ISSN:0893-0341    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

The objective of this study was to assess the diagnostic value for Alzheimer disease (AD) of single-photon-emission computed tomography (SPECT) and magnetic resonance imaging (MRI), separately and in combination. The study was part of a two-stage population-based study of mental functioning among noninstitutionalized 65− to 85-year-olds living in Amsterdam, The Netherlands. Participants (n= 51) were randomly selected within strata of cognitive function to obtain a sample of AD patients (n= 10) and clinically normal subjects (n= 41), of whom 22 displayed some cognitive impairment and fulfilled criteria for “minimal dementia” according to the Cambridge Examination for Mental Disorders of the Elderly. Coronal T1-weighted MRI was used to visualize the medial temporal lobe. Medial temporal lobe atrophy (MTA) was assessed qualitatively on a 0–4 scale. Regional cerebral blood flow on SPECT was assessed with the use of technetium 99m-HMPAO in three manually drawn regions of interest (frontal, parietal, and temporoparietal). Ratios were calculated by using the cerebellum as the reference area. MTA differed significantly between AD patients and clinically normal subjects (p= 0.0009), with a sensitivity for AD of 70% and a specificity of 76%. None of the three SPECT ratios differed between normal and AD subjects. The temporoparietal/cerebellar ratio had a sensitivity of 30% and a specificity of 71% at a cutoff of 0.76. When both tests were positive the combined sensitivity was low (20%), but the falsepositive rate was also very low (5%). A negative result on MRI or any SPECT ratio yielded a high specificity (93–98%) but also a high false-negative rate (60–80%). Adding SPECT to MRI seems useful only if a diagnosis of AD is suspected clinically and confirmation is needed. When the clinical probability that AD is absent is high, normal results on either MPI or SPECT may confirm this notion. Given the fact that structural imaging should be performed in a clinical workup for dementia, using MRI only would be the most cost-effective approach.

ISSN:0893-0341    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

We evaluated the floor effect and convergent, discriminant, and known-group validity of the Bedford Alzheimer Nursing Severity scale (BANS-s), a rating scale comprising cognitive and functional items recently developed for grading severe dementia. Ninety-nine demented patients (81 females and 18 males aged 55–100 years) in two nursing homes were assessed with the BANS-s, established cognitive and functional scales [Mini Mental State Examination, the extended version of the Clinical Dementia Rating (CDR), Katz's basic activities of daily living, Tinetti balance and gait, and Crichton scales], a behavioral scale (UCLA Neuropsychiatric Inventory), and indicators of malnutrition (Prognostic Nutritional Index). A relevant proportion (40%) of patients scored close to the floor of all scales except BANS-s and CDR, which showed a more uniform distribution of scores throughout the possible range. Convergent validity of BANS-s with the other cognitive and functional scales was good, with Pearson'srranging from 0.62 to 0.79. Discriminant validity analysis of BANS-s versus the UCLA Neuropsychiatric Inventory showed that the two scales measure different domains (Pearson'sr= 0.36). To test known-group validity, all patients were divided into two groups of different dementia severity as defined by the Prognostic Nutritional Index. BANS-s and CDR were the scales with the best ability to discriminate malnourished from nonmalnourished patients. As a further validity test, the 37 patients reaching the floor on other cognitive and functional scales were divided into two subgroups of different dementia severity as defined by the Tinetti scale. BANS-s but not CDR was able to differentiate the two groups.

ISSN:0893-0341    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

There is a diversity of opinions concerning the function of the blood-brain barrier and the blood-cerebrospinal fluid barrier (BCB) in Alzheimer disease and other neuropsychiatric disorders. In this paper we investigate and review the evidence for BCB dysfunction in Alzheimer disease and major depression. The hypothetical roles of immunologically mediated mechanisms in the central nervous system (CNS) are discussed. Special consideration is given to methodological factors influencing BCB function and analysis. Serum and cerebrospinal fluid (CSF) of 29 patients with major depression (MD) and 51 patients with “probable Alzheimer disease” (AD) were investigated. The AD patients were subdivided in two groups of 21 early-onset (EO) and 30 late-onset (LO) cases and assayed for concentrations of albumin and IgG. The results were compared with those for 11 age-matched healthy controls. The severity of dementia was assessed with the Mini-Mental State Examination (MMSE). AD and MD patients showed significantly lower serum albumin [AD:p< 0.05 (LO:p< 0.038); MD:P< 0.01] and IgG (AD:P< 0.01; MD:p< 0.013) concentrations compared with controls. MD (p< 0.001) and LO-AD (p< 0.07) patients displayed significantly lower absolute serum albumin levels than did EO-AD patients. The CSF/serum ratio for albumin and IgG was used to evaluate BCB function. There were no significant group differences; however, subsets of MD (29%) and AD (16%) patients showed a higher frequency of a pathological albumin ratio than did control subjects. Furthermore, a subset of 24% of MD and 18% of AD patients and none of the controls showed an elevated IgG ratio. Different mechanisms of alteration of IgG distribution are presented. The degree of cognitive impairment in AD did not correlate positively with protein and ratio parameters. The BCB is critical to the maintenance of homeostasis within nervous system tissue. We suggest that the altered function can result from immune-mediated events such as altered levels of circulating inflammatory mediators. Furthermore, we assume that in the AD and MD subgroups, the BCB dysfunction for high molecular weight proteins permits access of components of the immune system to the CNS, which may contribute to disease pathology.

ISSN:0893-0341    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Patients with Alzheimer disease (AD) show visual impairments in color discrimination (blue hues), stereoacuity, and contrast sensitivity. We asked whether the AD-type visual profile occurs in Down syndrome (DS) in light of the fact that AD neuropathology is present in DS by age 40. We tested 22 adults with DS and 18 adults with mental retardation of non-DS etiology (MR). DS subjects made more tritanomalous errors on the test of color vision than predicted by chance (p< 0.05), indicating a deficiency in the discrimination of short wavelengths (blue hues) but not more of other types of hue discrimination errors. DS subjects had higher stereoacuity thresholds than MR subjects (p< 0.01) and reduced contrast sensitivity across the frequency range (p< 0.01). Taken together, the results point to AD-like visual deficits in DS. Like classic AD, DS may be associated with pathological changes in the parastriate and peristriate visual cortex. DS performance was not correlated with age, suggesting that in individual subjects, the AD-like visual deficits may present prior to and independent of age-associated dementia.

ISSN:0893-0341    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Although much of the care of Alzheimer disease (AD) patients and their families is carried out by health professionals who are not specialists in AD or geriatrics, little is known about how knowledgeable these health professionals are about AD. An AD knowledge test was constructed through careful instrument development procedures and then administered through a mail survey. Subjects were 693 individuals, including experts in AD care, generalist health care professionals (primary care physicians, psychologists, social workers, and nurses), nursing students, hospital staff nurses, and assorted health professionals. A 12-item scale with excellent psychometric properties was developed. Experts in AD care performed significantly better than generalist health care professionals on all items. All four groups of generalist health care professionals showed important deficits in fundamental knowledge about AD; for example, only 40% of generalists (vs. 97% of experts) knew that AD is the most common cause of severe memory loss in people over age 65. Results suggest that, although knowledge about assessment and management of AD has increased and has been widely disseminated, many health care professionals remain uninformed about AD. Suggestions for professional education and for use of the UAB AD Knowledge Test for Health Professionals are discussed.

ISSN:0893-0341    

出版商:OVID    

年代:1997

数据来源: OVID

ISSN:0893-0341    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Delusions of theft are commonly found in patients with dementia of the Alzheimer type (DAT). This report describes the frequency, onset, and characteristics of delusions of theft in DAT patients. The sample consisted of 54 geropsychiatric inpatients with DAT; delusions of theft were found in 30 (55.6%) patients. Two thirds of these patients had delusions of theft within 1 year after onset of illness. There were no significant differences in age, age of onset, duration of disease, years of education, or the Mini-Mental State Examination (MMSE) score between patients with and without delusions of theft. Delusions of theft frequently occur in the early stage of dementia, when the patients' cognitive impairments are relatively mild. The presence of this symptom may warrant a diagnosis of DAT.

ISSN:0893-0341    

出版商:OVID    

年代:1997

数据来源: OVID

ISSN:0893-0341    

出版商:OVID    

年代:1997

数据来源: OVID