[Relevance of Omega-3 and Omega-6 / Omega-3 Ratio in Preventing Cognitive Impairment]. / Relevância dos Índices Ómega-3 e Razão Ómega-6 / Ómega-3 na Prevenção do Défice Cognitivo.

INTRODUCTION: The epidemiological and social relevance of dementia and mild cognitive impairment increases with life expectancy and prevalence of metabolic disorders. The recognition of an important role for dietary nutrients on cognitive functioning opens new preventive strategies. This work analyses the association between erythrocyte omega-3 index and omega-6 / omega-3 ratio and cognitive performance/ mild cognitive impairment. MATERIAL AND METHODS: We selected a random sample of individuals registered at a health centre aged ≥ 55 years. Participants were asked about their alimentary habits, erythrocyte indexes were determined and neuropsychological evaluation included the Montreal Cognitive Assessment and a comprehensive test battery. RESULTS: Mean age of 90 participants was 64 years (sd = 5.6), 71.1% had four years of education and 40% of them had more than one vascular risk factor. Limits for omega-3 index and omega-6 / omega-3 ratio were 2.90 - 9.79 (mean = 6.20; sd = 1.50) and 1.14 - 2.95 (mean = 2.12; sd = 0.39), respectively. Montreal Cognitive Assessment scores ranged from 10 to 29 (mean = 22; sd = 4.5), increasing on average 1 - 2 points for above average omega-3 values and an omega-6 / omega-3 ratio ≤ 2 (Group 1) and decreasing 5 - 6 points for omega-3 below mean values and the same omega-6 / omega-3 ratio (Group 2). Prevalence of mild cognitive impairment was 25.6% (95% CI: 16.4 - 34.7), ranging from 12.5% to 83.3% in the two groups above. DISCUSSION: This preliminary study is one of the first analyzing the repercussion of omega-3 index and omega-6 / omega-3 ratio on cognitive functioning, considering additionally the participant clinical and dietary profiles. CONCLUSION: The association found suggests that omega-3 and omega-6 / omega-3 ratio could be important biomarkers in the prevention of cognitive impairment.

Introdução: A relevância epidemiológica e social da demência e do défice cognitivo ligeiro aumenta com a esperança de vida e prevalência das doenças metabólicas. O reconhecimento da importância dos nutrientes no funcionamento cognitivo perspectiva novas estratégias preventivas. Neste trabalho analisamos a associação entre os valores do índice ómega-3 e da razão ómega-6 / ómega-3 e desempenho cognitivo/ défice cognitivo ligeiro. Material e Métodos: Selecionamos uma amostra aleatória de utentes de um centro de saúde com idade ≥ 55 anos, que foram inquiridos sobre hábitos alimentares e sujeitos a avaliação neuropsicológica, incluindo o Montreal Cognitive Assessment, e determinando-se os índices indicados. Resultados: Os 90 participantes tinham em média 64 anos (dp = 5,6), 71,1% quatro anos de escolaridade e 40% mais de um factor de risco vascular. Os limites dos valores de ómega-3 e da razão ómega-6 / ómega-3 foram respectivamente 2,90 - 9,79 (média = 6,20; dp = 1,50) e 1,14 - 2,95 (média = 2,12; dp = 0,39). A pontuação no Montreal Cognitive Assessment variou entre 10 - 29 (média = 22,0; dp = 4,5), aumentando em média 1 - 2 pontos para valores de ómega-3 acima da média e uma razão ómega-6 / ómega-3 ≤ 2 (Grupo 1) e diminuindo 5 - 6 pontos para um valor de ómega-3 abaixo da média e a mesma razão ómega-6 / ómega-3 (Grupo 2). A prevalência de défice cognitivo ligeiro foi 25,6% (IC 95%:16,4 - 34,7%), variando entre 12,5% e 83,3% nos dois grupos mencionados. Discussão: Este estudo preliminar é um dos primeiros a analisar a repercussão do índice ómega-3 e da razão ómega-6 / ómega-3 na função cognitiva, considerando adicionalmente o perfil clínico e consumo alimentar dos participantes. Conclusão: A associação encontrada sugere que o índice ómega-3 e a razão ómega-6 / ómega-3 podem ser biomarcadores importantes na prevenção da deterioração cognitiva.

Prevalence and pattern of cognitive impairment in rural and urban populations from Northern Portugal.

BACKGROUND: Despite worldwide recognition of the burden of dementia, no epidemiological data is yet available in Portugal. The objective of this study is to estimate the prevalence and describe the pattern of cognitive impairment with dementia or no dementia (CIND) in rural and urban populations from Northern Portugal. METHODS: Two random samples of residents aged 55 to 79 years in rural and urban communities were drawn from the health centres registries to be screened for cognitive impairment. The screening criteria for dementia were an abnormal Mini-Mental State Examination (MMSE) score or a Blessed Dementia Scale score. After excluding those who tested positive for dementia, cut-off points for CIND were set at 1 standard deviation below the mean of the MMSE according to educational level. All those who screened positive either for dementia or CIND were examined by a neurologist for establishing a definitive diagnosis. RESULTS: The prevalence of cognitive impairment was higher in rural than in urban populations, 16.8% (95% CI: 14.3-19.8%) vs. 12.0% (95%CI: 9.3-15.4%), with a rural/urban prevalence ratio (PR) of 2.16 (95% CI: 1.04-4.50) in the eldest and 2.19 (95% CI: 1.01-4.76) in persons with vascular risk factors. The prevalence of dementia was 2.7% (95% CI: 1.9-3.8%) with a rural/urban PR = 2.1 and the prevalence of CIND was 12.3% (95% CI: 10.4-14.4%) and PR = 1.3. The prevalence of dementia increases exponentially with age and in those with cerebrovascular disease or other comorbid conditions while the prevalence of CIND, besides these factors, is also higher in persons with low levels of education or vascular risk factors. Alzheimer's and vascular disease were equally likely aetiologies of dementia (38.7%), the later more common in men PR(F:M = 0.3) as opposed to the former PR(F:M = 2.0). Vascular CIND, associated either with cerebrovascular disease or vascular risk factors was more frequent (39.7%) then depression (18.4%) or any other aetiology. CONCLUSIONS: The prevalence of cognitive impairment is higher in rural compared with urban populations. This is shown in the synergy between age and rurality, with the rural/urban prevalence ratio increasing with age. In this relatively young population from Northern Portugal, cerebrovascular disease as well as vascular risk factors account for 48% of overall cognitive impairment.

[The initial symptoms of Alzheimer disease: caregiver perception]. / Sintomas iniciais de demência de Alzheimer: a percepção dos familiares.

INTRODUCTION: Early recognition of Alzheimer's disease (AD) symptoms is crucial to the integration of patient and caregiver in the healthcare system. Family perception of initial cognitive and behavioural symptoms is decisive and has impact on quality of life of both patient and family. OBJECTIVES: To analyse caregiver's perception of initial AD symptoms and characterize the degree of cognitive decline that determines disease recognition. PARTICIPANTS AND METHODS: A semi-structured interview was performed including questions about: i) socio-economic characterization of patient and caregiver; ii) disease natural history; iii) DA first symptoms. The interview was applied by phone to a sample of caregivers of patients from two memory clinics. RESULTS: Were included 41 patients (22 M;19 F) with age at onset of 69 years (51-81) and a mean of 14.6 months (2-43) since diagnosis. School level: patients = 3.2 +/- 2.2 and caregivers = 5.37 +/- 3.2 years; leisure activities score: patients = 2.6 +/- 1.9 and caregivers = 2.9 +/- 2. Patients were recognized with involvement of 4-6 cognitive areas in 58.5%; only 12.2% had one cognitive area involved. Women cared by their husbands had less cognitive areas involved at initial perception than men cared by their wives (2.7 +/- 1.5 vs 4 +/- 2.5). Time interval since family perception until reporting to the general practitioner (GP) was 4.16 +/- 5.7 months and to neurological observation 27.7 +/- 13.9. No correlation was found between these intervals and school level or leisure activities. CONCLUSIONS: Families have difficulties in the detection of initial dementia symptoms and in adequately transmitting them to GP. The pair of patient and caregiver seemed determinant in dementia recognition: female patients were recognized with less cognitive areas involved, probably in relation with their greater enrollment in household activities. The characterization of the process of perception in dementia is crucial for definition of adequate strategies of detection and intervention in AD.

Cardiac arrest: long-term cognitive and imaging analysis.

BACKGROUND: Neurological and cognitive sequelae resulting from cardiac arrest (CA), despite their potential personal and social impact, are usually not considered as major outcome measures in long-term analysis of survivors. The aim of this study is to analyze the contribution of neuropsychological testing and cerebral imaging to the development of a long-term classification of neurological impairment. PATIENTS AND METHODS: A total of 19 patients admitted over a 3 years period in an eight-bed intensive care unit of a tertiary care hospital with a diagnosis of CA were alive and attended a 6-month follow-up consultation. Eleven of these patients agreed to participate in this study carried out between 1 and 3 years after CA. Patients were classified using the Cerebral Performance Categories (CPC), neurological examination, detailed cognitive testing and computerized tomography (CT) scan with qualitative and quantitative imaging analysis. RESULTS: Six of the 11 patients had good cerebral performance. Verbal and visuo-spatial short-term memory scores were associated with CPC. All patients with at least moderate cerebral disability had abnormal verbal memory test results compared with only one survivor with CPC 1; visuo-spatial short-term memory was abnormal in four moderately affected survivors and normal in those with CPC 1. The bicaudate ratio evaluated in the CT scan was correlated with the verbal memory score while the III ventricle diameter correlated with the executive functions score, suggesting involvement of different brain areas in these functions. CONCLUSIONS: Neuropsychological and CT scan measurements are proxy measures of long-term impairment of CA survivors, providing a dichotomized global evaluation of CA survivors in close agreement with CPC.

Cortical remapping in amputees and dysmelic patients: a functional MRI study.

OBJECTIVES: To investigate motor cortex function in upper and lower limb amputees and dysmelic patients using fMRI. MATERIAL AND METHODS: Five amputees and two dysmelic patients were examined. Motor and imagery tasks were defined according to each patient limb deficiency. Cortical activation patterns were analysed for each patient and compared between groups, integrating patients clinical data. RESULTS: There is a consistent pattern of cortical reorganization in all amputees: predominance of activation in the ipsilateral motor cortex and extension to premotor and sensory areas of the contralateral cortex. On the contrary, cortical maps of dysmelic patients were similar to those of healthy volunteers, predominantly with activation of contralateral primary motor cortex areas. CONCLUSIONS: fMRI discloses specific patterns of cortical reorganization on amputees and dysmelic patients, suggesting influence by prosthesis adaptation or stump use with dexterity. These findings could be further applied in influencing neurorehabilitation and development of prosthetic devices.