Validity of the ischemic score in degenerative and vascular dementia and depression in old age

Thirty six male and 45 female patients (mean age 66 years) suffering from either dementia of Alzheimer type (DAT) or dementia of vascular type (DVT) with comparable severity and suffering from depression in old age were included in the investigation. The study was performed to evaluate the diagnostic value of Ischemic Score, EEG and CT scan of the brain in differentiating dementia types and depression in old age. The patients underwent physical, psychiatric, psychometric, neurological, neurophysiological and CT scan examinations. Clinical diagnosis and diagnosis related to Ischemic Score were consistent in 86% of DAT and in 65% of DVT. Patients suffering from DVT showed significantly higher incidence of distinct Ischemic Scale items than was found in DAT patients. The Ischemic Scale items were found to be of major importance in differentiating vascular dementia from both DAT and depression. However, it was insufficient to distinguish between the latter two. In EEG, general slowing predominated in DAT (68%), and focal disturbances in DVT (71%). Patients with DAT and depression could not be differentiated on the basis of their EEG findings. CT scans of the brain yielded a higher incidence of brain atrophy in patients with DAT (71%) and DVT (70%) as compared to depressive patients (37%). In DAT, ventricular enlargement seems to be rather disease- than age-related. Psychological testing showed abnormalities in attention and memory performance in DAT and DVT to a significantly greater extent as compared to depression. This study demonstrated that the combination of Ischemic Score and EEG was found to be most valid in differentiating DAT from DVT. Additional cranial computerized tomography and the psychological testing of attention and memory were able to confirm the diagnosis of dementia and to differentiate dementia from depression in old age.     

Assessment and treatment of patients with dementia of the Alzheimer type]

Recently more than a dozen clinical trials for dementia of the Alzheimer type (DAT) have been conducted in Japan using almost the same diagnostic criteria and assessment procedures. Cholinomimetic drugs such as AChE or M1 agonist are the most common in the current clinical drug trials. DSM-IIIR and NINCDS-ADRDA are usually employed as diagnostic criteria. In the recent report on the sensitivity and specificity of these diagnostic criteria, it has been indicated that the clinician or researcher who wishes to ensure that patients classified as DAT are more likely DAT should choose DSM-III, whereas the investigator who wishes to include the greatest number or DAT cases, seldom assigning a diagnosis of no DAT to a true case, should choose NINCDS-ADRAD. Also, development of exclusion criteria for DAT would be essential to improve interrater reliability of these diagnostic criteria. In the recent clinical trials outside Japan, a dual assessment procedure consisting of objective psychometric test(s) to assess cognitive impairment and global clinical impression of change is a standard method to evaluate the clinical efficacy of drugs for DAT. In psychometric tests, Alzheimer's Disease Assessment Scale (ADAS) is the most common in the US and Hasegawa's Dementia Scale (HDS) in Japan. A Japanese version of ADAS-cog. has been already developed for use in clinical trials in Japan. Also, HDS has recently been revised to improve the sensitivity of the test. In addition, Clinical Dementia Rating (CDR) that is one of the common measures staging severity of dementia in Japan might be a better alternative to the conventional Clinical Global Impression of Change (CGIC) in the US.(ABSTRACT TRUNCATED AT 250 WORDS)     

Accuracy of collateral source reports in very mild to mild dementia of the Alzheimer type

OBJECTIVES: To examine the reporting accuracy of collateral sources (knowledgeable informants) regarding very mild and mild dementia of the Alzheimer type (DAT) and to identify characteristics associated with collateral source accuracy. DESIGN: Secondary data analysis of initial visits of individuals enrolled in a longitudinal study of healthy aging and Alzheimer disease. SETTING: Urban Alzheimer disease research center. PARTICIPANTS: Pairs of 515 individuals with very mild (n = 203) or mild (n = 312) DAT and their collateral sources. MEASUREMENTS: Collateral sources were asked separately during a semistructured interview by experienced clinicians to report current ability of the individual with DAT in memory, orientation, and judgment and problem solving. The clinical performance of the individuals with DAT in these domains was compared with these predictions. RESULTS: Collateral sources were consistently and significantly accurate in reporting the cognitive capabilities of individuals with very mild and mild DAT. Although all types of collateral sources performed significantly better than chance, individual variables that correlated with collateral source accuracy included spousal relationship; living with the individual with DAT; frequent exposure to the individual; and age, education level, sex and dementia severity of the individual with DAT. CONCLUSION: Collateral sources are accurate in reporting the cognitive capabilities of individuals with DAT, even in the very mild stage of dementia.     

The abnormally aged brain. Its blood flow and oxidative metabolism. A review — Part II

The most common brain disease in middle and old age is dementia. Primary dementias comprise degenerative (dementia of Alzheimer type, DAT) and cerebrovascular (dementia of vascular type, DVT) types. These dementia types differ in morphological, clinical, and pathobiochemical terms. In DAT, large amounts of neuritic plaques and neurofibrillary tangles or paired helical filaments, are present throughout the whole brain cortex, but particularly numerous in temporal areas. Here and in hippocampus, the presynaptic cholinergic system seems to be predominantly affected. In DVT, multiple small infarcts are scattered over brain cortex and white matter obviously due to disturbances in cerebral microcirculation. Dementia is closely related to disturbances in brain blood flow and oxidative metabolism. In the beginning of DAT, cerebral blood flow and CMR-oxygen are found to be in normal ranges, but CMR-glucose is reduced. In DVT, cerebral blood flow and CMR-oxygen are also within the normal range, but CMR-glucose is found to be abnormally increased. When dementia symptoms are well developed in DAT, the same relationship between circulation and metabolism are found. Well-developed DVT symptoms seem to be associated with changes in blood flow and metabolism similar to variations after ischemic/anoxic lesions. In the beginning of both dementia types, a close correlation exists between cerebral blood flow and CMR-oxygen, but there is a dissociation from CMR-glucose. In the further course of both dementia types, cerebral blood flow and metabolism run into a final common path of a low functional level. No distinction between the dementia types is possible. In general, severity of dementia symptoms are correlated to the deviation of cerebral blood flow and metabolism from normal. There is much evidence that dementia, i.e. abnormal cerebral aging is different from normal cerebral aging. Dementia is not a form of accelerated cerebral aging.     

EEG changes in senile dementia of the Alzheimer type

Character and extent of changes in EEG in 45 patients with senile dementia of Alzheimer type (SDAT) were reported and the EEG-findings of patients with moderate (18) or severe (27) dementia were compared. The EEG-findings in these patients were compared with a group of 82 patients with multi-infarct dementia (MID). The EEG showed pathological results in 37 patients with predominating general changes (59%). In patients with severe dementia significantly more pathological results especially a significantly slower basic rhythm could be found. The degree of the cerebral atrophy verified by CT did not correspond with character and extent of the changes in EEG. The comparison between patients with SDAT and 82 patients with MID, revealed a significantly more frequent occurrence of unilateral slowing of the basic rhythm but a less frequent occurrence of focal changes. However, there was no significant difference in the number of normal and pathological EEG. The comparison between patients with SDAT and patients with MID without neurological deficit failed to show a significant difference in the number of normal and pathological EEG as well. It could be shown that in patients with severe dementia the EEG revealed significantly more pathological results as well as a significantly slower basic rhythm. However, the EEG could not differentiate between SDAT and MID.     

Issues in memory assessment of the elderly

The pattern of memory test performance by elderly individuals demonstrates significant overlap between populations. Consequently, the memory tests themselves poorly differentiate normal aging, dementia, and depression. The additional problem of relatively little adequate normative information for elderly individuals compounds this problem. Thus, inferences regarding the nature of assessed deficits should be based in part on information that extends beyond the traditional quantitative numerical analyses of test performances. For example, depressed individuals tend to make fewer false-positive responses and frequently will respond stating "I don't know." Similarly, if there is evidence for risk of memory impairment, the threshold for inferring assessed memory deficit may be altered. Finally, when independent information is present to confirm the presence of structural change in the brain, the inference of specific memory impairments can be strengthened. One not only needs to look at the entire pattern of neuropsychological deficits, but also use the neuropsychological findings in the context of other clinical findings. Perhaps the greatest utility of neuropsychological memory assessment of the elderly is providing standardized assessments for repeat evaluations. By repeating the assessment, deterioration as a function of a progressive dementia can be assessed. Alternatively, the effect of treatment for depression can be monitored and an improvement in memory test scores would be expected. Throughout, however, the careful clinician will remember that the inferences regarding an individual's level of function are not stronger than the reliability, representativeness, and validity of the instruments employed.     

Longitudinal diagnosis of memory disorders.

Early referral for specialist assessment is becoming more common with memory disorders and dementia: the mean Mini-Mental State Examination (MMSE) score of new patients at our clinic rose from 18.7 to 20.7 between 1986 and 1990. The clinical diagnosis of mild to moderate dementia has been recognized to be difficult, but several studies have reported cross-sectional diagnosis. We examined the number of visits required to establish a clinical diagnosis of dementia in the first 125 patients attending a Memory Disorders Clinic who had at least two visits (six months apart) and the stability of the diagnoses. Just under half of the patients required at least two visits to establish the clinical diagnosis. The MMSE was not a good guide to the number of visits required but the diagnosis at the first visit remained stable in all patients who scored < or = 10/30. Sixteen per cent of patients interchanged between the categories of Alzheimer's, mixed and vascular dementias. Possible age-associated memory impairment progressed to dementia in six of eight cases, and depression to dementia in three cases. The diagnosis of mild to moderate dementia should not be restricted to a cross-sectional approach, but should involve serial clinical, psychological and affective assessments.     

Low Body Mass Index in demented outpatients

In order to determine the association between dementia and low body weight in outpatients, Body Mass Index (BMI) was evaluated prospectively in 346 frail elderly outpatients presenting for comprehensive geriatric assessment. Patients were categorized into four groups (cognitively intact, dementia of the Alzheimer's type (DAT), other dementia, and patients with depressive symptoms). Patients were assessed for severity of dementia by the Clinical Dementia Rating scale. Differences between groups for various clinical parameters were evaluated using an analysis of variance and Duncan's Multiple Range Test. Patients with dementia, regardless of etiologic type or severity, and patients with depressive symptoms had BMI's greater than or equal to 10% lower than the cognitively intact patients. BMI was positively correlated with Instrumental Activities of Daily Living (IADL) but not Activities of Daily Living (ADL) or Mini-Mental State Exam (MMSE) score. Low BMI was not associated with increased physical illness. In fact, in the subset of patients with DAT, lower BMI correlated with significantly lesser amounts of comorbid physical illness. Finally, compared to cognitively intact outpatients, patients with DAT appeared to be physically healthier despite their having a lower BMI. These results suggest an association between dementia and low BMI. On the other hand, the presence of comorbid physical illness, a common focus of evaluation in these patients, was not more common in those patients with lower BMI's.     

Comparison of the quick mild cognitive impairment (Qmci) screen and the SMMSE in screening for mild cognitive impairment

Introduction: differentiating mild cognitive impairment (MCI) from normal cognition (NC) is difficult. The AB Cognitive Screen (ABCS) 135, sensitive in differentiating MCI from dementia, was modified to improve sensitivity and specificity, producing the quick mild cognitive impairment (Qmci) screen. Objective: this study compared the sensitivity and specificity of the Qmci with the Standardised MMSE and ABCS 135, to differentiate NC, MCI and dementia. Methods: weightings and subtests of the ABCS 135 were changed and a new section 'logical memory' added, creating the Qmci. From four memory clinics in Ontario, Canada, 335 subjects (154 with MCI, 181 with dementia) were recruited and underwent comprehensive assessment. Caregivers, attending with the subjects, without cognitive symptoms, were recruited as controls (n?=?630). Results: the Qmci was more sensitive than the SMMSE and ABCS 135, in differentiating MCI from NC, with an area under the curve (AUC) of 0.86 compared with 0.67 and 0.83, respectively, and in differentiating MCI from mild dementia, AUC of 0.92 versus 0.91 and 0.91. The ability of the Qmci to identify MCI was better for those over 75 years. Conclusion: the Qmci is more sensitive than the SMMSE in differentiating MCI and NC, making it a useful test, for MCI in clinical practice, especially for older adults.     

Clinical significance of cerebral white matter lesions in older Asians with suspected dementia

BACKGROUND: cerebral white matter lesions are commonly seen on neuroimaging in older people and have been associated with clinical features such as gait abnormalities, urinary incontinence and depression. The significance of cerebral white matter lesions in older people with dementia remains uncertain. OBJECTIVES: to study the association between cerebral white matter lesions and the presence or absence of dementia in a group of elderly Asian patients; and to determine the clinical significance of cerebral white matter lesions in patients who are diagnosed to have dementia in terms of associated clinical features and the impact of cerebral white matter lesions on cognitive status. METHODS: for the first objective, the records of 141 older people of Asian ethnicity presenting to a memory clinic for the evaluation of suspected dementia were reviewed to compare the prevalence of cerebral white matter lesions in patients who did not fulfil the criteria for dementia, patients diagnosed to have Alzheimer's disease and patients diagnosed to have vascular dementia. For the second objective, 115 of these patients who were diagnosed to have dementia were studied to determine if demented patients with cerebral white matter lesions were more likely to have urinary incontinence, Parkinsonism, depression and greater severity of dementia. In addition, a comparison was made between demented patients with cerebral white matter lesions and those without cerebral white matter lesions in terms of psychometric assessment scores. RESULTS: cerebral white matter lesions were more common in Asian patients with vascular dementia. Demented patients with cerebral white matter lesions were also found to have more severe dementia and greater functional disability. CONCLUSION: cerebral white matter lesions are common, and are associated with greater functional disability in elderly Asian patients with dementia.     

Different accuracies of rapid enzyme-linked immunosorbent, turbidimetric, and agglutination D-dimer assays for thrombosis exclusion: impact on diagnostic work-ups of outpatients with suspected deep vein thrombosis and pulmonary embolism

The requirement for a safe diagnostic strategy should be based on an overall posttest incidence of venous thromboembolism (VTE) of less than 1%, with a negative predictive value of more than 99 to 100% during 3-month follow-up. Compression ultrasonography (CUS) and spiral computed tomography (CT) currently are the methods of choice to confirm or rule out deep venous thrombosis (DVT) and pulmonary embolism (PE), respectively. CUS has a negative predictive value (NPV) of 97 to 98%, indicating the need to improve the diagnostic work-up of patients with suspected DVT by clinical score assessment and D-dimer testing. Spiral CT as a stand-alone method detects all clinically relevant PEs and a large number of alternative diagnoses. It rules out PE with a NPV of 98 to 99%. Spiral CT is expensive, emphasizing the need to improve the diagnostic work-up of patients with suspected PE by the use of clinical score assessment and D-dimer testing. Clinical score assessment for DVT and PE has not safely ruled out VTE in multicenter studies and in routine daily practices. Modification of the Wells clinical score assessment for DVT by elimination of the "minus 2 points" for alternative diagnosis will improve the reproducibility of the clinical score assessment. The combination of a first negative CUS and a negative SimpliRed or an enzyme-linked immunosorbent assay (ELISA) VIDAS D-dimer of < 1,000 ng/mL safely exclude DVT (NPV > 99%) irrespective of clinical score assessment and without the need to repeat CUS in approximately 60 to 70% of patients. The rapid quantitative and qualitative agglutination D-dimer assays for the exclusion of VTE are not sensitive enough as stand-alone tests and should be used in combination with clinical score assessment. A normal rapid ELISA VIDAS D-dimer test as a stand-alone test safely excludes DVT and PE, with a NPV of 99 to 100%, irrespective of clinical score, without the need of CUS or spiral CT. The combined strategy of a rapid ELISA VIDAS D-dimer followed by objective testing with CUS for DVT and by spiral CT for PE will reduce the need for noninvasive imaging techniques by 40 to 50%.     

Quantitative evaluation of magnetic resonance imaging (MRI) abnormalities in subclinical hepatic encephalopathy

BACKGROUND/AIMS: Cirrhotic patients often demonstrate high signal intensity on T1-weighted magnetic resonance (MRI) images in basal ganglia with accumulation of manganese being the predominant causing factor. In these patients, electrophysiological tests and especially electroencephalogram (EEG) are considered to be the most sensitive methods in detection of subclinical hepatic encephalopathy. The aim of this study is to correlate MRI findings with biochemical parameters and EEG alterations in cirrhotic patients without clinically overt encephalopathy. METHODOLOGY: Twenty-two cirrhotic patients (16 males and 6 females, mean age of 65.2 +/- 9.5 years), classified according to Child-Pugh score, were submitted to brain MRI, neurological assessment (including psychometric tests and EEG) and complete biochemical testing. None of them had any clinical signs of brain dysfunction. MRI findings were evaluated both qualitatively (normal, mild, moderate and severe) and quantitatively with the ROI method. EEG alterations were also classified as normal, mild, moderate and severe. RESULTS: Statistical analysis revealed a significant linear association between EEG grading and MRI signal intensity (r2=0.248, p=0.035). Among clinical and biochemical parameters, overall Child-Pugh score and albumin levels were identified as significant predictors of the MRI signal intensity (p=0.006 and p=0.021 respectively). CONCLUSIONS: Although further investigation must be performed to confirm the clinical impact of brain MRI in hepatic cirrhosis, our study strongly suggests that MRI alterations are good predictors of liver and brain dysfunction in cirrhotic patients.     

Enhancing dementia care: a primary care-based memory clinic

Memory clinics have been promoted as opportunities for improving dementia diagnosis and care. This article describes the implementation of an interdisciplinary memory clinic within primary care in Ontario, Canada, that aims to provide timely access to comprehensive assessment and care and to improve referring physicians' knowledge of the management of dementia through collaborative care and practice-based mentorship. Between July 2006 and September 2009, 246 initial and follow-up assessments were conducted with 151 patients, a high proportion of whom received a new diagnosis of mild cognitive impairment (44.4%) or dementia (19.2%). A trial of cholinesterase inhibitors was recommended for almost all patients newly diagnosed with dementia. Management interventions and recommendations included social worker outreach, long-term care planning, home safety or driving assessments, referral to community resources, and periodic follow-up and monitoring. A small proportion of patients (7.8%) were referred to a specialist. Surveyed patients and caregivers were very satisfied with their visit to the clinic. A chart audit conducted by two independent geriatricians indicated agreement with diagnosis and intervention, particularly related to use of specialists. The results indicate that memory clinics within primary care settings can support capacity building to ensure quality assessment and management of dementia at a primary care level.     

The generation effect and reality monitoring: evidence from dementia and normal aging

The role of semantic memory activation in accounting for generation effects and reality monitoring was investigated in young and old normal adults and in patients with dementia of the Alzheimer's type (DAT). Both young and old normal adults demonstrated higher recall for internally generated information than for externally presented information, whereas the DAT patients failed to demonstrate a generation effect. Similarly, reality monitoring scores (discrimination between internal and external items) were high for both age groups of normals, but near chance levels for the DAT group. These results implicate semantic memory as an important factor in generation effects.     

Non invasive study of carotid arteries by echo-doppler and metabolic abnormalities in patients with dementia

In order to evaluate the prevalence of common and/or internal carotid stenoses together with metabolic abnormalities in dementia nineteen patients were investigated. Dementia and differential diagnosis between Alzheimer type (DAT) and multi-infarctual (MID) dementia were performed on the basis of Computerized Tomography scan, behavioural anamnesis, neurological and neuropsychological examinations. Eight patients were diagnosed as MID and 11 as DAT. Noninvasive study of neck arteries was performed in supine position by a Duplex Scanner, able of detecting a wide range of stenosis, even when very mild. Arterial hypertension, hyperlipidemia, diabetes and high hematocrit level were present in both groups, although to a higher extent in MID (p 0.05). Results from Duplex Scanner demonstrate 12 vascular stenoses 16-49% and one between 50-99% (13/76), being vascular abnormalities equally distributed among DAT and MID patients. These data suggest that patients with metabolic abnormalities and arteriosclerosis can develop dementia not necessarily of vascular type. On the other hand, MID patients do not present higher number of stenosis as compared to DAT, indicating that vascular disease of carotid arteries is not prominent in the clinical context of dementia.     

Longitudinal driving performance in early-stage dementia of the Alzheimer type

OBJECTIVES: To longitudinally assess on-road driving performance in healthy older adults and those with early-stage dementia of the Alzheimer type (DAT). DESIGN: A prospective longitudinal study. SETTING: Large urban medical center and surrounding area. PARTICIPANTS: A sample of 58 healthy controls, 21 participants with very mild DAT, and 29 participants with mild DAT participated. DAT was diagnosed using validated clinical diagnostic criteria and staged according to the Clinical Dementia Rating (CDR) Scale. MEASUREMENTS: Healthy controls and individuals with very mild DAT and mild DAT were administered a standardized on-road driving assessment over repeated times of testing. RESULTS: Subjects in the CDR=1 group (mild DAT) had a faster rate of receiving a rating of not safe on the driving test than subjects in the CDR=0 group (healthy controls; log rank test, P=.006), and the survival function of the CDR=0.5 group (very mild DAT) fell between those of the CDR=0 and CDR=1 groups. A Cox proportional hazards model indicated a significant difference in survival functions between the CDR=0 and CDR=1 groups after baseline age was controlled for (P<.001). Cox regression analysis also indicated that baseline age was a significant risk factor for a rating of "not safe" (P=.002). CONCLUSION: This study provides longitudinal evidence for a decline in driving performance over time, primarily in early-stage DAT, and supports the need not only for driving assessments, but also for reevaluation of individuals with very mild and mild DAT.     

The power of personality in discriminating between healthy aging and early-stage Alzheimer's disease

This study examined differences in personality in the earliest stages of dementia of the Alzheimer type (DAT) relative to healthy aging, and the power of personality in discriminating healthy aging from early-stage DAT. Four groups of participants (middle-aged controls, older controls, persons with very mild DAT, and persons with mild DAT) and their families were administered Costa and McCrae's NEO Five-Factor Inventory. On the basis of both self-report and informant report, there was an increase in neuroticism and a decrease in conscientiousness in persons with very mild DAT relative to healthy individuals without it, and in persons with mild DAT relative to those with very mild DAT. Moreover, informant reports of neuroticism and conscientiousness capture substantial unique variance in discriminating healthy aging and very mild DAT, above and beyond standard neuropsychological tests. Discussion focuses on the importance of personality traits as a noncognitive indicator of early-stage DAT.     

Amnestic behavior in dementia: symptoms to assist in early detection and diagnosis

OBJECTIVES: This study evaluated two amnestic behavior changes (repetitive questioning and repetitive actions) to determine their utility in screening for early dementia. DESIGN: Patient data were collected through a retrospective chart review. Comparison data from nondemented older people were collected prospectively from acquaintances of clinic patients. SETTING: The setting was a hospital-based outpatient memory disorder clinic. PARTICIPANTS: Participants were older individuals with no cognitive impairment (n = 25), undetermined dementia (n = 50), and definite dementia (n = 25). The undetermined cases were followed for at least 1 year to assess for conversion to dementia. MEASUREMENTS: Amnestic behaviors were assessed using informant-report for all participants. The behaviors were examined for their ability to distinguish between definite dementia cases and noncases. They were further evaluated for the ability to differentiate undetermined cases that eventually converted to definite dementia from cases that did not convert. RESULTS: Results indicated that repetitive behaviors were common in early and more-severe dementia cases. Repetitive behaviors were relatively uncommon in cognitively intact older participants. In analyses of the full study sample, engagement in repetitive behaviors had high sensitivity (0.97) in identifying dementia cases. CONCLUSIONS: Assessing repetitive behaviors in patients may be a useful means for family members and primary care physicians to screen for early cognitive impairment. The assessment can help to identify individuals that should be evaluated further for dementia.     

Patterns of neuropsychological impairment in dementia of the Alzheimer type and multi-infarct dementia

Patterns of performance on 22 neuropsychological tests were examined in 58 patients with presumed dementia of the Alzheimer type (DAT) and 58 patients with presumed multi-infarct dementia (MID). Few differences between patterns of performance in DAT and MID were found when overall level of performance was taken into account. Within the DAT group, there were some age-related differences in performance that in themselves might support other studies suggesting clinical and neuropathological differences between subtypes of DAT that are related in part to the age at which the condition occurs. However, similar age-related patterns were found in the MID group and the DAT and MID groups did not differ significantly in this respect. Considerable inter-individual variability in pattern of performance was apparent within each group. A proportion of patients were re-assessed 10 months after initial assessment: the extent of decline over time was not predictable from patients' characteristics or test performances at initial assessment. 'De-differentiation' in patterns of impairment, over time or with increasing severity of impairment, was not observed.     

Cognitive screening and neuropsychological assessment in early Alzheimer's disease

Cognitive screening and detailed neuropsychological assessment provide a reliable means of detecting dementia in its earliest stages, tracking the progression of cognitive decline over time, and aiding in the differential diagnosis of various dementing disorders. In addition, recent studies have shown that mild cognitive changes, and particularly declines in memory function, are evident in the "preclinical" phase of Alzheimer's disease and may help to identify elderly individuals who are likely to develop dementia in the near future. Until effective and easily obtainable biological markers for detecting the onset and progression of Alzheimer's disease are developed, neuropsychological assessment will continue to have an important role in the dementia evaluation.