Showing papers on "Cognitive decline published in 1991"

Cognitive dysfunction in multiple sclerosis. I. Frequency, patterns, and prediction

Abstract: Previous frequency estimates of cognitive dysfunction in multiple sclerosis have ranged from 54 to 65 percent. These studies may overestimate the frequency in the general MS population, since the patients in these studies were recruited from clinic populations. In the present study, we administered a comprehensive neuropsychological test battery to 100 community‐based MS patients and 100 demographically matched healthy controls. Of 31 cognitive test indices examined, 48 MS patients and five controls were impaired on four or more test indices, yielding an overall frequency rate of 43% for the MS group. The pattern of cognitive decline was not uniform: MS patients were more frequently impaired on measures of recent memory, sustained attention, verbal fluency, conceptual reasoning, and visuospatial perception, and less frequently impaired on measures of language and immediate and remote memory. We developed a brief (20‐minute) screening battery empirically by selecting the four most sensitive test indices from the comprehensive battery. The brief battery yielded a sensitivity value of 71% and a specificity value of 94% in discriminating cognitively intact from impaired MS patients, as defined by the comprehensive battery. Cognitive impairment was not significantly associated with illness duration, depression, disease course, or medication usage, but was significantly (albeit weakly) correlated with physical disability. NEUROLOGY 1991;41:685‐691

Theoretical Perspectives on Cognitive Aging

Abstract: The phenomenon of age-related cognitive decline has long been controversial, both in terms of mere existence, and with respect to how it is explained. Some researchers have dismissed it as an artifact of declining health or lower levels of education, and others have attributed it to general changes occurring in the external environment. Still other interpretations have been based on the "use it or lose it" principle -- known as the Disuse Hypothesis -- or on the idea that there are qualitative differences in either the structure or the process of cognition across the adult years. Perhaps the most popular approach at present relies on the information-processing perspective and attempts to identify the critical processing component most responsible for age-related differences in cognition. The primary purposes of this book are first to review the evidence of age-related differences in cognitive functioning and then to evaluate the major explanations proposed to account for the negative relations between age and cognition that have been established. Included is a discussion of theoretical dimensions and levels of scientific theorizing assumed to be helpful in understanding and evaluating alternative perspectives on cognitive aging. The various perspectives are then covered in detail and analyzed. The text concludes with observations about the progress that has been made in explaining cognitive aging phenomena, plus recommendations for research practices that might contribute to greater progress in the future.

Mild cognitive impairment in the elderly: predictors of dementia.

Abstract: We conducted full diagnostic evaluations, including a comprehensive cognitive assessment battery, of a group of 32 elderly subjects with a clinically identified mild cognitive impairment and a group of 32 age-matched and education-matched normal subjects. The mildly impaired subjects performed significantly more poorly than the controls on tests of recent memory, remote memory, language function, concept formation, and visuospatial praxis. Follow-up evaluations of cognitive status 2 years later revealed clinically detectable cognitive decline relative baseline in 23 (72%) of the mildly impaired subjects. Several of the objective psychological tests accurately discriminated at baseline between the decliners and nondecliners in the mildly impaired group. Among the 20 mildly impaired subjects with no complicating conditions, 16 exhibited cognitive deterioration between baseline and follow-up. These results suggest that most elderly subjects with mild cognitive deficits, as determined by clinical evaluation and objective psychological testing, will manifest the progressive mental deterioration characteristic of dementia and that psychometric predictors can be used to distinguish between benign and more significant underlying disorders in mildly impaired elderly subjects.

The role of interactions between the cholinergic system and other neuromodulatory systems in learning and memory.

Abstract: Extensive evidence indicates that disruption of cholinergic function is characteristic of aging and Alzheimer's disease (AD), and experimental manipulation of the cholinergic system in laboratory animals suggests age-related cholinergic dysfunction may play an important role in cognitive deterioration associated with aging and AD. Recent research, however, suggests that cholinergic dysfunction does not provide a complete account of age-related cognitive deficits and that age-related changes in cholinergic function typically occur within the context of changes in several other neuromodulatory systems. Evidence reviewed in this paper suggests that interactions between the cholinergic system and several of these neurotransmitters and neuromodulators--including norepinephrine, dopamine, serotonin, GABA, opioid peptides, galanin, substance P, and angiotensin II--may be important in learning and memory. Thus, it is important to consider not only the independent contributions of age-related changes in neuromodulatory systems to cognitive decline, but also the contribution of interactions between these systems to the learning and memory deficits associated with aging and AD.

Hypertension in the elderly is associated with white matter lesions and cognitive decline.

Abstract: Forty-two elderly patients (mean age, 66.2 +/- 5.1 yr) with hypertension, treated for an average of 17.3 years (standard deviation, 10.3), and 42 control subjects (mean age, 66.5 +/- 4.8 yr), matched for age, sex, and level of education, were studied with regard to the detection of lesions in the cerebral white matter with magnetic resonance imaging (MRI), particularly with axial T2-weighted images. The assessment of the MRI scans was blinded. Ten hypertensive patients showed confluent lesions in the white matter, versus only 1 control subject (Chi-square test, p = 0.01). The presence of diffuse lesions of the white matter was related to age but not to the known duration of hypertension, nor to the presence of any other cardiovascular risk factors. Cognitive function was measured in 34 hypertensive patients and in 18 control subjects. Results of the Mini-Mental State Examination, the Stroop color-word test, Trailmaking test, and the visual subtest of the Wechsler Memory Scale were worse in patients with confluent lesions of the white matter; there was no difference in mental functioning between hypertensive patients and control subjects with normal white matter or with only small focal lesions. Our findings suggest that long-standing hypertension in some patients may cause not only strokes but also chronic end-organ damage of the brain in the form of demyelination of the white matter, with cognitive decline.

Clinical Correlates of White-Matter Changes on Magnetic Resonance Imaging Scans of the Brain

Abstract: • We report our observations on the clinical and radiologic correlates of changes in cerebral white matter based on 94 subjects undergoing magnetic resonance imaging in a prospective study of dementia. Periventricular hyperintensity occurred twice as often in patients with Alzheimer's disease as in healthy control subjects. Within the control group, the presence of periventricular hyperintensity correlated significantly with one measure of cerebral atrophy and with the presence of changes in the adjoining deep white matter. The significance of white-matter changes distinct from the ventricles (leuko-araiosis) remains unsettled. Leuko-araiosis on the magnetic resonance imaging scan, unlike its correlate on the computed tomographic scan, was not shown to relate to cognitive decline or to the presence of focal abnormalities on neurologic examination. This is likely to reflect the heterogeneity of the changes detected with magnetic resonance imaging and their limited extent in our subjects.

Estimating WAIS-R IQ from the national adult reading test: A cross-validation

Abstract: The National Adult Reading Test (NART) was devised to predict premorbid intellectual functioning in people suspected of having dementia, so that the extent of cognitive decline could be assessed by comparing these results with current performances This study undertook a double cross-validation of the NART on a neurologically normal sample (N = 104) and on a clinically relevant sample (49 aged subjects) The results provide encouragement for the clinical utility of the NART The study also demonstrated that the inclusion of demographic variables with the NART gives a substantially better estimate of premorbid cognitive functioning than that given by the NART or by demographic data alone

The Relative Influence of Intelligence and Age on Everyday Memory

Abstract: A short memory test that provides analogs of everyday activities was used to investigate the relationship between everyday memory, cognitive abilities, participation in social, domestic, and leisure pursuits, and health status among 94 community-dwelling people aged between 70 and 93 years. Multiple regression analysis revealed that while fluid intelligence was a significant predictor of performance on most of the memory items, age was also a significant predictor of performance on prospective and verbal memory items, over and above the effects of intelligence. Crystallized intelligence and years of formal education showed little predictive power, but an index of participation in social and domestic activities was a good predictor of verbal, visual, and spatial memory items. It is concluded that cognitive decline in aging involves more than a simple decline in fluid intelligence.

Metacognition in HIV-1 seropositive asymptomatic individuals: Self-ratings versus objective neuropsychological performance

Abstract: This study examined the relationship between actual and self-reported neuropsychological deficits, depression, and HIV-1 serostatus. The subjects, who consisted of 479 individuals, 256 who were HIV seronegative (SN) and 233 who were HIV-1 seropositive though still asymptomatic (ASP), were administered a standardized neuropsychological screening battery consisting of measures of attention, motor speed, psychomotor speed, verbal memory, verbal fluency, and depression. To assess subjects' subjective sense of their cognitive status, the Cognitive Failures Questionnaire (CFQ), a 25-item self-report questionnaire, was also administered. The results of MANOVA failed to reveal group differences between the SN and ASP groups on the measures of neuropsychological function. Similarly, the ASP and SN groups did not differ on the number or severity of reported cognitive failures. However, a positive correlation was found between CFQ scores and level of depression. These results do not support the hypothesis that ASP individuals are aware of cognitive decline prior to detection using standard neuropsychologic screening instruments. The data do suggest that the presence of depressed mood, independent of serostatus or actual neuropsychological impairment, is associated with increased cognitive complaints.

Hearing and cognition in the elderly. New findings and a review of the literature.

Abstract: The purpose of this study was to determine the relationship between hearing status and cognitive status initially and at 5-year follow-up in a cohort of healthy elderly men and women and to relate the results to published reports on this topic. Volunteers older than 60 years with no major illnesses and taking no long-term prescription medications were examined. Baseline testing of hearing and cognition was performed in 224 subjects; 112 subjects underwent cognitive testing at 5-year follow-up. Hearing was measured by the Speech Perception in Noise test; cognition was measured by two parts of the Wechsler Memory Scale and by the Jacobs Cognitive Screening Test, an oral screening instrument. At baseline there were small correlations between hearing acuity and memory scores, but these disappeared after adjustment for age and gender. Analysis of follow-up memory and cognitive screening test scores in relation to baseline hearing ability showed no correlation between hearing at entry and cognitive function at 5 years. In addition, baseline hearing level did not predict change in memory or cognitive screening test scores during the follow-up period. The power of the study was 90% to detect a correlation of.30 between measures of hearing and cognition. There was no evidence for a major effect of hearing acuity on cognitive function over time in this group of healthy elderly. Review of published studies suggests that hearing ability is related to cognitive status in demented subjects, but there is little to suggest that in the normal elderly, hearing impairment leads to cognitive decline. (Arch Intern Med. 1991;151:2259-2264)

Piracetam. An overview of its pharmacological properties and a review of its therapeutic use in senile cognitive disorders

Abstract: Piracetam is the first of the so-called 'nootropic' drugs, a unique class of drugs which affect mental function. In animal models and in healthy volunteers, the drug improves the efficiency of the higher telencephalic functions of the brain involved in cognitive processes such as learning and memory. The pharmacology of piracetam is unusual because it protects against various physical and chemical insults applied to the brain. It facilitates learning and memory in healthy animals and in animals whose brain function has been compromised, and it enhances interhemispheric transfer of information via callosal transmission. At the same time, even in relatively high dosages it is devoid of any sedative, analeptic or autonomic activities. How piracetam exerts its effects on memory disorders is still under investigation, although among other proposed mechanisms of action it is thought to facilitate central nervous system efficiency of cholinergic neurotransmission. Results from trials involving elderly patients with senile cognitive disorders have been equivocal, as have the results obtained when piracetam has been combined with acetylcholine precursors. Piracetam seems to be almost completely devoid of adverse effects, and is extremely well tolerated. In conclusion, opinion is divided as to the benefits of piracetam in the treatment of senile cognitive decline. Although double-blind studies in the elderly have produced mixed results, some such trials (particularly those involving larger numbers of patients) have reported favourable findings, thus offering some reason for cautious optimism in a notoriously difficult area of therapeutics. However, further investigations of piracetam alone and in combination therapy are required before any absolute conclusions can be drawn.

Is age kinder to the initially more able? A study of eminent scientists and academics.

Abstract: Elderly eminent academics and blue-collar workers were compared with Doctor of Philosophy students and trade apprentices to investigate whether intelligence and memory deteriorate at a slower rate in persons with high ability. The elderly groups showed decline on tests of perceptual-motor speed, visuospatial reasoning, inferential thinking and memory relative to the young subjects. Initial ability determined the level of intellectual performance, such that elderly academics maintained their initial advantage over the elderly blue-collar workers. However, with the exception of the Similarities subtest of the Wechsler Adult Intelligence Scale, the rate of change on tests of memory and intelligence did not differ for the high- and low-ability groups. The hypothesis that high ability is associated with a slower rate of cognitive decline was not supported.

The accuracy of early diagnosis and predictors of death in Alzheimer's disease and vascular dementia--a follow-up study.

Abstract: A total of 87 patients with mild or moderate degree of dementia of the Alzheimer type (AD) or vascular dementia (VD) was identified (DSM-III criteria), and their cognitive capacity was evaluated by means of rating scales and psychometric tests. Three years later 30 patients (34%) were dead. Significantly more VD than AD patients died. Eight of the survivors declined to participate in a follow-up study, and 1 patient was excluded by mistake. Of the survivors, 17 had indisputably suffered cognitive decline during the follow-up period (4 VD and 13 AD, 35%). In the case of 11 patients (2 VD and 9 AD) cognitive decline remained doubtful, and 20 patients (9 VD and 11 AD, 42%) underwent no intellectual deterioration during the follow-up period. The results underline the problems of early diagnosis of dementia according to DSM-III criteria. For both sexes a high ischemia score and a low body mass index predicted death. A low score on a verbal fluency test predicted death for men but not for women, and a high difference between systolic and diastolic blood pressure increased the risk of death for men but not for women.

Different patterns of cognitive decline related to normal or deteriorating EEG in a 3‐year follow‐up study of patients with Alzheimer's disease

Abstract: To determine if the pattern of cognitive decline in Alzheimer9s disease (AD) patients with normal EEG differs from that in patients with abnormal EEG at the early stage of the disease, we have followed 12 AD patients with normal EEG (NEEG) and 12 patients with deteriorating EEG (DEEG). The AD patients with DEEG showed a decline of praxic functions, confrontation naming, and automatic speech functions. In contrast, the AD patients with NEEG did not show a deterioration of these functions during the 3-year follow-up period. Visual functions, understanding of speech, and memory functions deteriorated similarly in both groups. The clinical severity of dementia increased in both groups. Patients with DEEG showed a tendency toward a higher frequency of extrapyramidal symptoms and a higher risk of institutionalization than the patients with NEEG. Thus, an abnormal EEG at the early stage of AD may predict a more severe decline in cognitive functions.

Cognitive decline in patients with Alzheimer disease: differences in patients with and without extrapyramidal signs.

Abstract: We investigated the relationship between extrapyramidal signs (EPSs) in patients diagnosed with Alzheimer disease (AD) and the average rate of decline in different areas of cognition The presence of tremors, cogwheel rigidity, or bradykinesia were scored as EPS using the California State Department of Health Services AD Diagnostic and Treatment Center Form Measures of decline were computed by determining patients' average rates of decline on the Mini-Mental State Examination (MMSE) Of the 81 patients, 24 were determined to have EPS not related to medications Overall, patients with EPS deteriorated 67% faster on MMSE (45 points per year) than did patients with no evidence of EPS (27 points per year) Our findings indicate that the clinical presence of EPS is a poor overall prognostic sign in patients with a clinical diagnosis of AD

Clinical use of CT and MR scans in psychiatric patients.

Abstract: During a three-year period, 337 CT or MR scans were ordered for psychiatric patients in a teaching hospital. Scans were normal in 185 instances, equivocal in 34, and abnormal in 118 instances. When a history of neurologic disorder and/or the presence of abnormal neurologic/organic mental signs was positive, scans were abnormal in 74% of cases; when these indicators were negative, scans were normal in 72% of cases. In all, only 4 new diagnoses were made. Two patients, both with markedly abnormal neurological findings, were shown to have brain tumors, which changed their management. Two others showed abnormalities which would have been missed, both of which were of no clinical consequence. The following are suggested as sound indications for ordering CT or MR brain imaging among psychiatric patients: 1) positive history of head injury, stroke or other neurologic disease, as well as suspected Alzheimer disease or multi-infarct dementia; 2) presence of abnormal neurologic signs or organic mental signs, such as confusion or cognitive decline; and, 3) a first psychotic break or personality change after the age of 50 years.

Dressing for success. Promoting independence among cognitively impaired elderly.

Abstract: In demented persons, activities of daily living skills may deteriorate more quickly than their cognitive decline warrants because caregivers do not allow them to perform ADLs to the full extent of their abilities. Caregiver actions that promote independent behaviors were used with subjects in home and nursing home settings. Four of five home subjects showed decreased caregiver assistance and increased ability to dress more independently. Although nursing home subjects did not show a decrease in caregiver assistance, observation showed that some nursing home caregivers did incorporate behavioral strategies, suggesting potential clinical efficacy of the strategies.

Are there clinical and epidemiological differences between familial and non-familial Alzheimer's disease?

Abstract: To determine whether there are clinical and epidemiological differences between familial and non-familial Alzheimer's disease, we studied 151 patients with the clinical diagnosis of Dementia of the Alzheimer Type (DAT). Eighty-four index patients (56%) had at least one relative with reported DAT-type memory loss; the remaining 67 did not. For comparison, patients with a positive family history were grouped into a suspected familial DAT (FDAT), and those with a negative family history were grouped into a suspected non-familial DAT (NFDAT). There were no significant differences between FDAT and NFDAT patients with respect to age of symptom onset, survival time, rate of cognitive decline, motor function, behavioral signs or symptoms, head trauma, thyroid dysfunction, maternal age, or birth order. There were no significant differences between pedigrees of FDAT and NFDAT patients in respect to the prevalence of Down's syndrome or age of mortality. To examine a more "familial" set of FDAT patients, an FDAT subgroup (F2DAT) consisting of 33 index patients with two or more affected relatives with DAT-type memory loss was compared to the 67 NFDAT patients in a similar analysis. No significant differences were found. However, NFDAT index patients had a higher reported prevalence of head trauma than those patients in the F2DAT subgroup (NFDAT 22%, F2DAT 7%, OR = 4.2, CI = 0.9-20.0, P = 0.08). Thus severe head trauma may be a more important etiological factor in the non-familial form of DAT. To better examine this tendency, future studies should be conducted utilizing a larger number of pedigrees and familial criteria which account for the number of persons at risk and the age at onset of disease.

Heterogeneity of the Course of Alzheimer's Disease: A Differentiation of Subgroups

Abstract: 78 patients with Alzheimer''s disease (AD) were divided into four subgroups on the basis of their rate of cognitive decline. One group was distinguished by a higher age at onset (mean = 72, range 50–8

Diagnosis of multi-infarct dementia.

Abstract: Multi-infarct dementia (MID) is commonly considered a dementia syndrome evolving in connection with multiple ischemic brain lesions, without other changes known to cause dementia. The ischemic brain lesions result from various vascular mechanisms, and different brain mechanisms are involved in the genesis of MID. Typical features for MID are abrupt onset of cognitive symptoms, stepwise deterioration of mental functioning, and focal neurologic symptoms or signs, but in 20% of cases the onset is insidious and the course is even. The main steps in diagnosis of MID include diagnosis of dementia, diagnosis of specific causes of dementia and secondary factors potentially aggravating cognitive decline, and demonstration of ischemic brain changes assumed to be responsible for the evolution of dementia. Methods used for clinical diagnosis of MID include clinical history and examination, brain imaging, ischemic scores, neurophysiologic investigations, and a variety of laboratory investigations designed to detect concomitant illness. According to strict clinical criteria for MID, the accuracy of the antemortem diagnosis as verified postmortem in one series was approximately 90%.

Tetrahydroaminoacridine in Alzheimer's dementia: Clinical and biochemical results of a double-blind crossover trial

Abstract: The cognitive decline in Alzheimer's disease has been shown to correlate with deficits in central cholinergic neurotransmission. Among various treatment attempts using cholinergic drugs a trial of the cholinesterase inhibitor tetrahydroaminoacridine (THA) (Summers et al., 1986) attracted considerable interest due to the positive effects reported on dementia symptoms. We have studied the effects of THA and placebo in a double-blind crossover trial over 9 weeks in 15 patients with dementia of Alzheimer type. Doses of the drug (75–150mg/day) were titrated for each patient before entering the study. Clinical and biochemical effects were monitored using a battery of psychological tests, clinical rating scales and laboratory tests, including measurements of monoamine metabolites in the cerebrospinal fluid (CSF). The clinical results were mostly negative. Almost half of the patients had elevated liver enzymes (ALT and AST) in the THA period and these subjects showed more improvements of clinical ratings and psychological tests than did the patients without elevated liver enzymes. Levels of acetylcholine and the monoamine metabolites HVA and 5-HIAA in CSF were elevated on THA. The results indicate that THA has a therapeutic potential, although its pharmacokinetic profile and its liability to induce liver damage may limit the clinical use of the drug in the future.

Autoimmunity and Cognitive Decline in Aging and Alzheimer's Disease

Abstract: Publisher Summary This chapter focuses on the presence of important psychoneuroimmunological factors in the etiology of neurobehavioral pathology associated with aging and Alzheimer's disease The neuroimmunopathological effector mechanisms that could be involved have been identified and characterized in studies of other neurological diseases, and various sites and mechanisms for interactions between the central nervous system and peripheral immune system have also been revealed Brain-reactive antibodies are found in the sera and cerebrospinal fluid of patients with Alzheimer's disease, and some of the antibody populations have specificities matching the neurological targets known to undergo deterioration in Alzheimer's disease The identification of brain-reactive antibodies in association with Alzheimer's disease has suggested both novel diagnostics and potentially successful therapeutic approaches Aging mice show formation of both diverse and specific brain-reactive antibodies, and immune transfer studies have implicated age-related changes in immune function as important factors in the appearance of these antibodies The same immune factors may be involved in age-related changes in brain functions related to capacity for avoidance acquisition of the age-related acquisition deficits following transfer of immunity from aged to young mice

A follow‐up study of elderly depressives and Alzheimer‐type dementia—relationship with DST status

Abstract: Seventy-three elderly patients (38 with Alzheimer-type dementia (ATD) and 35 with major depressive disorder) were followed up 2–5 years after an index admission during which a dexamethasone suppression test (DST) had been performed. Clinical state, cognitive function, neurological status and repeat DST were assessed where possible. The death rate was high in both groups (greater in the ATD group) but was not influenced by original DST status. Original DST status did not predict on survival time, development of physical illness or admission rate in either group, but DST non-suppression in the depressed group was associated with significant cognitive decline and abnormal neurological features. Possible mechanisms of the association are discussed.

Glycosaminoglycan polysulfate in the treatment of old age dementias.

Abstract: 1. In a multicenter, placebo-controlled, double-blind clinical trial in 155 elderly patients with cognitive decline, glycosaminoglycan polysulfate was found to be a therapeutically effective agent in the treatment of old age dementias. 2. Treatment with glycosaminoglycan polysulfate in the daily dosage of 600 LRU, administered on the basis of a divided dosage schedule for 12 weeks, was significantly superior to an inactive placebo on several outcome measures including the Wechsler Memory Scale-Russell Revision (Easy Paired Associates Learning and Immediate Visual Reproduction), Mini Mental State Examination, the Sandoz Clinical Assessment Geriatric (Cognitive Dysfunction and Depression), Hachinski Dementia Scale, Brief Psychiatric Rating Scale (Confusion and Depressive Withdrawal) and Global Improvement Scale of the Clinical Global Impression. 3. Adverse effects with glycosaminoglycan polysulfate were few and mild. The drug was equally well tolerated and equally effective in the two major dementias of old age, i.e., primary degenerative and multi-infarct. The number of abnormal laboratory test readings remained essentially unchanged from pre-treatment to post-treatment.