Economic considerations of Alzheimer's disease and related disorders

Economic analyses of geriatric syndromes are seldom performed. However, demographic and epidemiological imperatives have led to significant interest in the evaluation of AD-related costs. Over 300 papers devoted to economic considerations of Alzheimer's disease have been published in peer-reviewed journals, within the last five years. In these papers, the chosen perspective (costs to society or to specific payers) is important. Analytical methods are still evolving and remain complex. Unresolved methodological issues will need to be addressed to further our understanding of long-term economic consequences. At present, it is clear that diagnostic and drug costs are low compared to the major cost of institutionalization. Thus, directing efforts at early diagnosis and delaying nursing home placement are two key cost-containment interventions. In this respect, the need to support informal care should not be underestimated.

Immediate causes of death of demented and non-demented elderly

OBJECTIVE

To investigate the immediate causes of death, in autopsied demented and non-demented elderly.

DESIGN

Retrospective clinicopathologic correlations.

SETTING

Acute and intermediate care geriatric hospital.

PARTICIPANTS

342 hospitalized demented and non-demented elderly (mean age 84.94 +/- 6.9 years) who underwent consecutive postmortem examinations: 120 demented patients with either vascular dementia (VaD, n = 34), mixed dementia (MD, n = 65) or Alzheimer's disease (AD, n=21) neuropathologically confirmed and 222 nondemented elderly.

RESULTS

Primary causes of death were similar in both demented and non-demented patients; the commonest were cardiovascular disease and bronchopneumonia. Cardiac causes of death and especially cardiac failure were more frequent in VaD than in AD or MD (respectively P = 0.027 and 0.005). Dementia was an underlying but never a primary cause of death.

CONCLUSIONS

Immediate causes of death are similar in elderly demented and non-demented patients.

Does the mini nutritional assessment predict hospitalization outcomes in older people?

BACKGROUND

the Mini Nutritional Assessment is a validated clinical tool for the assessment of nutritional status in older people. Moderate to severe malnutrition is common in elderly patients in hospital and is associated with a poor outcome.

OBJECTIVES

to determine whether the Mini Nutritional Assessment can predict the outcome of hospital stay in older individuals.

SETTING

a tertiary-care geriatric hospital.

METHODS

we evaluated nutritional status using the Mini Nutritional Assessment in 1319 patients (mean age 84.2, 70% women) admitted between February 1996 and January 1998; 1145 complete assessments were available for analysis. The assessment was carried out on admission and studied in relation to length of stay and in-hospital mortality for all patients, and discharge to a nursing home for those living at home before admission.

RESULTS

Mini Nutritional Assessment scores averaged 19.9+/-3.8 (mean+/-SD) with a range of 8.0-27.5, and a median of 20.5. A score below 17, corresponding to malnutrition, was associated with an almost threefold increase in mortality and in the rate of discharge to a nursing home; this contrasted with a score above 24, which indicates satisfactory nutritional status (11.3% vs 3.7%; P<0.01 and 20.3% vs 7.7%; P<0.001, respectively). Length of stay was longer in the low scoring group (42.0 days vs 30.5 days; P<0.0002).

CONCLUSION

Poor nutritional status as measured by the Mini Nutritional Assessment was associated with increased in-hospital mortality, a higher rate of discharge to nursing homes and a longer length of stay.

Health services utilization after induced abortions in Ontario: a comparison between community clinics and hospitals

The purpose of this study was to compare postabortion health services utilization of hospital abortion patients with community clinic abortion patients using administrative databases. The study was a retrospective cohort study. The study group consisted of patients with induced abortions (n = 41,039) performed in hospitals or community clinics recorded in the 1995 Ontario Health Insurance Plan claims (OHIP) database. An age-matched cohort of 39,220 women who did not undergo induced abortions was selected from the same data source to serve as controls. The main outcome measures were health services utilization indicators constructed from OHIP data within 3 months postabortion from office consultations, emergency room consultations, and hospital admissions. Hospitalization indicators were constructed from Canadian Institute for Health Information hospital discharge data within 3 months postabortion and included data on hospitalizations for infection, certain surgical events, or psychiatric problems. Postabortion health services utilization and hospitalization were higher in the patient population, regardless of service location, than in the age-matched cohort. Within the abortion patient population, hospital day-surgery patients had higher rates of postabortion utilization and hospitalization than did community clinic patients. Multivariate analysis revealed that hospital day surgery patients had a higher risk of subsequent post-abortion hospitalizations for infections (odds ratio [OR] 1.67, 95% confidence interval [CI] 1.23-2.28), surgical events (OR 1.70, 95% CI 1.30-3.24) and psychiatric problems (OR 2.65, 95% CI 1.77-3.98) than community clinic patients. The rates of postabortion health services utilization and risk of hospitalization were lower in community clinic abortion patients than in hospital day-surgery patients. However, it is not possible to fully control for important confounding variables when using these administrative data.

Impaired processing of famous faces in Alzheimer's disease is related to neurofibrillary tangle densities in the prefrontal and anterior cingulate cortex

To examine the neuroanatomical correlates of impaired processing of famous faces in Alzheimer's disease (AD), we performed an anterograde clinicopathological study of 25 patients with clinically and neuropathologically confirmed AD. Famous face recognition, identification and naming was assessed using the Famous Face Test. The assessment of neurofibrillary tangle (NFT) and senile plaque (SP) densities was performed in ten cortical areas in both hemispheres, and statistical analysis was made using forward stepwise logistic regression models. A statistically significant relationship was found between NFT densities in Brodmann's areas 9 and 24 in both hemispheres and impaired famous face naming and identification. SP counts did not correlate with any of the neuropsychological parameters. These data suggest that NFT formation in prefrontal and anterior cingulate cortex, two areas involved in semantic memory processes, is a key event in famous face naming and identification deficits. In agreement with previous studies, they also indicate that SP densities are not a good pathological correlate of neuropsychological deficits in AD.

Neural substrates of spatial and temporal disorientation in Alzheimer's disease

To examine the neuroanatomical correlates of spatial and temporal disorientation in Alzheimer's disease (AD), we performed an anterograde clinicopathological study of 29 patients with clinically and neuropathologically confirmed AD. Spatial and temporal disorientation was assessed using the locational orientation subtests of the Mini Mental State Examination and the Benton's test for temporal orientation. Quantitative analysis of neurofibrillary tangles and senile plaques were performed in the CA1 field of the hippocampus, layers II and V of the entorhinal cortex, and layers II-III and V-VI of areas 9, 7, 39, 19, 37, 20 and 23 in the right hemisphere. Forward stepwise logistic regression was used to assess the relationship between lesion densities and the presence of either spatial or temporal disorientation; severity scores and brain weight were included as covariants. A statistically significant relationship was found between neurofibrillary tangle densities in Brodmann's areas 7, 23 and the CA1 field of hippocampus and both spatial and temporal disorientation. Senile plaque counts did not correlate with any of the neuropsychological parameters. Both temporal and spatial disorientation in AD are related to the degeneration of the same pathways linking the hippocampus with the superior parietal and posterior cingulate cortex in the right hemisphere. These observations are discussed with respect to the notion of global corticocortical disconnection in AD.

Imidazoline receptor antisera-selected (IRAS) cDNA: cloning and characterization

The imidazoline-1 receptor (IR1) is considered a novel target for drug discovery. Toward cloning an IR1, a truncated cDNA clone was isolated from a human hippocampal lambda gt11 cDNA expression library by relying on the selectivity of two antisera directed against candidate IR proteins. Amplification reactions were performed to extend the 5' and 3' ends of this cDNA, followed by end-to-end PCR and conventional cloning. The resultant 5131-basepair molecule, designated imidazoline receptor-antisera-selected (IRAS) cDNA, was shown to encode a 1504-amino acid protein (IRAS-1). No relation exists between the amino acid sequence of IRAS-1 and proteins known to bind imidazolines (e.g., it is not an alpha2-adrenoceptor or monoamine oxidase subtype). However, certain sequences within IRAS-1 are consistent with signaling motifs found in cytokine receptors, as previously suggested for an IR1. An acidic region in IRAS-1 having an amino acid sequence nearly identical to that of ryanodine receptors led to the demonstration that ruthenium red, a dye that binds the acidic region in ryanodine receptors, also stained IRAS-1 as a 167-kD band on SDS gels and inhibited radioligand binding of native I1 sites in untransfected PC-12 cells (a source of authentic I1 binding sites). Two epitope-selective antisera were also generated against IRAS-1, and both reacted with the same 167-kD band on Western blots. In a host-cell-specific manner, transfection of IRAS cDNA into Chinese hamster ovary cells led to high-affinity I1 binding sites by criteria of nanomolar affinity for moxonidine and rilmenidine. Thus, IRAS-1 is the first protein discovered with characteristics of an IR1.

Possible relationship between changes in islet neogenesis and islet neogenesis-associated protein-positive cell mass induced by sucrose administration to normal hamsters

The possible relationship between changes in islet cell mass and in islet neogenesis-associated protein (INGAP)-cell mass induced by sucrose administration to normal hamsters was investigated. Normal hamsters were given sucrose (10% in drinking water) for 5 (S8) or 21 (S24) weeks and compared with control (C) fed hamsters. Serum glucose and insulin levels were measured and quantitative immunocytochemistry of the endocrine pancreas was performed. Serum glucose levels were comparable among the groups, while insulin levels were higher in S hamsters. There was a significant increase in beta-cell mass (P<0.02) and in beta-cell 5-bromo-2'-deoxyuridine index (P<0.01), and a significant decrease in islet volume (P<0.01) only in S8 vs C8 hamsters. Cytokeratin (CK)-labelled cells were detected only in S8 hamsters. INGAP-positive cell mass was significantly larger only in S8 vs C8 hamsters. Endocrine INGAP-positive cells were located at the islet periphery ( approximately 96%), spread within the exocrine pancreas ( approximately 3%), and in ductal cells (<1%) in all groups. INGAP positivity and glucagon co-localization varied according to topographic location and type of treatment. In C8 hamsters, 49.1+/-6. 9% cells were INGAP- and glucagon-positive in the islets, while this percentage decreased by almost half in endocrine extra-insular and ductal cells. In S8 animals, co-expression increased in endocrine extra-insular cells to 36.3+/-9.5%, with similar figures in the islets, decreasing to 19.7+/-6.9% in ductal cells. INGAP-positive cells located at the islet periphery also co-expressed CK. In conclusion, a significant increase of INGAP-positive cell mass was only observed at 8 weeks when neogenesis was present, suggesting that this peptide might participate in the control of islet neogenesis. Thus, INGAP could be a potentially useful tool to treat conditions in which there is a decrease in beta-cell mass.

Patient satisfaction as an indicator of quality care in independent health facilities: developing and assessing a tool to enhance public accountability

The objective of this research was to examine the performance of a brief patient survey about quality of care received in community-based diagnostic and therapeutic facilities. The survey was administered to patients in 44 facilities that were also scheduled for a formal external assessment. The response rate was 53%. Patients generally rated their care positively; 18.5% of patients rated at least 1 item as fair or poor. The amount of information received about risks and complications was rated least favorably; concern and caring shown by staff was rated most favorably. The 10 items which patients rated regarding aspects of quality formed an internally consistent scale (alpha = .93). Patients' ratings were not useful predictors of assessor ratings. Although patients' ratings cannot substitute for expert on-site assessments, they are an important part of a quality management program. The patient survey provides additional, complementary information about components of quality care that are important to them.

Clinical validity of Braak neuropathological staging in the oldest-old

Several studies have demonstrated a good correlation between clinical severity and Braak's neuropathological staging in Alzheimer's disease (AD). However, nonagenarians and centenarians display a different pattern of cortical vulnerability to the neurodegenerative process compared to younger elderly, and it is not known whether correlations between clinical severity and neuropathological stages remain valid in this age group. To address this issue we compared Clinical Dementia Rating scale (CDR) scores and Braak stages in 116 patients over 90 years of age with either no cognitive impairment or very mild to severe AD. There is a strong positive correlation between CDR scores and Braak staging (Spearman coefficient = 0.66; P < 0.01). However, neuropathological staging does not distinguish cases with normal cognition (CDR 0) from those with mild cognitive changes (CDR 0.5). Unlike younger cohorts, Braak stages I and II are frequently associated with questionable dementia in this age group. Braak stage III overlaps with all CDR levels and correlates poorly with cognitive function. Braak stages IV or greater are consistently associated with at least mild dementia. Consistent with our previous neuropathological analyses of nonagenarians and centenarians, the present data suggest that the substantial involvement of the hippocampus which characterizes Braak stage IV is a key step in the development of overt clinical signs of dementia in the oldest-old. Moreover, they indicate that Braak staging represents a broad concept of the evolution of neurofibrillary tangles rather than a precise hierarchical model associated with a stepwise deterioration of cognitive abilities near the upper limit of life.

Threonine phosphorylations induced by RX-871024 and insulin secretagogues in betaTC6-F7 cells

Treatment of the pancreatic beta-cell line betaTC6-F7 with an imidazoline compound, RX-871024, KCl, or tolbutamide resulted in increased threonine phosphorylation of a 220-kDa protein (p220) concurrent with enhanced insulin secretion, which can be partially antagonized by diazoxide, an ATP-sensitive potassium (K(ATP)) channel activator. Although phosphorylation of p220 was regulated by cytoplasmic free calcium concentration ([Ca(2+)](i)), membrane depolarization alone was not sufficient to induce phosphorylation. Phosphorylation of p220 also was not directly mediated by protein kinase A, protein kinase C, or insulin exocytosis. Analysis of subcellular fractions indicated that p220 is a hydrophilic protein localized exclusively in the cytosol. Subsequently, p220 was purified to homogeneity, sequenced, and identified as nonmuscle myosin heavy chain-A (MHC-A). Stimulation of threonine phosphorylation of nonmuscle MHC-A by KCl treatment also resulted in increased phosphorylation of a 40-kDa protein, which was coimmunoprecipitated by antibody to MHC-A. Our results suggest that both nonmuscle MHC-A and the 40-kDa protein may play roles in regulating signal transduction, leading to insulin secretion.

Neuroanatomic correlates of visual agnosia in Alzheimer's disease: a clinicopathologic study

OBJECTIVE

To examine the neuroanatomic correlates of visual agnosia in AD.

METHODS

The authors performed an anterograde clinicopathologic study of 23 patients with clinically and neuropathologically confirmed AD in a 305-bed acute care geriatric hospital and a 165-bed acute care psychiatric hospital. The presence of apperceptive visual agnosia was assessed using the Ghent's overlapping figure test and the Gottschaldt's hidden figure test. Associative visual agnosia was examined using the conceptual items of the Columbia Mental Maturity Test. Correlations between neurofibrillary tangle (NFT) and senile plaque (SP) densities and visual agnosia were studied using forward stepwise logistic regression.

RESULTS

A statistically significant relation was found between NFT densities in Brodmann's areas 18, 19, and 37, and associative visual agnosia, whereas NFT densities in the areas studied did not correlate with the presence of apperceptive visual agnosia. Senile plaque counts did not correlate with any of the neuropsychological parameters.

CONCLUSIONS

These results support the existence of a dichotomy between associative and apperceptive agnosia, and show that only the former is related to the damage of secondary and high-order visual association areas in AD. In addition, the results suggest that SP densities do not represent a valuable pathologic correlate of visual agnosia in this disorder.

Re-evaluating the role of vascular changes in the differential diagnosis of Alzheimer's disease and vascular dementia

Alzheimer's disease (AD) and vascular dementia (VaD) are the two most common causes of dementia, and much effort has been devoted to their differential diagnosis. However, current epidemiological, clinical and neuropathological evidence points to a substantial overlap between AD and VaD and suggests that vascular pathology, the traditional cornerstone of the differential diagnosis between the two entities, may not represent as clear a line of demarcation as originally believed. It may be time to reevaluate the dichotomy between AD and VaD.

Cellular vulnerability in brain aging and Alzheimer's disease. Clinical correlates and molecular background

The neuropathological changes associated with normal brain aging and Alzheimer's disease involve specific cortical circuits. Extensive hippocampal alterations are correlated with age-associated memory impairment, while substantial neurofibrillary tangle formation in neocortical association areas of the temporal lobe is a prerequisite for the development of Alzheimer's disease. Several lines of evidence indicate that there is no correlation between senile plaque densities and the degree of dementia in this disorder. The cortical involvement in the ninth and tenth decades of life is different from that observed in younger patients in that parietal and cingulate areas are affected early in the course of Alzheimer's disease, and neocortical senile plaques densities are strongly correlated with the severity of dementia. Moreover, Alzheimer's disease pathology is characterized in these very old patients by high neurofibrillary tangle densities in the anterior CA1 field, but not in the entorhinal cortex and inferior temporal cortex. These patterns of lesion distribution are discussed in respect to the neurochemical, genetic and metabolic factors which may influence the neuronal vulnerability in Alzheimer's disease.

Vascular dementia. Differential diagnosis and therapeutic issues

Although it has long been felt that dementia may be due to atherosclerosis, the concept has recently evolved to include multiple pathophysiological mechanisms related to deficiencies in cerebral blood supply. Epidemiological data has identified hypertension and stroke as the most potent risk factors for the development of vascular dementia (VaD). New diagnostic criteria have been proposed and new neuroimaging techniques have led to a better detection of cerebral vascular pathology. However, the differential diagnosis between Alzheimer's disease and VaD, the two most common causes of dementia, remains clinically challenging. Therapeutic interventions for VaD are limited, nevertheless several lines of evidence suggest a strong potential for preventive treatment through the control of vascular risk factors.

Pathologic correlates of apraxia in Alzheimer disease

OBJECTIVE

To examine the neuroanatomical correlates of apraxia in Alzheimer disease.

PATIENTS

Twenty-three patients with clinically overt Alzheimer disease.

DESIGN

Anterograde study and neuropathologic case series. Clinical severity was assessed using the Global Deterioration Scale. Ideomotor praxis was examined on transitive and intransitive movements and meaningless gestures, and dressing ability was evaluated clinically. Constructive praxis was tested using a 3-dimensional figure copying task. Correlations between neurofibrillary tangle and senile plaque densities and praxis test performance were studied using stepwise logistic regression models.

SETTING

Studies were conducted at the Psychiatric and Geriatric Hospitals of the University of Geneva School of Medicine, Geneva, Switzerland.

MAIN OUTCOME MEASURES

Odds ratios to estimate the associations between neurofibrillary tangle and senile plaque densities in each neocortical area and the presence of ideomotor, dressing, and constructional apraxia.

RESULTS

Statistically significant relationships were found between neurofibrillary tangle densities in the anterior cingulate cortex and ideomotor and dressing apraxia and between neurofibrillary tangle densities in the superior parietal, posterior cingulate, and occipital cortex and constructional apraxia. Senile plaque counts did not correlate with praxic performance.

CONCLUSIONS

These results suggest that ideomotor and dressing apraxia are associated with mild damage of the anterior cingulate cortex, whereas constructional apraxia is related to the disruption of cortical pathways mediating visuospatial cognition in Alzheimer disease. Senile plaque densities do not represent a valuable pathologic correlate of apraxia in this disorder.

Free-standing health care facilities: financial arrangements, quality assurance and a pilot study

Free-standing health care facilities now deliver many diagnostic and therapeutic services formerly provided only in hospitals. The financial arrangements available to these facilities differ according to whether the services are uninsured or insured. For an uninsured service, such as cosmetic surgery, the patient pays a fee directly to the service provider. For an insured service, such as cataract surgery, the provincial government uses tax revenues to fund the facility by paying it a facility fee and remunerates the physician who provided the service with a professional fee. No comprehensive, proactive quality assurance efforts have been implemented for either these facilities or the clinical practice provided within them. A pilot study involving therapeutic facilities in Ontario has suggested that a large-scale quality improvement effort could be undertaken in these facilities and rigorously evaluated.