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Results for “Predictive Value of Tests”

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PubMed2006

A new definition of aspirin non-responsiveness by platelet function analyzer-100 and its predictors.

BACKGROUND: Aspirin non-responsiveness has been described as having a normal closure time (CT) by platelet function analyzer (PFA)-100 assay despite confirmed treatment with aspirin. There is no standard definition of aspirin non-responsiveness by PFA-100, with a variety of cut-off values having been used. We proposed an alternative definition of aspirin non-responsiveness by PFA-100 assay. METHODS: One hundred eighty-four patients with diagnosis of stable coronary artery disease or diabetes mellitus were included in the study. Blood samples were drawn before and after the 7 days of aspirin therapy. An individual was labelled as aspirin non-responder if his/her post-aspirin CT was not 2SD above his/her baseline CT, where SD was calculated from the baseline CTs of the study population. Aspirin non-responsiveness was also defined as having a normal post-aspirin CT (< or =193 s) regardless of pre-aspirin CT. RESULTS: The baseline CT ranged 82-187 s (mean 129.1 +/- 27.5, median 128 s) in the study population. At the end of 1 week of aspirin administration, CT increased to a mean of 260.7 +/- 63.6 s (range 102-301). According to our definition, 28 (15.2%) of 184 patients were aspirin non-responders. Univariate analysis indicated that aspirin non-responsiveness was closely associated with gender (P = 0.012) diabetes (P = 0.006), smoking (P = 0.0496) and hypertension (P = 0.021). Multivariate analysis identified diabetes (P = 0.016) as the only significant independent predictor for the presence of aspirin non-responsiveness. Thirty-four of 184 patients (18.5%) classified as aspirin non-responders according to the second criteria. Seven patients with prolongation of post-aspirin CT more than 2SD were classified as aspirin non-responders by the second criteria. Only 1 patient without prolongation of CT more than 2SD was classified as aspirin responsive by the second criteria. CONCLUSION: Definition of aspirin non-responsiveness as post-aspirin CTs < or =193 s might overestimate the prevalence of aspirin non-responsiveness. Nevertheless, definition of aspirin non-responsiveness by PFA-100 must be standardized and its utility as a predictor of cardiovascular events needs to be further investigated.

Aspirin↗

PubMed1991

[Microbiological tests of patients at risk].

The Streptococcus- and Lactobacillus-tests available in The Netherlands for the selection of patients at risk are discussed. Attention is paid tot the calculation of sensitivity, specificity and predictive value of microbiological tests. Although the predictive values or diagnostic power of the saliva tests are rather low, the use of such tests in dental practice is advocated.

Colony Count, Microbial↗

PubMedDate not supplied

Costs and outcomes of PAPNET secondary screening technology for cervical cytologic evaluation. A community hospital's experience.

OBJECTIVE: To determine the effectiveness of and costs associated with semiautomated rescreening of Papanicolaou smears with negative findings at a community hospital. DESIGN: A prospective study of 1200 Papanicolaou smear slides with negative findings using the PAPNET screening system (Neuromedical Systems, Incorporated, Suffern, NY). SETTING: Community hospital laboratory. PATIENTS: Patients with negative findings on Papanicolaou smears who agreed to have their smears reviewed using PAPNET. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Results of rescreening and resources involved in processing the PAPNET review. RESULTS: Screening with PAPNET identified 8 patients with atypical squamous cells of undetermined significance (ASCUS) that were not diagnosed on initial screening, yielding a false-negative rate in our laboratory of 0.7% for ASCUS. No low- or high-grade squamous intraepithelial lesions were identified. Based on our laboratory processing 6000 Papanicolaou smears a year, at $19 per slide, it would cost our laboratory $102,600 for PAPNET review of all smears with negative findings. In contrast, the estimated cost to have another cytotechnologist review all such smears manually would cost $11,977. The rate of changed diagnoses in the PAPNET group was similar to the rate in our standard rescreening of 10% of all smears with negative findings. Mean turnaround time for a PAPNET screen was 13.9 days, compared with 3.9 days for manual review. CONCLUSIONS: For a laboratory with a low percentage of smears with abnormal findings, a quality cytotechnologist and pathologist, and required quality assurance standards in place, PAPNET may not improve appreciably the pick-up rate for missed cervical lesions, and may add significantly to the cost and turnaround time of cytologic evaluation of cervical smears.

Carcinoma, Squamous Cell↗

PubMed1990

Heritability of cognitive performance in aging twins. The National Heart, Lung, and Blood Institute Twin Study.

The genetic contribution to performance on scales designed to measure mild to moderate decrements in cognitive functioning in a population at risk is unknown. In the present analysis, 134 monozygotic and 133 dizygotic male twin pairs (mean age, 63 years) were given three cognitive tests: the Mini-Mental State examination, the Iowa Screening Battery for Mental Decline, and, for comparison, the Digit Symbol Substitution Test from the Wechsler Adult Intelligence Scale. The primary objective of the analysis was to test for a significant heritable component to performance on these measures. A secondary objective was to determine the extent to which shared variance with significant confounders such as education, age, and depression affects the outcome of the heritability analysis. Results indicate that performance on tests intended to measure cognitive decline in the elderly does have a significant genetic component and that these estimates tend to increase after adjustment for covariates. Heritability estimates adjusted for covariates were 30% for the Iowa Screening score, 60% for the Mini-Mental State score, and 67% for the Digit Symbol Substitution score.

Age Factors↗

PubMed1990

Clinical and demographic predictors of cognitive performance in multiple sclerosis. Do diagnostic type, disease duration, and disability matter?

Patients with chronic progressive multiple sclerosis often perform more poorly on cognitive tasks than do patients with the relapsing-remitting form of this disease. Whether these differences reflect an independent influence of disease type on cognitive performance is uncertain. We used multiple regression techniques to determine how well performance on a number of tasks done poorly by groups of patients with multiple sclerosis could be predicted by disease type and its confounds: age, disease duration, and disability status as well as other demographic variables. Disease types were assigned longitudinally, based on serial neurological examinations at 6-month intervals over a minimum of 2 years. None of the demographic or clinical variables predicted cognitive performance with more than minimal accuracy. These findings fail to provide support for the assertion that disease type is an important independent determinant of cognitive impairment in multiple sclerosis.

Adult↗

PubMed1996

Apolipoprotein E genotype determines survival in the oldest old (85 years or older) who have good cognition.

OBJECTIVE: To quantify the influence of apolipoprotein E (APOE) polymorphism on cognition and survival in a population sample aged 75 years or older. DESIGN: The Kungsholmen Project established a cohort of 1810 residents in a district in Stockholm, Sweden, aged 75 years or older in 1987. Information on cognition at cohort inception is available for all subjects. Subjects were followed up for mortality to January 1, 1995. SUBJECTS: Included in this study are 1077 subjects (of 1124 genotyped for APOE) with the common epsilon 2/3, epsilon 3/3, and epsilon 3/4 APOE genotypes. RESULTS: The odds of cognitive impairment for the epsilon 3/4 vs epsilon 3/3 genotype declined with age: 4.8 for age 75 through 79 years; 1.7 for age 80 through 84 years; and 1.0 (i.e., no association) for age 85 years or older. Despite this association, APOE polymorphism did not significantly predict survival in subjects younger than 85 years, nor did it predict survival in subjects 85 years or older who were cognitively impaired. Instead, survival varied fourfold with respect to APOE polymorphism in those 85 years or older who had good cognition: Mortality in subjects with the epsilon 2/3 genotype was half that in those who carried the epsilon 3/3 genotype (hazard ratio, 0.5; 95% confidence interval, 0.2 to 0.9), and mortality in subjects with the epsilon 3/4 genotype was twice that in those who carried the epsilon 3/3 genotype (hazard ratio, 2.0; 95% confidence interval, 1.1 to 3.5). This fourfold variation resulted in 2-year differences in survival. CONCLUSIONS: The minor sequence variation in the apolipoprotein E isoforms resulted in a fourfold difference in the risk of death among the oldest old (age > or = 85 years) with good cognition. The observed variation in mortality was unlikely to have been caused by cognitive impairment, as APOE polymorphism was not a risk factor for cognitive impairment in this age group.

Age Factors↗

PubMed2000

Predicting conversion to Alzheimer disease using standardized clinical information.

OBJECTIVE: To identify aspects of a standardized clinical assessment that can predict which individuals within the category of "questionable" Alzheimer disease (AD) have a high likelihood of converting to AD over time. DESIGN: Detailed semistructured interviews were performed at baseline and annually for 3 years. SETTING: University-based gerontology research program. PATIENTS: The patient population consisted of 165 individuals 65 years and older: 42 of the participants had a Clinical Dementia Rating (CDR) of normal cognition (CDR rating, 0.0) and 123 had a rating of questionable AD (CDR rating, 0.5). After 3 years of follow-up, 23 of the 123 subjects with questionable AD were diagnosed with probable AD. MAIN OUTCOME MEASURES: The interview was used to generate a summary measure based on the sum of 6 CDR categories, known as the Total Box Score. The responses to 32 selected questions from the interview also were examined. RESULTS: Likelihood of progression to AD during the follow-up period was strongly related to the Total Box Score. For example, more than 50% of individuals with a Total Box Score of 2.0 or higher at baseline developed AD during the follow-up interval, whereas about 10% of individuals with a Total Box Score of 1.0 or lower developed AD during this same period. Selected questions from the standardized clinical interview also were highly predictive of subsequent conversion to AD among the study population. Eight selected questions from the clinical interview at baseline, combined with the CDR Total Box Score, identified 88.6% of such individuals accurately (questionable group, 82/91; converter group, 19/23). CONCLUSIONS: A standardized clinical assessment can be used to identify the subgroup of individuals within the category of questionable AD who have a high likelihood of converting to AD over time. Subjects who met the criteria for questionable AD had a variety of trajectories during a 3-year follow-up, suggesting that diverse factors may influence the functional changes observed in this population.

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PubMed2000

The course of cognitive impairment in preclinical Alzheimer disease: three- and 6-year follow-up of a population-based sample.

OBJECTIVES: To examine the ability of the total score and individual items from the Mini-Mental State Examination in predicting the development of Alzheimer disease (AD) across a 3- and 6-year period in a population-based sample, and to describe the longitudinal changes in these measures across the same follow-up periods. DESIGN: Prospective follow-up of a community-based cohort, with 3 times of testing across a 6-year period. At each time of measurement, participants were clinically examined by physicians to identify demented and nondemented participants according to Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition, criteria. PARTICIPANTS: The study population consisted of all participants who were nondemented at the first follow-up and participated in the second follow-up examination. Among those, 459 remained nondemented and 73 developed AD during the second follow-up period. RESULTS: Baseline differences in the total Mini-Mental State Examination score and the delayed memory item were seen 6 years before eventual dementia diagnosis (P<.01). Analysis of the longitudinal changes showed no differences in the rate of decline for the incident AD or nondemented group between time 1 and time 2 (P>.10). However, the incident AD group exhibited precipitous declines in 8 of the 10 subscales between time 2 and time 3, the point at which they were clinically diagnosed (P<.01). Logistic regression analyses showed that only the delayed memory item was a significant predictor of who would develop AD, independent of age, sex, and years of education, at both of the first 2 times of measurement (P<.001). CONCLUSIONS: The diagnosis of AD is preceded by a long preclinical phase in which deficits in memory performance are most common. These deficits remain relatively stable up until the time that a dementia diagnosis can be rendered. Arch Neurol. 2000.

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PubMed2000

Clinical significance of the multiple sclerosis functional composite: relationship to patient-reported quality of life.

BACKGROUND: The Multiple Sclerosis Functional Composite (MSFC) was recommended by a task force of the National Multiple Sclerosis Society as a new clinical outcome measure for clinical trials. The task force recommended that the MSFC be validated against other measures of the disease, such as patient-reported quality of life. METHODS: Three hundred patients with multiple sclerosis (MS) representing the spectrum of disease severity were included in this cross-sectional study. The MSFC and Kurtzke Expanded Disability Status Scale (EDSS) were used as measures of disease severity. Clinical relevance of the disease severity scores was analyzed using measures included in the Multiple Sclerosis Quality of Life Inventory. The MSFC and EDSS scores were correlated with self-reported employment status, the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), and the Sickness Impact Profile (SIP). RESULTS: The MSFC and EDSS scores were strongly correlated (r = -0.80, P<.001). The MSFC scores were correlated with patient-reported physical functioning (SIP Physical Summary Scale: r = -0.71, P<.001; SF-36 Physical Component Score: r = -0.41, P<.001). The MSFC scores were significantly but more weakly correlated with emotional functioning (SIP Psychosocial Summary Scale: r = -0.34, P<.001). After controlling for EDSS scores, there were significant residual correlations between the MSFC scores and measures of health-related quality of life, suggesting that the MSFC accounts for the variability in health-related quality of life measures not reflected by the EDSS. CONCLUSIONS: The observed strong correlations between MSFC scores and validated measures of self-reported quality of life indicate that the MSFC scores are clinically relevant. This study supports a recommendation by the National Multiple Sclerosis Society Task Force to use the MSFC as a clinical outcome measure.

Adult↗

PubMed2001

Factors associated with incident human immunodeficiency virus-dementia.

BACKGROUND: Antecedents to human immunodeficiency virus-dementia (HIV-D) are poorly understood. OBJECTIVE: To identify risk factors for HIV-D. METHODS: Subjects who are positive for HIV who have CD4+ counts either below 200/microL or below 300/microL with evidence of cognitive impairment were enrolled in this study. Neurologic, cognitive, functional, and laboratory assessments were done semiannually for up to 30 months. Human immunodeficiency virus-dementia was diagnosed using American Academy of Neurology criteria for probable HIV-1-associated dementia complex. RESULTS: One hundred forty-six nondemented patients were enrolled, 45 of whom subsequently met criteria for incident HIV-D. In univariate analyses using the Cox proportional hazards regression model, the following variables were significantly associated with time to develop dementia: cognitive: abnormal scores on Timed Gait, Verbal Fluency, Grooved Pegboard, and Digit Symbol tests; attention-memory, psychomotor, and executive function domain scores; and the diagnosis of minor cognitive/motor disorder; neurologic and medical: increased abnormalities on the neurologic examination, extrapyramidal signs, history of HIV-related medical symptoms; functional: higher reported role or physical function difficulties. Depression was also a strong risk factor, along with sex, hematocrit, hemoglobin, and beta2-microglobulin levels. In a multivariate model that used cognitive domain scores, covariates with significant hazard ratios included depression, executive dysfunction, and the presence of minor cognitive/motor disorder. CONCLUSION: Cognitive deficits, minor cognitive/motor disorder, and depression may be early manifestations of HIV-D.

AIDS Dementia Complex↗

PubMed2002

Research evaluation and prospective diagnosis of dementia with Lewy bodies.

OBJECTIVE: To evaluate the relative merits of recently developed criteria for dementia with Lewy bodies (DLBs) in a longitudinal study of dementia. DESIGN: The diagnosis of DLBs was used in combination with other clinical diagnosis. Patients were classified primarily based on the NINCDS-ADRDA (National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association) clinical criteria for probable or possible Alzheimer disease, or with other disease process that can cause dementia (eg, Parkinson disease), and secondarily according to the consensus guidelines for DLBs. This "double" clinical diagnosis was implemented to capture different pathological entities. The neuropathological diagnosis of Lewy bodies was made with monoclonal antibodies against alpha-synuclein. SETTING: Multidisciplinary research clinic. RESULTS: Prospective application of the consensus guidelines for DLBs from January 1, 1997, to September 29, 2000, identified 11 patients having the diagnosis of probable DLBs and 35 having possible DLBs. The diagnosis of probable or possible DLBs was associated with probable Alzheimer disease in 34 patients, with possible Alzheimer disease in 5 patients, with Parkinson disease in 2 patients, and with other disease processes in 2 patients. Three patients were diagnosed as having probable DLBs alone. An autopsy was performed in 26 of the cases who were clinically examined during the study period. Cortical Lewy bodies were identified in 13 cases; 4 had had premortem diagnosis of DLBs (sensitivity, 30.7%; specificity, 100%). CONCLUSIONS: The prospective validation of the clinical criteria for DLBs showed poor accuracy in this series. We believe that current criteria for DLBs are useful when DLBs occur in isolation, but have low sensitivity when Lewy bodies coexist with the pathological abnormalities of Alzheimer disease.

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PubMed2003

Incipient CADASIL.

BACKGROUND: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is caused by mutations in the NOTCH3 gene. Knowledge of disease expression in young adult NOTCH3 mutation carriers (MCs) is limited. OBJECTIVE: To characterize clinical, neuropsychological, and radiological status in NOTCH3 MCs younger than 35 years. DESIGN: Clinical characterization and blinded survey comparing MCs with non-MCs. SETTING: Referral center. PARTICIPANTS: Individuals younger than 35 years who were at a 50% risk of a NOTCH3 mutation, from our CADASIL database. Thirteen individuals, from 8 families, met the criteria. METHODS: Comprehensive clinical, genetic, neuropsychological, and radiological investigations. Magnetic resonance images were scored according to a standardized white matter hyperintensities rating scale. RESULTS: Six individuals, from 5 families, were MCs. Clinical symptoms consisted of migraine (with aura), stroke, and stroke-like episodes. We did not find evidence for psychiatric disturbances, functional disability, or cognitive dysfunction, compared with non-MCs. Radiologically, a characteristic magnetic resonance imaging lesion pattern emerged for all MCs. This comprised white matter hyperintensities in the anterior temporal lobes, the frontal lobes, and the periventricular frontal caps. CONCLUSIONS: Migraine (with aura) and stroke can present in NOTCH3 MCs younger than 35 years; however, more importantly, physical function and cognition are intact. Possible subtle cognitive dysfunction needs to be assessed in a larger study. White matter hyperintensities on magnetic resonance imaging are characteristic, and are consistently visualized from the age of 21 years and onward. Awareness of the clinical and radiological features of CADASIL in those younger than 35 years should increase early diagnosis and allow for customized counseling of young adults from families with CADASIL.

Adult↗

PubMed2004

Prediction of neuropsychological impairment in multiple sclerosis: comparison of conventional magnetic resonance imaging measures of atrophy and lesion burden.

BACKGROUND: Cognition and magnetic resonance imaging correlations are well established in patients with multiple sclerosis (MS), but it is unclear whether lesion burden or atrophy accounts for most of the predictive variance. These indices have been directly compared in only a few studies. No such study included measurement of the third ventricle, which was strongly predictive of neuropsychological competence in the early literature. Furthermore, few studies accounted for the influence of age, premorbid intelligence, or depression. OBJECTIVE: To determine if conventional measures of lesion burden or atrophy predict cognitive dysfunction in MS while accounting for age, premorbid intelligence, and depression. METHODS: We studied 37 patients with MS and 27 controls matched according to demographic variables. Correlations between neuropsychological tests and the following magnetic resonance imaging indices were considered: T1 hypointense lesion volume, fluid-attenuated inversion recovery hyperintense lesion volume, third ventricle width, bicaudate ratio, and brain parenchymal fraction. Regression models predicting neuropsychological performance controlled for the effects of age, premorbid intelligence, and depression. We included only those tests discriminating patients with MS from controls. RESULTS: In each regression model, third ventricle width was the sole magnetic resonance imaging measure retained. When this variable was removed from consideration, brain parenchymal fraction was retained in all analyses. CONCLUSIONS: Brain atrophy accounts for more variance than lesion burden in predicting cognitive impairment in MS, and central atrophy in particular is strongly associated with neuropsychological morbidity. This finding may be explained in part by atrophy of the thalamus, a deep gray matter structure that mediates cognitive function via cortical and subcortical pathways. Enthusiasm for the clinical utility of third ventricle width is tempered by modest intraobserver and interobserver reliability.

Adult↗

PubMed2005

Identification of Alzheimer disease risk by functional magnetic resonance imaging.

BACKGROUND: Functional magnetic resonance imaging plays a promising role in the preclinical characterization of Alzheimer disease (AD) for use in early diagnosis and in preventive drug trials. OBJECTIVE: To determine whether functional magnetic resonance imaging can reliably distinguish risk groups for AD among cognitively normal middle-aged adults. DESIGN: Cross-sectional case-control study. SETTING: University of California, San Diego, Alzheimer Disease Research Center participants and San Diego community volunteers. PARTICIPANTS: Twenty cognitively normal individuals (10 high risk and 10 low risk), aged 58 to 65 years, were divided into 2 groups based on the presence or absence of the apolipoprotein E epsilon4 allele and a positive family history of AD. MAIN OUTCOME MEASURES: Word pairs were presented in a blocked design alternating between conditions of novel pairs, repeated pairs, and fixation. Whole-brain differences in blood oxygenation level-dependent brain responses between conditions were compared across risk groups. RESULTS: Compared with the low-risk group, the high-risk group showed many areas of differential blood oxygenation level-dependent response in regions commonly associated with AD pathology (eg, the left medial temporal lobe). Furthermore, different patterns of association between left medial temporal lobe activity and memory performance were demonstrated. CONCLUSIONS: Results support a theory of up-regulation in neuronal memory systems in people at risk for AD many years before the typical age at disease onset. They further demonstrate that functional magnetic resonance imaging is a viable technique to identify persons at risk for AD.

Aged↗

PubMed2005

Predictors of preclinical Alzheimer disease and dementia: a clinicopathologic study.

BACKGROUND: To understand the earliest signs of cognitive decline caused by Alzheimer disease (AD) and other illnesses causing dementia, information is needed from well-characterized individuals without dementia studied longitudinally until autopsy. OBJECTIVE: To determine clinical and cognitive features associated with the development of AD or other dementias in older adults. DESIGN: Longitudinal study of memory and aging. SETTING: Alzheimer's Disease Research Center, St Louis, Mo. MAIN OUTCOME MEASURES: Clinical Dementia Rating, its sum of boxes, and neuropathologic diagnosis of dementia. PARTICIPANTS: Eighty control participants who eventually came to autopsy. RESULTS: Individuals who did not develop dementia showed stable cognitive performance. Entry predictors of dementia were age, deficits in problem solving as well as memory, slowed psychomotor performance, and depressive features. Minimal cognitive decline occurred prior to dementia diagnosis, after which sharp decline was noted. Even individuals who were minimally cognitively impaired (Clinical Dementia Rating = 0.5) typically had neuropathologic AD at autopsy. Histopathologic AD also was present in 34% of individuals who did not have dementia at death; these individuals without dementia showed an absence of practice effects on cognitive testing. CONCLUSIONS: Increased age, depressive features, and even minimal cognitive impairment, as determined clinically by Clinical Dementia Rating sum of boxes and by slowed psychomotor performance, identify older individuals without dementia who develop dementia. Older adults who do not develop dementia have stable cognitive performance. The absence of practice effects may denote the subset of older adults without dementia with histopathologic AD, which may reflect a preclinical stage of the illness.

Aged↗

PubMed2006

Measurements of the amygdala and hippocampus in pathologically confirmed Alzheimer disease and frontotemporal lobar degeneration.

BACKGROUND: Differentiating between Alzheimer disease (AD) and frontotemporal lobar degeneration (FTLD) can be difficult, particularly in the earliest stages of the diseases. Patterns of atrophy on magnetic resonance imaging may help distinguish these diseases and aid diagnosis. OBJECTIVE: To assess the diagnostic utility of magnetic resonance imaging-derived amygdala and hippocampal volumes from patients with pathologically proved AD and FTLD. DESIGN: Cross-sectional volumetric magnetic resonance imaging study of the hippocampus and amygdala. SETTING: Specialist cognitive disorders clinic. Subjects Thirty-seven subjects, including 10 patients with pathologically proved AD, 17 patients with pathologically proved FTLD, and 10 age-matched control subjects. MAIN OUTCOME MEASURES: Hippocampal and amygdala volumes. RESULTS: Geometric mean amygdala and hippocampal volumes were, respectively, 15.0% (95% confidence interval [CI], 4.2%-24.5%) and 16.4% (95% CI, 5.9%-25.6%) lower in the AD than in the control group. In FTLD, the equivalent differences were 43.1% (95% CI, 31.9%-52.6%) in the amygdala and 36.1% (95% CI, 27.5%-43.7%) in the hippocampus. Volumes were significantly lower in the FTLD than in the AD group (P<.01 in both regions). Within the FTLD clinical subgroups, there was evidence of a difference in pattern of atrophy with greater asymmetry (left smaller than right) in semantic dementia compared with frontal variant FTLD (P<.001). On average, the left hippocampus was 14% smaller in semantic dementia than in frontal variant FTLD, whereas the right hippocampus was 37% larger. On average, the left amygdala was 39% smaller in semantic dementia than in frontal variant FTLD, whereas the right amygdala was only 1% smaller. CONCLUSIONS: Hippocampal atrophy is not specific to AD or FTLD. However, severe or asymmetrical amygdala atrophy should suggest FTLD. Atrophy patterns follow clinical syndromes rather than pathology.

Adult↗

PubMed2006

Correlation of global N-acetyl aspartate with cognitive impairment in multiple sclerosis.

BACKGROUND: Whole-brain N-acetyl aspartate (NAA), a measure of neuronal function, can be assessed by multislice echo-planar spectroscopic imaging. OBJECTIVE: To test the hypothesis that the global brain NAA/creatine (Cr) ratio is a better predictor of cognitive dysfunction in multiple sclerosis than conventional magnetic resonance imaging measures. DESIGN: Survey. SETTING: Research-oriented hospitals. PATIENTS: Twenty patients, 16 women and 4 men (mean age, 36 years), with early relapsing-remitting multiple sclerosis (mean Expanded Disability Status Scale score, 2.5). MAIN OUTCOME MEASURES: Correlation between the global NAA/Cr ratio and a cognitive dysfunction factor comprising 16 measures from an extensive neuropsychological test battery that best distinguished patients with multiple sclerosis from healthy control subjects. RESULTS: A significant partial correlation between the global NAA/Cr ratio and the cognitive dysfunction factor was found (partial r = 0.62, P = .01), and 9 cognitively impaired patients had significantly lower global NAA/Cr ratios than 11 unimpaired patients (P = .04). No significant correlations were found between the cognitive dysfunction factor and conventional magnetic resonance imaging measures (ie, brain parenchymal fraction and lesion volume). CONCLUSIONS: Multislice echo-planar spectroscopic imaging provides global metabolic measures that distinguish between cognitively impaired and unimpaired patients with multiple sclerosis and correlate with a global cognitive measure. Standardization of the technique is needed, and larger-scale studies that include healthy controls are suggested.

Adult↗

PubMed2006

Intrathecal chemokine synthesis in mild cognitive impairment and Alzheimer disease.

BACKGROUND: Immunoreactivity for several chemokines and for their related receptors has been demonstrated in resident cells of the central nervous system, and the up-regulation of some of them is associated with pathological changes found in Alzheimer disease (AD). OBJECTIVE: To determine interferon-gamma-inducible protein 10 (IP-10), monocyte chemotactic protein 1 (MCP-1), and interleukin 8 (IL-8) levels in cerebrospinal fluid (CSF) from subjects with amnestic mild cognitive impairment (MCI) and patients with AD as compared with age-matched controls. PATIENTS: Thirty-eight subjects with amnestic MCI, 36 patients with AD, and 41 age-matched subjects with noninflammatory affections of the nervous system. DESIGN: Evaluation of CSF chemokine production at time of diagnosis of MCI and AD; correlation with clinical and personal data. Longitudinal evaluation of subjects with MCI until conversion to AD. RESULTS: Cerebrospinal fluid IP-10 concentration was significantly increased in patients with MCI and mild AD but not in patients with severe AD (Mini-Mental State Examination score <15), whereas MCP-1 and IL-8 levels were increased in patients with MCI and all patients with AD. A significant positive correlation between Mini-Mental State Examination score and CSF IP-10 or MCP-1 concentration was observed in patients with AD. No correlation between IP-10 levels and age was found, whereas MCP-1 and IL-8 levels correlated positively with age. Out of 38 subjects with MCI, 19 developed AD within a 1- to 3-year follow-up. CONCLUSIONS: The presence of inflammatory molecules is likely to be a very early event in AD pathogenesis, even preceding the clinical onset of the disease, as demonstrated by subjects with MCI who developed AD over time. Interferon-gamma-inducible protein 10 is specifically increased in MCI and seems to decrease with the progression of AD, whereas MCP-1 and IL-8 are up-regulated also in late stages of the disease, suggesting a role in phases in which neurodegeneration is prevalent.

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