: FACEHBI is a clinical trial (EudraCT: 2014-000798-38) embedded within a long-term observational study of individuals with SCD. SETTING: Participants have been recruited at the memory clinic of Fundació ACE (Barcelona) from two different sources: patients referred by a general practitioner and individuals from an Open House Initiative. PARTICIPANTS: 200 individuals diagnosed with SCD with a strictly normal performance in a comprehensive neuropsychological battery. MEASUREMENTS: Individuals will undergo an extensive neuropsychological protocol, risk factor assessment and a set of multimodal biomarkers including florbetaben PET, structural and functional MRI, diffusion tensor imaging, determination of amyloid species in plasma and neurophthalmologic assessment with optical coherence tomography. RESULTS: Two hundred individuals have been recruited in 15 months. Mean age was 65.9 years; mean MMSE was 29.2 with a mean of 14.8 years of education. CONCLUSIONS: FACEHBI is a long-term study of cognition, biomarkers and lifestyle that has been designed upon an innovative symptom-based approach using SCD as target population. It will shed light on the pathophysiology of preclinical AD and the role of SCD as a risk marker for the development of cognitive impairment.

Visual hallucinations in patients with acute stroke: a prospective exploratory study.

BACKGROUND AND PURPOSE: The incidence, underlying physiopathology, features and association with lesion topography of visual hallucinations in acute stroke have scarcely been investigated. METHODS: Patients with a diagnosis of acute stroke (ischaemic or haemorrhagic) in any vascular territory, admitted within 24 h after the onset of symptoms, were consecutively included in the study. Patients with a previous history of psychosis or cognitive impairment were excluded. They and/or their caregivers answered a structured hallucination and sleep questionnaire at admission, within the first 15 days and at the clinical follow-up 3-6 months after discharge. Lesion location (IMAIOS online atlas) and leukoaraiosis (Wahlund scale) were determined by magnetic resonance imaging or computed tomography scan. Subsets of patients also underwent a neuropsychological evaluation (N = 50) and an electroencephalogram (N = 33) before discharge. RESULTS: In all, 77 patients with a mean age of 71 ± 12 years were included of whom 57.1% were men. The incidence of visual hallucinations was 16.7%. These hallucinations were mostly complex, in black and white and self-limited. The appearance of hallucinations was not influenced by age, sex, neuropsychological performance during admission or modified Rankin scale score at discharge. Visual hallucinations were associated with occipital cortex lesions (P = 0.04), and with sleep disturbances during and before admission (P = 0.041 and P = 0.03 respectively). CONCLUSIONS: Visual hallucinations are relatively frequent in patients with acute stroke and they are self-limited. Patients with occipital lesions and sleep disturbances are more likely to suffer them.