Cognitive assessment in Alzheimer's disease: cross-sectional and longitudinal perspectives

Effectiveness of collaborative treatment using Korean and Western medicine for mild cognitive impairment or dementia: A protocol for a prospective observational exploratory study

BACKGROUND

South Korea has a dual medical system comprising conventional Western medicine (WM) and traditional Korean medicine (KM), which has yielded both positive results (increased opportunity to choose medical care) and negative results (increased medical costs). Thus, the Ministry of Health and Welfare has been performing a pilot project to evaluate this collaborative system in the real clinical situation. As treatment of dementia requires a social approach, the Korean government aims to strengthen the role of the national health care system to reduce the burden of dementia. The aim of this study was to evaluate the clinical - and cost-effectiveness of collaborative KM and WM treatment in patients with dementia or mild cognitive impairment (MCI) in Korea.

METHOD/DESIGN

In total, 180 patients with dementia or MCI will be recruited and will undergo monthly check-up for 12 weeks. Information regarding demographic characteristics, baseline disease-related data, and outcomes related to cognitive function and quality of life will be obtained. For data analysis, the patients will be classified into 2 groups using a comparative observational study design: the sole treatment group, which will receive either WM or KM alone, and the collaborative treatment group, which will receive both WM and KM.

DISCUSSION

The treatment of dementia/MCI in South Korea will be studied in the real world during the pilot project. There will be no limitations on the type of treatment or the specific treatment method. Examining the clinical- and cost- effectiveness of the different methods will supply information for building an optimal medical system for the treatment of dementia/MCI.

TRIAL REGISTRATION

The protocol for this study has been registered at the clinical research information service (CRIS: KCT0002868).

Activities of Daily Living, Cognitive Impairment and Social Function in Community Residents with Alzheimer Disease

One hundred and one patients with Alzheimer disease who were residing in the community were surveyed twice, in a six-month longitudinal study. A strong linear relationship was found between function, as measured by activities of daily living and cognitive impairment and between activities of daily living and social function.

At the first interview the proportion of variance in activities of daily living explained by cognitive impairment and social function, controlling for age, estimated duration of the disease and marital status was 65%. After six months the proportion had increased to 67%. The proportion of social function accounted for by activities of daily living was 30% at the initial interview; the proportion increased to 43% after six months. Patients lose the ability to perform instrumental activities of daily living before they lose the ability to perform self-care activities. The pattern of deterioration in activities of daily living is hierarchical.

The results of the study have implications for assessment and for intervention programmes. For those patients who have a diagnosis of Alzheimer disease, measures of activities of daily living are more useful for helping caregivers and for planning intervention programmes than measures of cognitive impairment.

Diagnostic utility of sound naming in early Alzheimer's disease

While it is well known that picture naming (PN) is impaired in Alzheimer's disease (AD), sound naming (SN) has not been thoroughly investigated. We postulated that SN might be impaired more severely and earlier than PN, given the early involvement of the temporal cortex by AD-related pathology. SN and PN were assessed in 21 normal participants, 40 patients with mild cognitive impairment (MCI), and 27 patients in early stages of AD. Our results showed that SN accuracy and latency were more sensitive to advancing pathology in AD than PN accuracy and latency. SN was more useful and specific in distinguishing MCI patients from normal participants and therefore in potentially identifying the subset of MCI patients who already have impairment in more than one cognitive domain and may actually have incipient AD. These findings indicate a potential diagnostic utility of SN for early detection of the disease. Furthermore, even though most AD patients demonstrated more or less comparable impairment in both tasks, some were disproportionately impaired on SN and others were differentially impaired on PN. Future studies may be able to show that these discrepant groups correspond to patients with right and left hemisphere predominant AD, respectively.

Neuropsychological profiles of persons with mental retardation and dementia

This study examined the use of neuropsychological tests to assist in the differential diagnosis of dementia among persons with mental retardation. The author compared performances of persons with mental retardation and dementia (n = 10) to persons with mental retardation without dementia (n = 12). Participants were matched by IQ (mild or moderate mental retardation), age, presence of Down syndrome, and gender. In addition, all participants in the dementia group had corroborative medical tests (i.e., imaging, EEG, or high tau low AB42 protein testing) consistent with diagnosis of dementia. Test performance was compared on measures of attention and executive functions, language, memory and learning, and a dementia screening. Results from MANOVAs and nonparametric tests revealed significantly lower performance for persons with mental retardation and dementia in all areas assessed. Cut-off scores were also developed for the sample in order to maximize sensitivity and specificity for the test battery. Despite the small sample size, these findings suggest that there are significant measurable differences in several neurocognitive domains between the two groups.

Progress in clinical neurosciences: cognitive markers of progression in Alzheimer's disease

The objective of this review is to summarize the literature on Alzheimer's disease progression utilizing cognitive batteries to track change over time. Studies published in English and obtained through PubMed searches (1983-2004) were included (i) if they had a longitudinal design and followed probable Alzheimer's patients diagnosed by National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer's Disease and Related Disorders Association or Diagnostic and Statistical Manual III/IV criteria, and (ii) if the techniques used for serial assessment were well-established in terms of validity and reliability. Longitudinal studies examining Alzheimer's disease progression report highly variable annual rates of change in decline rate. It remains unclear if this reflects disease subgroups or stage-related rate of decline. In conclusion a combination of stage-appropriate cognitive tests such as the Mattis Dementia Rating Scale and the Severe Impairment Battery, along with appropriate statistical methods to account for individual variability in decline rates, can capture the progression of Alzheimer disease and may be useful in further investigation.

Confrontation naming does not add incremental diagnostic utility in MCI and Alzheimer's disease

As the incidence of dementia increases, there is a growing need to determine the diagnostic utility of specific neuropsychological tests in the early diagnosis of Alzheimer's disease (AD). In this study, the relative utility of Boston Naming Test (BNT) in the diagnosis of AD was examined and compared to the diagnostic utility of other neuropsychological measures commonly used in the evaluation of AD. Individuals with AD (n = 306), Mild Cognitive Impairment (MCI; n = 67), and cognitively normal subjects (n = 409) with at least 2 annual evaluations were included. Logistic regression analysis suggested that initial BNT impairment is associated with increased risk of subsequent AD diagnosis. However, this risk is significantly less than that imparted by measures of delayed recall impairments. A multivariate Cox proportional hazards regression analysis suggested that BNT impairment imparted no additional risk for subsequent AD diagnosis after delayed recall impairments were included in the model. Although BNT impairment occurred in all severity groups, it was ubiquitous only in moderate to severe dementia. Collectively these results suggest that although BNT impairments become more common as AD progresses, they are neither necessary for the diagnosis of AD nor particularly useful in identifying early AD.

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.

Effects of a history of heavy alcohol consumption on Alzheimer's disease

Neuropsychological and psychiatric evaluations were made of 39 subjects with possible Alzheimer's disease and a history of excessive alcohol consumption (AD + ETOH), who had been abstinent or had drunk minimally for at least three months before evaluation, and 225 patients with probable Alzheimer's disease (PAD) of comparable age, years of education, and baseline global impairment. At baseline, there were no significant differences between the groups in terms of age of onset of dementia, neuropsychological test scores, or current behavioural or psychiatric symptoms. One year later, no differences in rates of decline between 20 abstinent AD + ETOH patients and 88 PAD subjects could be shown. Thus, past heavy alcohol consumption does not appear to modify the presentation of dementia of the Alzheimer's type, nor does it modify progression over a one-year interval.

Alzheimer's disease

Alzheimer's disease is one of the most severe and most common chronic diseases of older persons. Because occurrence of the disease is strongly related to age, its public health impact is likely to continue to increase as the population ages. As with many other diseases, a diagnosis of Alzheimer's disease is made through a combination of clinical history, physical, and neurologic examination, and laboratory evaluation. Because the dominant feature of this disease is its effect on cognition, its diagnosis requires careful evaluation of cognitive function usually with formal neuropsychological performance testing. Clinical evaluation of persons for Alzheimer's disease has four objectives: (1) to determine as accurately as possible if the person has dementia; (2) if dementia is present, to determine whether its presentation and course are consistent with a diagnosis of Alzheimer's disease; (3) to assess evidence for any alternate diagnoses, especially if the presentation and course are atypical for Alzheimer's disease; and (4) to evaluate evidence of other, coexisting, diseases that may contribute to the dementia, with strong emphasis on conditions that might respond to treatment. There is no reliable antemortem diagnostic test for Alzheimer's disease; the main purpose of laboratory testing is to identify other conditions that might cause or exacerbate dementia. Pathologically, Alzheimer's disease is characterized by the presence of two lesions on microscopic examination of the brain: neuritic plaques and neurofibrillary tangles. Both lesions can be seen in the brains of older persons without dementia. However, they are found in greater numbers in the neocortex and hippocampus with Alzheimer's disease. Caring for patients with Alzheimer's disease is demanding and requires compassion and skills that go beyond the choices among sophisticated and effective therapies that characterize much of modern medical practice. The current lack of effective pharmacotherapy for cognitive dysfunction in Alzheimer's disease should not obscure that there are many areas in which intervention can improve quality of life for both the patient and the caregiver. Achieving success in these areas typically requires that the physician work effectively with providers of many other medical and nonmedical services. Community resources, advocacy, behavior management, and experimental therapies and procedures, should be discussed with the family of each patient. In addition, persons with mild disease should be promptly informed of their diagnosis in order to obtain their wishes regarding life prolonging measures and extended care options.

Treatment of Alzheimer's disease: hopes and reality

The relative failure of symptomatic therapeutic trials for Alzheimer's disease using non-selective cholinergic agonists brings about the need for longitudinal studies with parallel designs aimed at disease stabilization, using trophic substances or amyloid suppressors.

Development of an "early" detection battery for dementia of the Alzheimer type

1. To develop a diagnostic battery sensitive to and specific for the early detection of Alzheimer disease (AD) dementia, the authors reviewed over 400 journal articles dealing with the diagnosis of A.D. or senile dementia and cognitive assessment in organic brain dysfunction and closed head injury. 2. We culled those studies that met our criteria for solid, reliable and statistically significant results and recommend the testing paradigms that most often produced good discrimination of mild AD dementia from normal senescence. 3. These include tests of language, verbal and non-verbal memory, perception, praxis, attention and reasoning. 4. The battery we assembled takes less than 1 hour to administer, requires no special equipment, and was designed as an early screen for use by psychologists, psychiatrists and other trained health care professionals; it is not intended for repeated administration, as in pharmacological or longitudinal studies.

Use of agraphia in subtyping of Alzheimer's disease

Agraphia, the inability to write a sentence, was studied in 46 Alzheimer's disease (AD) patients to explore the potential usefulness of this measure in the subtyping of AD. In this sample there was significant correlation between the agraphia and the severity of the cognitive impairment. However, there was no correlation between agraphia and the patients' age, age at onset, duration of the illness, presence of family history of AD, cerebrospinal fluid choline and acetylcholinesterase levels. Agraphia does not seem to help in the subtyping of Alzheimer disease.

Longitudinal cognitive decline in patients with Alzheimer's disease

Progressive cognitive impairment is a defining feature of the dementia of Alzheimer's disease (AD), yet disagreement exists over which abilities decline most precipitously and which cognitive tests are more sensitive. In this study, 51 AD patients in the early to middle stages of illness and 22 age-matched normal controls were administered a battery of neuropsychological tests at 6-month intervals over a 2-year period. While the performance of the normal controls remained stable over the 2 years, the AD patients displayed progressive decline on all tests. The greatest declines occurred on tests requiring lexical/semantic processing (Boston Naming Test) and comprehension of syntactic relationships (Token Test). Performance on visuospatial tests (Wechsler Adult Intelligence Scale-Revised Block Design, Benton Visual Retention Test, Spatial Delayed Recognition Span Test) declined less rapidly. The findings support previous reports that language impairment may be central to the dementia of AD, and that confrontation naming is particularly sensitive to decline in this illness.

New intrathecal drugs in Alzheimer's disease and psychometric testing

Bethanechol chloride, a muscarinic agonist, was administered intrathecally to a sample of AD patients in double-blind crossover and open escalating-dose trials. There was a modest amelioration of disturbed behavior at a moderately high dose level, but no improvement in memory or cognition was seen at any dose. At the highest dose, cognition deteriorated. These findings, in conjunction with the results of the multicenter trial described by Harbaugh, suggest that the clinical efficacy of bethanechol in AD is limited. The disappointing results of trials with varied cholinomimetic therapies suggest that more than one biochemical abnormality is responsible for the AD dementia. The neuropeptide, somatostatin, is also reduced in AD, and the level of reduction is correlated with the degree of dementia. Manipulation of this transmitter, alone or in conjunction with acetylcholine, would appear to be a next logical step in the development of an effective neurotransmitter replacement therapy for AD. Implanted drug pumps will be needed for such clinical trials. The naturally occurring somatostatin-14 is not suitable because of its short half life. Sandostatin, an analog, is chemically stable and not metabolized by brain tissue. It does not cross the blood-brain barrier so that intrathecal administration is necessary. Pharmacological research in AD is complicated by a variety of psychometric problems including the criterion-related and construct validity of the outcome measures. Patients differ in their tolerance of various therapeutic agents and in the extent of the neurochemical pathology. It is critically important, therefore, to evaluate individual, as well as group, responses to treatment. The telephone log method may provide a useful way of generating enough observations for single subject analyses without overburdening the patient with repeated testing.

The role of clinical neuropsychology in the neurological diagnosis of Alzheimer's disease

This survey on the early diagnosis of Alzheimer's disease (AD) reinstates the role of clinical neuropsychology in describing the cognitive status of AD and its evolution. The role of clinical neuropsychology is restricted to the clinical diagnosis of organic mental deterioration and its contribution to the diagnosis of AD is separate from that of neurology and neuroradiology. The frequency of a single neuropsychological disturbance in early AD patients is illustrated by our own observations.

Cognition in Alzheimer's disease: theoretic models and clinical implications

Riege and Metter review studies of cognitive functioning in probable Alzheimer's disease (pAD), representative of three distinguishable models: severity or staging, heterogeneity or subtyping, and information processing. As Riege and Metter point out, apparent differences in both disease description and implications for diagnostic assessment are dependent upon the model employed. The present commentary examines clinical and research implications derived from consideration of interactions between these three models, drawing upon recent cross-sectional and longitudinal studies of information processing in pAD.