Biomedical subjects

Marilyn Albert

Publications and source records attributed to Marilyn Albert.

24 records · Page 2Linked to original sources

PubMed2003

Putting names to faces: successful encoding of associative memories activates the anterior hippocampal formation.

The ability to form associations between previously unrelated items of information, such as names and faces, is an essential aspect of episodic memory function. The neural substrate that determines success vs. failure in learning these associations remains to be elucidated. Using event-related functional MRI during the encoding of novel face-name associations, we found that successfully remembered face-name pairs showed significantly greater activation in the anterior hippocampal formation bilaterally and left inferior prefrontal cortex, compared to pairs that were forgotten. Functional connectivity analyses revealed significant correlated activity between the right and left hippocampus and neocortical regions during successful, but not attempted, encoding. These findings suggest that anterior regions of the hippocampal formation, in particular, are crucial for successful associative encoding and that the degree of coordination between hippocampal and neocortical activity may predict the likelihood of subsequent memory.

Adult↗

PubMed2003

Psychopathological features in Alzheimer's disease: course and relationship with cognitive status.

OBJECTIVES: To examine the course, clinical correlates, and relationship between cognitive status and psychopathological features in patients with probable Alzheimer's disease (AD) followed over a 5-year period. DESIGN: Cohort study with follow-up of 5 years. SETTING: Patients were recruited at three sites: 91 patients at Columbia Medical Center, 84 at Johns Hopkins School of Medicine, and 61 at Massachusetts General Hospital. PARTICIPANTS: Patients diagnosed with probable AD (n = 236) enrolled in a longitudinal study (Predictors study). MEASUREMENTS: Wandering/agitation, physical aggression, hallucinations, and delusions were evaluated at 6-month intervals using the Columbia Scale for Psychopathology in Alzheimer's Disease. Descriptive analyses were used to provide estimates of prevalence and course of psychopathological features. General estimating equations determined the odds of having any of the four psychopathological behaviors as a function of cognitive status. Markov analyses provided 6-month transition probabilities for psychopathological behaviors given patients' cognitive status and the presence or absence of such behaviors in the previous evaluation. RESULTS: For wandering/agitation, prevalence (39-57%) and persistence increased as a function of time and decrement in cognitive status. Physical aggression was less prevalent (6-22%) and increased as a function of cognitive decline but tended to persist only in the more severely impaired patients. Delusions (34-49%) reached a peak at the second year and then declined. The odds of delusions were maximal with intermediate decline but remained persistent regardless of cognitive status. Hallucinations, despite some fluctuations, were relatively stable during the follow-up period (8-17%) and moderately persistent. CONCLUSION: Psychopathological features, particularly wandering/agitation and delusions, in AD were common throughout the disease course. The natural history and persistence of the four psychopathological features varied. These findings provide important information to clinicians and caregivers regarding the course, predictability, and possible treatment of psychopathological behaviors in patients with probable AD.

Aged↗

PubMed2002

Whole brain segmentation: automated labeling of neuroanatomical structures in the human brain.

We present a technique for automatically assigning a neuroanatomical label to each voxel in an MRI volume based on probabilistic information automatically estimated from a manually labeled training set. In contrast to existing segmentation procedures that only label a small number of tissue classes, the current method assigns one of 37 labels to each voxel, including left and right caudate, putamen, pallidum, thalamus, lateral ventricles, hippocampus, and amygdala. The classification technique employs a registration procedure that is robust to anatomical variability, including the ventricular enlargement typically associated with neurological diseases and aging. The technique is shown to be comparable in accuracy to manual labeling, and of sufficient sensitivity to robustly detect changes in the volume of noncortical structures that presage the onset of probable Alzheimer's disease.

Aged↗

PubMed2002

Longitudinal assessment of patient dependence in Alzheimer disease.

BACKGROUND: The Dependence Scale measures the amount of assistance patients with dementia require in performing daily activities. Validity and reliability of this scale have been demonstrated, but the progression throughout long periods in patients with Alzheimer disease (AD) has not previously been examined. OBJECTIVE: To determine the longitudinal course of patient dependence in a cohort of prospectively followed AD patients. METHODS: Two hundred thirty AD patients enrolled in the Predictors Study were followed up prospectively at 6-month intervals for an average of 6.5 visits. The Dependence Scale was administered to a caregiver, and patients were assessed with the modified Mini-Mental State Examination (mMMSE) and the Blessed Dementia Rating Scale. Dependence level and the additive sum of the Dependence Scale items were considered for analysis. RESULTS: Generalized estimating equations to regression analyses were used to determine that both Dependence Scale scores and dependence level significantly decline with time. By covarying mMMSE scores and self-care deficits factor scores of the Blessed Dementia Rating Scale, generalized estimating equations analysis also demonstrated that change in patient dependence was independent of global cognitive decline and other measures of activities of daily living, respectively. CONCLUSIONS: This study shows the validity of the Dependence Scale and demonstrated that dependency in AD significantly declines with time independent of global cognition and other self-care deficits. The scale is a valuable instrument for outcomes research, efficacy trials, and behavioral research in AD.

Activities of Daily Living↗

PubMed2001

Functional MRI detection of pharmacologically induced memory impairment.

To examine alterations in brain activation associated with pharmacologically induced memory impairment, we used functional MRI (fMRI) to study the effects of lorazepam and scopolamine on a face-name associative encoding paradigm. Ten healthy young subjects were scanned on four occasions, 2 weeks apart; they were administered i.v. saline during two placebo-scanning sessions and then alternately administered i.v. lorazepam (1 mg) or scopolamine (0.4 mg) in a double-blind, randomized, cross-over design. Both the extent and magnitude of activation within anatomic regions of interest (ROIs) were examined to determine the reproducibility of activation in the placebo sessions and the regional specificity of the pharmacologic effects. Activation within all ROIs was consistent across the two placebo scans during the encoding of novel face-name pairs (compared with visual fixation). With the administration of either lorazepam or scopolamine, significant decreases were observed in both the extent and magnitude of activation within the hippocampal, fusiform, and inferior prefrontal ROIs, but no significant alterations in activation in the striate cortex were found. Both medications impaired performance on postscan memory measures, and significant correlations between memory performance and extent of activation were found in hippocampal and fusiform ROIs. These findings suggest that pharmacologic effects can be detected with fMRI by using a reproducible experimental paradigm and that medications that impair memory also diminish activation in specific brain regions thought to subserve complex memory processes.

Adult↗

PubMedDate not supplied

Psychiatric symptomatology and prodromal Alzheimer's disease.

The aim of this study was to determine the prevalence of psychiatric symptoms among nondemented individuals with memory changes and whether such symptoms predict progression of functional decline or diagnosis of Alzheimer disease (AD). A semi-structured interview was administered at baseline to controls (n = 32) and to nondemented subjects with memory changes (n = 112) and to each subject's collateral source. The interview assessed the impact of cognition on functional abilities in daily life and a variety of psychiatric symptoms, including symptoms of psychosis, depression, and personality change. Participants were followed annually for 3 years to determine who had progressive functional decline and who progressed to meet clinical criteria for AD. Those diagnosed with AD on follow-up had more symptoms of personality change, such as agitation and passivity, at baseline than those who did not progress to meet clinical criteria for AD. Mild depressive symptoms were also more common among individuals at baseline who subsequently 'converted' to AD. Symptoms of personality change were associated with a more rapid increase in functional difficulty over time, whereas depressive symptoms were not. Changes in personality are more common among subjects with memory changes who go on to develop AD. Particular types of personality change, such as agitation and passivity, are related to progression of functional difficulty over time. Depressive symptoms, although common in prodromal AD, are not associated with a more rapid functional decline.

Aged↗