RESUMEN
BACKGROUND: In the field of Alzheimer's disease (AD), the validation of biomarkers for early AD diagnosis and for use as a surrogate outcome in AD clinical trials is of considerable research interest. OBJECTIVE: To characterize the clinical profile and genetic, neuroimaging and neurophysiological biomarkers of prodromal AD in amnestic mild cognitive impairment (aMCI) patients enrolled in the IMI WP5 PharmaCog (also referred to as the European ADNI study). METHODS: A total of 147 aMCI patients were enrolled in 13 European memory clinics. Patients underwent clinical and neuropsychological evaluation, magnetic resonance imaging (MRI), electroencephalography (EEG) and lumbar puncture to assess the levels of amyloid ß peptide 1-42 (Aß42), tau and p-tau, and blood samples were collected. Genetic (APOE), neuroimaging (3T morphometry and diffusion MRI) and EEG (with resting-state and auditory oddball event-related potential (AO-ERP) paradigm) biomarkers were evaluated. RESULTS: Prodromal AD was found in 55 aMCI patients defined by low Aß42 in the cerebrospinal fluid (Aß positive). Compared to the aMCI group with high Aß42 levels (Aß negative), Aß positive patients showed poorer visual (P = 0.001), spatial recognition (P < 0.0005) and working (P = 0.024) memory, as well as a higher frequency of APOE4 (P < 0.0005), lower hippocampal volume (P = 0.04), reduced thickness of the parietal cortex (P < 0.009) and structural connectivity of the corpus callosum (P < 0.05), higher amplitude of delta rhythms at rest (P = 0.03) and lower amplitude of posterior cingulate sources of AO-ERP (P = 0.03). CONCLUSION: These results suggest that, in aMCI patients, prodromal AD is characterized by a distinctive cognitive profile and genetic, neuroimaging and neurophysiological biomarkers. Longitudinal assessment will help to identify the role of these biomarkers in AD progression.
Asunto(s)
Enfermedad de Alzheimer/diagnóstico , Anciano , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/genética , Péptidos beta-Amiloides/líquido cefalorraquídeo , Apolipoproteínas E/genética , Biomarcadores/líquido cefalorraquídeo , Encéfalo/diagnóstico por imagen , Electroencefalografía , Femenino , Genotipo , Humanos , Imagen por Resonancia Magnética , Masculino , Pruebas Neuropsicológicas , Fragmentos de Péptidos/líquido cefalorraquídeo , Punción Espinal , Proteínas tau/líquido cefalorraquídeoRESUMEN
Background: Neuropsychiatric symptoms (NPS) are common in patients with vascular cognitive impairment (VCI). We aimed to establish sex differences in the manifestation of NPS in memory clinic patients with possible VCI and identify which NPS are determinants of clinical progression in women and men separately. Methods: We included 718 memory clinic patients (age 68 ± 8; 45% women) with cognitive complaints and vascular brain lesions on MRI (i.e. possible VCI). NPS were measured using the 12-item Neuropsychiatric Inventory. Clinical progression after two years (women 18%, men 14%) was defined as increase in CDR ≥1 or institutionalization (available n = 589 without advanced dementia at baseline). The association between NPS and clinical progression was assessed with Cox proportional hazard models stratified by sex, adjusted for age and clinical diagnosis and in a second model additionally for manifestations of vascular brain lesions. Results: Men more often presented with agitation (29% versus 17%, p<.05) and irritability (58% versus 45%, p<.05), the other 10 NPS (delusions, hallucinations, depression, anxiety, euphoria, apathy, disinhibition, aberrant motor behavior, nighttime disturbances and appetite & eating abnormalities) did not differ between sexes. In women the presence of apathy (HR 2.1[1.1;4.3]) was associated with higher risk of clinical progression. In men the presence of depression (HR 2.7[1.4;5.1]) and aberrant motor behavior (HR 2.1[1.1;3.8]) were associated with increased risk of clinical progression. Conclusion: Manifestations of NPS in patients with possible VCI differ by sex. Different NPS are associated with future clinical progression in men and women. Management strategies of NPS could benefit from sex-specific approaches.