Ana Verdelho

University of Lisbon, Lisboa, Lisbon, Portugal

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Publications (40)190.52 Total impact

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    ABSTRACT: Physical activity reduces the risk of cognitive decline but may affect cognitive domains differently. We examined whether physical activity modifies processing speed, executive function and memory in a population of non-dementia elderly subjects with age-related white matter changes (ARWMC).
    International Journal of Geriatric Psychiatry 11/2014; · 3.09 Impact Factor
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    ABSTRACT: Alzheimer's disease (AD) is the most common form of dementia in the elderly individuals, resulting from a complex interaction between environmental and genetic factors. Impaired brain iron homeostasis has been recognized as an important mechanism underlying the pathogenesis of this disease. Nevertheless, the knowledge gathered so far at the systemic level is clearly insufficient. Herein, we used an integrative approach to study iron metabolism in the periphery, at both genotypic and phenotypic levels, in a sample of 116 patients with AD and 89 healthy control subjects. To assess the potential impact of iron metabolism on the risk of developing AD, genetic analyses were performed along with the evaluation of the iron status profile in peripheral blood by biochemical and gene expression studies. The results obtained showed a significant decrease of serum iron, ferritin, and transferrin concentrations in patients compared with the control subjects. Also, a significant decrease of ferroportin (SLC40A1) and both transferrin receptors TFRC and TFR2 transcripts was found in peripheral blood mononuclear cells from patients. At the genetic level, significant associations with AD were found for single nucleotide polymorphisms in TF, TFR2, ACO1, and SLC40A1 genes. Apolipoprotein E gene, a well-known risk factor for AD, was also found significantly associated with the disease in this study. Taken together, we hypothesize that the alterations on systemic iron status observed in patients could reflect an iron homeostasis dysregulation, particularly in cellular iron efflux. The intracellular iron accumulation would lead to a rise in oxidative damage, contributing to AD pathophysiology.
    Neurobiology of aging 10/2013; · 5.94 Impact Factor
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    ABSTRACT: http://www.karger.com/Article/Abstract/354142
    22nd World Congress on Psychosomatic Medicine. Lisbon, 2013 (oral presentation), Lisbon, Portugal; 09/2013
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    ABSTRACT: Vitamin B12 deficiency is common in older people, and may be responsible for reversible dementia. Low serum vitamin B12 levels were also observed in patients with Mild Cognitive Impairment (MCI). It is not known whether patients with vitamin B12 deficiency have a distinctive profile of cognitive impairment different from the episodic memory deficit usually observed in MCI. From a cohort of 310 patients with MCI followed in a memory clinic in Lisbon, only 10 cases with vitamin B12 deficiency were found. From collaboration with other neurologists, 5 further patients with vitamin B12 deficiency were added. These cases were compared to MCI patients with normal vitamin B12 levels in a ratio 1:3. The duration of subjective cognitive symptoms was significantly shorter in MCI patients with B12 deficiency (1.2+/-1.0 years) as compared to MCI patients with normal vitamin B12 levels (3.4+/-3.0 years, p<0.001, Student' t test). There were no statistically significant differences in the neuropsychological tests between MCI patients with and without vitamin B12 deficiency. Vitamin B12 was started in MCI patients with vitamin B12 deficiency, with no noticeable clinical improvement. MCI patients with low levels of vitamin B12 had no particular profile of cognitive impairment, however vitamin B12 deficiency might have precipitated the onset of symptoms. The effect of vitamin B12 supplementation in patients with MCI and low vitamin B12 levels should be clarified by future prospective studies.
    BMC Research Notes 09/2013; 6(1):357.
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    ABSTRACT: The clinical phenotype of frontotemporal dementia patients carrying progranulin (GRN) mutations is known to be heterogeneous. We present a patient with corticobasal syndrome and a family with progressive aphasia and behavioral features who were found to have the same p.Gln257Profs*27 mutation. These cases depict the variability of GRN mutation carriers regarding clinical presentation and age of onset. In addition to giving a detailed report of a GRN mutation, we highlight the importance of searching for the presence of GRN mutations in selected sporadic cases and suggest a broadening of GRN genetic screening to better understand the clinical spectrum of these mutations.
    Journal of Alzheimer's disease: JAD 06/2013; · 3.61 Impact Factor
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    ABSTRACT: ABSTRACT Background: Quality of Life-Alzheimer's Disease (QOL-AD) is a widely used scale for the study of quality of life in patients with dementia. The aim of this study is the transcultural adaptation and validation of the QOL-AD scale in Portugal. Methods: Translation and transcultural adaptation was performed according to state-of-the-art recommendations. For the validation study, 104 patient/caregiver pairs were enrolled. Patients had mild cognitive impairment or mild-to-moderate dementia (due to Alzheimer's disease or vascular dementia). Participants were recruited in a dementia outpatient clinic setting and a long-term care dementia ward. An additional comparison group of 22 patients without cognitive impairment, and their proxies, was recruited in a family practice outpatient clinic. Sociodemographic information on patients and caregivers was obtained. Acceptability, reliability, and construct validity were analyzed. Results: Internal consistency of the Portuguese version of QOL-AD was good for both patient and caregiver report (Cronbach's α = 0.867 and 0.858, respectively). Construct validity was confirmed by the correlation of patient reported QOL-AD with patient geriatric depression scale scores (ρ = -0.702, p < 0.001) and satisfaction with life scale scores (ρ = 0.543, p < 0.001). Caregiver ratings were correlated with neuropsychiatric inventory (NPI) total score (ρ = -0.404, p < 0.001), NPI-distress (ρ = -0.346, p < 0.001), and patient Mini-Mental State Examination (ρ = 0.319, p < 0.01). QOL-AD patient ratings were higher than caregiver ratings (p < 0.001). Both patient- and caregiver-rated QOL-AD scores were lower in patients with cognitive impairment than in the comparison group without cognitive impairment (p < 0.01). Conclusions: A Portuguese version of QOL-AD with consistent psychometric properties was obtained and is proposed as a useful tool for research and clinical purposes.
    International Psychogeriatrics 03/2013; · 1.89 Impact Factor
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    ABSTRACT: Age-related white matter changes have been associated with cognitive functioning, even though their role is not fully understood. This work aimed to test a 3-factor model of the neuropsychological assessment battery and evaluate how the model fit the data longitudinally. Confirmatory factor analysis (CFA) was used to investigate the dimensions of a structured set of neuropsychological tests administered to a multicenter, international sample of independent older adults (LADIS study). Six hundred and thirty-eight older adults completed baseline neuropsychological, clinical, functional and motor assessments, which were repeated each year for a 3-year follow-up. CFA provided support for a 3-factor model. These factors involve the dimensions of executive functions, memory functions, and speed and motor control abilities. Performance decreased in most neuropsychological measures. Results showed that executive functioning, memory and speed of motor abilities are valid latent variables of neuropsychological performance among older adults, and that this structure is relatively consistent longitudinally, even though performance decreases with time.
    Journal of Clinical and Experimental Neuropsychology 02/2013; · 2.16 Impact Factor
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    ABSTRACT: OBJECTIVE: A study was undertaken to determine whether diffusion-weighted imaging (DWI) abnormalities in normal-appearing brain tissue (NABT) and in white matter hyperintensities (WMH) predict longitudinal cognitive decline and disability in older individuals independently of the concomitant magnetic resonance imaging (MRI) findings. METHODS: A total of 340 LADIS (Leukoaraiosis and Disability Study) participants, aged 65 to 84 years, underwent brain MRI including DWI at baseline. Neuropsychological and functional assessments were carried out at study entry and repeated annually over a 3-year observational period. Linear mixed models and Cox regression survival analysis adjusted for demographics, WMH volume, lacunes, and brain atrophy were used to evaluate the independent effect of the DWI measures on change in cognitive performance and functional abilities. RESULTS: The mean global apparent diffusion coefficient (ADC) and the relative peak height and peak position of the ADC histogram in NABT predicted faster rate of decline in a composite score for speed and motor control. Higher mean ADC and lower peak height were also related to deterioration in executive functions and memory (specifically working memory), with peak height also being related to more rapid transition to disability and higher rate of mortality. Mean ADC in WMH had less pronounced effects on cognitive and functional outcomes. INTERPRETATION: DWI microstructural changes in NABT predict faster decline in psychomotor speed, executive functions, and working memory regardless of conventional MRI findings. Moreover, these changes are related to functional disability and higher mortality. ANN NEUROL 2013.
    Annals of Neurology 11/2012; 73(5). · 11.91 Impact Factor
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    ABSTRACT: BACKGROUND AND PURPOSE: We aimed to study if physical activity could interfere with progression for cognitive impairment and dementia in older people with white matter changes living independently. METHODS: The LADIS (Leukoaraiosis and Disability) prospective multinational European study evaluates the impact of white matter changes on the transition of independent elderly subjects into disability. Subjects were evaluated yearly during 3 years with a comprehensive clinical protocol and cognitive assessment with classification of cognitive impairment and dementia according to usual clinical criteria. Physical activity was recorded during the clinical interview. MRI was performed at entry and at the end of the study. RESULTS: Six hundred thirty-nine subjects were included (74.1±5 years old, 55% women, 9.6±3.8 years of schooling, 64% physically active). At the end of follow-up, 90 patients had dementia (vascular dementia, 54; Alzheimer disease with vascular component, 34; frontotemporal dementia, 2), and 147 had cognitive impairment not dementia. Using Cox regression analysis, physical activity reduced the risk of cognitive impairment (dementia and not dementia: β=-0.45, P=0.002; hazard ratio, 0.64; 95% CI, 0.48-0.85), dementia (β=-0.49, P=0.043; hazard ratio, 0.61; 95% CI, 0.38-0.98), and vascular dementia (β=-0.86, P=0.008; hazard ratio, 0.42; 95% CI, 0.22-0.80), independent of age, education, white matter change severity, medial temporal atrophy, previous and incident stroke, and diabetes. CONCLUSIONS: Physical activity reduces the risk of cognitive impairment, mainly vascular dementia, in older people living independently.
    Stroke 11/2012; · 6.02 Impact Factor
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    ABSTRACT: BACKGROUND AND PURPOSE: White matter lesion (WML) progression has been advocated as a surrogate marker in intervention trials on cerebral small vessel disease. We assessed the rate of visually rated WML progression, studied correlations between lesion progression and cognition, and estimated sample sizes for clinical trials with pure WML progression vs combined WML progression-cognitive outcomes. METHODS: Those 394 participants of the Leukoaraiosis and Disability Study (LADIS) study with magnetic resonance imaging scanning at baseline and 3-year follow-up were analyzed. WML progression rating relied on the modified Rotterdam Progression Scale. The Vascular Dementia Assessment Scale global score and a composite score of specific executive function tests assessed longitudinal change in cognition. Sample size calculations were based on the assumption that treatment reduces WML progression by 1 grade on the Rotterdam Progression Scale. RESULTS: WML progression related to deterioration in cognitive functioning. This relationship was less pronounced in subjects with early confluent and confluent lesions. Consequently, studies in which the outcome is cognitive change resulting from treatment effects on lesion progression will need between 1809 subjects per treatment arm when using executive tests and up to 18 853 subjects when using the Vascular Dementia Assessment Scale score. Studies having WML progression as the sole outcome will need only 58 or 70 individuals per treatment arm. CONCLUSIONS: WML progression is an interesting outcome for proof-of-concept studies in cerebral small vessel disease. If cognitive outcome measures are added to protocols, then sample size estimates increase substantially. Our data support the use of an executive test battery rather than the Vascular Dementia Assessment Scale as the primary cognitive outcome measure.
    Stroke 08/2012; 43(10):2643-2647. · 6.02 Impact Factor
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    ABSTRACT: To examine the independent contributions and combined interactions of medial temporal lobe atrophy (MTA), cortical and subcortical atrophy, and white matter lesion (WML) volume in longitudinal cognitive performance. A total of 477 subjects with age-related WML were evaluated with brain MRI and annual neuropsychological examinations in 3-year follow-up. Baseline MRI determinants of cognitive decline were analyzed with linear mixed models controlling for multiple confounders. MTA and subcortical atrophy predicted significantly steeper rate of decline in global cognitive measures as well as compound scores for psychomotor speed, executive functions, and memory after adjusting for age, gender, education, lacunes/infarcts, and WML volume. Cortical atrophy independently predicted decline in psychomotor speed. WML volume remained significantly associated with cognitive decline even after controlling for the atrophy scores. Moreover, significant synergistic interactions were found between WML and atrophy measures in overall cognitive performance across time and the rate of cognitive decline. Synergistic effects were also observed between baseline lacunar infarcts and all atrophy measures on change in psychomotor speed. The main results remained robust after exclusion of subjects with clinical stroke or incident dementia, and after additional adjustments for progression of WML and lacunes. Brain atrophy and WML are independently related to longitudinal cognitive decline in small vessel disease. MTA, subcortical, and cortical atrophy seem to potentiate the effect of WML and lacunes on cognitive decline.
    Neurology 05/2012; 78(22):1785-92. · 8.30 Impact Factor
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    ABSTRACT: Cross-sectional studies have suggested that corpus callosum (CC) atrophy is related to impairment in global cognitive function, mental speed, and executive functions in the elderly. Longitudinal studies confirming these findings have been lacking. We investigated whether CC tissue loss is associated with change in cognitive performance over time in subjects with age-related white matter lesions (WML). Two-hundred-fifty-three subjects, aged 65-84 years, were evaluated by using repeated MRI and neuropsychological evaluation at baseline and after 3 years. The effect of overall and regional CC tissue loss on cognitive decline was analyzed with hierarchical linear regression models. After controlling for age, sex, education, and baseline cognitive performance, the rates of tissue loss in the total CC area, and in rostrum/genu and midbody subregions were significantly associated with decline in a compound measure of cognitive speed and motor control, but not in those of executive functions, memory, or global cognitive function. Total CC area and midbody remained significant predictors of speed also after adjusting for baseline WML volume, WML progression, and global brain atrophy. However, the relationship between anterior CC and speed performance was mediated by WML volume. In conclusion, the overall and regional rate of CC tissue loss parallels longitudinal slowing of psychomotor performance. The adverse effect of CC tissue loss on psychomotor function may be driven by altered interhemispheric information transfer between homologous cortical areas.
    Neuropsychologia 04/2012; 50(7):1650-5. · 3.45 Impact Factor
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    ABSTRACT: Memory complaints are frequent in the elderly but its implications in cognition over time remain a controversial issue. Our objective was to evaluate the risk of self perceived memory complaints in the evolution for future dementia. The LADIS (Leukoaraiosis and Disability) prospective multinational European study evaluates the impact of white matter changes (WMC) on the transition of independent elderly subjects into disability. Independent elderly were enrolled due to the presence of WMC. Subjects were evaluated yearly during 3 years with a comprehensive clinical protocol and a neuropsychological battery. Dementia and subtypes of dementia were classified. Self perceived memory complaints in independent elderly were collected during the interview. MRI was performed at entry and at the end of the study. 639 subjects were included (74.1 ± 5 years old, 55% women, 9.6 ± 3.8 years of schooling). At end of follow-up, 90 patients were demented (vascular dementia, 54; Alzheimer's disease (AD) and AD with vascular component, 34; frontotemporal dementia, 2). Using Cox regression analysis, we found that self perceived memory complaints were a strong predictor of AD and AD with vascular component during the follow-up (β = 2.7, p = 0.008; HR = 15.5, CI 95% [2.04, 117.6]), independently of other confounders, namely depressive symptoms, WMC severity, medial temporal lobe atrophy, and global cognition status at baseline. Self perceived memory complaints did not predict vascular dementia. In the LADIS study, self perceived memory complaints predicted AD but not vascular dementia in elderly subjects with WMC living independently.
    Journal of Alzheimer's disease: JAD 08/2011; 27(3):491-8. · 3.61 Impact Factor
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    ABSTRACT: In cerebral small vessel disease, the core MRI findings include white matter lesions (WML) and lacunar infarcts. While the clinical significance of WML is better understood, the contribution of lacunes to the rate of cognitive decline has not been established. This study investigated whether incident lacunes on MRI determine longitudinal cognitive change in elderly subjects with WML. Within the Leukoaraiosis and Disability Study (LADIS), 387 subjects were evaluated with repeated MRI and neuropsychological assessment at baseline and after 3 years. Predictors of change in global cognitive function and specific cognitive domains over time were analyzed with multivariate linear regression. After controlling for demographic factors, baseline cognitive performance, baseline lacunar and WML lesion load, and WML progression, the number of new lacunes was related to subtle decrease in compound scores for executive functions (p = 0.021) and speed and motor control (p = 0.045), but not for memory or global cognitive function. Irrespective of lacunes, WML progression was associated with decrease in executive functions score (p = 0.016). Incident lacunes on MRI parallel a steeper rate of decline in executive functions and psychomotor speed. Accordingly, in addition to WML, lacunes determine longitudinal cognitive impairment in small vessel disease. Although the individual contribution of lacunes on cognition was modest, they cannot be considered benign findings, but indicate a risk of progressive cognitive impairment.
    Neurology 05/2011; 76(22):1872-8. · 8.30 Impact Factor
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    ABSTRACT: To examine the impact of corpus callosum (CC) tissue loss on the development of global cognitive and motor impairment in the elderly. This study was based on the Leukoaraiosis and Disability (LADIS) study. Assessment of cognitive and motor functions and magnetic resonance imaging (MRI) were done at baseline and at a 3-year follow-up in nondemented elderly subjects. 328 of 639 LADIS subjects had MRIs at baseline and at the 3-year follow-up, which allowed for assessment of CC. Logistic regression revealed differential tissue loss rates in posterior CC in subjects converting to dementia, compared to nonconverters (p < 0.05). Anterior and posterior CC tissue loss was significantly correlated with self-perceived memory impairment in nonconverters (p < 0.05). CC tissue loss was also significantly associated with impaired single leg stance time (p < 0.01). The present longitudinal study on CC supports the role of callosal tissue loss in the development of global cognitive as well as motor impairment.
    Dementia and Geriatric Cognitive Disorders 01/2011; 32(4):279-86. · 2.79 Impact Factor
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    Journal of aging research 01/2011; 2011:841913.
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    ABSTRACT: We aimed to study if age-related white matter changes (WMC) and vascular risk factors were predictors of cognitive decline in elderly subjects with WMC living independently. The Leukoaraiosis and Disability prospective multinational European study (LADIS) evaluates the impact of WMC on the transition of independent elderly subjects into disability. Independent elderly were enrolled due to the presence of WMC. Subjects were evaluated yearly during 3 years with a comprehensive clinical protocol and a neuropsychological battery. Additionally, dementia, subtypes of dementia, and cognitive decline without dementia were classified according to usual clinical criteria. MRI was performed at entry and at the end of the study. A total of 639 subjects were included (74.1 +/- 5 years, 55% women, 9.6 +/- 3.8 years of schooling). At end of follow-up, 90 patients had dementia and 147 had cognitive impairment no dementia. Using Cox regression analysis, WMC severity independently predicted cognitive decline (dementia and not dementia), independently of age, education, and medial temporal atrophy (MTA). Diabetes at baseline was the only vascular risk factor that independently predicted cognitive decline during follow-up, controlling for age, education, WMC severity, and temporal atrophy. Considering subtypes of dementia, Alzheimer disease (AD) was predicted only by MTA, while vascular dementia was predicted by previous stroke, WMC severity, and MTA. WMC severity and diabetes are independent predictors of cognitive decline in an initially nondisabled elderly population. Vascular dementia is predicted by previous stroke and WMC, while AD is predicted only by MTA.
    Neurology 07/2010; 75(2):160-7. · 8.30 Impact Factor
  • Alzheimer's and Dementia 07/2010; 6(4). · 17.47 Impact Factor
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    ABSTRACT: White matter changes (WMC) are related to cognitive deficits and dementia. Our aim was to determine the extent to which the performance in neuropsychological tests would be able to predict the clinical diagnosis of dementia. The LADIS (Leukoaraiosis and Disability) is a prospective study that evaluates the impact of WMC on the transition of independent elderly to disability. The subjects were evaluated at baseline and yearly during 3 years with a comprehensive clinical, functional and neuropsychological protocol. At each visit, dementia was classified according to clinical criteria. The performance in the neuropsychological batteries was compared according to the clinical diagnosis of dementia. From the initially enrolled 639 subjects, 480 were evaluated at year 3. Dementia was diagnosed in 90 participants. The demented subjects had worse performance in almost all the baseline cognitive tests. Using receiver operating characteristic curves, we found that the Vascular Dementia Assessment Scale (VADAS) battery had higher sensitivity and specificity rates (area under the curve = 82%) to identify dementia compared with the Mini-Mental State Examination (MMSE) and Alzheimer's Disease Assessment Scale. Worse performance on baseline MMSE (beta = 0.33; p < 0.001) and VADAS (beta = -0.07; p = 0.02) were predictors of dementia (regression analyses). Performance on the MMSE and the VADAS battery were important predictors of dementia at a 3-year period.
    Dementia and Geriatric Cognitive Disorders 04/2010; 29(4):325-34. · 2.79 Impact Factor

Publication Stats

559 Citations
190.52 Total Impact Points

Institutions

  • 2013–2014
    • University of Lisbon
      • Institute of Molecular Medicine
      Lisboa, Lisbon, Portugal
    • Instituto de Medicina Molecular
      Lisboa, Lisbon, Portugal
  • 2012
    • University of Florence
      • Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino
      Florence, Tuscany, Italy
  • 1999–2012
    • Hospital de Santa Maria
      Lisboa, Lisbon, Portugal
  • 2009
    • University of Helsinki
      • Department of Psychology
      Helsinki, Province of Southern Finland, Finland
  • 2001
    • Hospital Egas Moniz
      Lisboa, Lisbon, Portugal