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1.
Osteoporos Int ; 35(2): 353-363, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37897507

RESUMO

This nationwide study used data-linked records to assess the effect of COVID-19 vaccination among hip fracture patients. Vaccination was associated with a lower risk of contracting COVID-19 and, among COVID-positive patients, it reduced the mortality risk to that of COVID-negative patients. This provides essential data for future communicable disease outbreaks. PURPOSE: COVID-19 confers a three-fold increased mortality risk among hip fracture patients. The aims were to investigate whether vaccination was associated with: i) lower mortality risk, and ii) lower likelihood of contracting COVID-19 within 30 days of fracture. METHODS: This nationwide cohort study included all patients aged > 50 years that sustained a hip fracture in Scotland between 01/03/20-31/12/21. Data from the Scottish Hip Fracture Audit were collected and included: demographics, injury and management variables, discharge destination, and 30-day mortality status. These variables were linked to government-managed population level records of COVID-19 vaccination and laboratory testing. RESULTS: There were 13,345 patients with a median age of 82.0 years (IQR 74.0-88.0), and 9329/13345 (69.9%) were female. Of 3022/13345 (22.6%) patients diagnosed with COVID-19, 606/13345 (4.5%) were COVID-positive within 30 days of fracture. Multivariable logistic regression demonstrated that vaccinated patients were less likely to be COVID-positive (odds ratio (OR) 0.41, 95% confidence interval (CI) 0.34-0.48, p < 0.001) than unvaccinated patients. 30-day mortality rate was higher for COVID-positive than COVID-negative patients (15.8% vs 7.9%, p < 0.001). Controlling for confounders (age, sex, comorbidity, deprivation, pre-fracture residence), unvaccinated patients with COVID-19 had a greater mortality risk than COVID-negative patients (OR 2.77, CI 2.12-3.62, p < 0.001), but vaccinated COVID19-positive patients were not at increased risk of death (OR 0.93, CI 0.53-1.60, p = 0.783). CONCLUSION: Vaccination was associated with lower COVID-19 infection risk. Vaccinated COVID-positive patients had a similar mortality risk to COVID-negative patients, suggesting a reduced severity of infection. This study demonstrates the efficacy of vaccination in this vulnerable patient group, and presents data that will be valid in the management of future outbreaks.


Assuntos
COVID-19 , Fraturas do Quadril , Humanos , Feminino , Idoso , Idoso de 80 Anos ou mais , Masculino , COVID-19/complicações , COVID-19/epidemiologia , COVID-19/prevenção & controle , Estudos de Coortes , Vacinas contra COVID-19 , Vacinação , Estudos Retrospectivos
3.
Anaesthesia ; 74(10): 1260-1266, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31038212

RESUMO

Postoperative delirium is common and has multiple adverse consequences. Guidelines recommend routine screening for postoperative delirium beginning in the post-anaesthesia care unit. The 4 A's test (4AT) is a widely used assessment tool for delirium but there are no studies evaluating its use in the post-anaesthesia care unit. We evaluated the performance of the 4AT in the post-anaesthesia care unit in a tertiary German medical centre. Adults who were able to provide informed consent, were not scheduled for postoperative intensive care, and who did not have dementia or severe neuropsychiatric disorders underwent screening by trained research staff with the Nurse Delirium Screening Scale and a new German translation of the 4AT in a random order at the point of discharge from the post-anaesthesia care unit. Reference standard assessment of delirium was psychiatric evaluation by experienced clinicians. Five hundred and forty-three patients (mean age (SD) 52 (18) years) were analysed; 22 (4.1%) patients developed delirium. The sensitivity and specificity of the 4AT were 95.5% (95%CI 77.2-99.9) and 99.2% (95%CI 98.1-99.8), respectively. The area under the receiver operator characteristic curve was 0.998 (95%CI 0.995-1.000). The Nursing Delirium Screening Scale had a sensitivity of 27.3% (95%CI 10.7-50.2) and specificity of 99.4% (95%CI 98.3-99.9), with an area under the curve of 0.761 (95%CI 0.629-0.894). These findings suggest that the 4AT is an effective and robust instrument for delirium detection in the post-anaesthesia care unit.


Assuntos
Delírio do Despertar/psicologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Área Sob a Curva , Cuidados Críticos , Delírio do Despertar/diagnóstico , Feminino , Alemanha , Humanos , Unidades de Terapia Intensiva , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , Testes Neuropsicológicos , Valor Preditivo dos Testes , Estudos Prospectivos , Sensibilidade e Especificidade , Traduções , Adulto Jovem
5.
Eur J Intern Med ; 26(9): 696-704, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26333532

RESUMO

BACKGROUND: Delirium is a neuropsychiatric disorder, triggered by medical precipitants causes. Study aims were to describe the prevalence and impact on in-hospital mortality of delirium identified through ICD-9 codes as well as evidence of neurocognitive deficits demonstrated in a population of older patients admitted to acute medical wards. METHODS: This was a prospective cohort multicenter study of 2521 older patients enrolled in the "Registro Politerapie SIMI (REPOSI)" during the years 2010 and 2012. The diagnosis of delirium was obtained by ICD-9 codes. Cognitive function was evaluated with the Short Blessed Test (SBT) and single SBT items were used as measures of deficits in attention, orientation and memory. Combination of deficits in SBT items was used as a proxy for delirium. Logistic regression was used to evaluate the association with in-hospital mortality of delirium and combined deficits in SBT items. RESULTS: Delirium was coded in 2.9%, while deficits in attention, orientation, and memory were found in 35.4%, 29.7% and 77.5% of patients. Inattention and either disorientation or memory deficits were found in 14.1%, while combination of the 3 deficits in 19.8%. Delirium, as per ICD-9 codes, was not a predictor of in-hospital mortality. In contrast, objective deficits of inattention, in combination with orientation and memory disorders, were stronger predictors after adjusting for covariates. CONCLUSIONS: The documentation of delirium is poor in medical wards of Italian acute hospitals. Neurocognitive deficits on objective testing (in a pattern suggestive of undiagnosed delirium) should be used to raise awareness of delirium, given their association with in-hospital mortality.


Assuntos
Cognição , Delírio/diagnóstico , Delírio/epidemiologia , Conhecimentos, Atitudes e Prática em Saúde , Mortalidade Hospitalar , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Feminino , Hospitalização , Humanos , Itália , Modelos Logísticos , Masculino , Análise Multivariada , Estudos Prospectivos , Escalas de Graduação Psiquiátrica , Fatores de Risco
6.
Transl Psychiatry ; 4: e477, 2014 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-25369144

RESUMO

Delirium is a common cause and complication of hospitalization in older people, being associated with higher risk of future dementia and progression of existing dementia. However relatively little data are available on which biochemical pathways are dysregulated in the brain during delirium episodes, whether there are protein expression changes common among delirium subjects and whether there are any changes which correlate with the severity of delirium. We now present the first proteomic analysis of delirium cerebrospinal fluid (CSF), and one of few studies exploring protein expression changes in delirium. More than 270 proteins were identified in two delirium cohorts, 16 of which were dysregulated in at least 8 of 17 delirium subjects compared with a mild Alzheimer's disease neurological control group, and 31 proteins were significantly correlated with cognitive scores (mini-mental state exam and acute physiology and chronic health evaluation III). Bioinformatics analyses revealed expression changes in several protein family groups, including apolipoproteins, secretogranins/chromogranins, clotting/fibrinolysis factors, serine protease inhibitors and acute-phase response elements. These data not only provide confirmatory evidence that the inflammatory response is a component of delirium, but also reveal dysregulation of protein expression in a number of novel and unexpected clusters of proteins, in particular the granins. Another surprising outcome of this work is the level of similarity of CSF protein profiles in delirium patients, given the diversity of causes of this syndrome. These data provide additional elements for consideration in the pathophysiology of delirium as well as potential biomarker candidates for delirium diagnosis.


Assuntos
Doença de Alzheimer/líquido cefalorraquidiano , Proteínas do Líquido Cefalorraquidiano/análise , Delírio/líquido cefalorraquidiano , Proteômica/métodos , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/líquido cefalorraquidiano , Feminino , Humanos , Masculino
7.
Int Psychogeriatr ; 26(4): 693-702, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24429062

RESUMO

BACKGROUND: Delirium is a common neuropsychiatric syndrome with considerable heterogeneity in clinical profile. Identification of clinical subtypes can allow for more targeted clinical and research efforts. We sought to develop a brief method for clinical subtyping in clinical and research settings. METHODS: A multi-site database, including motor symptom assessments conducted in 487 patients from palliative care, adult and old age consultation-liaison psychiatry services was used to document motor activity disturbances as per the Delirium Motor Checklist (DMC). Latent class analysis (LCA) was used to identify the class structure underpinning DMC data and also items for a brief subtyping scale. The concordance of the abbreviated scale was then compared with the original Delirium Motor Subtype Scale (DMSS) in 375 patients having delirium as per the American Psychiatric Association's Diagnostic and Statistical Manual (4th edition) criteria. RESULTS: Latent class analysis identified four classes that corresponded closely with the four recognized motor subtypes of delirium. Further, LCA of items (n = 15) that loaded >60% to the model identified four features that reliably identified the classes/subtypes, and these were combined as a brief motor subtyping scale (DMSS-4). There was good concordance for subtype attribution between the original DMSS and the DMSS-4 (κ = 0.63). CONCLUSIONS: The DMSS-4 allows for rapid assessment of clinical subtypes in delirium and has high concordance with the longer and well-validated DMSS. More consistent clinical subtyping in delirium can facilitate better delirium management and more focused research effort.


Assuntos
Delírio/classificação , Atividade Motora , Transtornos Psicomotores/diagnóstico , Idoso , Delírio/diagnóstico , Manual Diagnóstico e Estatístico de Transtornos Mentais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Transtornos Psicomotores/psicologia , Curva ROC , Reprodutibilidade dos Testes , Índice de Gravidade de Doença
8.
Int Psychogeriatr ; 25(12): 2067-75, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23962713

RESUMO

BACKGROUND: There are still substantial uncertainties over best practice in delirium care. The European Delirium Association (EDA) conducted a survey of its members and other interested parties on various aspects of delirium care. METHODS: The invitation to participate in the online survey was distributed among the EDA membership. The survey covered assessment, treatment of hyperactive and hypoactive delirium, and organizational management. RESULTS: A total of 200 responses were collected (United Kingdom 28.6%, Netherlands 25.3%, Italy 15%, Switzerland 9.7%, Germany 7.1%, Spain 3.8%, Portugal 2.5%, Ireland 2.5%, Sweden 0.6%, Denmark 0.6%, Austria 0.6%, and others 3.2%). Most of the responders were doctors (80%), working in geriatrics (45%) or internal medicine (14%). Ninety-two per cent of the responders assessed patients for delirium daily. The most commonly used assessment tools were the Confusion Assessment Method (52%) and the Delirium Observation Screening Scale (30%). The first-line choice in the management of hyperactive delirium was a combination of non-pharmacological and pharmacological approaches (61%). Conversely, non-pharmacological management was the first-line choice in hypoactive delirium (67%). Delirium awareness (34%), knowledge (33%), and lack of education (13%) were the most commonly reported barriers to improving the detection of delirium. Interestingly, 63% of the responders referred patients after an episode of delirium to a follow-up clinic. CONCLUSIONS: This is the first systematic survey involving an international group of specialists in delirium. Several areas of lack of consensus were found. These results emphasise the importance of further research to improve care of this major unmet medical need.


Assuntos
Delírio/terapia , Psiquiatria Geriátrica/estatística & dados numéricos , Coleta de Dados , Europa (Continente)/epidemiologia , Psiquiatria Geriátrica/métodos , Psiquiatria Geriátrica/normas , Humanos , Guias de Prática Clínica como Assunto/normas , Inquéritos e Questionários
9.
J Neurol Neurosurg Psychiatry ; 80(6): 594-9, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19237384

RESUMO

BACKGROUND: Delirium is a neuropsychiatric disorder characterised by severe cognitive impairment, but the specific neuropsychological profile of this condition has not yet been clearly delineated. Psychiatric symptoms of perceptual disturbance--such as hallucinations, illusions and misperceptions--are common in delirium, suggesting that patients may have deficits in the cognitive systems underlying visual perception. METHODS: Five neuropsychological tests of visual perception were administered to 17 older patients with delirium, as well as to two control groups comprising 14 patients with Alzheimer's dementia and 18 cognitively normal patients. The Mini Mental State Examination and the Consortium to Establish a Registry for Alzheimer's Disease verbal memory test were also administered to assess the specificity of any perceptual impairments. RESULTS: Patients with delirium scored significantly lower than cognitively normal patients on all perceptual tasks and significantly lower than patients with dementia on three of these tasks. Mini Mental State Examination scores did not differ between the delirium and dementia groups, and patients with delirium showed significantly better verbal recognition performance than those with dementia. CONCLUSIONS: Patients with delirium have specific visual perceptual deficits that cannot be accounted for by general cognitive impairment. These novel findings provide insights into the neural mechanisms underling delirium and might help to improve clinical detection and management of the disorder. The results also support previous suggestions that cognitive perceptual deficits play a causal role in eliciting psychiatric symptoms of perceptual disturbance.


Assuntos
Transtornos Cognitivos/diagnóstico , Delírio/diagnóstico , Transtornos da Percepção/diagnóstico , Percepção Visual , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/psicologia , Transtornos Cognitivos/psicologia , Confusão/diagnóstico , Confusão/psicologia , Delírio/psicologia , Demência Vascular/diagnóstico , Demência Vascular/psicologia , Diagnóstico Diferencial , Discriminação Psicológica , Feminino , Área de Dependência-Independência , Humanos , Masculino , Rememoração Mental , Entrevista Psiquiátrica Padronizada , Testes Neuropsicológicos , Orientação , Reconhecimento Visual de Modelos , Transtornos da Percepção/psicologia , Aprendizagem Verbal
10.
Eur Radiol ; 19(1): 177-83, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18690455

RESUMO

Interpretation of brain images from older patients requires knowledge of changes that occur with healthy ageing. We constructed and tested a reference template for older subjects. We used MR images from normal subjects aged 65-70 and 75-80 to generate average age-specific images. We ranked the T2-weighted images by worsening brain tissue loss to create a diagram of key centiles. Two neuroradiologists tested the template during routine reporting; eight radiologists read 99 MR examinations without and then with the template. Fifty-four subjects (65-70 years) and 25 subjects (75-80 years) formed the reference images. For the two neuroradiologists, the reference template reduced the abnormal scan reporting from 28/42 without to 3/42 with the template. Of 99 MR examinations assessed by eight radiologists, 39/58 scans (67%) reported as moderate or severe atrophy without the template were reported as normal with the template (p = 0.00011). Reference templates of the brain at older ages can "calibrate" radiology reporting. They could also be useful for research into ageing and related conditions. Larger numbers of examinations from more diverse populations and at different ages are required to increase the versatility of these templates.


Assuntos
Encéfalo/patologia , Interpretação de Imagem Assistida por Computador/métodos , Interpretação de Imagem Assistida por Computador/normas , Imageamento por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética/normas , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/patologia , Atrofia/patologia , Feminino , Humanos , Masculino , Valores de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Reino Unido
11.
Postgrad Med J ; 82(973): 767-70, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17101612

RESUMO

OBJECTIVES: To examine the research activities and perceived barriers to research among higher specialist trainees in geriatric medicine and to show how trainees active in research might have a role in assisting their peers in getting started in research. DESIGN: Cross-sectional questionnaire survey on research activities, attitudes to doing research and perceived difficulties in doing research. SETTING AND PARTICIPANTS: Trainee members of the British Geriatrics Society (BGS) in the UK. RESULTS: A total of 122 responses (30% response rate) were received after a single mailing and a follow-up questionnaire to trainees attending the BGS national conference. Although 64% (67/104) of respondents would like to undertake a period of research, many perceived barriers preventing them from planning, funding and executing a research project. Among those who had not undertaken research, the majority (70%, 42/60) indicated that they have no clear idea of a topic to research, 64% (39/61) did not know how to develop an idea and 62% (38/61) indicated that they did not know how to get funding. Trainees motivated to do research were faced with particular difficulties with regards to funding and selection of a project topic. CONCLUSIONS: One useful method would be systematically to provide basic information to trainees on how to enter into the early stages of research. This would help to overcome some of the unnecessary uncertainty that many trainees keen to do research seem to have.


Assuntos
Pesquisa Biomédica , Educação de Pós-Graduação em Medicina , Geriatria/educação , Corpo Clínico Hospitalar/educação , Atitude do Pessoal de Saúde , Estudos Transversais , Humanos , Inquéritos e Questionários , Reino Unido
12.
J Neurol Neurosurg Psychiatry ; 75(11): 1519-23, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15489380

RESUMO

OBJECTIVES: Increased white matter (WM) lesions on magnetic resonance imaging (MRI) are associated with worse cognitive function in older people. Enlarged perivascular spaces (EPVS) commonly coexist with and share some risk factors for WM lesions but are not quantified in published scales. It is not known whether the extent of EPVS is also associated with cognitive function. We tested the hypothesis that more EPVS would be associated with worse cognitive function. METHODS: Ninety seven healthy men (65-70 years), not on medications, underwent MRI scanning and comprehensive cognitive testing. EPVS were quantified in both the basal ganglia/centrum semiovale and the hippocampus, and WM lesions were measured. RESULTS: Scores on published WM lesion rating scales intercorrelated highly significantly and positively (rho = 0.61 to 0.91, p<0.0001). A summary (WML) factor derived from principal components analysis of the WM scales correlated with EPVS in the basal ganglia/centrum semiovale (rho = 0.48, p<0.0001) but not in the hippocampus. EPVS scores in the basal ganglia/centrum semiovale correlated significantly and negatively with non-verbal reasoning (rho = -0.21, p = 0.038) and general visuospatial ability (rho = -0.22, p = 0.032), adjusted for prior intelligence. The WML factor correlated significantly and negatively with visuospatial ability, as previously reported, and showed an unexpected positive correlation with one test of verbal memory (list-learning). CONCLUSIONS: These findings suggest that increased EPVS are correlated with worse cognitive function. Future studies examining changes in WM with ageing should consider incorporating measures of EPVS and examine the sequence of EPVS and WM lesion development over time. More work is needed to develop valid and reliable measures of EPVS.


Assuntos
Envelhecimento/fisiologia , Encéfalo/patologia , Artérias Cerebrais/patologia , Cognição/fisiologia , Imageamento por Ressonância Magnética , Espaço Subaracnóideo/patologia , Idoso , Atrofia , Gânglios da Base/patologia , Hipocampo/patologia , Humanos , Masculino , Análise Multivariada , Testes Neuropsicológicos/estatística & dados numéricos , Análise de Componente Principal , Psicometria/estatística & dados numéricos , Valores de Referência , Estatística como Assunto
13.
J Neurol Neurosurg Psychiatry ; 74(1): 70-6, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12486269

RESUMO

OBJECTIVES: Patients with type II diabetes are at increased risk of cognitive impairment. The retinal and renal complications of diabetes follow microvascular damage permitting small arterioles to leak, hence the cerebral damage might also follow loss of blood-brain barrier (BBB) integrity. Magnetic resonance (MR) brain imaging with intravenous gadolinium (Gd) diethylenetriamine pentaacetic acid (Gd-DTPA) was used to identify increased BBB permeability. METHODS: Ten well controlled type II diabetic patients aged 65-70 years and 10 controls underwent MR brain imaging with fluid attenuated inversion recovery (FLAIR); T1 weighted (T1W) volumetric imaging before; and T1W volumetric imaging at 5, 15, 30, 45, 60, and 90 minutes after intravenous Gd-DTPA. The T1W image before Gd-DTPA was subtracted from the images at each time point after Gd-DTPA. Net signal intensity was plotted against time for different brain regions. White matter hyperintensities were scored from the FLAIR image. RESULTS: The signal intensity/time curves showed that brain signal intensity increased more in the diabetic group than controls during the first 15 minutes after Gd-DTPA, particularly in the basal ganglia (p=0.018). Signal intensity in controls peaked at five minutes and diabetics at 15 minutes. Subjects with more white matter hyperintensities had greater signal increase after Gd-DTPA, whether diabetic or not (p=0.001). CONCLUSIONS: Increased BBB permeability with MR imaging was detected in patients with type II diabetes or white matter hyperintensities. Increased permeability of the BBB might account for some of the cerebral effects of type II diabetes, and so possibly also for the effect of other conditions that affect the microvasculature (like hypertension), on the brain.


Assuntos
Barreira Hematoencefálica/fisiopatologia , Permeabilidade Capilar , Diabetes Mellitus Tipo 2/fisiopatologia , Gadolínio DTPA/farmacocinética , Idoso , Encéfalo/irrigação sanguínea , Encéfalo/fisiopatologia , Permeabilidade Capilar/fisiologia , Líquido Cefalorraquidiano/metabolismo , Meios de Contraste/farmacocinética , Humanos , Imageamento por Ressonância Magnética , Masculino , Valores de Referência , Fatores de Tempo
14.
Neurology ; 59(2): 169-74, 2002 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-12136052

RESUMO

BACKGROUND: Brain size and intracranial capacity are correlated with cognitive performance in young healthy adults, but data are lacking on these relationships in older healthy adults. OBJECTIVE: To test the hypotheses that intracranial capacity, volumes of specific brain regions, and a measure of the shared variance between brain regions are positively associated with cognitive function in a sample of healthy, unmedicated elderly men (n = 97; mean age 67.8, SD 1.3). METHODS: Individuals underwent MRI, with measurements of intracranial area and volumetric measurements of hippocampi, temporal lobes, and frontal lobes. Cognitive testing included measures of premorbid intelligence, fluid intelligence, verbal memory, visuospatial memory, verbal fluency, and attention and processing speed. RESULTS: Cognitive tests showed significant positive intercorrelations throughout, and regional brain volumes were also universally, significantly, and positively intercorrelated. Intracranial area and several regional brain volumes correlated with tests of premorbid and fluid intelligence and tests of visuospatial memory. Tests of verbal memory and verbal fluency did not correlate significantly with brain volumes. Structural equation modeling demonstrated that the relationships between specific cognitive tests and regional brain volumes could best be summarized by a significant positive relationship between a general brain size factor and a general cognitive factor, and not by associations between individual tests and particular brain regions. CONCLUSIONS: In healthy elderly men, there are significant relationships between multiple cognitive tests and both intracranial capacity and regional brain volumes. These relationships may be largely due to longstanding associations between general cognitive ability and overall brain size.


Assuntos
Encéfalo/anatomia & histologia , Cognição , Idoso , Lobo Frontal/anatomia & histologia , Hipocampo/anatomia & histologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos , Valores de Referência , Lobo Temporal/anatomia & histologia
15.
Magn Reson Med ; 44(4): 646-9, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11025522

RESUMO

The use of Lorentzian model lineshapes leads to systematic errors in the quantification of in vivo (1)H NMR spectra. Experimental lineshapes are better modeled by the Voigt (mixed Lorentzian-Gaussian) function, leading to more accurate fits (reduced chi(2)). In this work, results from a group of 41 subjects are presented. It is shown that not only are the estimated metabolite peak areas affected by the choice of lineshape model, but so too are the metabolite ratios. For example, the NAA/choline ratio was 1.92 +/- 0.06 (mean +/- standard error) using the Lorentzian lineshape model and 1.85 +/- 0.05 using the Voigt lineshape model. The corresponding figures for NAA/creatine were 2.32 +/- 0.06 and 2. 10 +/- 0.05 respectively, which are significantly different for the two lineshape models. An explanation of this previously unreported effect is given. This finding clearly has serious implications for the methodology and reporting of spectroscopic studies.


Assuntos
Encéfalo/metabolismo , Espectroscopia de Ressonância Magnética/métodos , Idoso , Envelhecimento/metabolismo , Encéfalo/anatomia & histologia , Cognição/fisiologia , Glucocorticoides/metabolismo , Humanos , Masculino
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