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1.
Kinesiologia ; 42(4): 291-299, 20231215.
Artigo em Espanhol, Inglês | LILACS-Express | LILACS | ID: biblio-1552540

RESUMO

Introducción. Determinar el efecto de ocho semanas de entrenamiento por hiperpnea isocápnica voluntaria (HIV) sobre el costo energético asociado a la respiración (COB) reflejado en los cambios en la oxigenación de los músculos intercostales (∆SmO2-m. intercostales) inducida por ejercicio físico de intensidad incremental. Métodos. Doce participantes físicamente activos fueron entrenados durante ocho semanas de HIV 3 días x semana, 12 minutos, al 60% de ventilación voluntaria máxima (VVM). En la semana previa y posterior al entrenamiento HIV se realizó un test cardiopulmonar (CPET) de intensidad incremental en cicloergómetro, durante esta prueba se registró la ∆SmO2-m. intercostales mediante el dispositivo MOXY®. El efecto de HIV sobre la ∆SmO2-m. intercostales se analizó mediante la prueba two-way mixed ANOVA considerando los factores (fase × tarea). Resultados. ∆SmO2-m.intercostales fue significativamente menor a partir del 30% (­5,0±4,7%; p<0.01) hasta el 100% (­10,6±12,8%; p<0.01) de la tarea luego de ocho semanas de HIV. Además, se reportó un aumento de la presión inspiratoria máxima (PIM)=16,5±11,4 cmH2O (p<0.01); y de la resistencia muscular respiratoria=106,6±149,0 s (p<0.01). El tiempo total de ejercicio aumentó en 106,6±149,0 s (p=0.04), así como la carga total en 10,50± 10,12 vatios (p<0.01). Conclusión. El HIV disminuye el COB inducido por ejercicio incremental asociado a un incremento en la performance física y de los músculos respiratorios. En futuros estudios se sugiere estudiar esta estrategia de entrenamiento analítico de los músculos respiratorios en usuarios con limitación física relacionada al aumento prematuro del COB.


Background. Objetive. To determine the effect of eight weeks of voluntary isocapnic hyperpnea (VIH) training on cost of breathing (COB) as reflected by intercostales muscles deoxygenation (∆SmO2-m. intercostales) induced by incremental-intensity physical exercise. Methods. Twelve physically active participants underwent eight weeks of VIH training, three days a week, for 12 minutes each session, at 60% of maximal voluntary ventilation (MVV). In the week before and after VIH training, a cardiopulmonary test (CPET) of incremental intensity was performed on a cycloergometer. During this test, intercostal ∆SmO2-m.intercostales was recorded using the MOXY® device. The effect of VIH on ∆SmO2-m.intercostales were analyzed using a two-way mixed ANOVA test considering the factors (phase × task). Results. ∆SmO2-m.intercostales significantly decreased from 30% (­5.0±4.7%; p<0.01) to 100% (­10.6±12.8%; p<0.01) of the task after eight weeks of VIH. Additionally, an increase in maximal inspiratory pressure (MIP) of 16.5±11.4 cmH2O (p<0.01) and respiratory muscle endurance of 106.6±149.0 s (p<0.01) was reported. Total exercise time increased by 106.6±149.0 s (p=0.04), as well as total workload by 10.50±10.12 watts (p<0.01). Conclusion. VIH reduces COB induced by incremental exercise and is associated with increased physical and respiratory muscle performance. Future studies should explore this respiratory muscle training strategy for individuals with physical limitations related to a premature increase in COB.

2.
Biology (Basel) ; 12(2)2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36829497

RESUMO

Respiratory muscle training (RMT) improves physical performance, although it is still debated whether this effect depends on the type of training. The purpose of this study was to compare the effects of two different types of RMT, i.e., voluntary isocapnic hyperpnea (VIH) and inspiratory threshold loading (ITL), on the deoxygenation of intercostal (ΔSmO2-m. intercostales) and vastus lateralis (ΔSmO2-m. vastus lateralis) muscles during exercise. Twenty-four participants performed eight weeks of RMT by: (i) VIH (3 days·week-1 for 12 min at 60% maximal voluntary ventilation) or (ii) ITL (5 sets·week-1 of 30 breaths·minute-1 at 60% maximal inspiratory pressure). Cardiopulmonary exercise testing (CPET) included ΔSmO2 (the change from baseline to end of test) of intercostal and vastus lateralis muscles. After RMT, both groups showed decreased ΔSmO2-m. intercostales (VIH = 12.8 ± 14.6%, p = 0.04 (effect size, ES = 0.59), and ITL = 8.4 ± 9.8%, p = 0.04 (ES = 0.48)), without a coincident change of ∆SmO2-m. vastus lateralis. ITL training induced higher V˙O2-peak absolute values than VIH (mean Δ post-pre, ITL = 229 ± 254 mL·min-1 [95% CI 67-391] vs. VIH, 39 ± 153 mL·min-1 [95% CI -58-136.0], p = 0.01). In conclusion, both RMT improved the balance between supply and oxygen consumption levels of m. intercostales during CPET, with ITL also inducing an increase of aerobic capacity.

3.
São Paulo; s.n; 2017. 100 p. ilus, tab.
Monografia em Português | Sec. Est. Saúde SP, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: biblio-1085447

RESUMO

A principal causa de estenose mitral (EM) é a doença reumática que é mais prevalente em países em desenvolvimento, como é o caso do Brasil. Com o advento de técnicas percutâneas, cirurgias abertas foram cada vez mais sendo utilizadas para o tratamento de EM e, atualmente, a valvoplastia mitral percutânea (VMP) é considerada padrão-ouro para o tratamento desta patologia...


Assuntos
Cardiopatias , Doenças Reumáticas , Estenose da Valva Mitral
4.
Curr Alzheimer Res ; 12(8): 802-12, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26159191

RESUMO

Cohorts from a defined geographical area enable ad hoc genotype-phenotype correlation studies providing novel and unique insight into disease. We analysed genetic risk factors associated with early and late onset Alzheimer's disease (EOAD and LOAD) in a population from Liguria (northern Italy), as part of an ongoing longitudinal study. We screened 37 AD, 8 mild cognitive impairment (MCI), 3 AD and CVD (cerebrovascular disease), 3 MCI and CVD, 8 frontotemporal dementia (FTD) and 2 progressive supranuclear palsy (PSP) patients, and 28 normal controls (NCs).We sequenced PSEN1, PSEN2 and APP (EOAD risk factors), as well as MAPT, GRN and TARDBP for all cases and NCs, and analysed the APOE, CLU, CR1 and PICALM genotypes as well as the MAPT and ACE haplotypes (LOAD risk factors) for the AD (n = 37) and AD + MCI (n = 45) cases and NCs (n = 28).We identified variants in PSEN1, PSEN2 and TARDBP across a range of phenotypes (AD, AD and CVD, FTD and PSP), suggesting that screening of all known candidate genes of Alzheimer's and non-Alzheimer's forms of dementias in all dementia cases might be warranted. The analysis of the LOAD risk factors revealed no association with AD or AD + MCI status after Bonferroni correction. Lack of association with APOE is supported by previous studies in the Italian population. Our data also evidenced: 1) a potentially protective haplotype at the PSEN2 locus; 2) a nominal association with the GWAS-risk allele A for rs3818361 in CR1 and; 3) a threefold prevalence of AD in the female population compared to men.Our results will need to be further assessed and confirmed in larger cohorts from this area.


Assuntos
Doença de Alzheimer/genética , Demência/genética , Predisposição Genética para Doença/genética , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Disfunção Cognitiva/genética , Estudos de Coortes , Feminino , Estudos de Associação Genética , Genótipo , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Fatores de Risco
5.
Dis Aquat Organ ; 107(3): 173-80, 2014 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-24429468

RESUMO

Lacaziosis (also known as lobomycosis) is a chronic dermal disease caused by the fungal agent Lacazia loboi, which affects both humans and dolphins. Photographic data have been used to identify lacaziosis-like disease (LLD) among dolphins in the waters of North and South America, and here we report LLD in bottlenose dolphins Tursiops truncatus off the coast of Costa Rica, the first reporting in Central American waters. During the periods of 1991 to 1992 and 2010 to 2011, 3 research teams conducted separate dolphin surveys in the Pacific tropical fiord Golfo Dulce, and each documented skin lesions in the resident population of bottlenose dolphins. Photo-ID records were used to identify LLD-affected bottlenose dolphins and to assess their lesions. Findings showed between 13.2 and 16.1% of the identified dolphins exhibited lesions grossly resembling lacaziosis. By combining efforts and cross-referencing photographic data, the teams explored the presence of LLD in Golfo Dulce over a time gap of approximately 20 yr. Our findings expand the geographical range of the disease and offer insight into its longevity within a given population of dolphins.


Assuntos
Golfinho Nariz-de-Garrafa , Lobomicose/veterinária , Animais , Costa Rica , Lobomicose/epidemiologia , Lobomicose/patologia , Oceano Pacífico/epidemiologia
6.
Neurobiol Aging ; 35(1): 130-42, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23906617

RESUMO

Cortical sources of resting state electroencephalographic (EEG) rhythms are abnormal in subjects with mild cognitive impairment (MCI). Here, we tested the hypothesis that these sources in amnesic MCI subjects further deteriorate over 1 year. To this aim, the resting state eyes-closed EEG data were recorded in 54 MCI subjects at baseline (Mini Mental State Examination I = 26.9; standard error [SE], 0.2) and at approximately 1-year follow-up (13.8 months; SE, 0.5; Mini Mental State Examination II = 25.8; SE, 0.2). As a control, EEG recordings were also performed in 45 normal elderly and in 50 mild Alzheimer's disease subjects. EEG rhythms of interest were delta (2-4 Hz), theta (4-8 Hz), alpha1 (8-10.5 Hz), alpha2 (10.5-13 Hz), beta1 (13-20 Hz), and beta2 (20-30 Hz). Cortical EEG sources were estimated using low-resolution brain electromagnetic tomography. Compared with the normal elderly and mild Alzheimer's disease subjects, the MCI subjects were characterized by an intermediate power of posterior alpha1 sources. In the MCI subjects, the follow-up EEG recordings showed a decreased power of posterior alpha1 and alpha2 sources. These results suggest that the resting state EEG alpha sources were sensitive-at least at the group level-to the cognitive decline occurring in the amnesic MCI group over 1 year, and might represent cost-effective, noninvasive and widely available markers to follow amnesic MCI populations in large clinical trials.


Assuntos
Ritmo alfa , Córtex Cerebral/fisiopatologia , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/fisiopatologia , Descanso/fisiologia , Idoso , Feminino , Seguimentos , Humanos , Masculino , Fatores de Tempo
7.
J Alzheimers Dis ; 39(1): 103-13, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24150105

RESUMO

We evaluated the brain metabolic correlates of main indexes of a widely used word list learning test, the Rey Auditory Verbal Memory Test (RAVLT), in a group of elderly subjects with memory complaints. Fifty-four subjects (age: 72.02 ± 7.45; Mini-Mental State Examination (MMSE) score: 28.9 ± 1.24) presenting at a memory clinic complaining of memory deficit, but not demented, and thirty controls (age: 71.87 ± 7.08; MMSE score: 29.1 ± 1.1) were included. Subjects with memory complaints included both patients with (amnestic mild cognitive impairment, aMCI) and without (subjective memory complaints, SMC) impairment on memory tests. All subjects underwent 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), analyzed with statistical parametric. Patients with aMCI but not those with SMC showed the expected posterior cingulate-precuneus and parietal hypometabolism as compared to controls. Correlation was determined for between four indexes of the RAVLT and brain metabolism. The results show a significant correlation between the delayed recall score and metabolism in posterior cingulate gyrus of both hemispheres and in left precuneus, as well as between a score of long-term percent retention and metabolism in left posterior cingulate gyrus, precuneus, and orbitofrontal areas. These correlations survived correction for age, education, and MMSE score. No correlation was found between immediate or total recall scores and glucose metabolism. These data show the relevant role of posterior cingulate-precuneus and orbitofrontal cortices in retention and retrieval of de-contextualized verbal memory material in a group of elderly subjects with memory complaints and shed light on the topography of synaptic dysfunction in these subjects, overlapping that found in the earliest stages of Alzheimer-type neurodegeneration.


Assuntos
Encéfalo/metabolismo , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/metabolismo , Rememoração Mental/fisiologia , Aprendizagem Verbal/fisiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Fluordesoxiglucose F18 , Lobo Frontal/metabolismo , Glucose/metabolismo , Giro do Cíngulo/metabolismo , Humanos , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Lobo Parietal/metabolismo , Tomografia por Emissão de Pósitrons
8.
Dement Geriatr Cogn Disord ; 36(1-2): 1-19, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23651945

RESUMO

BACKGROUND/AIMS: To identify prodromal Alzheimer's disease (AD) subjects using a data-driven approach to determine cognitive profiles in mild cognitive impairment (MCI). METHODS: A total of 881 MCI subjects were recruited from 20 memory clinics and followed for up to 5 years. Outcome measures included cognitive variables, conversion to AD, and biomarkers (e.g. CSF, and MRI markers). Two hierarchical cluster analyses (HCA) were performed to identify clusters of subjects with distinct cognitive profiles. The first HCA included all subjects with complete cognitive data, whereas the second one selected subjects with very mild MCI (MMSE ≥28). ANOVAs and ANCOVAs were computed to examine whether the clusters differed with regard to conversion to AD, and to AD-specific biomarkers. RESULTS: The HCAs identified 4-cluster solutions that best reflected the sample structure. One cluster (aMCIsingle) had a significantly higher conversion rate (19%), compared to subjective cognitive impairment (SCI, p < 0.0001), and non-amnestic MCI (naMCI, p = 0.012). This cluster was the only one showing a significantly different biomarker profile (Aß42, t-tau, APOE ε4, and medial temporal atrophy), compared to SCI or naMCI. CONCLUSION: In subjects with mild MCI, the single-domain amnestic MCI profile was associated with the highest risk of conversion, even if memory impairment did not necessarily cross specific cut-off points. A cognitive profile characterized by isolated memory deficits may be sufficient to warrant applying prevention strategies in MCI, whether or not memory performance lies below specific z-scores. This is supported by our preliminary biomarker analyses. However, further analyses with bigger samples are needed to corroborate these findings.


Assuntos
Doença de Alzheimer/epidemiologia , Disfunção Cognitiva/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/complicações , Doença de Alzheimer/psicologia , Apolipoproteínas E/genética , Biomarcadores , Análise por Conglomerados , Disfunção Cognitiva/complicações , Disfunção Cognitiva/psicologia , Estudos de Coortes , Progressão da Doença , Europa (Continente)/epidemiologia , Feminino , Genótipo , Humanos , Modelos Logísticos , Imageamento por Ressonância Magnética , Masculino , Rememoração Mental/fisiologia , Pessoa de Meia-Idade , Testes Neuropsicológicos , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X
9.
J Ultrasound Med ; 32(5): 763-8, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23620317

RESUMO

OBJECTIVES: To investigate common carotid intima-media thickness in a cohort of patients who were vertically infected with human immunodeficiency virus 1 (HIV-1). METHODS: We conducted a cross-sectional observational study. Human immunodeficiency virus 1-infected patients were compared with age-, sex-, and body mass index-matched healthy participants. Common carotid intima-media thickness was measured in all participants on both sides of the neck, and the mean intima-media thickness was calculated. Metabolic parameters and markers of inflammation were measured only in HIV-1-infected patients. Statistical analysis was performed by multiple regression and by a matrix of Pearson correlation coefficients. The Student t test was used to compare mean common carotid intima-media thickness values between groups. RESULTS: Forty patients (21 female) with HIV-1 infection acquired from birth with a mean age ± SD of 16.3 ± 4.7 years and 27 healthy participants (11 female) with a mean age of 17.7 ± 4.6 years were included in the study. Mean common carotid intima-media thickness in the HIV-1-infected group (0.450 ± 0.088 mm) was significantly higher (P < .05) than in the control group (0.407 ± 0.079 mm). No significant association was found between intima-media thickness and a specific antiretroviral regimen, exposure to combined antiretroviral agents, and HIV status. In multiple regression analyses, higher levels of insulin (P= .007) and elevated levels of glycated hemoglobin (P= .01) were associated with intima-media thickness changes. CONCLUSIONS: Patients perinatally infected with HIV have increased common carotid intima-media thickness compared with healthy individuals. These changes were more pronounced with increasing age and inflammation markers. Interventions that improve cardiovascular risk profiles should be considered in HIV-infected young adults.


Assuntos
Aterosclerose/diagnóstico por imagem , Aterosclerose/epidemiologia , Espessura Intima-Media Carotídea/estatística & dados numéricos , Estenose das Carótidas/diagnóstico por imagem , Estenose das Carótidas/epidemiologia , HIV-1 , Adolescente , Causalidade , Criança , Pré-Escolar , Comorbidade , Feminino , Infecções por HIV , Humanos , Incidência , Transmissão Vertical de Doenças Infecciosas/estatística & dados numéricos , Itália/epidemiologia , Masculino , Medição de Risco
10.
J Alzheimers Dis ; 34(4): 1015-35, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23340039

RESUMO

Cortical sources of resting state electroencephalographic (EEG) rhythms are abnormal in subjects with Alzheimer's disease (AD). Here we tested the hypothesis that these sources are also sensitive to the progression of early stage AD over the course of one year. The resting state eyes-closed EEG data were recorded in 88 mild AD patients at baseline (Mini Mental State Evaluation, MMSE I = 21.7 ± 0.2 standard error, SE) and at approximately one-year follow up (13.3 months ± 0.5 SE; MMSE II = 20 ± 0.4 SE). All patients received standard therapy with acetylcholinesterase inhibitors. EEG recordings were also performed in 35 normal elderly (Nold) subjects as controls. EEG rhythms of interest were delta (2-4 Hz), theta (4-8 Hz), alpha 1 (8-10.5 Hz), alpha 2 (10.5-13 Hz), beta 1 (13-20 Hz), beta 2 (20-30 Hz), and gamma (30-40 Hz). Cortical EEG sources were estimated by low-resolution brain electromagnetic tomography (LORETA). Compared to the Nold subjects, the mild AD patients were characterized by a power increase of widespread delta sources and by a power decrease of posterior alpha sources. In the mild AD patients, the follow-up EEG recordings showed increased power of widespread delta sources as well as decreased power of widespread alpha and posterior beta 1 sources. These results suggest that the resting state EEG sources were sensitive, at least at group level, to the cognitive decline occurring in the mild AD group over a one-year period, and might represent cost-effective and non-invasive markers with which to enrich cohorts of AD patients that decline faster for clinical studies.


Assuntos
Doença de Alzheimer/patologia , Doença de Alzheimer/fisiopatologia , Córtex Cerebral/fisiopatologia , Periodicidade , Descanso/fisiologia , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/tratamento farmacológico , Análise de Variância , Mapeamento Encefálico , Córtex Cerebral/efeitos dos fármacos , Inibidores da Colinesterase/farmacologia , Inibidores da Colinesterase/uso terapêutico , Progressão da Doença , Eletroencefalografia , Eletroculografia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Espectrometria de Massas , Entrevista Psiquiátrica Padronizada , Pessoa de Meia-Idade , Testes Neuropsicológicos , Sensibilidade e Especificidade
11.
Dement Geriatr Cogn Disord ; 33(4): 255-65, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22738937

RESUMO

AIMS: To validate the Italian version of the Short Cognitive Evaluation Battery (SCEB), consisting of 4 tests (temporal orientation, five words, clock drawing and verbal fluency) in healthy controls (CONT), patients with mild Alzheimer's disease (AD), mild cognitive impairment (MCI), and major depressive disorder (DEP). METHODS: Twenty-nine AD patients (mean Mini-Mental State Examination, MMSE, score: 22.1 ± 3.1), 27 MCI patients (mean MMSE score: 26.5 ± 2.0), 27 depressed patients (mean MMSE score: 26.9 ± 2.8), and 48 controls (mean MMSE score: 29.7 ± 0.5) were enrolled. RESULTS: MANCOVA showed highly significant (p < 0.0001) difference among groups. As for total SCEB score, AD were separated from CONT with high accuracy (93%; with sensitivity 93%, specificity 92%, area under ROC curve, AUC, 0.96) and from DEP with satisfying accuracy (84%; with sensitivity 76%, specificity 93%, AUC 0.84). Results in MCI versus CONT comparison yielded more moderate accuracy (80%; with sensitivity 70%, specificity 87%, AUC 0.80), which increased in the subgroup of MCI patients who later converted to AD (85%; with sensitivity 75%, specificity 83%, AUC 0.86). The direct comparison between MCI converters and nonconverters did not yield accurate results. CONCLUSION: The Italian version of the SCEB is a short (between 6 min in CONT and 12 min in DEP) screening tool in cognitive disorders of the elderly, and is potentially useful in clinical practice.


Assuntos
Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/psicologia , Cognição/fisiologia , Testes Neuropsicológicos , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/psicologia , Análise de Variância , Área Sob a Curva , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/psicologia , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/psicologia , Diagnóstico Diferencial , Feminino , Humanos , Itália , Idioma , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Curva ROC , Reprodutibilidade dos Testes
12.
J Alzheimers Dis ; 26 Suppl 3: 201-14, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21971461

RESUMO

Physiological brain aging is characterized by a combination of synaptic pruning, loss of cortico-cortical connections and neuronal apoptosis that provoke age-dependent decline of cognitive functions. Neural/synaptic redundancy and plastic remodeling of brain networking, also secondary to mental and physical training, promotes maintenance of brain activity in healthy elderly for everyday life and fully productive affective and intellectual capabilities. Unfortunately, in pathological situations, aging triggers neurodegenerative processes that impact on cognition, like Alzheimer's disease (AD). Oscillatory electromagnetic brain activity is a hallmark of neuronal network function in various brain regions. Modern neurophysiological techniques including digital electroencephalography (EEG) allow non-invasive analysis of cortico-cortical connectivity and neuronal synchronization of firing, and coherence of brain rhythmic oscillations at various frequencies. The present review of field EEG literature suggests that discrimination between physiological and pathological brain aging clearly emerges at the group level, with some promising result on the informative value of EEG markers at the individual level. Integrated approaches utilizing neurophysiological techniques together with biological markers and structural and functional imaging are promising for large-scale, low-cost, widely available on the territory and non-invasive screening of at-risk populations.


Assuntos
Doença de Alzheimer/patologia , Córtex Cerebral/fisiopatologia , Disfunção Cognitiva/patologia , Eletroencefalografia , Periodicidade , Descanso/fisiologia , Mapeamento Encefálico , Humanos
13.
Acad Radiol ; 18(12): 1485-91, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21889897

RESUMO

RATIONALE AND OBJECTIVES: Cross-sectional imaging is being increasingly proposed as a suitable tool to characterize carotid plaques. The aim of this work was to correlate the Doppler velocity parameters with the cross-sectional percent stenosis (CPoS) of internal carotid artery (ICA) and to identify the cutoff values of these parameters in five progressive classes of stenosis area severity (ie, 40%-49%, 50%-59%, 60%-69%, 70%-79%, 80%-90%). MATERIALS AND METHODS: High-quality scans from 90 patients (mean age, 74 ± 9 years) with 43%-90% ICA stenosis were analyzed. ICA peak-systolic (PSV) and end-diastolic (EDV) velocities were measured at maximum stenosis level. Total ICA area and residual lumen (RL) were measured to derive the CPoS. A simple physical model described by the equation Velocity = Flow rate/Area was considered. Effectively, the CPoS is expected to negatively correlate with the inverse of velocity parameters, assuming flow rate to be constant. Multiple stepwise regression analyses were used to investigate the relationships between velocity and echographic measures. RESULTS: With CPoS as the dependent variable, the first significant regressor was the inverse ICA-EDV (r(2) = 0.64; P < .0001) followed by inverse ICA-PSV (r(2) = 0.43; P < .0001). ICA-EDV mean values throughout five progressive classes of stenosis were: 28 cm/second for 40%-49% stenosis, 35 cm/second for 50%-59%, 43 cm/second for 60%-69%, 69 cm/second for 70%-79%. and 103 cm/second for 80%-90%. ICA-PSV mean values were: 97 cm/second for 40%-49%, 110 cm/second for 50%-59%, 136 cm/second for 60%-69%, 224 cm/second for 70%-79%, and 286 cm/second for 80%-90%. CONCLUSION: ICA-EDV is the parameter that better correlates with CPoS. Nevertheless, ICA-PSV maintained a highly significant correlation with CPoS. Moreover, the categorization of Doppler parameters in five progressive classes of severity of stenosis could provide physicians with an easily accessible tool in clinical practice, complementary to the morphological evaluation of cross-sectional stenosis.


Assuntos
Estenose das Carótidas/diagnóstico por imagem , Efeito Doppler , Ultrassonografia Doppler Dupla , Idoso , Velocidade do Fluxo Sanguíneo , Artéria Carótida Interna/diagnóstico por imagem , Humanos , Modelos Biológicos , Placa Aterosclerótica , Índice de Gravidade de Doença
14.
Neuroimage ; 58(2): 469-80, 2011 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-21718788

RESUMO

BACKGROUND: Medial temporal lobe (MTL) atrophy is one of the key biomarkers to detect early neurodegenerative changes in the course of Alzheimer's disease (AD). There is active research aimed at identifying automated methodologies able to extract accurate classification indexes from T1-weighted magnetic resonance images (MRI). Such indexes should be fit for identifying AD patients as early as possible. SUBJECTS: A reference group composed of 144AD patients and 189 age-matched controls was used to train and test the procedure. It was then applied on a study group composed of 302 MCI subjects, 136 having progressed to clinically probable AD (MCI-converters) and 166 having remained stable or recovered to normal condition after a 24month follow-up (MCI-non converters). All subjects came from the ADNI database. METHODS: We sampled the brain with 7 relatively small volumes, mainly centered on the MTL, and 2 control regions. These volumes were filtered to give intensity and textural MRI-based features. Each filtered region was analyzed with a Random Forest (RF) classifier to extract relevant features, which were subsequently processed with a Support Vector Machine (SVM) classifier. Once a prediction model was trained and tested on the reference group, it was used to compute a classification index (CI) on the MCI cohort and to assess its accuracy in predicting AD conversion in MCI patients. The performance of the classification based on the features extracted by the whole 9 volumes is compared with that derived from each single volume. All experiments were performed using a bootstrap sampling estimation, and classifier performance was cross-validated with a 20-fold paradigm. RESULTS: We identified a restricted set of image features correlated with the conversion to AD. It is shown that most information originate from a small subset of the total available features, and that it is enough to give a reliable assessment. We found multiple, highly localized image-based features which alone are responsible for the overall clinical diagnosis and prognosis. The classification index is able to discriminate Controls from AD with an Area Under Curve (AUC)=0.97 (sensitivity ≃89% at specificity ≃94%) and Controls from MCI-converters with an AUC=0.92 (sensitivity ≃89% at specificity ≃80%). MCI-converters are separated from MCI-non converters with AUC=0.74(sensitivity ≃72% at specificity ≃65%). FINDINGS: The present automated MRI-based technique revealed a strong relationship between highly localized baseline-MRI features and the baseline clinical assessment. In addition, the classification index was also used to predict the probability of AD conversion within a time frame of two years. The definition of a single index combining local analysis of several regions can be useful to detect AD neurodegeneration in a typical MCI population.


Assuntos
Doença de Alzheimer/diagnóstico , Processamento de Imagem Assistida por Computador/classificação , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/classificação , Imageamento por Ressonância Magnética/métodos , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Doença de Alzheimer/patologia , Área Sob a Curva , Inteligência Artificial , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/patologia , Interpretação Estatística de Dados , Bases de Dados Factuais , Progressão da Doença , Feminino , Seguimentos , Hipocampo/fisiologia , Humanos , Masculino , Reprodutibilidade dos Testes
15.
Eur J Nucl Med Mol Imaging ; 38(12): 2209-18, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21744112

RESUMO

PURPOSE: Subtle cognitive impairment is recognized in the first stages of Parkinson's disease (PD), including executive, memory and visuospatial dysfunction, but its pathophysiological basis is still debated. METHODS: Twenty-six consecutive, drug-naïve, de novo PD patients underwent an extended neuropsychological battery, dopamine transporter (DAT) and brain perfusion single photon emission computed tomography (SPECT). We previously reported that nigrocaudate impairment correlates with executive functions, and nigroputaminal impairment with visuospatial abilities. Here perfusion SPECT was first compared between the PD group and age-matched controls (CTR). Then, perfusion SPECT was correlated with both DAT SPECT and four neuropsychological factors by means of voxel-based analysis (SPM8) with a height threshold of p < 0.005 at peak level and p < 0.05 false discovery rate-corrected at cluster level. Both perfusion and DAT SPECT images were flipped in order to have the more affected hemisphere (MAH), defined clinically, on the same side. RESULTS: Significant hypoperfusion was found in an occipital area of the MAH in PD patients as compared to CTR. Executive functions directly correlated with brain perfusion in bilateral posterior cingulate cortex and precuneus in the less affected hemisphere (LAH), while verbal memory directly correlated with perfusion in the precuneus, inferior parietal lobule and superior temporal gyrus in the LAH. Furthermore, positive correlation was highlighted between nigrocaudate and nigroputaminal impairment and brain perfusion in the precuneus, posterior cingulate and parahippocampal gyri of the LAH. CONCLUSION: These data support the evidence showing an early involvement of the cholinergic system in the early cognitive dysfunction and point to a more relevant role of parietal lobes and posterior cingulate in executive functions in PD.


Assuntos
Encéfalo/fisiopatologia , Circulação Cerebrovascular , Transtornos Cognitivos/fisiopatologia , Cognição , Corpo Estriado/fisiopatologia , Doença de Parkinson/fisiopatologia , Substância Negra/fisiopatologia , Idoso , Velocidade do Fluxo Sanguíneo , Encéfalo/diagnóstico por imagem , Transtornos Cognitivos/diagnóstico por imagem , Transtornos Cognitivos/etiologia , Corpo Estriado/diagnóstico por imagem , Feminino , Humanos , Masculino , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiopatologia , Doença de Parkinson/complicações , Doença de Parkinson/diagnóstico por imagem , Imagem de Perfusão , Estatística como Assunto , Substância Negra/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Resultado do Tratamento
16.
J Neurol Sci ; 310(1-2): 31-5, 2011 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-21762928

RESUMO

A subtle cognitive impairment can be detected early in the course of Parkinson's disease (PD). Executive, memory and visuospatial functions are specifically affected, but the underlying pathophysiological basis is not well elucidated yet and may be heterogeneous. The recent identification of a PD-related cognitive metabolic pattern (PDCP), including hypometabolism in associative frontal, parietal and posterior limbic structures, has integrated the classical notion of a striato-frontal syndrome at the basis of cognitive dys-function. Recent evidence suggests that whilst executive dys-function is seen in virtually all PD patients, visuospatial and memory impairment may share a higher risk for the subsequent development of dementia. By means of perfusion SPECT and [18F]FDG-PET, cortical dys-function may be highlighted since the early stages, it is more evident in PD patients with Mild Cognitive Impairment (MCI), and reaches the maximum in PD dementia (PDD). Posterior temporo-parieto-occipital dys-function in associative and limbic cortex, closely resembling that found in Alzheimer's disease patients, is found in PDD, with a more severe occipital hypometabolism and a relatively milder hypometabolism in medial temporal lobe structures. Furthermore, deficit of acetylcholinesterase (AchE) can be found by means of [11C]MP4A-PET already in early stage of PD, especially in posterior regions, then becoming more severe in PDD and in dementia with Lewy bodies (DLB). Administration of AchE inhibitors to PDD patients increased brain metabolism in bilateral frontal and left parietal regions, and left posterior cingulate. Finally, the recent availability of radiopharmaceuticals able to disclose amyloid brain deposition has allowed to demonstrate amyloid load in a part of patients with PDD, possibly due to diffuse rather than neuritic plaques. Brain PET and SPECT have strongly contributed to the understanding of the pathophysiology of cognitive impairment in PD and may serve as probes to monitor the effects of therapeutic interventions.


Assuntos
Encéfalo/diagnóstico por imagem , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/patologia , Doença de Parkinson/complicações , Compostos de Anilina , Benzotiazóis , Encéfalo/efeitos dos fármacos , Mapeamento Encefálico , Transtornos Cognitivos/diagnóstico por imagem , Transtornos Cognitivos/tratamento farmacológico , Fluordesoxiglucose F18 , Humanos , Doença de Parkinson/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Tiazóis , Tomografia Computadorizada de Emissão de Fóton Único
17.
Int J Alzheimers Dis ; 2011: 927573, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21629714

RESUMO

Physiological brain aging is characterized by synapses loss and neurodegeneration that slowly lead to an age-related decline of cognition. Neural/synaptic redundancy and plastic remodelling of brain networking, also due to mental and physical training, promotes maintenance of brain activity in healthy elderly subjects for everyday life and good social behaviour and intellectual capabilities. However, age is the major risk factor for most common neurodegenerative disorders that impact on cognition, like Alzheimer's disease (AD). Brain electromagnetic activity is a feature of neuronal network function in various brain regions. Modern neurophysiological techniques, such as electroencephalography (EEG) and event-related potentials (ERPs), are useful tools in the investigation of brain cognitive function in normal and pathological aging with an excellent time resolution. These techniques can index normal and abnormal brain aging analysis of corticocortical connectivity and neuronal synchronization of rhythmic oscillations at various frequencies. The present review suggests that discrimination between physiological and pathological brain aging clearly emerges at the group level, with suggested applications also at the level of single individual. The possibility of combining the use of EEG together with biological/neuropsychological markers and structural/functional imaging is promising for a low-cost, non-invasive, and widely available assessment of groups of individuals at-risk.

18.
Int J Alzheimers Dis ; 2011: 481903, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21629749

RESUMO

Alzheimer's disease (AD) is the most common type of dementia that is clinically characterized by the presence of memory impairment and later by impairment in other cognitive domains. The clinical diagnosis is based on interviews with the patient and his/her relatives and on neuropsychological assessment, which are also used to monitor cognitive decline over time. Several biomarkers have been proposed for detecting AD in its earliest stages, that is, in the predementia stage. In an attempt to find noninvasive biomarkers, researchers have investigated the feasibility of neuroimaging tools, such as MR, SPECT, and FDG-PET imaging, as well as neurophysiological measurements using EEG. In this paper, we investigate the brain functional networks in AD, focusing on main neurophysiological techniques, integrating with most relevant functional brain imaging findings.

19.
Hum Brain Mapp ; 32(11): 1916-31, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21181798

RESUMO

Previous evidence has shown that resting eyes-closed cortical alpha rhythms are higher in amplitude in mild cognitive impairment (MCI) than Alzheimer's disease (AD) subjects (Babiloni et al. [2006a]: Human Brain Mapp 27:162-172; [2006b]: Clin Neurophysiol 117:252-268; [2006c]: Neuroimage 29:948-964; [2006d]: Ann Neurol 59:323-334; [2006e]: Clin Neurophysiol 117:1113-1129; [2006f]: Neuroimage 31:1650-1665). This study tested the hypothesis that, in amnesic MCI subjects, high amplitude of baseline cortical alpha rhythms is related to long-term stability of global cognition on clinical follow-up. Resting electroencephalographic (EEG) data were recorded in 100 amnesic MCI subjects during eyes-closed condition. EEG rhythms of interest were delta (2-4 Hz), theta (4-8 Hz), alpha1 (8-10.5 Hz), alpha2 (10.5-13 Hz), beta1 (13-20 Hz), and beta2 (20-30 Hz). Cortical EEG sources were estimated by low-resolution brain electromagnetic tomography (LORETA). Global cognition was indexed by mini mental state evaluation (MMSE) score at the time of EEG recordings (baseline) and about after 1 year. Based on the MMSE percentage difference between baseline and 1-year follow-up (MMSEvar), the MCI subjects were retrospectively divided into three arbitrary groups: DECREASED (MMSEvar ≤ -4%; N = 43), STABLE (MMSEvar ≈ 0; N = 27), and INCREASED (MMSEvar ≥ +4%; N = 30). Subjects' age, education, individual alpha frequency, gender, and MMSE scores were used as covariates for statistical analysis. Baseline posterior cortical sources of alpha 1 rhythms were higher in amplitude in the STABLE than in the DECREASED and INCREASED groups. These results suggest that preserved resting cortical neural synchronization at alpha frequency is related to a long-term (1 year) stable cognitive function in MCI subjects. Future studies should use serial MMSE measurements to confirm and refine the present results.


Assuntos
Ritmo alfa/fisiologia , Disfunção Cognitiva/fisiopatologia , Disfunção Cognitiva/psicologia , Eletroencefalografia , Idoso , Doença de Alzheimer/fisiopatologia , Doença de Alzheimer/psicologia , Cognição/fisiologia , Sincronização Cortical , Interpretação Estatística de Dados , Manual Diagnóstico e Estatístico de Transtornos Mentais , Progressão da Doença , Função Executiva/fisiologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Memória/fisiologia , Testes Neuropsicológicos
20.
Int Psychogeriatr ; 23(1): 86-95, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20602861

RESUMO

BACKGROUND: In most European countries the ethnic minority migrant populations are currently reaching an age where dementia becomes an increasingly important issue. There is no European consensus on good clinical practice with these patient groups, who often have special needs and expectations with regard to dementia services. METHODS: A survey was conducted in clinical dementia centers in 15 European countries. Questionnaires focusing on different points in the clinical assessment of dementia in ethnic minority patients were mailed to leading dementia experts of the European Alzheimer's Disease Consortium. RESULTS: Thirty-six centers from 15 countries responded to the survey. Ethnic minority patients were seen on a regular basis in 69% of these centers. The diagnostic evaluation was in accordance with evidence-based clinical guidelines in 84-100% of the centers, but most centers performed cognitive assessment with instruments that are only validated in Western cultures and frequently relied on family members for interpretation. Diagnostic evaluation of the patients was considered to be challenging in 64% of the centers, mainly because of communication problems and lack of adequate assessment tools. In general, there were few indicators of culturally sensitive dementia services in the centers. CONCLUSIONS: Ethnic minority patients are seen on a regular basis in European dementia clinics. Assessment of such patients is difficult for a number of reasons. Results from this study show that the most challenging issues are communication problems and assessment of cognitive function where there is a need to develop specific tests for ethnic minority patients.


Assuntos
Doença de Alzheimer/etnologia , Doença de Alzheimer/psicologia , Etnicidade/psicologia , Grupos Minoritários/psicologia , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico , Competência Cultural , Europa (Continente)/epidemiologia , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Inquéritos e Questionários
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