Dementia diagnostic guidelines: methodologies, results, and implementation costs

OBJECTIVE

To facilitate the diagnostic process for dementia. Five guidelines and four consensus statements on specific diagnostic recommendations, specialist referral recommendations, and costs of recommended diagnostic procedures were compared and summarized.

DATA SOURCES AND SELECTION

A MEDLINE search from 1984 to 1999 and queries to experts yielded 14 guidelines and consensus statements that addressed the diagnosis of dementia. Only nine documents which had national or international scopes were reviewed.

METHODS

Comparisons were made on the specific diagnostic criteria for patient history, clinical examination, functional assessment, laboratory tests, neuroimaging, and other diagnostic tests, as well as specialist referral recommendations and costs for the recommended diagnostic procedures. The first three authors reviewed independently each document and completed a table on specific recommendations in each document. To settle disagreements about specific recommendations, they discussed them until they reached a consensus. To interpret the intent of vague statements, they used their best judgment.

RESULTS

The documents differed in content, recommendations, and development methodology. They were based on either expert opinion or scientific evidence, or both. Although the nine documents were nearly unanimous in several recommendations, including assessing the presenting problem, taking a medical history, conducting physical and neurological examinations, and assessing the patient's mental and cognitive status, considerable differences in recommendations were common. Such differences led to large differentials in the estimated costs (range, $190 to $2,001) for recommended diagnostic assessments.

CONCLUSIONS

A systematic approach to diagnostic recommendations for dementia may induce greater consistency among guidelines and consensus statements. The current approach leads to considerable variability in recommendations and estimated costs.

Regional cerebral glucose metabolism in healthy volunteers determined by fluordeoxyglucose positron emission tomography: appearance and variance in the transaxial, coronal, and sagittal planes

PURPOSE

In this study, the contribution of the transaxial, coronal, and sagittal planes in evaluations of regional cerebral glucose metabolism was investigated in healthy volunteers as determined by fluorine-18-labeled 2-deoxy-2-fluoro-D-glucose (FDG) and high-resolution positron emission tomography (PET).

METHODS

One hundred twenty-seven healthy right-handed volunteers were injected with 4.2 MBq/kg (0.11 mCi) body weight FDG and imaged in a PENN PET H 240 scanner. Images were corrected for scatter and random coincidences and reconstructed in all three planes into 6- to 8-mm-thick slices. The reconstructed images were corrected for attenuation using the Chang algorithm. The transverse, coronal, and sagittal images were read independently of each other using a qualitative scale in which 1 = equal to, 2 = mildly, 3 = moderately, and 4 = markedly less than the area with the highest glucose metabolism in the respective plane.

RESULTS

The areas with the highest glucose metabolisms were the posterior cingulate gyri with mean scores of 1.1 to 1.2, thalami (1.2 to 1.3), basal ganglia (1.5 to 1.9), and visual cortex (1.6). The lowest values were found in the occipital cortex (2.7 to 2.8) and the cerebellum (2.3 to 2.4). Whereas reliable analysis of the mesial temporal aspects was not feasible in the sagittal plane, the anterior poles of the temporal and frontal lobes could not be evaluated in the coronal or the inferior temporal areas in the transaxial slices. In all three planes, regional glucose metabolism was less in the lateral temporal areas on the left than on the right (P < 0.001). The consistency of readings as measured in terms of coefficients of variation was greatest in the coronal plane for the caudates and posterior cingulate gyri, in the transaxial plane for the lateral temporal regions, and in the sagittal plane for the visual cortex. Age-dependent decreases in regional glucose metabolism in the inferior and lateral frontal regions and the parietal lobes were found in all three planes.

CONCLUSIONS

All three projection planes must be used for a comprehensive qualitative evaluation of the regional glucose metabolism of the brain.

Nursing documentation versus standardized assessment of cognitive status in hospitalized medical patients

Although the literature discusses the importance of assessing cognitive status, little research has explored the concordance of nurses' documentation of cognitive status and standardized assessment. This study examined nurses documentation of cognitive status in 42 medically hospitalized individuals (mean age 51.9, SD = 10.1 years) using a variety of standardized measures. Although the chart review revealed no documentation of impaired cognitive status, impaired performance in 24 to 67% of the cognitive measures was identified. This study suggests nurses are missing cognitive impairment in hospitalized patients by limiting assessment to orientation. Use of a combination of several brief screening measures, such as the Clock Drawing Test and the standardized Mini-Mental State Examination, would provide timely, effective, and inexpensive assessment of cognitive status.

Identifying patterns of disruptive behavior in long-term care residents

OBJECTIVES

To determine the frequency, timing, and pattern of 45 operationalized disruptive behaviors (DB) in older people in long-term care units.

DESIGN

Nursing staff collected prospective descriptive data over 21 consecutive shifts for each patient to document prevalence, frequency, and co-occurrences of DBs.

SETTING

All of the eight long-term care units and one acute/admission unit of a large Veterans Administration Medical Center (VAMC). Each 40-bed unit had patients with varying levels of cognitive impairment and skilled nursing needs.

PARTICIPANTS

The sample consisted of 240 hospitalized VA patients with a mean age of 72.8 (SD = 8.6) years and mean length of stay of 4.02 (SD = 8.6) years. Residents had dementia, a psychiatric diagnosis, or mixed dementia and psychiatric diagnoses.

MEASUREMENTS

The Disruptive Behavior Scale (DBS), an instrument designed for collecting patient-level data on 45 separate DBs.

RESULTS

In a 24-hour period, the average frequency was 3.6 DBs per subject. We found that 41.2% of DB occurred during the day shift, 39.2% during the evening shift, and 19.6% during the night shift. In 32% of observed occurrences, only one DB occurred within the hour. In the remaining 68% of observations, two or more DBs occurred within the same hour. We found two behaviors, Does Not Follow Directions and Excessive Motor Activity, to occur with multiple behaviors in multiple categories. Several characteristic patterns were noted; e.g., physically aggressive behaviors rarely co-occurred with verbal DBs. Physically nonaggressive behaviors seemed to occur most frequently with other physically nonaggressive behaviors and, to a lesser extent, with verbal DBs.

CONCLUSIONS

These findings lend support to the existence of patterns of DBs in long-term care patients, a useful step toward targeting interventions early in the behavioral sequence.

Assessing dressing ability in dementia

Cognitive impairment can profoundly affect the skills required for activities of daily living (ADL). Most cognitive screening measures assess cognitive status rather than the cognitive functions that underlie ADL tasks. The dressing assessment guide (DAG) assesses the cognitive and functional abilities in dressing of patients with dementia. The DAG evaluates everyday and overlearned tasks and uses cues to provide a context for action. Nurses can easily administer the guide, and the resulting data provide the basis for nursing interventions.

The older driver: a handy tool to assess competence behind the wheel

Predicting with certainty which older patient will have driving problems is not possible, as standardized guidelines do not exist. In the absence of guidelines, the mnemonic SAFE DRIVE outlined in this article can help you identify important risk factors for unsafe driving. Risk factors included in SAFE DRIVE are problems with vision and reaction time, intellectual impairment, a poor safety record, alcohol abuse, use of certain medications, poor attentional skills, impaired executive functions, and a family report of driving problems. Most of these factors can be identified with a careful history, physical examination, in-office tests of cognitive function and alcohol use, and an interview with family member(s).

Relation of denial of alcohol problems to neurocognitive impairment and depression

Forty-six participants in an alcohol rehabilitation program were assessed to determine whether neuropsychological impairment was associated with a higher level of denial of alcohol-related problems and whether depressive symptoms were associated with a lower level of denial. Denial was measured based on the discrepancy between patients' rating of their alcohol-related problems on a visual analogue scale and a psychiatrist's rating. The neuropsychological functioning of the 15 patients in the group who denied alcohol problems was similar to that of the other patients. A modest inverse correlation was found between the level of depressive symptomatology and the level of denial.

Multi-modal assessment in Alzheimer's disease. ADL in relation to PET, MRI and neuropsychology

Alzheimer's disease (AD) causes a deterioration in functional status which may best be understood as a multi-dimensional concept. Results of multi-modal functional assessment in two patients with probable AD and comparable Mini-Mental State Examination scores demonstrated the heterogeneity of disease profiles and individual variations in functional status. Measures included direct assessment of ADL performance (SAILS), self and family perception of "current" and "best ever" functioning (NBFADL-60), neuropsychological test battery, magnetic resonance imaging (MRI) and positron emission tomography (FDG-PET). The multi-modal assessment yielded complementary information, and permitted correlation of physiological and behavioral data. Future studies should examine the potential heuristic and clinical utility of this approach.

Regional cerebral function determined by FDG-PET in healthy volunteers: normal patterns and changes with age

The main objective of this study was to determine patterns of regional brain metabolic activity utilizing high-resolution PET in normal healthy volunteers and variations in different age groups.

METHODS

High-resolution [18F]FDG PET images of the entire brain were obtained in 120 healthy normal volunteers (64 men, 56 women), age range from 19 to 79 yr. Each anatomic region was assessed using a qualitative rating scale with a score ranging from 1 to 6 (1 = definitely normal and 6 = definitely abnormal). Local metabolic activity was also estimated as showing increased (+) or decreased (-) compared to normal (0) states.

RESULTS

The most consistent finding in normal aging was decreased cortical metabolism, particularly in the frontal lobes. Temporal, parietal and occipital lobe metabolism varied considerably among subjects within the same age group as well as over decades. Basal ganglia, hippocampal area, thalami, cerebellum, posterior cingulate gyrus and visual cortex remained metabolically unchanged with advancing age.

CONCLUSION

These data indicate that qualitative interpretation of FDG-PET images allows accurate assessment of regional metabolic activity of the brain in normal subjects similar to those described with quantitative techniques. Adequate knowledge of normal variations and changes related to normal aging is necessary for optimal assessment of pathologic states.

A comparison of neuroimaging modalities for diagnosing dementia

Advances in neuroimaging have permitted knowledge of brain structures and physiology that were unknown 20 years ago and are playing an increasingly important role in the diagnosis of dementia. This article provides information on the types of brain scans, usual indications, risks, costs, and preparation of patients undergoing neuroimaging for the diagnosis of dementia. Each of the major imaging modalities is discussed from the perspective of what it uniquely offers to the diagnostic process. In general, the information gained from anatomic imaging complements that obtained from functional studies. In early stages of dementia, anatomic scans may appear normal while significant abnormalities are evident in functional images. This review familiarizes clinicians with these major developments to prepare them to educate and communicate with patients and their families.

Quantitative analysis of PET and MRI data in normal aging and Alzheimer's disease: atrophy weighted total brain metabolism and absolute whole brain metabolism as reliable discriminators

Average whole brain metabolic rates, when corrected for brain atrophy, are similar between patients with Alzheimer's disease (AD) and age-matched controls. To elucidate the relationship between reduced cognitive function and cerebral metabolism in patients with AD, we hypothesized that the absolute amount of glucose used by the entire brain may prove to be a more reliable indicator of the disease than metabolic rates calculated for a unit of brain weight. Twenty patients with the probable diagnosis of AD and 17 similarly aged controls underwent 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) studies as well as magnetic resonance imaging (MRI) within a few days of each other. Average metabolic rates, when corrected for atrophy, were 3.91 +/- 1.02 and 4.43 +/- 0.87 (mg of glucose per 100 cc brain tissue per min +/- s.d.) respectively for AD patients and controls. Two other indices were determined, atrophy weighted total brain metabolism (calculated by multiplying the brain volume, determined by MR analysis, by the average metabolic rate) and absolute whole brain metabolism (calculated by multiplying the brain volume by the average metabolic rate corrected for atrophy). The former showed a very significant difference between the two groups (29.96 +/- 7.90 for AD patients compared to 39.1 +/- 7.0 for controls, p < 0.001). Atrophy weighted total brain metabolism also correlated very well with mini mental status exam (MMSE) scores (r = 0.59, p < 0.01). Absolute whole brain metabolism was significantly different between AD and control groups and correlated well with MMSE. These data demonstrate that although the metabolic rate per unit weight of the brain is unchanged in AD compared to controls, atrophy weighted total brain metabolism and absolute whole brain metabolism are significantly affected. Both indices may prove to be a sensitive correlate for cognitive dysfunction in AD.

Olfaction: the neglected sense

Although olfactory complaints prompt an estimated 200,000 people each year to seek medical consultation in the U.S., there is a dearth of information available in the nursing literature. Recent research links olfaction to degenerative processes in Alzheimer's disease, Parkinson's disease and human immunodeficiency virus infection. This article reviews anatomy and physiology of the olfactory system, describes alterations in smell function and reviews assessment with the University of Pennsylvania Smell Identification Test and odor detection threshold testing. Nurses can advocate thorough assessment and prompt treatment of associated conditions, and educate the patient and family regarding ways to maximize current functioning when olfaction is impaired.

Autopsy: cutting away the myths

Autopsy serves to monitor quality of care, determines means of death in puzzling medical situations and medicolegal cases, documents true disease rates and provides other essential data for registries and research. This article discusses the current status of autopsy, reasons for the declining rate, and myths commonly held by patients and their families. The neuroscience nurse can clarify misperceptions, provide accurate and timely information in a sensitive and articulate manner, and support patients and their families in their decisions about autopsy.

Diagnosing dementia. Current clinical concepts

Increasing numbers of Americans who live to advanced age are at risk for dementia. Despite an array of sophisticated assessment measures, a specific diagnostic test is lacking for dementia and it has been found to be both under- and overdiagnosed. Misdiagnosis is of concern because treatable conditions that mimic dementia may go untreated, and families of those who lack correct diagnosis are unable to properly plan for subsequent care needs. Well-informed nurses can serve important roles by sharing accurate information within the community, supporting and educating families during the diagnostic process, and referring families to appropriate resources.

High-intensity signals in Alzheimer's disease without cerebrovascular risk factors: a magnetic resonance imaging evaluation

The authors examined the relationship between Alzheimer's disease, without cerebrovascular risk factors, and high-intensity signals on magnetic resonance imaging (MRI) with a 1.5-tesla scanner. There were no significant differences in MRI high-intensity signals between subjects with Alzheimer's disease (N = 16) and healthy control subjects (N = 23).

The postdoctoral fellowship experience

This paper describes postdoctoral fellowships, commonalities among programs, advantages and disadvantages of postdoctoral training, and issues to be considered when contemplating postdoctoral education. How to find a fellowship, questions that one should ask when considering a specific program, and criteria used to select potential candidates are also discussed.