Biomedical subjects

Y Stern

Publications and source records attributed to Y Stern.

At least 37 records · Page 2Linked to original sources

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↗

PubMed2001

Selective deficits in verbal working memory associated with a known genetic etiology: the neuropsychological profile of duchenne muscular dystrophy.

Forty-one boys diagnosed with Duchenne muscular dystrophy (DMD) were each compared to an unaffected sibling on a battery of neuropsychological tests. Verbal. visuospatial, attention/memory, abstract thinking, and academic achievement skills were tested. Results indicated the boys with DMD performed similarly to their siblings on the majority of measures, indicating intact verbal, visuospatial, long-term memory, and abstract skills. However, the DMD group did significantly more poorly than their siblings on specific measures of story recall, digit span, and auditory comprehension, as well as in all areas of academic achievement (reading, writing, and math). This profile indicates that verbal working memory skills are selectively impaired in DMD, and that that likely contributes to limited academic achievement. The association between the known impact of the genetic mutation on the development of the central nervous system and boys' cognitive profile is discussed.

Adolescent↗

PubMed2001

Circuit mechanisms underlying memory encoding and retrieval in the long axis of the hippocampal formation.

Circuits within the hippocampal formation are active during memory processing. Here we used functional magnetic resonance imaging (fMRI) to examine multiple sites across the long axis of the hippocampal formation while subjects performed different phases of an associative memory task, learning to associate faces with names. Viewing faces and hearing names in isolation resulted in separate hippocampal activation patterns. Pairing faces with names resulted a spatially redistributed activation pattern, rather than a simple summation of the activation patterns resulting from viewing faces and hearing names in isolation. Recalling names when cued with faces reactivated a pattern similar to that found during paired training. Finally, the activation patterns representing faces and names were found to be experience dependent, emerging with repeated exposure. Interpreted in the context of hippocampal anatomy and physiology, these findings reveal hippocampal circuit mechanisms that underlie memory encoding and retrieval.

Adult↗

PubMed2001

Persistent mobility deficit in the absence of deficits in activities of daily living: a risk factor for mortality.

OBJECTIVES: To investigate the extent to which self-reported mobility deficit in the absence of impairment in activities of daily living (ADL) is associated with elevated mortality risk. DESIGN: Prospective cohort study, with annual assessments of mobility and ADL status and ongoing monitoring of vital status. SETTING: Population-based cohort drawn from Medicare enrollees in New York City. PARTICIPANTS: One thousand two hundred ninety-eight older adults reporting functional status at baseline (1992-1994) and 2 years later. MEASUREMENTS: Subjects reported mobility (e.g., walking, climbing stairs, and rising from a chair) and ADL (e.g., bathing, toilet use, dressing, grooming, and feeding) limitations. Two-year functional status trajectories were noted. We used two additional follow-up periods, at 2 and 4 years, to examine the likelihood that older people with mobility deficit may face an increased risk of death without first passing through a state of enduring ADL disability. RESULTS: At 2 years, 12.7% had incident mobility deficit without ADL disability, and 21.3% were persistently disabled in mobility without ADL disability. Relative to subjects free of disability at baseline and follow-up, risk of mortality in the incident mobility deficit group was elevated at 2 and 4 years but did not achieve statistical significance. By contrast, for subjects with persistent mobility impairment who did not report ADL impairment, the mortality risk was significantly elevated both at 2 years (relative risk (RR) = 2.5; 95% confidence interval (CI) = 1.1-5.7)) and 4 years (RR = 2.9; 95% CI = 1.7-4.9)) of follow-up. Mortality was significantly elevated in this group in analyses restricted to respondents with no or only one comorbid condition. CONCLUSION: Continuing, self-reported mobility impairment in the absence of ADL deficit is a risk factor for mortality. Older people with self-reported mobility deficit face an increased risk of mortality without first passing through enduring states of ADL disability.

Activities of Daily Living↗

PubMed2001

Neuropsychological test performance: a study of non-Hispanic White elderly.

This study examined within-group differences in neuropsychological test performance between US versus foreign-born English-speaking White elders. Participants included 193 randomly selected English-speaking elderly community residents who self-identified as non-Hispanic White. Participants were classified as US (n = 106) or foreign-born (n = 87). All participants were independently diagnosed by a physician as nondemented. After controlling for years of education, participants born in the United States obtained significantly higher scores on measures of verbal abstract reasoning, naming, and fluency than foreign-born elders. These results suggest that although non-Hispanics White are often treated as a homogeneous group, performance differences exist even within this group. Effects of acculturation level and language use on cognitive styles may help explain these findings.

Aged↗

PubMed2001

Predictor index of mortality in dementia patients upon entry into long-term care.

BACKGROUND: The purpose of this study was to develop an algorithm that predicts survival in patients with dementia upon entry into long-term care. There are, as yet, no predictive equations developed for those in the late stages of Alzheimer's disease (AD). METHODS: This was a prospective, observational study of 132 patients with dementia (61% with AD) followed for up to 5.0 years (median of 41.0 months) after admission to a long-term care facility for dementia patients. Information on demographic characteristics, physical health, and cognitive, emotional, and behavioral characteristics was collected shortly after admission and entered as predictors of time until death in Cox regressions. Findings were used to derive an index predicting mortality. RESULTS: There were 60 deaths among the 132 patients (45.4% mortality), with an average survival of 22.4 months in those who died. Better physical health and the presence of delusions were associated with longer survival. These two variables were aggregated into the Copper Ridge Index (CRI). Each one-point increase on the CRI was associated with a four-fold greater likelihood of death over 5 years. CONCLUSIONS: A predictive equation incorporating measures of general physical health and delusions accurately predicted time to death in dementia patients in long-term care.

Aged↗

PubMed2001

Serum S100B protein levels are correlated with subclinical neurocognitive declines after carotid endarterectomy.

OBJECTIVE: Carotid endarterectomy (CEA) is an effective means of stroke prevention among appropriately selected patients; however, neuropsychometric testing has revealed subtle cognitive injuries in the early postoperative period. The purpose of this study was to establish whether serum levels of two biochemical markers of cerebral injury were correlated with postoperative declines in neuropsychometric test performance after CEA. METHODS: Fifty-five consecutive patients underwent a battery of neuropsychometric tests 24 hours before and 24 hours after elective CEA. Two patients were excluded because of postoperative strokes. The pre- and postoperative serum levels of S100B protein and neuron-specific enolase for injured patients, defined as those who exhibited significant declines in neuropsychometric test performance (n = 12), were compared with the levels for uninjured patients (n = 41). RESULTS: There were no significant differences in the baseline S100B levels for the two groups. Injured patients exhibited significantly higher S100B levels, compared with uninjured patients, at 24, 48, and 72 hours after surgery (P < 0.05). There were no significant differences in neuron-specific enolase levels for injured and uninjured patients at any time point. CONCLUSION: These data suggest that subtle cerebral injuries after CEA, even in the absence of overt strokes, are associated with significant increases in serum S100B but not neuron-specific enolase levels. Analyses of earlier time points in future studies of subtle cognitive injuries and biochemical markers of cerebral injury after CEA may be revealing.

Aged↗

PubMed2001

Overcoming the language barrier in visual field testing.

PURPOSE: To evaluate the effect of using recorded instructions in patients' native language compared with interpreter-assisted instructions on the reliability and duration of the visual field test. PATIENTS AND METHODS: Sixty patients referred for visual field testing were included in the study. Thirty-five had limited or no knowledge of the Hebrew language, and 25 control patients were fluent in Hebrew, the native language. None had previous experience with automated perimetry. Patients were randomized to receive recorded instructions on the visual field test in their native language or translator-assisted instructions by the technician before performing the test. For each patient, the time required for instructions and test performance and the reliability indices were documented. RESULTS: The method of instruction (recorded or interpreter-assisted) did not affect the time required for patient instructions (66 +/- 24 seconds and 57 +/- 30 seconds, respectively), the time for test performance (7.2 +/- 1.5 minutes and 7.8 +/- 1.8 minutes, respectively), and test reliability as measured by the rate of fixation losses. Regardless of the method of explanation, the time required for instructions and for performing the test were significantly shorter for Hebrew speakers than for non-Hebrew speakers. CONCLUSION: The use of a recorded explanation in the patient's native language before visual field testing is an applicable method for patient instruction. Clinics in areas with multilingual populations may use this method to save technicians time, without adversely affecting the time required for performing the test and its reliability.

Aged↗

PubMed2001

Cognitive correlates of obsessive and compulsive symptoms in Huntington's disease.

OBJECTIVE: The authors' goal was to examine the frequency and type of obsessive and compulsive symptoms in Huntington's disease. METHOD: The Yale-Brown Obsessive Compulsive Scale was used to assess obsessive and compulsive symptoms in 27 patients with Huntington's disease. The neuropsychological test performance of the 14 patients with at least one obsessive symptom and the seven patients with at least one compulsive symptom was compared with the performance of the patients without such symptoms. RESULTS: More than half of the patients with Huntington's disease endorsed obsessive or compulsive symptoms on the Yale-Brown scale. Patients with obsessive or compulsive symptoms showed significantly greater impairment on neuropsychological tests measuring executive function than those without such symptoms. CONCLUSIONS: Basal ganglia pathology in Huntington's disease may contribute to production of obsessive and compulsive symptoms and to executive performance deficits in these patients.

Analysis of Variance↗

PubMed2001

Role of laryngoscopy, dual pH probe monitoring, and laryngeal mucosal biopsy in the diagnosis of pharyngoesophageal reflux.

There is no standard for determining significant pharyngoesophageal reflux. This prospective blind comparison study compared dual pH probe studies, direct laryngoscopy, and mucosal biopsy in children without symptoms of gastroesophageal reflux who underwent airway evaluation. Significant reflux to the lower esophageal probe did not correlate with statistical significance with reflux to the upper probe. In this group of asymptomatic patients, a positive lower pH probe finding did not correlate with upper or lower esophageal mucosal inflammation. Eosinophilia in the esophageal mucosa is diagnostic of gastroesophageal reflux disease, and was seen in 5 of the laryngeal biopsies. A weak correlation was seen between positive findings at laryngoscopy and positive posterior cricoid biopsy in this group. There may be no consistent way to predict significant pharyngoesophageal reflux in asymptomatic patients. Single-probe pH testing will not predict significant pharyngoesophageal reflux with mucosal changes. Laryngoscopy and upper pH probe findings only weakly correlate with significant histologic findings. Laryngeal and posterior cricoid biopsy may be the only sensitive test for mucosal injury. Clinical trials of empiric antireflux therapy should be used to determine whether the laryngeal changes seen in these patients are reversible.

Biopsy↗

PubMed2001

Cognitive correlates of mnemonics usage and verbal recall memory in old age.

OBJECTIVES: The objectives of this study were to determine whether minimizing requisite processing resources to learn a word list would differentially improve recall of older adults and to examine the associations between memory and nonmemory cognitive abilities. BACKGROUND: It has been hypothesized that a reduction in general processing resources contributes to age-related declines in memory and other cognitive abilities. METHODS: Twenty-four young adults and 47 older adults were administered two semantically related word lists, one list with words blocked into their categories and the other with categories intermixed. Tests of attention and working memory, language, and abstract reasoning were interspersed with the memory tasks. Participants were classified as young (age range: 17-30 years), young-old (age range: 65-73 years), and old-old (age range: 74-87 years) to compare the effects of list condition (i.e., blocked vs. unblocked) on recall performance. Correlation and regression analyses were used to examine the cognitive correlates of recall performance. RESULTS: Expected age differences in recall performance were observed. Based on the resource-reduction hypothesis of cognitive aging, we hypothesized that the blocked presentation of the to-be-remembered list would minimize processing demands and therefore differentially benefit recall in older elderly participants. Contrary to our prediction, however, the relative benefits of blocked list presentation on recall measures were comparable for young and older participants. Correlations and regression analyses revealed that recall performance was more strongly associated with word finding ability than with working memory or abstract reasoning skills. CONCLUSIONS: Results suggest that level of recall of a semantically related word list and use of semantic clustering as an encoding strategy are associated more strongly with general word finding skills than with processing capacity.

Adolescent↗

PubMed2001

Longitudinal study of quality of life in people with advanced Alzheimer's disease.

The authors examined three indicators of health-related quality of life in people with advanced Alzheimer's disease ([AD]; N=150): confinement to home, null activity, and null positive affect, as reported by patient proxies. Dementia severity predicted time-to-onset for all three disease milestones in models that controlled for sociodemographic indicators, nursing home status, and death in the follow-up period. Patients whose dementia worsened over follow-up were more likely to reach each milestone. These outcomes represent key milestones in the care of patients; they are sensitive to disease progression, and they are likely to be useful for studying treatment in advanced AD.

Activities of Daily Living↗

PubMed2000

Different brain networks mediate task performance in normal aging and AD: defining compensation.

OBJECTIVE: To determine whether the pathologic mechanisms of AD alter the brain networks subserving performance of a verbal recognition task. BACKGROUND: Functional imaging studies comparing task-related activation in AD patients and controls generally have not used network analysis and have not controlled for task difficulty. METHODS: H2 15O PET was used to measure regional cerebral blood flow in 14 patients and 11 healthy elders during the performance of a serial verbal recognition task under two conditions: low demand, with study list size (SLS) equal to one; and titrated demand, with SLS adjusted so that each subject recognized words at 75% accuracy. The Scaled Subprofile Model was used to identify networks of regionally covarying activity across these task conditions. RESULTS: In the elders, higher SLS was associated with the recruitment of a network of brain areas involving left anterior cingulate and anterior insula (R2 = 0.94; p < 0.0001). Three patients also expressed this network. In the remaining patients, higher SLS was associated with the recruitment of an alternate network consisting of left posterior temporal cortex, calcarine cortex, posterior cingulate, and the vermis (R2 = 0.81, p < 0.001). Expression of this network was unrelated to SLS in the elders and more intact AD patients. CONCLUSIONS: The patients' use of the alternate network may indicate compensation for processing deficits. The transition from the normal to the alternate network may indicate a point where brain disease has irreversibly altered brain function and thus may have important implications for therapeutic intervention.

Aged↗

PubMed2000

Evaluating the function of hippocampal subregions with high-resolution MRI in Alzheimer's disease and aging.

Memory ability declines in older age groups. There is a growing list of physiological processes that target the hippocampal formation in an age-related fashion, and some might underlie the hippocampal component of memory decline. The hippocampal formation is comprised of separate subregions, and physiological processes differentially target these subregions. The ability to evaluate the functional integrity of individual subregions-performing subregional analysis-is a major clinical goal since it can aid in the diagnosis of memory decline, as well as in elucidating mechanisms of disease and testing potential interventions. Because of its superior spatial resolution, magnetic resonance imaging (MRI) is best suited to accomplish this goal. Despite limited success, most functional MRI (fMRI) protocols have difficulty in performing complete subregional analysis of the hippocampal formation. Here we address sources of difficulty by (1) generating T2* -weighted maps of the hippocampal formation with sub-millimeter resolution; and (2) by adapting an approach used by animal investigators to identify the hippocampal subregions using anatomical landmarks. The protocol is tested in patients with Alzheimer's disease and in healthy controls, in an effort to determine whether it can detect neuronal dysfunction. Results showed diminished signal in the hippocampal formation of patients with Alzheimer's disease (AD) compared to controls, and multivariate analysis showed that this difference was most prominent in the entorhinal cortex. The protocol can be used to perform subregional analysis of the hippocampal formation. Testing the protocol in other clinical populations is needed to demonstrate its efficacy in evaluating the neuronal integrity of all hippocampal subregions.

Aged↗

PubMed2000

Motor impairment in PD: relationship to incident dementia and age.

OBJECTIVE: To analyze the relationship of specific motor impairment in idiopathic PD to incident dementia. BACKGROUND: The total Unified PD Rating Scale (UPDRS) motor score at baseline has been associated with an increased risk of developing dementia in PD. METHODS: A cohort of 214 nondemented community-dwelling patients with PD was followed annually with neurologic and neuropsychological evaluations. The association of baseline motor impairment with incident dementia was analyzed using Cox proportional hazards models. Facial expression, tremor, rigidity, and bradykinesia were analyzed as part of subscore A (indicative of dopaminergic deficiency); speech and axial impairment were analyzed as part of subscore B (indicative of predominantly nondopaminergic deficiency). The correlation between the six motor domains and age was also analyzed. RESULTS: Of 173 patients followed for at least 1 year, 50 became demented according to the Diagnostic and Statistical Manual of Mental Disorders, revised 3rd edition (DSM III-R) criteria (mean follow-up, 3.6 +/- 2. 2 years). When both subscores A and B were entered into the Cox model, subscore B was associated with incident dementia (relative risk = 1.19; 95% CI, 1.09 to 1.30; p = 0.0001), in addition to gender, age, and education, whereas subscore A was not (relative risk = 1.03; 95% CI, 0.99 to 1.07; p = 0.19). Of the six motor domains, speech and bradykinesia were associated with incident dementia (p < 0.05), and axial impairment approached significance (p = 0.06). Only axial impairment was correlated with age (correlation coefficient = 0.32; p < 0.001). CONCLUSION: The findings suggest that motor impairment mediated predominantly by nondopaminergic systems is associated with incident dementia in PD. Axial impairment may be the result of a combined effect of the disease and the aging process.

Age Factors↗

PubMed2000

Poor verbal working memory across intellectual level in boys with Duchenne dystrophy.

OBJECTIVE: To determine whether all boys with Duchenne muscular dystrophy (DMD) have a similar verbal and memory profile of skills, or whether only a subset is affected, and to determine whether the weak areas in their profile are substantially different from a control group. METHODS: Performance of patients with DMD on neuropsychological tests of verbal and memory skills was examined in two ways. Standardized test scores for 80 boys with DMD (estimated IQ range, 70 to 160) were ranked individually from worst to best, and the individual rankings were compared across the group using Friedman rank analysis. Additionally, performance of 41 boys with DMD was compared with that of their sibling control subjects of similar age and estimated IQ using multivariate analysis of variance. RESULTS: Individual cognitive profiles were significantly similar among the subjects with DMD, such that for most subjects digit span, story recall, and comprehension were the tests on which each performed most poorly. This finding remained true regardless of whether they were of high or low intellectual function. In contrast, no significant cognitive profile was found among their sibling control subjects, and when compared with their siblings, the DMD group scored significantly more poorly on digit span, comprehension, and story recall, but not on other verbal and memory measures. CONCLUSIONS: Boys with DMD have a specific cognitive profile, regardless of their general level of cognitive function. Specifically, boys with DMD performed more poorly on tests requiring attention to complex verbal information than they did on other verbal or memory measures. The possibility that the missing dystrophin brain products may contribute to selective cognitive processing is considered.

Adolescent↗

PubMed2000

Frequency and clinical determinants of dementia after ischemic stroke.

OBJECTIVE: To investigate the frequency and clinical determinants of dementia after ischemic stroke. METHODS: The authors administered neurologic, neuropsychological, and functional assessments to 453 patients (age 72.0 +/- 8.3 years) 3 months after ischemic stroke. They diagnosed dementia using modified Diagnostic and Statistical Manual of Mental Disorders, 3rd ed., revised criteria requiring deficits in memory and two or more additional cognitive domains as well as functional impairment. RESULTS: The authors diagnosed dementia in 119 of the 453 patients (26.3%). Regarding dementia subtypes, 68 of the 119 patients (57.1%) were diagnosed with vascular dementia, 46 patients (38.7%) were diagnosed with AD with concomitant stroke, and 5 patients (4.2%) had dementia for other reasons. Logistic regression suggested that dementia was associated with a major hemispheral stroke syndrome (OR 3.0), left hemisphere (OR 2.1) and right hemisphere (OR 1.8) infarct locations versus brainstem/cerebellar locations, infarcts in the pooled anterior and posterior cerebral artery territories versus infarcts in other vascular territories (OR 1.7), diabetes mellitus (OR 1.8), prior stroke (OR 1.7), age 80 years or older (OR 12.7) and 70 to 79 years (OR 3.9) versus 60 to 69 years, 8 or fewer years of education (OR 4.1) and 9 to 12 years of education (OR 3.0) versus 13 or more years of education, black race (OR 2.6) and Hispanic ethnicity (OR 3.1) versus white race, and northern Manhattan residence (OR 1.6). CONCLUSIONS: Dementia is frequent after ischemic stroke, occurring in one-fourth of the elderly patients in the authors' cohort. The clinical determinants of dementia include the location and severity of the presenting stroke, vascular risk factors such as diabetes mellitus and prior stroke, and host characteristics such as older age, fewer years of education, and nonwhite race/ethnicity. The results also suggest that concomitant AD plays an etiologic role in approximately one-third of cases of dementia after stroke.

Aged↗

PubMed2000

Familial aggregation of Alzheimer disease among whites, African Americans, and Caribbean Hispanics in northern Manhattan.

BACKGROUND: Alzheimer disease (AD) aggregates in families. OBJECTIVE: To compare the familial aggregation and lifetime risk of AD to the age of 90 years in the first-degree relatives of patients with AD and unrelated controls among Caribbean Hispanics, African Americans, and whites in Washington Heights, Manhattan, New York, NY. METHODS: Family history of AD and demographic information were obtained from informants of 435 patients with probable or possible AD concerning 1577 siblings and parents and from 1094 controls without dementia concerning 3952 siblings and parents. RESULTS: Lifetime risk of AD to the age of 90 years was 25.9% in relatives of patients and 19.1% in relatives of controls. Rate ratio (RR) for AD in relatives of patients compared with relatives of controls was 1.5 overall (95% confidence interval [CI], 1.2-1.9), and was greater for siblings (RR, 1.8; 95% CI, 1.2-2.5) than for parents (RR, 1.2; 95% CI, 0.9-1.8). Within ethnic groups, RR for AD among relatives was significantly elevated in whites (RR, 2.0; 95% CI, 1.2-3.3) and Hispanics (RR, 1.5; 95% CI, 1.1-2.1), but the difference did not reach statistical significance in African Americans (RR, 1.4; 95% CI, 0.7-2.7). Risk of AD was greater among relatives who were women compared with men (RR, 1.5; 95% CI, 1.2-1.9). CONCLUSIONS: Familial aggregation of AD was increased among families of patients compared with those of controls in all 3 ethnic groups. Risk of AD was highest among siblings and women relatives.

Aged↗