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A Satlin

Publications and source records attributed to A Satlin.

36 records · Page 2Linked to original sources
PubMed1994

A neural network classifier for cerebral perfusion imaging.

UNLABELLED: Artificial neural networks have been applied to a variety of pattern recognition tasks in medical imaging and have been shown to be a powerful classification tool. The potential usefulness to discriminate normal from abnormal cerebral perfusion patterns was investigated. METHODS: Cerebral perfusion imaging with 99mTc-labeled hexamethylpropyleneimine oxime was performed on 52 normal control subjects, 29 patients with clinically diagnosed Alzheimer's disease (AD) and 25 patients with chronic cocaine polydrug abuse. Each study was registered and scaled to a common anatomic coordinate system, yielding 120 standardized cortical regions. A back-propagation neural network classifier based on regional perfusion was used to classify normal and abnormal perfusion patterns. The neural network was trained to discriminate patients with AD from age-matched normal controls and cocaine polydrug abuse patients from normal controls. The performance of the neural network in these two tasks was evaluated quantitatively by receiver operating characteristic (ROC) analysis using cross-validation. RESULTS: For patients with AD, the area under the ROC curve was 0.93 +/- 0.04. When testing with the cocaine polydrug abuser data, the area under the ROC curve was 0.89 +/- 0.04. CONCLUSION: Neural networks provide a potentially useful tool in the decision-making task to discriminate patients with AD and cocaine abuse from normal controls.

Adult↗
PubMed1993

Quantitative brain SPECT in Alzheimer's disease and normal aging.

To improve the diagnostic utility of brain single-photon emission computed tomography (SPECT) in Alzheimer's disease (AD), we have developed and evaluated an objective method of differentiating patients and healthy elderly controls using a quantitative image analysis protocol. HMPAO-SPECT image datasets from 29 patients with probable AD and 78 age-matched controls were registered to a common anatomic frame of reference. Activity levels within 120 standardized cortical volumes were determined by an automated procedure. Subjects were classified into normal and AD groups by quadratic discriminant analysis using two features: global average activity level and average normalized activity levels within the two clusters of standardized volumes identified as most significantly different in AD by analysis of covariance. The classification used split-half replication to ensure valid results. Classification performance quantified by the area under a binormal ROC curve fitted to the data was 0.923 +/- 0.036; at a threshold likelihood ratio of 1, the sample sensitivity was 91% and specificity was 86%. We conclude that quantitative SPECT accurately distinguishes AD patients from elderly controls.

Aged↗
PubMed1992

Mania compared with unipolar depression in old age.

OBJECTIVE: The goal of this study was to clarify the meaning and importance of mania in old age. METHOD: The authors conducted a retrospective study of 50 elderly patients consecutively admitted to a private mental hospital with an index episode of mania. As a comparison group, they used 50 age- and sex-matched patients with unipolar depression. They reviewed the charts of the 100 patients for family history, clinical course, and neurological disorders. Outcome was determined by contacting patients, families, physicians, institutional settings, and vital statistics records. Survival analysis compared mortality rates. RESULTS: The manic patients had a greater familial predisposition to affective disorder and were younger at first psychiatric hospitalization. For the 20 manic patients whose first affective episode was depression, an average of 15 years elapsed before mania became manifest. Eighteen of the manic patients, compared with only four of the depressed patients, had neurological disorders. The manic patients had a significantly higher mortality rate than the depressed patients; by the end of the follow-up, 25 of the manic patients, compared with 10 of the depressed patients, had died. CONCLUSIONS: Mania appears to have a poorer prognosis and to be a more severe form of affective illness than unipolar depression. The 18 manic patients with neurological disorders seemed to have "secondary mania." Subtle cerebral changes due to aging may have been responsible for the conversion to mania in the 20 patients who experienced a long latency from first depression to onset of mania. The low frequency of early-onset mania in this study group highlights the need to differentiate early- from late-onset mania.

Adult↗
PubMed1992

Bright light treatment of behavioral and sleep disturbances in patients with Alzheimer's disease.

OBJECTIVE: The authors tested the hypothesis that evening bright light pulses would improve sleep-wake patterns and reduce agitation in patients with Alzheimer's disease who have severe sundowning (a syndrome of recurring confusion and increased agitation in the late afternoon or early evening) and sleep disorders. METHOD: Ten inpatients with Alzheimer's disease on a research ward of a veterans' hospital were studied in an open clinical trial. All patients had sundowning behavior and sleep disturbances. After a week of baseline measurements, patients received 2 hours/day of exposure to bright light between 7:00 p.m. and 9:00 p.m. for 1 week. During the baseline week, the treatment week, and a posttreatment week, patients were rated by nurses for agitation, sleep-wake patterns, use of restraints, and use of prescribed-as-needed medication. On the last 2 days of each week, patients wore activity monitors. Activity counts were analyzed for circadian rhythmicity. RESULTS: Clinical ratings of sleep-wakefulness on the evening nursing shift improved with light treatment in eight of the 10 patients. The proportion of total daily activity occurring during the nighttime decreased during the light-treatment week. The relative amplitude of the circadian locomotor activity rhythm, a measure of its stability, increased during the light-treatment week. More severe sundowning at baseline predicted greater clinical improvement. CONCLUSIONS: Evening bright light pulses may ameliorate sleep-wake cycle disturbances in some patients with Alzheimer's disease. This effect may be mediated through a chronobiological mechanism.

Aged↗
PubMed1992

The scintigraphic appearance of Alzheimer's disease: a prospective study using technetium-99m-HMPAO SPECT.

Alzheimer's disease produces regional abnormalities in brain blood flow and metabolism that may result in recognizable scintigraphic patterns. We determined the predictive value of 99mTc-HMPAO SPECT for the presence of Alzheimer's disease based on a prospective study of 132 consecutive patients coming to our nuclear medicine clinical unit for evaluation of their memory loss or cognitive abnormalities. During clinical follow-up averaging 10.1 mo, a final diagnosis was established in 113 patients, 52 of which had Alzheimer's disease. The probability of Alzheimer's disease was determined for seven scintigraphic patterns. The probability was 19% that patients with memory loss and normal perfusion had Alzheimer's disease. For abnormal perfusion patterns, the probability of Alzheimer's disease was 82% with bilateral temporoparietal defects, 77% with bilateral temporoparietal defects with additional defects, 57% with unilateral temporoparietal defects, 43% with frontal defects only, 18% with other large defects and 0% with multiple small cortical defects. We conclude that for 99mTc-HMPAO SPECT the predictive value of bilateral temporoparietal defects for Alzheimer's disease is high, while the perfusion patterns of unilateral temporoparietal perfusion defects and frontal defects only, which occur in 20% of patients with Alzheimer's disease, are not predictive of that disease.

AIDS Dementia Complex↗
PubMed1991

Prevalence and severity of akathisia in patients on clozapine.

The atypical antipsychotic clozapine is reported to have unique therapeutic effects and to produce minimal extrapyramidal side effects. However, in a blind survey, akathisia was observed to be similar in prevalence and severity in patients treated with clozapine and those receiving standard neuroleptic antipsychotic drugs. In addition, as with standard antipsychotic drugs, the presence of akathisia in patients receiving clozapine was associated with a worse overall clinical outcome. The results suggest that akathisia may be a common side effect of all antipsychotic drugs, that akathisia may be produced by a mechanism distinct from other locomotor effects of these medications, and that patients receiving clozapine, like patients receiving standard antipsychotic drugs, should be monitored for akathisia.

Adult↗
PubMed1991

Circadian locomotor activity rhythms in Alzheimer's disease.

Circadian motor activity rhythms in 19 severely demented, institutionalized patients with Alzheimer's disease (AD) were evaluated with small, waist-worn electronic monitors which recorded 5-minute epochs for 48 to 72 hours. Controls were eight normal subjects of the same age (71 to 73 years) in a similar environment. As expected, computer-assisted analysis indicated more than twofold average increases in nocturnal activity and in the proportion of nocturnal to total daily activity in the AD patients. In patients (n = 8) with virtually constant pacing, daytime activity was markedly increased over that of normal controls; these "pacers" also had a significantly decreased amplitude of the circadian activity rhythm compared with controls. Moreover, AD patients showed a marked phase-delay, with individual afternoon maxima (acrophases) averaging 2.1 hours later than in controls (p less than 0.005). These findings quantitatively document clinical observations that AD patients, and especially a subgroup with pacing behavior, have markedly disturbed levels and modulation of daily locomotor activity. They accord with reports of altered circadian rhythms of endocrine and other physiologic parameters in such patients. Activity monitoring may represent a relatively simple, objective measure with which to characterize demented patients and to assess responses to treatment.

Aged↗
PubMed1990

Vitamin B12 and folate status in acute geropsychiatric inpatients: affective and cognitive characteristics of a vitamin nondeficient population.

This chart review study examined the serum vitamin B12 and folate status of 102 geriatric patients newly admitted to a private psychiatric hospital. Only 3.7% were B12 deficient and 1.3% were folate deficient; 4% were anemic. Nevertheless, those with below-median values of both vitamins had significantly lower Mini-Mental State scores than patients higher in one or both vitamins. Patients with "organic psychosis" with a negative family history for psychiatric disorder had significantly lower B12 levels than those with a positive family history. In major depression, folate levels correlated negatively with age at onset of psychiatric illness and length of hospitalization. These data suggest that (1) biochemically interrelated vitamins such as B12 and folate may exert both a separate and a concomitant influence on affect and cognition; (2) poorer vitamin status may contribute to certain geropsychiatric disorders that begin at a later age and lack a familial predisposition.

Affective Disorders, Psychotic↗
PubMed1988

S-adenosyl-L-methionine in the treatment of Alzheimer's disease.

Patients with Alzheimer's disease (AD) have an apparent abnormality possibly representing an increase in the average fluidity of their cell membranes. Changes in membrane fluidity of similar magnitude to those observed in AD have been noted to lead to marked alterations in cell function. Therefore, the changes in fluidity observed in AD may be related to the symptoms of that disorder, representing either an underlying cause of dysfunction or cellular attempts to compensate for dysfunction in AD. To test these possibilities, we administered S-adenosyl-L-methionine (SAMe), an agent shown to increase membrane fluidity in animals, to patients with AD. Treatment with SAMe led to marked increases in membrane fluidity. However, it produced neither improvement nor worsening of symptoms. The results imply that while SAMe may be useful for other conditions associated with altered membrane fluidity (such as normal aging), changing membrane fluidity per se is not likely to lead to marked changes in symptoms in AD.

Aged↗
PubMed1984

Undiagnosed vomiting in an older woman: unsuspected bulimia.

Bulimia, believed to occur primarily in young women, is rarely suspected in older individuals. The authors report on a 56-year-old woman with rapid cycling bipolar disorder, whose unexplained vomiting proved attributable to bulimia.

Bipolar Disorder↗
PubMedDate not supplied

Regional cerebral blood volume measured by dynamic susceptibility contrast MR imaging in Alzheimer's disease: a principal components analysis.

Dynamic susceptibility contrast (DSC) MRI is an alternative to positron emission tomography (PET) and single photon emission computed tomography (SPECT) for the evaluation of cerebral hemodynamics in patients with Alzheimer's disease. DSC MRI allows the construction of high resolution images of cerebral blood volume (CBV) without the use of radionuclides or ionizing radiation. In this study, DSC MRI data were collected from 16 patients with probable Alzheimer's disease and 16 age-matched control subjects. Characteristic patterns of regional CBV variation were found using principal component analysis. Three such patterns were identified: a global variation pattern, an anterior-to-posterior CBV gradient, and a temporoparietal pattern. Group differences in the principal component scores associated with the global and temporoparietal patterns (P = .08 and P = .007, respectively) suggest that these deficits reflect characteristic CBV abnormalities in Alzheimer's disease. Using only these two scores, the Alzheimer's disease group was classified with a sensitivity of 81% and a specificity of 88%. Additionally, disease severity, as measured by the Mini-Mental State Examination (MMSE), was correlated significantly with the third principal component score (Pearson's r = .50, P = .05).

Aged↗
PubMedDate not supplied

Circadian locomotor activity and core-body temperature rhythms in Alzheimer's disease.

Sleep-wake cycle disturbances suggest that circadian rhythms may be disrupted in patients with Alzheimer's disease (AD). In this study, we examined the circadian rhythms of core-body temperature and locomotor activity in 28 patients with probable AD and 10 healthy controls. AD patients had higher percent nocturnal activity than controls, corresponding to the clinical picture of fragmented sleep. The amplitude of the activity cycle in the AD patients was lower than that of controls and the acrophase of this cycle in AD patients was 4.5 h later. There was no difference in the amplitude of the core-body temperature circadian rhythm, but AD patients had delayed temperature acrophases. A subgroup of AD patients with large mean time differences between the acrophases of their activity and temperature cycles had lower temperature amplitudes and greater activity during the night. These findings suggest that a subgroup of AD patients with impaired endogenous pacemaker function may have a diminished capacity to synchronize the rhythm of core-body temperature with the circadian cycle of rest-activity. This circadian rhythm dysfunction may partly explain the fragmented nocturnal sleep exhibited by these patients.

Aged↗
PubMedDate not supplied

Glycopyrrolate versus atropine in post-ECT amnesia in the elderly.

The neurotransmitter acetylcholine is important in memory function, and low brain concentrations may be associated with cognitive impairment. Our hypothesis was that atropine, a centrally acting anticholinergic drug known to cause amnesia, confusion, and delirium, may further exacerbate the amnesia and/or confusion resulting from electroconvulsive therapy (ECT) when used as a preanesthetic, and that the peripherally acting glycopyrrolate would by comparison decrease these side effects. We randomly administered glycopyrrolate versus atropine in equivalent doses as the preanesthetic agent to 20 consecutively admitted geriatric patients with major depression, for whom ECT was the clinical treatment of choice. Patients were matched for age, Hamilton Scale for Depression, and baseline performance on the Buschke Selective Reminding Task (BSRT). We found no significant difference in outcome between patients treated prior to ECT with atropine versus glycopyrrolate, as assessed by the above measures. We conclude from this study that atropine is no more deleterious to memory than is glycopyrrolate when given before ECT.

Aged↗
PubMedDate not supplied

Changes in tardive dyskinesia symptoms in elderly patients treated with ganglioside GM1 or placebo.

The unique role of ganglioside GM1 in neuronal plasticity led two centers, New York University and McLean Hospital, to study the effect of GM1 or placebo in patients with tardive dyskinesia. Results from the NYU cohort have already been published. We now present data from the entire cohort, allowing us to evaluate the effects of GM1 in the elderly compared to young adults. Subjects with tardive dyskinesia were randomly assigned to single-blind placebo injections for 1 week, followed by 1 month of double-blind intramuscular placebo or GM1 100 mg. The final sample included 29 patients: 12 younger than 55 years of age and 17 older. There was no GM1-versus-placebo difference observed in either age group, or in the total group. However, whether on placebo or GM1, repeated measures analysis of variance (RANOVA) found a significant difference in response between Abnormal Involuntary Movement Scale scores, taken baseline and week 4, in the elderly compared to young adults. Scores for the young adults show initial improvement then deterioration back to baseline, and those for the elderly show continuing improvement during the 4-week trial. The importance of the placebo effect in the elderly and its meaning for studies of GM1 in tardive dyskinesia are discussed.

Adult↗
PubMedDate not supplied

Late-life suicide: a review.

Suicide ranked as the ninth leading cause of death in the United States in 1992, with persons over the age of 65 years being at the highest risk. Suicidologists predict a dramatic increase in both the rate and the total number of late-life suicides over the next three decades, highlighting the urgent need for prevention and treatment strategies specifically targeting at-risk older individuals. Comprehensive Medline and PsycLit searches of elderly suicide (and various synonyms thereof) were conducted for English-language publications dating back to 1989, and the bibliographies in these sources were examined for additional publications. An overview of the epidemiology, biology, psychopathology, and frequent medical concomitants of late-life suicide is presented here. Innovative preventive strategies are also briefly summarized. It is concluded that further investigation is needed in several areas: the neurobiology of aging, affective disorders, and suicide; the complex interactions between somatic and psychiatric illnesses; personality traits that may confer vulnerability to suicide in late life; and age-related variations in the prevalence and phenomenology of Axis I psychopathology in suicide victims.

Female↗