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R Mayeux

Publications and source records attributed to R Mayeux.

At least 109 records · Page 6Linked to original sources
PubMed1996

Relative risk of Alzheimer disease and age-at-onset distributions, based on APOE genotypes among elderly African Americans, Caucasians, and Hispanics in New York City.

Apolipoprotein-E epsilon 4 (APOE-epsilon 4) has been consistently associated with Alzheimer disease (AD) and may be responsible for an earlier age at onset. We have previously reported a diminished association between APOE-epsilon 4 and AD in African Americans. Using a new method, which allows inclusion of censored information, we compared relative risks by APOE genotypes in an expanded collection of cases and controls from three ethnic groups in a New York community. The relative risk for AD associated with APOE-epsilon 4 homozygosity was increased in all ethnic groups (African American relative risk [RR]=3.0; 95% confidence interval [CI]=1.5-5.9; Caucasian RR=7.3, 95% CI=2.5-21.6; and Hispanic RR=2.5, 95% CI=1.1-5.7), compared with those with APOE-epsilon 3/epsilon 3 genotypes. The risk was also increased for APOE-epsilon 4 heterozygous Caucasians (RR=2.9, 95% CI=1.7-5.1) and Hispanics (RR=1.6, 95% CI=1.1-2.3), but not for African Americans (RR=0.6, 95% Ci=0.4-0.9). The age distribution of the proportion of Caucasians and Hispanics without AD was consistently lower for APOE-epsilon 4 homozygous and APOE-epsilon 4 heterozygous individuals than for those with other APOE genotypes. In African Americans this relationship was observed only in APOE-epsilon 4 homozygotes. These results confirm that APOE genotypes influence the RR of AD in Caucasians and Hispanics. Differences in risk among APOE-epsilon 4 heterozygote African Americans suggest that other genetic or environmental factors may modify the effect of APOE-epsilon 4 in some populations.

Age of Onset↗
PubMed1995

APOE genotype influences functional status among elderly without dementia.

The presence of apolipoprotein-epsilon 4 (APOE-epsilon 4) significantly increases the risk of Alzheimer's disease (AD). The association between APOE-epsilon 4 status and functional abilities was explored further in a multicultural sample of community-dwelling, non-demented elders. The sample was limited to cognitively-intact, community-dwelling elders, who were free of stroke or other neurologic disability. In 218 elders who met research criteria, the presence of APO-epsilon 4 was associated with poorer functional status, apart from the effects of neuropsychological performance, gender, age, and education (OR = 2.5, 95% CI: 1.3, 4.9). In 158 subjects without an APOE-epsilon 4 allele, 50% reported no functional limitation; in the 60 subjects with an epsilon 4 allele, only 28% reported no functional limitation (P < .01). The relationship was not explained by the distribution of co-morbidities. The association between poorer function and the presence of an APOE-epsilon 4 allele was evident in each ethnic group. In path analyses, the presence of an APOE-epsilon 4 allele was associated with decreased functional ability in non-demented elders not simply through an association with poorer cognitive status, but also independently. These results suggest that the APOE-epsilon 4 genotype is associated with functional deficit in people with normal neuropsychological profiles.

Aged↗
PubMed1995

Linear rank tests for doubly censored data.

This paper establishes the asymptotic properties of the non-parametric maximum likelihood estimator of the survival function based on data censored both from the left and the right. We show that the sample mean based on the survival estimator converges to a normal distribution, and we derive non-parametric tests for the differences in survival functions. The methods are applied to a study of dementia associated with Parkinson's disease.

Adult↗
PubMed1995

The frequency of idiopathic Parkinson's disease by age, ethnic group, and sex in northern Manhattan, 1988-1993.

Sex and ethnic differences in the frequency of Parkinson's disease have become increasingly important, because putative genetic and environmental risk factors have been identified. The authors estimated the prevalence and incidence of Parkinson's disease in a culturally diverse community in New York City over a 4-year period (January 1, 1988-December 31, 1991) using a disease registry substantiated, for older individuals, by a subsequent survey of a random sample of Medicare recipients between January 1, 1992, and December 31, 1993. The prevalence rate was 107 per 100,000 persons, and over a 3-year period the average incidence rate was 13 per 100,000 person-years. Age-adjusted prevalence rates were lower for women than for men in each ethnic group and were lower for blacks than for whites and Hispanics. Incidence rates were highest among black men, but they were otherwise comparable across the sex and ethnic groups. The estimated cumulative incidence of Parkinson's disease up to age 90 years was lower for women than for men, which could partially explain the lower prevalence rate. By ethnic group, the cumulative incidence was higher for blacks than for whites and Hispanics, but more deaths occurred among incident black cases. Discrepant prevalence and incidence rates of Parkinson's disease among blacks and women warrant further investigation. While selective mortality could partially account for this paradox, it is also possible that a delay in diagnosis due to limited access to appropriate health services among these individuals could have resulted in the observed discordant rates of disease.

Age Distribution↗
PubMed1995

The age at onset of Alzheimer's disease and an intracranial area measurement. A relationship.

OBJECTIVE: To examine the possibility that premorbid brain size may influence the age at onset of symptoms of Alzheimer's disease (AD). DESIGN: Retrospective case series. SETTING: Outpatients attending a memory disorders clinic in a tertiary referral center. PATIENTS: Twenty-eight female patients with the diagnosis of probable AD, selected for the availability of informant derived estimates of age at onset of symptoms and computed tomographic scans of the head satisfying angulation criteria. MAIN OUTCOME MEASURE: An average intracranial area of two adjacent computed tomographic scan sections appropriately angled was used as a correlate of premorbid brain size. Strict intracranial volume measurement was not performed. RESULTS: Age at onset of symptoms of AD correlated positively (r = .48, P = .009) with our measure of premorbid brain size. There was no confounding by education, height, or ethnicity. CONCLUSION: Premorbid brain size may be an important determinant of the age at onset of symptoms of AD. Epidemiologic studies of AD may need to assess the relationship between brain size and putative risk factors, eg, low educational attainment, since there is evidence that brain size is not distributed uniformly across populations.

Age of Onset↗
PubMed1995

Cerebral single-photon emission computed tomography abnormalities in human immunodeficiency virus type 1-infected gay men without cognitive impairment.

OBJECTIVE: To determine whether technetium Tc99m exametazime single-photon computed emission tomography (SPECT) can distinguish gay human immunodeficiency virus (HIV)-positive subjects, both with and without mild cognitive impairment, from gay HIV-negative control subjects. DESIGN: Twenty HIV-positive subjects (12 without cognitive impairment and eight with mild cognitive impairment) and 10 HIV-negative subjects underwent neurological, neuropsychological, magnetic resonance imaging, and technetium Tc 99m exametazime SPECT examinations. SETTING: Subjects were recruited from a natural history study of gay men with HIV infection. PATIENTS: Subjects from the cohort who had previously participated in a magnetic resonance imaging study were selected for the SPECT study. MAIN OUTCOME MEASURES: The SPECT scans were rated as abnormal if focal defects, confirmed by a horizontal profile analysis, were seen. RESULTS: Sixty-seven percent of HIV-positive subjects without cognitive impairment, 88% of HIV-positive subjects with mild cognitive impairment, and 20% of HIV-negative subjects had abnormal SPECT scans (P < .05 for both HIV-positive groups when each group was compared with HIV-negative subjects). CONCLUSION: Compared with gay HIV-negative control subjects, focal SPECT defects are seen with an increased frequency in HIV-positive gay men without cognitive impairment and in HIV-positive gay men with mild cognitive impairment.

AIDS Dementia Complex↗
PubMed1995

Serum neopterin level predicts HIV-related mortality but not progression to AIDS or development of neurological disease in gay men and parenteral drug users.

OBJECTIVE: To investigate the ability of elevated serum neopterin levels to predict independently mortality, progression to acquired immunodeficiency syndrome, and development of neurological disease. DESIGN: Cross-sectional and longitudinal study of gay and/or bisexual men and parenteral drug users. SETTING AND PATIENTS: Patients included human immunodeficiency virus (HIV)-negative and -positive gay and/or bisexual men and parenteral drug-using men and women who volunteered for an outpatient study of the natural history of HIV infection. RESULTS: Serum neopterin levels were significantly elevated in HIV-positive patients (mean, 18.0 nmol/L; SD, 19.2 nmol/L), compared with those in HIV-negative patients (mean, 7.5 nmol/L; SD, 5.5 nmol/L) (P < .001). No differences in the serum neopterin levels could be detected between gay men and parenteral drug users. In HIV-positive patients, women had a higher serum neopterin level than did men (P = .03). The elevated serum neopterin levels were associated with an advanced clinical stage of HIV infection. After adjusting for the CD4 lymphocyte count and other potential confounders, the serum neopterin level was a significant independent predictor of mortality. The elevated serum neopterin levels did not predict progression to acquired immunodeficiency syndrome or development of clinically significant neurological disease. CONCLUSION: An elevated serum neopterin level predicts mortality, but it does not predict progression to acquired immunodeficiency syndrome or development of neurological disease among HIV-infected individuals.

Acquired Immunodeficiency Syndrome↗
PubMed1995

The frequency and associated risk factors for dementia in patients with Parkinson's disease.

OBJECTIVES: To estimate the frequency and determine the risk factors for incident dementia in community-dwelling patients with Parkinson's disease (PD) and in control subjects. DESIGN: Prospective cohort study. During a 3.5-year period, 140 patients with idiopathic PD without evidence of dementia and 572 nondemented control subjects were identified in the community of Washington Heights-Inwood in New York, NY. All subjects underwent neurological and neuropsychological evaluations and follow-up examinations. RESULTS: Twenty-seven patients with PD (19.2%) became demented throughout 2 years, as compared with 87 (15.2%) of the control subjects. The relative risk (RR) for the development of dementia with PD was 1.7 (95% confidence interval [CI], 1.1 to 2.7) after adjusting for age, education, and gender. Predictive features of incident dementia were an extrapyramidal score greater than 25 (RR, 3.56; 95% CI, 1.4 to 8.9) and a Hamilton Depression Rating Scale score greater than 10 (RR, 3.55; 95% CI, 1.6 to 7.9). CONCLUSION: Patients with PD, especially those with severe extrapyramidal signs, have almost twice the risk for the development of dementia than do community-dwelling control subjects.

Aged↗
PubMed1995

A comparison of cerebral SPECT abnormalities in HIV-positive homosexual men with and without cognitive impairment.

OBJECTIVE: To determine whether technetium Tc 99m exametazime (HMPAO) single-photon emission computed tomography (SPECT) can distinguish between human immunodeficiency virus (HIV)-positive homosexual men with normal neuropsychologic test results and HIV-positive homosexual men with abnormal neuropsychologic test results. DESIGN: Neurologic, neuropsychologic, magnetic resonance imaging, and Tc 99m HMPAO SPECT examinations were performed on 10 HIV-positive homosexual men without cognitive impairment and five HIV-positive homosexual men with cognitive impairment. PATIENTS: Human immunodeficiency virus-positive homosexual men from New York City were recruited for the study. MAIN OUTCOME MEASURES: Findings on SPECT scans were evaluated qualitatively for focal defects, heterogeneity of the cortical margin, white matter hypoperfusion, and decreased global cortical uptake. All SPECT focal defects were coregistered with magnetic resonance images; SPECT heterogeneity and global cortical uptake were also measured quantitatively. RESULTS: Coregistration with magnetic resonance imaging revealed that 63% of the focal SPECT defects corresponded to brain gyri and 37% corresponded to sulci. There was no significant difference in the frequency of qualitative or quantitative SPECT abnormalities between HIV-positive homosexual men ith and without cognitive impairment. However, after examining individual neuropsychologic test factors, impaired motor speed performance was associated with decreased quantitative global cerebral uptake. CONCLUSIONS: Qualitative SPECT abnormalities are not increased in frequency in HIV-positive homosexual men with global cognitive impairment compared with those in HIV-positive homosexual men without cognitive impairment. Impaired motor speed performance may be associated with decreased quantitative global cerebral uptake.

Adult↗
PubMed1995

Differences in the prevalence of essential tremor among elderly African Americans, whites, and Hispanics in northern Manhattan, NY.

BACKGROUND: Until now there has been only one community-based study to examine interethnic differences in the prevalence of essential tremor (ET). The study suggested a higher prevalence among whites than African Americans. The present study is the first to examine differences in the prevalence of ET among Hispanics, African Americans, and whites. OBJECTIVE: To estimate the prevalence of essential tremor (ET) in a cohort of community-dwelling elderly of mixed ethnic background. METHODS: A random sample of 2117 Medicare recipients residing in Washington Heights-Inwood in northern Manhattan, NY, were interviewed. A standardized neurological assessment was performed on those who had neurological complaints and on a random sample of those who did not. Essential tremor was defined as a postural or kinetic tremor of the head or limbs. Diagnoses were independently confirmed by two neurologists based on videotaped examination. RESULTS: After age adjustment to the 1990 Washington Heights-Inwood census, the prevalence of ET was 40.2 per 1000 (95% confidence interval, 31.8 to 48.6). Among 46 cases with ET, ET was significantly more prevalent in men than in women (chi 2 = 5.0, P = .03). Prevalence increased significantly with age. The prevalence was higher in whites than African Americans. The prevalence in Hispanics was intermediate. CONCLUSION: The prevalence of ET increases with age and may be higher among men and whites. Prospective studies are needed to further examine these associations.

Black or African American↗
PubMed1995

Apolipoprotein E and Alzheimer's disease: ethnic variation in genotypic risks.

The presence of the apolipoprotein epsilon 4 (apo epsilon 4) allele significantly increases the risk of Alzheimer's disease. Whether this is due to biological effects of the apo epsilon 4 protein or reflects linkage disequilibrium with an as yet unidentified Alzheimer's disease susceptibility gene is of critical importance. In a community study in northern Manhattan we found a fivefold increase in the risk of Alzheimer's disease among African-Americans, Hispanics, and whites homozygous for apo epsilon 4. Overall, the risk between Alzheimer's disease and apo epsilon 4 heterozygosity was also increased by twofold, but the association was somewhat weaker for African-Americans than for Hispanics and whites. In contrast, the apo epsilon 2/epsilon 3 genotype was associated with an eightfold increased risk of Alzheimer's disease in African-Americans but it was associated with reduced risk in whites. Variability in the strength and type of association between Alzheimer's disease and the apo E polymorphisms in the three ethnic groups could not be fully explained by age differences. The allelic frequency of apo epsilon *4 was significantly higher in patients than control subjects in all ethnic groups at age 70 or younger, reflecting the higher proportion of apo epsilon 4 homozygotes, but this difference diminished with increasing age. The allelic frequency of apo epsilon *2 for African-Americans and Hispanics, but not whites, was significantly higher in patients than control subjects, but only after age 70.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

Increased risk of mortality in Alzheimer's disease patients with more advanced educational and occupational attainment.

A reserve hypothesis suggests that clinical symptoms of Alzheimer's disease (AD) begin earlier in individuals with less education. Therefore, patients with less education might survive longer after diagnosis than those with more education. Two hundred forty-six subjects with probable AD were followed for 1 to 4 years. There were 78 deaths; 30 deaths occurred in the 127 patients whose education was < or = 8 years, while 48 deaths occurred in the 119 patients with > 8 years of education. Cox proportional hazards models adjusted for age, gender, and clinical dementia rating (CDR) showed that patients with more education had increased mortality (continuous variable: RR = 1.06 for each year of education; 95% confidence interval [CI], 1.01-1.11; dichotomous variable at 8 yr: RR = 1.76; CI, 1.11-2.77). This observation might at first seem counterintuitive, since groups with lower socioeconomic status are often at greater mortality risk. It implies that at any level of assessed clinical severity, the underlying pathology of AD is more advanced in patients with more education, resulting in shorter duration of diagnosed disease before death. These findings suggest either that education systematically influences global ratings of disease severity or that education provides a reserve against the clinical manifestation of AD pathology.

Aged↗
PubMed1995

A flexible system of detection for Alzheimer's disease and related dementias.

Brief methods for detecting Alzheimer's disease and related dementias (ADRD) are widely used in epidemiological and clinical research, and, increasingly, for clinical purposes in health care settings, such as primary medical care and geriatric evaluation and management (GEM) units. There are many instruments from which to choose for these purposes, but they have generally been developed in isolation. Little is known about the gains in precision (incremental validity) from using more than one instrument in an integrated manner in the process of detection, nor has there been a systematic evaluation of the usefulness of being able to choose from a repertoire of instruments to suit specific screening contexts. The key characteristics of the techniques featured here, namely, brevity and ease of administration, allow such assessments to find a place in many different contexts. This paper presents findings supporting specific recommendations for a limited battery of brief screening techniques for detection of dementia, that can be tailored, standing alone or in combinations, to optimally suit particular requirements of (i) precision, or (ii) style of administration.

Alzheimer Disease↗
PubMed1995

Simple reaction time as a measure of global attention in Alzheimer's disease.

Alzheimer's disease (AD) is characterized by progressive decline in memory, language and other cognitive functions. Deficits in attentional processes have also been suggested. A simple reaction time (RT) task was used to assess global attention in AD. The length and consistency of a warning signal given prior to the response stimulus were manipulated to determine if patients with AD and age-matched controls benefit from predictability in RT tasks. Overall reaction time was slower in the AD group than in the and control group. Both groups demonstrated significant improvement in RT with long warning signals compared to short warning signals, but only the control group benefited from the consistency of the warning.

Aged↗
PubMed1995

Cortical perfusion and gray matter weight in frontal lobe dementia.

To evaluate the pathophysiology of frontal lobe dementia (FLD), the authors compared regional cerebral blood flow (rCBF) in matched groups of FLD, probable Alzheimer's disease (AD), and major depression patients and normal control subjects (n = 7 each). The planar xenon-133 technique allowed full quantification of cortical perfusion and estimates of the relative weight of gray matter (wg). FLD patients showed lower blood flow and wg in the frontal cortex than the other groups. Mean cortical perfusion was correlated with cortical wg in the FLD group only. These findings 1) suggest that matched reductions of frontal gray matter weight and perfusion occur in FLD and 2) support the use of rCBF in distinguishing FLD from AD and severe depression.

Aged↗
PubMed1995

Relationship between lifetime occupation and parietal flow: implications for a reserve against Alzheimer's disease pathology.

We previously reported an inverse relation between parietal cerebral blood flow and years of education in Alzheimer's disease (AD) patients matched for clinical severity. This suggested that the clinical manifestation of advancing AD pathology is delayed in patients with higher educational attainment. Other aspects of life experience may also provide a reserve against the clinical expression of AD. To test this hypothesis, we classified the primary life-time occupations of 51 AD patients using the Dictionary of Occupational Titles, published by the US Department of Labor, and derived six factor scores describing intellectual, interpersonal, and physical job demands. Regional cerebral blood flow was measured using the xenon-133 inhalation method. After controlling for age, clinical dementia severity, and education, there was less relative perfusion in the parietal region in subjects whose occupations were associated with higher interpersonal skills and physical demands factor scores. We conclude that independent of education, aspects of occupational experience may provide a reserve that delays the clinical manifestation of AD.

Administration, Inhalation↗
PubMed1995

Consistency of clinical diagnosis in a community-based longitudinal study of dementia and Alzheimer's disease.

We evaluated the consistency of the diagnosis of dementia in a multicultural, longitudinal community-based study of cognitive impairment and dementia. We diagnosed dementia using a fixed neuropsychological paradigm; the diagnosis also required historical evidence of functional impairment. In a sample of 656 subjects with at least one annual follow-up examination, dementia was confirmed at 1 year in 89% of the 304 subjects initially demented, and in 90% of the 136 subjects with the initial diagnosis of probable Alzheimer's disease (AD). The 34 initially demented subjects who failed to meet criteria for dementia at follow-up included 13 with an initial diagnosis of probable AD. All 34 still had evidence of cognitive impairment; this group was more likely to have a history of pulmonary disease, multiple medication use, or chronic alcohol use than other demented patients. Consistency of dementia diagnosis did not vary according to educational attainment or ethnic background. The use of a neuropsychological paradigm such as ours in large longitudinal studies of dementia may minimize interobserver diagnostic variability or diagnostic drift over time while contributing the benefits of a comprehensive cognitive evaluation to the diagnostic process.

Aged↗