Functional, global and cognitive decline correlates to accumulation of Alzheimer's pathology in MCI and AD

BACKGROUND

Cognitive, global and functional instruments have been extensively investigated for correlations with neuropathological changes such as neurofibrillary tangles (NFTs), plaques, and synapse loss in the brain.

OBJECTIVE

Our objective is to correlate the functional, global and cognitive decline assessed clinically with the neuropathological changes observed in a large prospectively characterized cohort of mild cognitive impairment (MCI) and Alzheimer's disease (AD).

METHODS

We examined 150 subjects (16 MCI and 134 AD) that were prospectively assessed and longitudinally followed to autopsy. MCI subjects clinically met Petersen criteria for single or multi-domain amnestic MCI. AD subjects clinically met NINCDS-ADRDA criteria for probable or possible AD. All subjects received the Functional Assessment Staging (FAST), the Global Deterioration Scale (GDS), and the Mini Mental State Examination (MMSE) ante-mortem. Plaque and tangle counts were gathered for hippocampus, entorhinal cortex, frontal, temporal and parietal cortices. Braak staging was performed as well.

RESULTS

The GDS, FAST and MMSE correlated with plaque counts in all regions. The GDS, FAST and MMSE correlated with tangle counts in in all regions. The three instruments also correlated with the Braak score. The MMSE and GDS correlate better than the FAST in most regions.

CONCLUSIONS

Accumulation of neuropathology appears to correlate with functional, global, and cognitive decline as people progress from MCI through AD.

Functional ability correlates with cognitive impairment in Parkinson's disease and Alzheimer's disease

BACKGROUND/AIMS

Previously we have shown that functional declines in Parkinson's disease (PD) and Alzheimer's disease (AD) correlate to global measures of cognitive decline. We now determine if the correlation between cognitive impairment and functional ability in PD is similar to that in AD using individual cognitive measures.

METHODS

93 PD subjects and 124 AD/MCI subjects underwent the Functional Assessment Staging (FAST), the Global Deterioration Scale (GDS), and a neuropsychological battery.

RESULTS

In PD subjects, the FAST and GDS correlated significantly with Rey Auditory Verbal Learning Test (AVLT), Controlled Oral Word Association (COWA), Animal Fluency, and Stroop but not with Clock Draw or Judgment Line Orientation (JLO). In AD/MCI subjects, FAST and GDS correlated with all neuropsychological components except Stroop. In the AD/MCI group, the UPDRS significantly correlated with the FAST, GDS, MMSE, and all neuropsychological parameters except the Stroop. In the PD group, the motor UPDRS significantly correlated significantly with FAST, GDS, MMSE and all neuropsychological parameters except Digit Span, Stroop, Clock Draw and JLO.

CONCLUSIONS

Similar to AD, functional decline in PD correlates with multiple measures of cognitive impairment. Some differences between PD and AD may be explained by the influence of motor disability and declines in visuospatial function in PD.

Longitudinal CSF and MRI biomarkers improve the diagnosis of mild cognitive impairment

The diagnosis of Alzheimer's disease (AD) in patients with mild cognitive impairment (MCI) is limited because it is based on non-specific behavioral and neuroimaging findings. The lesions of Alzheimer's disease: amyloid beta (Abeta) deposits, tau pathology and cellular oxidative damage, affect the hippocampus in the earlier stages causing memory impairment. In a 2-year longitudinal study of MCI patients and normal controls, we examined the hypothesis that cerebrospinal fluid (CSF) markers for these pathological features improve the diagnostic accuracy over memory and magnetic resonance imaging (MRI)-hippocampal volume evaluations. Relative to control, MCI patients showed decreased memory and hippocampal volumes and elevated CSF levels of hyperphosphorylated tau and isoprostane. These two CSF measures consistently improved the diagnostic accuracy over the memory measures and the isoprostane measure incremented the accuracy of the hippocampal volume achieving overall diagnostic accuracies of about 90%. Among MCI patients, over 2 years, longitudinal hippocampal volume losses were closely associated with increasing hyperphosphorylated tau and decreasing amyloid beta-42 levels. These results demonstrate that CSF biomarkers for AD contribute to the characterization of MCI.

Prediction of longitudinal cognitive decline in normal elderly with subjective complaints using electrophysiological imaging

An extensive literature reports changes in quantitative electroencephalogram (QEEG) with aging and a relationship between magnitude of changes and degree of clinical deterioration in progressive dementia. Longitudinal studies have demonstrated QEEG differences between mild cognitively impaired (MCI) elderly who go on to decline and those who do not. This study focuses on normal elderly with subjective cognitive complaints to assess the utility of QEEG in predicting future decline within 7 years. Forty-four normal elderly received extensive clinical, neurocognitive and QEEG examinations at baseline. All study subjects (N = 44) had only subjective complaints but no objective evidence of cognitive deficit (evaluated using the Global Deterioration Scale [GDS] score, GDS stage = 2) at baseline and were re-evaluated during 7-9 year follow-up. Baseline QEEGs of Decliners differed significantly (p < 0.0001, by MANOVA) from Non-Decliners, characterized by increases in theta power, slowing of mean frequency, and changes in covariance among regions, especially on the right hemisphere. Using logistic regression, an R2 of 0.93 (p < 0.001) was obtained between baseline QEEG features and probability of future decline, with an overall predictive accuracy of 90%. These data indicate high sensitivity and specificity for baseline QEEG as a differential predictor of future cognitive state in normal, subjectively impaired elderly.

[Behavioral pathology in Alzheimer's Disease Rating Scale (BEHAVE-AD): Spanish validation]

INTRODUCTION

The Behavioral Pathology in Alzheimer's Disease Rating Scale (BEHAVE-AD) is a screening instrument for the evaluation of behavioral disturbances in Alzheimer's patients. Our aim was to validate the BEHAVE-AD test in Spanish, intended for use in routine clinical practice.

METHOD

We assessed the validity of the BEHAVEAD in 79 nursing-home patients with diagnosis criteria of dementia, scoring 4 or higher on the Global Deterioration Scale (GDS) scale, by developing a crossed validated form between the Neuropsychiatric Inventory-Questionnaire (NPI-Q) and BEHAVE-AD tests. Both instruments were rated by an expert clinician. In order to study the concurrent validity of some of the BEHAVE-AD subscales, we compared the Cohen-Mansfield Agitation Inventory (CMAI) and the Hamilton Depression Rating Scale (HDRS) tests.

RESULTS

The Pearson correlation index between the BEHAVE-AD test and the NPI-Q, was significant but moderate (r=0.694). Pearson's correlation between BEHAVEAD's symptoms scale and NPI-Q's severity scale was r=0.698. When comparing BEHAVE-AD's global evaluation scale (caregiver's disturbance) and NPI-Q's distress scale, the correlation index was 0.535.

CONCLUSIONS

The BEHAVE-AD Spanish version offers the possibility to use a screening tool for the detection of neuropsychiatric symptoms in dementia patients, also applicable to nursing home residents, administered by an expert clinician.

Is the functional decline of Parkinson's disease similar to the functional decline of Alzheimer's disease?

Since many Parkinson's disease (PD) subjects develop dementia, we determined whether the correlation between functional and cognitive decline seen in Alzheimer's disease (AD) is seen in PD. Seventy-five PD subjects with and without dementia and 103 AD/MCI subjects underwent the Functional Assessment Staging (FAST), the Global Deterioration Scale (GDS), the UPDRS motor portion, and the MMSE. In AD/MCI subjects, changes in FAST and GDS scores correlated with MMSE (rho=-0.814, P<0.001; rho=-0.840, P<0.001, respectively). In PD subjects, the FAST and GDS also correlated with MMSE (rho=-0.675, P<0.001; rho=-0.647, P<0.001, respectively). The UPDRS correlated with the GDS and FAST more closely in PD than in AD. Similar to AD, functional declines in PD correlates with cognitive decline and may be influenced by motor disability in PD.

Benefits of cognitive-motor intervention in MCI and mild to moderate Alzheimer disease

OBJECTIVE

To evaluate the efficacy of a cognitive-motor program in patients with early Alzheimer disease (AD) who are treated with a cholinesterase inhibitor (ChEI).

METHODS

Patients with mild cognitive impairment (MCI) (12), mild AD (48), and moderate AD (24) (Global Deterioration Scale stages 3, 4, and 5) were randomized to receive psychosocial support plus cognitive-motor intervention (experimental group) or psychosocial support alone (control group). Cognitive-motor intervention (CMI) consisted of a 1-year structured program of 103 sessions of cognitive exercises, plus social and psychomotor activities. The primary efficacy measure was the cognitive subscale of the AD Assessment Scale (ADAS-cog). Secondary efficacy measures were the Mini-Mental State Examination, the Functional Activities Questionnaire, and the Geriatric Depression Scale. Evaluations were conducted at 1, 3, 6, and 12 months by blinded evaluators.

RESULTS

Patients in the CMI group maintained cognitive status at month 6, whereas patients in the control group had significantly declined at that time. Cognitive response was higher in the patients with fewer years of formal education. In addition, more patients in the experimental group maintained or improved their affective status at month 12 (experimental group, 75%; control group, 47%; p = 0.017).

CONCLUSIONS

A long-term CMI in ChEI-treated early Alzheimer disease patients produced additional mood and cognitive benefits.

MRI and CSF studies in the early diagnosis of Alzheimer's disease

The main goal of our studies has been to use MRI, FDG-PET, and CSF biomarkers to identify in cognitively normal elderly (NL) subjects and in patients with mild cognitive impairment (MCI), the earliest clinically detectable evidence for brain changes due to Alzheimer's disease (AD). A second goal has been to describe the cross-sectional and longitudinal interrelationships amongst anatomical, CSF and cognition measures in these patient groups. It is now well known that MRI-determined hippocampal atrophy predicts the conversion from MCI to AD. In our summarized studies, we show that the conversion of NL subjects to MCI can also be predicted by reduced entorhinal cortex (EC) glucose metabolism, and by the rate of medial temporal lobe atrophy as determined by a semi-automated regional boundary shift analysis (BSA-R). However, whilst atrophy rates are predictive under research conditions, they are not specific for AD and cannot be used as primary evidence for AD. Consequently, we will also review our effort to improve the diagnostic specificity by evaluating the use of CSF biomarkers and to evaluate their performance in combination with neuroimaging. Neuropathology studies of normal ageing and MCI identify the hippocampal formation as an early locus of neuronal damage, tau protein pathology, elevated isoprostane levels, and deposition of amyloid beta 1-42 (Abeta42). Many CSF studies of MCI and AD report elevated T-tau levels (a marker of neuronal damage) and reduced Abeta42 levels (possibly due to increased plaque sequestration). However, CSF T-tau and Abeta42 level elevations may not be specific to AD. Elevated isoprostane levels are also reported in AD and MCI but these too are not specific for AD. Importantly, it has been recently observed that CSF levels of P-tau, tau hyperphosphorylated at threonine 231 (P-tau231) are uniquely elevated in AD and elevations found in MCI are useful in predicting the conversion to AD. In our current MCI studies, we are examining the hypothesis that elevations in P-tau231 are accurate and specific indicators of AD-related changes in brain and cognition. In cross-section and longitudinally, our results show that evaluations of the P-tau231 level are highly correlated with reductions in the MRI hippocampal volume and by using CSF and MRI measures together one improves the separation of NL and MCI. The data suggests that by combining MRI and CSF measures, an early (sensitive) and more specific diagnosis of AD is at hand. Numerous studies show that neither T-tau nor P-tauX (X refers to all hyper-phosphorylation site assays) levels are sensitive to the longitudinal progression of AD. The explanation for the failure to observe longitudinal changes is not known. One possibility is that brain-derived proteins are diluted in the CSF compartment. We recently used MRI to estimate ventricular CSF volume and demonstrated that an MRI-based adjustment for CSF volume dilution enables detection of a diagnostically useful longitudinal P-tau231 elevation. Curiously, our most recent data show that the CSF isoprostane level does show significant longitudinal elevations in MCI in the absence of dilution correction. In summary, we conclude that the combined use of MRI and CSF incrementally contributes to the early diagnosis of AD and to monitor the course of AD. The interim results also suggest that a panel of CSF biomarkers can provide measures both sensitive to longitudinal change as well as measures that lend specificity to the AD diagnosis.

Measuring cognition in advanced Alzheimer's disease for clinical trials

Measurement of cognitive dysfunction and treatment response in the early stages of Alzheimer's disease (AD) has used such scales as the Mini-Mental State Examination (MMSE) and the AD Assessment Scale (ADAS). With the exception of clinical rating scales, however, there are only a few objective measures of cognition for tracking progression in advanced AD. Given renewed interest in potential therapies for advanced AD, objective measures of cognition are important for the adequate evaluation of change due to AD progression or therapy. Several cognitive measures for advanced AD are reviewed. One measure, the Severe Impairment Battery (SIB) is reviewed in detail. Preliminary analyses from a trial of memantine show significant change on the SIB in memory (p < 0.001) and visuospatial functions (p < 0.02) over six-months with a trend for language and praxis. Data from a donepezil trial also highlight the importance of accurate assessment in advanced AD.

Vascular fibrosis and calcification in the hippocampus in aging, Alzheimer disease, and Down syndrome

Study of the hippocampal formation of 82 subjects, including 25 control subjects from 33 to 83 years of age, 34 subjects with Alzheimer disease (AD) from 65 to 89 years of age, and 23 subjects with Down syndrome (DS) from 33 to 72 years of age, revealed hippocampal vasculopathy with fibrosis and calcification (VFC) in 40% of control, 59% of AD, and 4% of DS subjects. VFC starts in the precapillaries/capillaries in the molecular layer of the dentate gyrus (DG) and expands to the granule cell and polymorphic cell layer of the DG, and to the stratum lacunosum/molecular in the CA1 sector. Vasculopathy spreads from the tail to the body and, in a few cases, to the head of the hippocampal formation. Light and electron microscopy reveal thickening of the vascular wall with fibrosis, calcification, and enforcement of the astrocyte interface with vessels with anchorage densities associated with hemidesmosome-like structures. In moderately and severely affected cases, fragmentation and removal of calcified and occluded vessels result in local reduction of vascular network. In two AD subjects, severe vascular calcification extending from the tail to the head of the hippocampal formation was associated with loss of almost all neurons in the CA1 sector and in the subiculum proper, corresponding to hippocampal sclerosis. The topography of affected vessels and the patterns of neuronal loss reflect the middle hippocampal artery distribution with its precapillary/capillary network. The similar prevalence of vasculopathy in the AD group and in the age-matched control group, and the presence of hippocampal VFC in only one subject in the DS cohort, 96% of which is affected by Alzheimer-type pathology, oppose the link between AD and this form of vasculopathy. However, severe VFC affects the pattern of AD pathology locally by deletion of neurofibrillary degeneration and beta-amyloidosis in the CA1 sector, subiculum proper, and the molecular layer of the dentate gyrus. Hippocampal VFC appears to be a form of vascular pathology with a unique predilection for the middle hippocampal artery and corresponding capillary network, which results in patchy neuronal loss in moderately affected subjects and in almost total neuronal loss in the area of impaired blood supply in severely affected subjects. These observations suggest an etiologic link between hippocampal VFC and hippocampal sclerosis.

Prediction of cognitive decline in normal elderly subjects with 2-[(18)F]fluoro-2-deoxy-D-glucose/poitron-emission tomography (FDG/PET)

Neuropathology studies show that patients with mild cognitive impairment (MCI) and Alzheimer's disease typically have lesions of the entorhinal cortex (EC), hippocampus (Hip), and temporal neocortex. Related observations with in vivo imaging have enabled the prediction of dementia from MCI. Although individuals with normal cognition may have focal EC lesions, this anatomy has not been studied as a predictor of cognitive decline and brain change. The objective of this MRI-guided 2-[(18)F]fluoro-2-deoxy-d-glucose/positron-emission tomography (FDG/PET) study was to examine the hypothesis that among normal elderly subjects, EC METglu reductions predict decline and the involvement of the Hip and neocortex. In a 3-year longitudinal study of 48 healthy normal elderly, 12 individuals (mean age 72) demonstrated cognitive decline (11 to MCI and 1 to Alzheimer's disease). Nondeclining controls were matched on apolipoprotein E genotype, age, education, and gender. At baseline, metabolic reductions in the EC accurately predicted the conversion from normal to MCI. Among those who declined, the baseline EC predicted longitudinal memory and temporal neocortex metabolic reductions. At follow-up, those who declined showed memory impairment and hypometabolism in temporal lobe neocortex and Hip. Among those subjects who declined, apolipoprotein E E4 carriers showed marked longitudinal temporal neocortex reductions. In summary, these data suggest that an EC stage of brain involvement can be detected in normal elderly that predicts future cognitive and brain metabolism reductions. Progressive E4-related hypometabolism may underlie the known increased susceptibility for dementia. Further study is required to estimate individual risks and to determine the physiologic basis for METglu changes detected while cognition is normal.

The Alzheimer's disease activities of daily living international scale (ADL-IS)

BACKGROUND

Activities of daily living (ADL) deficits are integral components of dementia disorders, and ADL measures are among the most robust markers of the course of Alzheimer's disease (AD). Despite this acknowledged importance, no clearly useful ADL instrument for cross-cultural application in pharmacologic trials in the early stages of AD had been available.

METHOD

An international effort was launched to develop an ADL scale for pharmacologic trials in early AD. Steps taken from 1990 to the present included: (1) international scientific working group meetings and reviews, (2) reviews of existing measures, (3) collating of existent, nonredundant items, (4) querying experts for new items, (5) interviews with informants and subjects in the USA, France, and Germany, toward the identification of potential new items, (6) identification of an item pool based upon these procedures, (7) creation of a trial instrument, (8) piloting of this instrument, and (9) refinement of the scale based upon statistical analysis of the pilot data. Final item selection was based upon: (1) relevance for > or = 80% of subjects in severity-stratified USA and German samples; (2) absence of gender and national biases; (3) significant (p <.05) discrimination between (a) normal versus mildly impaired and (b) mildly impaired versus moderately to moderately severely impaired subjects; and (4) Global Deterioration Scale (GDS) scores accounting for > or = 12% of variance in the item after controlling for age and gender.

RESULTS

An ADL scale consisting of 40 items that correlate with the global and cognitive progress of AD is developed for international usage in pharmacologic trials in incipient, mild, moderate, and moderately severe AD. The scale contains 40 items falling within 13 ADL categories. The 40-item scale is shown to have .81 correlation with GDS staging, .81 with mental status assessment (Mini-Mental State Examination), and .81 with a psychometric test (the SKT) (p values < .001).

CONCLUSION

This scale can be used to measure therapeutic response in AD.

Fibrillar amyloid-beta affects neurofibrillary changes but only in neurons already involved in neurofibrillary degeneration

The aim of this study of the cerebral cortex of 8 non-demented elderly subjects and of 17 subjects in the severe stage of Alzheimer's disease (AD) (Global Deterioration Scale stage 7/Functional Assessment Staging procedure stage 7a-f) was to examine the relationships between amyloid-beta (Abeta) deposits and neurofibrillary degeneration. The study shows that neuronal processes with neurofibrillary changes are detectable in only a minority of fibrillar plaques: from 31% to 49% of fibrillar plaques within frontal, temporal, parietal, limbic, occipital, and insular cortices. The correlations observed between the numerical densities of neurons with neurofibrillary tangles (NFTs) and the densities of Thioflavin-S-positive fibrillar plaques with neurofibrillary changes (r=0.61; P<0.01) indicate that neurofibrillary pathology in neocortical plaques reflects the topography and rate of neurofibrillary changes in neocortical neurons. The accumulation of abnormally phosphorylated tau in only some plaques indicates that fibrillar Abeta enhances paired helical filament accumulation locally only in dystrophic neurites already involved in neurofibrillary degeneration. The lack of correlation between the number of neurons with neurofibrillary changes and the number of all Thioflavin-S-positive fibrillar plaques (with and without neurofibrillary changes) suggests that beta-amyloidosis does not contribute to initiation of neurofibrillary degeneration in neurons.

Addition of a frequency-weighted score to the Behavioral Pathology in Alzheimer's Disease Rating Scale: the BEHAVE-AD-FW: methodology and reliability

The Behavioral Pathology in Alzheimer's Disease Rating Scale (BEHAVE-AD) is a well-established instrument, designed to assess potentially remediable behavioral symptoms in Alzheimer's disease (AD) patients as well as to evaluate treatment outcome. It consists of 25 symptoms grouped into seven categories. Each symptom is scored on the basis of severity on a four-point scale. A knowledgeable caregiver is queried and items are scored on the basis of symptoms noted in the preceding two weeks. Reliability, construct validity and criterion validity data for the BEHAVE-AD have previously been published. Because of the significance of psychopathology in dementia, it is necessary to optimally describe and define the nature, magnitude and prevalence of behavioral symptomatology. Accordingly, a frequency component was added to each of the 25 items of the BEHAVE-AD scale. The objective of the present report is to describe this new Behavioral Pathology in Alzheimer's Disease Frequency-Weighted Severity Scale (BEHAVE-AD-FW) and to establish its inter-rater reliability. In this investigation the BEHAVE-AD-FW scale was administered to caregivers of 28 patients with either mildly impaired cognitive function or a dementia diagnosis. Two clinicians separately and independently rated the responses. Analyses determined that the intraclass correlation coefficients (ICCs) for the frequency component varied between 0.86 and 0.97 for each of the seven BEHAVE-AD categories (p(s) < 0.001). ICCs for the frequency-weighted scores (item severity score x item frequency score) ranged from 0.69 to 0.98 for the seven symptom categories (p(s) < 0.001). For the BEHAVE-AD-FW total scores, the ICC was 0.91 (P < 0.001). These results indicate that the frequency-weighted component is a reliable addition to the BEHAVE-AD scale.

Retrogenesis: clinical, physiologic, and pathologic mechanisms in brain aging, Alzheimer's and other dementing processes

Data from clinical, electrophysiologic, neurophysiologic, neuroimaging and neuropathologic sources indicates that the progression of brain aging and Alzheimer's disease (AD) deterioration proceeds inversely to human ontogenic acquisition patterns. A word for this process of degenerative developmental recapitulation, "retrogenesis", has been proposed. These retrogenic processes provide new insights into the pathologic mechanism of AD deterioration. An understanding of retrogenic phenonmena can also result in insights into the applicability of retrogenic pathologic mechanisms for non-AD dementing disorders. Management strategies based upon retrogenesis have recently been proposed. Retrogenic pathophysiology also points to previously unexplored pharmacologic approaches to dementia prevention and treatment.

The 1999 IPA/Bayer Research Awards

It is both an honor and a privilege to introduce the winners of the sixth biennial IPA Research Awards in Psychogeriatrics, sponsored by Bayer AG. On behalf of IPA and the entire psychogeriatric community, I want to thank Bayer for their very generous support of these awards since their inception in 1989.

Neuropsychological prediction of decline to dementia in nondemented elderly

This study examined whether baseline neuropsychological performance in elderly assessed at a research clinic could accurately predict subsequent decline to dementia. Logistic regression analyses were applied to (1) 213 nondemented elderly with a Global Deterioration Scale (GDS) score of 1, 2, or 3, of whom 74 (35%) subsequently declined to any diagnosis of dementia, and (2) a diagnostically more restricted subset of this sample (N = 179), of whom 56 (31%) declined to a diagnosis of probable Alzheimer's disease (AD). The mean follow-up intervals were 3.8 and 3.7 years, respectively. A small set of baseline neuropsychological measures (especially a Paragraph Delayed Recall Test) significantly differentiated decliners from nondecliners to dementia or AD, after accounting for the contribution of age, sex, education, follow-up interval, and the rating of global clinical status. When examined in combination with the other factors or alone, the cognitive tests produced reasonably high specificities (91%-97%) and sensitivities (73%-89%). Using the obtained regression model, a similar level of classification accuracy was replicated on an independent sample of 119 nondemented elderly. A subanalysis of the high-risk GDS 3 subgroup indicated that cut scores from the paragraph test distinguished nondecliners from decliners (overall accuracies 87%-91%), implying that this assessment may accurately predict future cognitive status in elderly with mild cognitive impairment.

Medical and economic benefit of a comprehensive infection control program that includes routine determination of microbial clonality

Nosocomial infections are a major part of the problem of reemerging pathogens causing infectious diseases, affecting 5% of patients hospitalized in the United States during 1995. We assessed the medical and economic effects on the overall nosocomial infection rate of an intervention that provided an enhanced, integrated infection control program, including an in-house molecular typing laboratory capability to rapidly assess microbial clonality. Data on nosocomial infections for 24 months prior to the change in approach to infection control were compared with data from the 24 months immediately following implementation of the new program. Infections per 1,000 patient-days and percentage of hospitalized patients in whom nosocomial infection developed were assessed. Overall, nosocomial infections per 1,000 patient-days decreased more than 10% (P = .027), and percentage of patients with nosocomial infection decreased 23% during the post-intervention period compared with the previous control 24 months. This translated to a mean reduction of some 270 patients per year with nosocomial infection, and lowering of actual health care costs for our institution by $4,368,100 over the 2 years of the intervention.

Equilibrium and limb coordination in mild cognitive impairment and mild Alzheimer's disease

OBJECTIVE

To examine changes in equilibrium and limb coordination in normal aging, mild cognitive impairment, and moderate cognitive impairment associated with early probable Alzheimer's disease (AD), by means of parametric clinical measures.

DESIGN

Case series

SETTING

Out-patient clinic.

PARTICIPANTS

A consecutive sample of 365 community-residing ambulatory volunteers (137 men, 228 women; mean age 70.4 +/- 9.4 years; mean educational attainment 14.6 +/- 3.1 years), who were followed in an ongoing longitudinal study of aging and AD, comprising cognitively intact individuals, persons with mild cognitive impairment, and patients with mild AD.

MEASUREMENTS

For general magnitude of cognitive function, the Global Deterioration Scale (GDS). For cognition, the Mini-Mental State Examination (MMSE). Equilibrium was assessed with parametric measurements of single leg stance (SLS) and tandem walking (TW). Limb coordination was assessed with parametric measurements of foot tapping (FT), alternating pronation and supination (PS), and sequential finger to thumb tapping (FTH).

MAIN RESULTS

After adjustment for age, persons with mild cognitive impairment or mild AD had significantly poorer performance on parametric clinical tests of equilibrium and limb coordination compared with cognitively intact individuals (P < .05).

CONCLUSIONS

Changes in equilibrium and limb coordination are clinically demonstrable in persons with mild cognitive impairment and mild AD using simple parametric tests. Such tests could potentially identify individuals with increased risk of falling. Early diagnosis and treatment of conditions that can jeopardize equilibrium and limb coordination, as well as balance and coordination training, might help cognitively impaired older people to maintain optimal function and may decrease the risk of falls and injuries.

Towards a science of Alzheimer's disease management: a model based upon current knowledge of retrogenesis

BACKGROUND

General relationships between dotage and infancy and childhood have been acknowledged for more than two millennia. Recent findings indicate precise relationships between functional, praxic, and feeding changes in the course of the degenerative dementia of Alzheimer's disease (AD) and inverse corresponding developmental sequences. Similar inverse relationships between AD and human development can be described for cognition and language skills; for physiologic measures of electroencephalographic activity, brain glucose metabolism, and developmental neurologic reflex changes; and for the neuropathologic and neuroanatomic progression of these processes. In AD, these processes may be termed "retrogenesis." The relevance of the retrogenesis model for AD management is explored.

METHOD

The functional stages of AD can be translated into developmental age equivalents that can be utilized to explicate observed changes in the disease.

RESULTS

The retrogenesis-based developmental age model can usefully inform an understanding of the general care needs, emotional and behavioral changes, and activity needs of the AD patient. This model must be amended by necessary caveats regarding physical differences, variations in age-associated pathology, differences in social and societal reactions, and differences in background between AD patients and their developmental age "peers."

CONCLUSIONS

Knowledge of retrogenesis and the developmental age of the AD patient can form a nidus for the development of a nascent science of disease management. Such a science must ultimately incorporate not only appropriate caveats but also relevant universal human needs, such as those for dignity, love, and movement.

Cerebellar atrophy in Alzheimer's disease-clinicopathological correlations

Morphometry of the cerebellum of 11 subjects who died in the severe, final stage of Alzheimer's disease (AD) and of five age-matched subjects without dementia revealed significant atrophy in the AD group, with a decrease in the volume of the molecular layer by 24% and of the granular layer by 22% in comparison with controls. The 32% decrease in the total number of Purkinje cells that was observed correlates with the atrophy of the molecular layer, whereas the 30% reduction in the total number of granule cells correlates with the atrophy of the molecular and granular layers. A unique pattern of Alzheimer-type pathology was observed in the cerebellum: (1) there were no neurofibrillary changes in the cerebellum of either the control or the AD subjects, (2) there was almost the same extent of leptomeningeal and cortical amyloid angiopathy in the normal aged subjects and in the AD patients, and (3) the presence of plaques was noted in the AD group, but not in the control group. This pattern of pathology suggests that two factors might be considered in the etiopathogenesis of cerebellar atrophy: (1) transneuronal degeneration and neuronal loss resulting from primary pathologic changes in cerebral structures and (2) parenchymal cerebellar ss-amyloidosis. The correlation between the temporal duration of AD and both the decrease of the total number of granule cells (r=0.86, p<0.01) and the volumetric loss of the molecular (r=0.73, p<0.05) and granular (r=0.93, p<0.001) layers of the cerebellar cortex indicates that these cerebellar atrophic changes are likely to be related to the basic pathologic process of AD. Similarly, the correlation between the most complex parameter the atrophy of the cerebellar cortex and the Functional Assessment Staging (FAST) measure of the clinical severity of AD at the time of demise (r=0.63, p<0.05) as well as with the duration of AD (r=0.78, p<0.01) indicates that cerebellar pathology, when viewed holistically, evolves continuously in association with clinical changes throughout the clinically manifest course of AD.

Progression of Alzheimer's disease: variability and consistency: ontogenic models, their applicability and relevance

Much has been learned about the clinical symptomatology of Alzheimer's disease (AD) and ontogenic reciprocal relationships in the past few decades. It is now possible to describe and verify inexorable symptomatic sequences and corresponding temporal relationships. It is also possible to identify more variable symptoms in AD. Ontogenic models can be useful in providing a clearer understanding of the nature of AD symptomatology in terms of both consistency and variability. These models can also be informative in explicating the management needs of AD patients and the treatment possibilities of AD symptoms as well as the etiology of variability in AD symptoms.

Neuronal and volume loss in CA1 of the hippocampal formation uniquely predicts duration and severity of Alzheimer disease

In a series of multiple regression models predicting either duration or severity of Alzheimer disease (AD) patients, significant linear correlations were found consistently for the volume of CA1, the subiculum, and the entorhinal cortex. Similarly, the total number of neurons in CA1, CA4, and the subiculum was correlated significantly with both the duration and the severity of AD. A hierarchical multiple regression model was used to examine whether any of these intercorrelated measures had any unique relationship to disease duration or severity. The results showed that only CA1 demonstrated a unique contribution to the explained variance in predicting duration or severity of AD for volume and for neuronal numbers. These results indicate that in the hippocampal formation, volume and neuronal numbers of CA1 appear to show a unique relationship with clinical measures of AD.

Reliability of routine clinical instruments for the assessment of Alzheimer's disease administered by telephone

We investigated the reliability, using a telephone interview procedure, of cognitive, functional, and behavioral scales in an elderly population with normal aging and dementia. Two clinicians performed the assessments: one performed the assessments in a telephone interview format and the other conducted the assessments at the clinic. The telephone interview always preceded the clinic evaluation (2-30 days apart), and both clinicians were blind to any previous evaluations of the patient. The intraclass correlation coefficients between the telephone interview and the ratings obtained by a different clinician on the clinic evaluation varied between 0.92 and 0.98 (P's < or = .001) for comprehensive test scores. These results indicate that a telephone interview format, although not a substitute for a face-to-face diagnostic evaluation, is a reliable procedure for obtaining the assessment modalities studied. These findings are particularly important in aged and dementia research populations where personal contact may not always be feasible.

Management of fluoroquinolone resistance in Pseudomonas aeruginosa--outcome of monitored use in a referral hospital

We evaluated a strategy designed to improve useful activity of ciprofloxacin against Pseudomonas aeruginosa. Following changes in antimicrobial agent use made by the institutional Pharmacy and Therapeutic Drug Committee, monthly drug usage and microbial susceptibility records from June 1992 through October 1995 were reviewed. From July 1992 through October 1992 (Period 1), ciprofloxacin and ofloxacin usage represented 95 and 5% of total quinolone doses; from December 1992 to March 1993 (Period 2), ciprofloxacin represented 19%; from July 1993 to October 1993 (Period 3), ciprofloxacin usage represented 85%; from July 1994 to October 1994 (Period 4), ciprofloxacin represented 95%; and from July 1995 to October 1995 (Period 5), ciprofloxacin and ofloxacin respectively represented 98 and 2% of total quinolone doses. Comparison of the anti-pseudomonal activity of the two fluoroquinolones to ofloxacin use, ciprofloxacin use and total quinolone use during the entire observational period showed the highest (negative) correlation with ofloxacin use versus ofloxacin activity (y = -15.04x + 1367.99, r2 = 0.06, w = 0.126). Increased use of quinolones plus a change to primarily ofloxacin usage appeared to adversely affect the activity of both ofloxacin and ciprofloxacin against P. aeruginosa.

Duration of neurofibrillary changes in the hippocampal pyramidal neurons

The total number of neurons with and without neurofibrillary changes in sectors CA1 to CA4, subiculum, and dentate gyrus of 16 subjects with Alzheimer disease (AD) was estimated. The duration of neurofibrillary changes was calculated on the basis of regressions between the duration of AD and neuronal numbers. In the CA1 and subiculum, it takes 3.4 and 5.4 years, respectively, for an intact neuron affected by neurofibrillary pathology to become a ghost tangle.

The GDS/FAST staging system

Staging methodologies are an essential tool in the assessment of disease severity in progressive dementing illness. Several different instruments have been developed for this purpose. One of the most widely used methodologies is the Global Deterioration Scale/Functional Assessment Staging (GDS/FAST) system. This system has been studied extensively and proven to be reliable and valid for staging dementia in Alzheimer's disease (AD) in diverse settings. One of the major advantages of this system is that it spans, demarcates, and describes the entire course of normal aging and progressive AD until the final substages of the disease process. Other advantages include: (a) greatly enhanced ability to track the longitudinal course of AD, (b) improved clinicopathologic observations of AD interrelationships, and (c) enhanced diagnostic, differential diagnostic, and prognostic information. This article presents a brief overview of the GDS/FAST staging system.

Neurologic markers of the progression of Alzheimer's disease

This article describes the results of studies conducted to determine the usefulness of reflex changes as markers of disease severity in Alzheimer's disease (AD). Standardized and quantified muscle stretch reflexes, cutaneous reflexes, and developmental (primitive) reflexes were studied in normal older adults, in individuals with mild memory impairment, and in patients with AD, in all clinical severity stages as assessed with the Global Deterioration Scale (GDS), the Mini-Mental State Examination (MMSE), and the Functional Assessment Staging (FAST) procedure. Changes in frequency and intensity of these individual reflex variables, as well as of variables consisting of combinations of these individual reflexes, appeared to be sensitive indicators of the progression of AD. These neurological reflex variables showed high Pearson correlations with the GDS (.72), the MMSE (.74), and the FAST (.80). Standardized quantified neurological reflex measures are useful as noncognitive, education-independent, and culture-independent markers of the course of AD.

Motor/psychomotor dysfunction in normal aging, mild cognitive decline, and early Alzheimer's disease: diagnostic and differential diagnostic features

To determine the association between cognitive dysfunction and motor behavior in older adults, 41 cognitively normal elderly (NL), 25 nondemented patients exhibiting mild cognitive impairment (MI) and at risk for future decline to dementia, and 25 patients with mild (early) Alzheimer's disease (AD) were examined using a wide array of motor/psychomotor and cognitive assessments. The three groups were recruited from an aging and dementia research center and were composed of well-characterized physically healthy volunteers, with similar ages and gender distributions. The outcome measures included 16 motor/psychomotor tests categorized a priori into gross, fine, and complex, as well as eight cognitive tests of memory and language. Relative to the NL group, MI individuals performed poorly on cognitive, fine, and complex motor measures but not on gross motor tests; AD patients performed worse on cognitive and all motor domains. Differences in complex motor function persisted after adjustment for performance on cognitive and on less complex motor tests. Classification analyses showed similar accuracies in discriminating NL from MI and NL from AD cases for both complex motor (79% and 92% accuracy, respectively) and cognitive tests (80% and 93% accuracy, respectively). Less complex motor tests produced poorer accuracies. Among nondemented subjects, education correlated with several cognitive scores but no motor scores. These results indicate that motor impairment is an important aspect of cognitive decline in older adults. Motor/psychomotor assessments were found to be comparably sensitive to traditional tests of cognitive function in identifying persons affected by the earliest stages of AD pathology and may improve identification of at-risk nondemented elderly, especially among diversely educated individuals.

Diagnosis of Alzheimer's disease. Report of an International Psychogeriatric Association Special Meeting Work Group under the cosponsorship of Alzheimer's Disease International, the European Federation of Neurological Societies, the World Health Organization, and the World Psychiatric Association

Current knowledge with respect to the diagnosis of Alzheimer's disease (AD) is reviewed. There is agreement that AD is a characteristic clinicopathologic entity that is amenable to diagnosis. The diagnosis of AD should no longer be considered one of exclusion. Rather, the diagnostic process is one of recognition of the characteristic features of AD and of conditions that can have an impact on presentation or mimic aspects of the clinicopathologic picture. The present availability of improved prognosis, management, and treatment strategies makes the proper, and state-of-the-art, diagnosis of AD a clinical imperative in all medical settings. Concurrently, information regarding the relevance and applicability of current diagnostic procedures in diverse cultural settings must continue to accrue.

Informant-rated activities-of-daily-living (ADL) assessments: results of a study of 141 items in the U.S.A., Germany, Russia, and Greece from the International ADL Scale Development Project

The analyses of an international pilot study presented in this article focused on the development of a cross-nationally valid activities-of-daily-living (ADL) scale sensitive to therapeutic effects in patients with mild memory impairment and mild to moderately severe dementia. The present report, which is part of an ongoing international research project, describes field testing results for 141 informant-rated items. The comparability of samples investigated in research centers in the U.S.A., Germany, Russia, and Greece concerning cognitive decline was evaluated globally as well as psychometrically using the Global Deterioration Scale, the Short Cognitive Performance Test, and the Mini-Mental State Examination. In the participating countries, a composite ADL score discriminated well between different stages of cognitive impairment because of dementia. However, international differences between the applied measures were observed. A practical ADL scale showing therapeutic sensitivity and international utility, will be constructed from the 141 informant-rated items under investigation in this pilot work.

Clinical global measures of dementia. Position paper from the International Working Group on Harmonization of Dementia Drug Guidelines

Following is the report of the committee working on clinical global measures for antidementia drug guidelines. The concepts involved in global scales, the distinctions between change and severity scales, advantages and disadvantages of structured interviews, and anchoring of change scores are discussed, and selected existing clinical global scales are described. In addition, the committee assessed the utility of global scales in clinical trials for antidementia drugs. There was a consensus among the members of the working group on the following: (1) Clinical global scales are interview based; in most cases, they include information obtained from caregivers as well as directly from patients, but they can rely on information from the subject only. (2) Clinicians' global ratings are intended to assess clinically meaningful change based on multidimensional clinical assessment and take into account the clinical heterogeneity of dementia by assessing at least cognition, behavior, and functioning. (3) There are two distinct types of clinical global measures: (a) clinicians' interview-based global severity scales, which generally incorporate classification by stage or severity of illness and (b) clinicians' interview-based global change scales, which incorporate global assessment ratings of clinical change. The committee could not reach a consensus on whether global scales should be required in phase II and phase III clinical trials, or whether other specific assessments such as well-designed activities of daily living, cognition, and behavior measures could, when used in appropriate combinations, replace the global as assessments of clinical meaningfulness.

Neuromotor changes in Alzheimer's disease: implications for patient care

As a result of the neuropathologic process of Alzheimer's disease (AD), significant changes occur in neuromotor function (e.g., paratonia and compulsive grasping). These changes become manifest in the moderately severe stage of AD, when patients begin to require ongoing assistance with activities of daily life (ADL), and they are prominent in the severe stage of AD, when patients are continuously dependent on a caregiver. Patients in these stages often display behavioral disturbances during care activities. These disturbing behaviors result not only from cognitive impairment, but also from a patient's physical inability to cooperate with the caregiver. When care management strategies take into account the characteristic physical restrictions resulting from the neuromotor changes that accompany advanced AD, the caregiving process may be significantly facilitated.

Relationships between regional neuronal loss and neurofibrillary changes in the hippocampal formation and duration and severity of Alzheimer disease

The total numbers of neurons with and without neurofibrillary changes in the hippocampal subdivisions were estimated in 16 subjects with Alzheimer disease (AD) and in 5 normal elderly controls. On the basis of clinical symptoms, AD patients were subdivided into relatively less (AD-1. Functional Assessment Staging [FAST] stages 7a to 7c) and more severely affected (AD-2, FAST stages 7e to 7f) patient groups. In the AD-1 group relative to controls, the total number of neurons was reduced only in CA1 and in the subiculum. In the AD-2 group, neuronal losses were found in all sectors of the cornu Ammonis and in the subiculum and ranged from 53% in CA3 to 86% in CA1. The dentate gyrus was the only hippocampal subdivision without significant neuronal loss. Within the combined AD patient groups, significant correlations were noted between both clinical stage and duration of AD and both the total number of neurons and the percentage of neurons with neurofibrillary changes in CA1, CA4, and the subiculum. Regression analyses predicted neuronal losses over the maximal observed duration of 22 years of 87% in CA1, 63% in CA4, and 77% in the subiculum. Our data suggest that over the course of AD, continuous neurofibrillary tangle formation and continuous neuronal loss occur in the hippocampal subdivisions. The rate of neuronal loss appears to be similar for CA1, CA4, and the subiculum.

Patterns of motor impairement in normal aging, mild cognitive decline, and early Alzheimer's disease

In order to determine the relationship between cognitive dysfunction and motor behavior in older adults, 41 cognitively normal elderly (NL), 25 cases exhibiting mild cognitive impairment (MI), and 25 patients with mild Alzheimer's disease (AD) were examined using a broad array to motor/psychomotor and cognitive tests. Relative to the NL group, MI individuals (at risk for future decline to AD) performed worse on tasks involving fine and complex motor function (e.g., tracking and manual dexterity). AD patients also exhibited motor dysfunction on tasks assessing relatively more rudimentary motor control. Motor tasks were able to distinguish NL vs MI and NL vs mild AD individuals as effectively as cognitive tests of memory and language. These results indicate that motor impairment is an important aspect of cognitive decline in older adults. Motor/psychomotor assessments may be comparably sensitive to traditional tests of cognitive function in identifying persons affected by the earliest stages of AD pathology.

Utility of developmental reflexes in the differential diagnosis and prognosis of incontinence in Alzheimer's disease

Four developmental reflexes, the tactile suck reflex, the palmar and plantar grasp reflexes, and the plantar extensor reflex, were examined in 784 individuals, including healthy elderly, cognitively and functionally mildly impaired individuals, and patients with Alzheimer's disease (AD) in all stages of clinical severity. The study population was classified into six categories of increasingly impaired functional performance, and prevalence of the four individual reflexes and of a summary reflex measure, consisting of a combination of these four reflexes, was determined for each category. Prevalence of all five reflex measures was more than six times higher for those categories that comprised only permanently doubly incontinent patients as compared to those categories that comprised only continent individuals (P < .001). Frequency of developmental reflexes rose sharply with the onset of progressive incontinence. Since the return of these reflexes in AD is associated with severe cortical dysfunction, it is concluded that these developmental reflexes are useful in differentiating incontinence of cortical origin from incontinence resulting from potentially reversible causes.

Validity and reliability of the Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change. The Alzheimer's Disease Cooperative Study

This article reports the development and psychometric properties of the Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC). At present, a number of unvalidated CGIC scales are used in clinical trials, with various methods for making ratings. The ADCS-CGIC was designed on the basis of a survey of ADCS clinicians and by adapting existing instruments. It includes an organized but unstructured format, with which a clinician can address clinically relevant change. The instrument's reliability and validity were assessed in a prospective trial of Alzheimer's disease (AD) and healthy subjects over a 12-month period. It showed good short-term reliability at 1 and 2 months, with 90 and 94% of AD subjects, respectively, rated as having changed not at all or only minimally. The ADCS-CGIC's face validity was demonstrated by untreated. AD subjects rated as having worsened over time at both 6 months (56% rated as having worsened) and 12 months (81% rated as having worsened), whereas only 2% of control subjects showed minimal worsening. As a measure of predictive validity, ADCS-CGIC ratings at 12 months were significantly associated with change on four severity scales. As with other measures, change ratings were sensitive to dementia severity. Moderately impaired subjects showed greater worsening than other subjects. ADCS-CGIC ratings of greater worsening were made after the informant interview, regardless of whether informants or subjects were interviewed first. The ADCS-CGIC is a valid and reliable instrument for use in clinical trials.

Frequency of hippocampal formation atrophy in normal aging and Alzheimer's disease

We used CT and MR to examine the frequency of occurrence of hippocampal formation atrophy (HA) in a research clinic population of 130 normal elderly, 72 nondemented patients with very mild memory and cognitive impairments (MCI), 73 mild Alzheimer's disease (AD) patients, and 130 patients with moderate to severe AD. HA was found in 29% of the normal elderly group and its frequency of occurrence was strongly related to increasing age. For normal elderly 60-75 years of age, 15% had HA: the proportion rose to 48% in subjects 76-90 years of age. Among the three groups of impaired patients, the frequencies of HA ranged from 78% in the MCI patients to 96% in the advanced AD group. Unlike the normal elderly group, the percentages were not related to age. In both the normal elderly group and MCI group disproportionately more males than females had HA. After controlling for learning and the effects of generalized brain changes as reflected in ventricular size, only in the normal group was HA associated with reduced delayed verbal recall performance. Follow-up examinations for 15 individuals with baseline HA. 4 who at entry were MCI and 11 probable AD, yielded clinical and neuropathologic diagnoses of AD in all cases. The results of the present study indicate that hippocampal formation atrophy is associated with memory and cognitive impairments. Further longitudinal and neuropathologic work is required to validate the relationship between hippocampal formation atrophy and AD.

Neurofibrillary pathology--correlation with hippocampal formation atrophy in Alzheimer disease

The three-dimensionally reconstructed hippocampal formations in three patients with very severe, immobile Alzheimer disease (AD) and three age-matched nondemented individuals were examined for a correlation between atrophy of hippocampal formation subdivisions and neurofibrillary changes, neuronal loss, and extent of amyloid deposition in plaques and vessels. In AD, a similar severe volume loss was observed in both cellular layers and layers composed of fibers. A strong correlation between the decrease in the volume of hippocampal formation subdivisions and the decrease in the total number of neurons suggests a causative role for neuronal loss in hippocampal formation volumetric loss. Strong regional correlations between the relative decreases in the total number of neurons and the relative increases in the total number of neurofibrillary tangles implicates neurofibrillary pathology as a possible etiologic proximate factor in neuronal and volumetric loss in the hippocampal formation of AD patients.

Clinical evaluation of global change in Alzheimer's disease: identifying consensus

It is important that clinicians who rate global change as part of Alzheimer's disease (AD) clinical drug trials agree on a relevant set of behaviors and information to be considered in formulating their rating. Yet, consensus among raters has been difficult to establish, and inter-rater reliability of clinical global impression of change (CGIC) ratings has been low. In preparation for the development of a new CGIC scale to be used in AD clinical trials, the Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC), we surveyed clinicians at sites comprising the National Institute on Aging-sponsored ADCS participating centers to identify whether or not consensus regarding CGICs exists. Overall, respondents reported that a CGIC should include an assessment of the patient's function and mental status, a care giver interview, and a standardized set of questions, and it should take approximately 20 minutes per interview. Depending on a patient's level of impairment, raters consider different areas of behavior in formulating a CGIC rating. These findings demonstrate the considerable consensus regarding the CGIC rating process, and were integrated into the design of the ADCS-CGIC, currently in use.

Staging methods for the assessment of dementia: Perspectives

Most dementias in old age are characterized by a progressive course with interindividual variability in pattern and rate of progression. Developing a system for staging such dementia poses a challenge in capturing this variability in a system that will afford comparisons among individuals and predictions of future change. Several core questions underlie the development of such systems: (1) Is there a definable order in which abilities are lost? (2) Which skills and functions should be considered essential for the staging of dementia and what is their relative weight? (3) Can the different skills be captured within one staging system? (4) How is the whole range of function captured, and are the differences between stages clearly defined? (5) Which populations can be rated with each staging system? The determination of this last question is based on understanding which other medical conditions may interfere with the course of dementia and how prior characteristics, such as education, affect ratings on specific scales for the staging of dementia. Several systems for staging dementia in older adults are described. These include the Clinical Dementia Rating, the Global Deterioration Scale/Brief Cognitive Rating Scale/Functional Assessment Staging System, the Six Clinical Phases of Cognitive Decline, the Hierarchic Dementia Scale, and the Functional Capacity Scale. Some aspects of the utility of these systems are reviewed, and the issues for further research are discussed.

Mortality and temporal course of probable Alzheimer's disease: a 5-year prospective study

Alzheimer's disease (AD) is associated with an increased mortality in comparison with aged control populations. The relationship between the clinical and the temporal course of AD has not been well studied over significant intervals. Community-residing patients with probable AD (N = 103, 42 men, mean age = 70.2 +/- 8.0 years) were studied at baseline on demographic and clinical variables, including measures of global deterioration (Global Deterioration Scale; GDS), mental status and cognition (e.g., Mini-Mental State Examination; MMSE), and functional impairment (Functional Assessment Staging; FAST). Baseline characteristics included a GDS range of Stage 4, 5, or 6 (38.8%, 39.8%, and 21.4%, respectively) and a mean MMSE score of 15.4 +/- 5.6. The mean follow-up interval was 4.6 +/- 1.4 years. Follow-ups were done blind to baseline measures and when necessary were conducted in residential and nursing home settings. Of locatable subjects (n = 95, 92%), 30 (31.6%) were decreased. Survivors (n = 65) had a mean GDS stage of 6.2 +/- 0.9 and a mean MMSE score of 5.1 +/- 6.9; 51% had MMSE scores of 0. Increased age and male gender, but not baseline clinical dementia variables, increased the risk of death (ps < .01). Change in clinical variables correlated significantly with time elapsed (r = .32, p < .05, for MMSE change, to r = .48, p < .001, for GDS change). Significant variance in temporal change (i.e., time elapsed) was accounted for by change in two of the five clinical measures studied (i.e., GDS and FAST; multiple r = .53). The results support previous estimates of mean duration of the GDS and FAST stages. For subjects with probable AD followed over approximately 5 years, clinical variables changed significantly over time in survivors. However, the majority of temporal variance in the course of AD remains unexplained.

Overview of methodologic issues for pharmacologic trials in mild, moderate, and severe Alzheimer's disease

To address the issue of mild, moderate, and severe Alzheimer's disease (AD), it is necessary to initially establish some agreement on terminology. In recent decades, these terms have frequently been defined using screening instrument scores with measures such as the Mini-Mental State Examination (MMSE). There are many problems with this approach, perhaps the most salient of which is that it has contributed to the total and tragic neglect of patients with severe AD. An alternative approach to the classification of AD severity is staging. This approach has advanced to the point where moderately severe and severe AD can be described in detail. Procedures for describing this previously neglected latter portion of AD have recently been extensively validated. Staging is also uniquely useful at the other end of the severity spectrum, in differentiating early aging brain/behavior changes, incipient AD, and mild AD. Temporally, with staging procedures, it is possible to track the course of AD approximately three times more accurately than with the MMSE. The net result of the advances in AD delineation is that issues such as prophylaxis, modification of course, treatment of behavioral disturbances, loss of ambulation, progressive rigidity, and the development of contractures in AD patients can now be addressed in a scientifically meaningful way that will hopefully bestow much benefit in AD patients and those who care for them.