The diagnosis and differential diagnosis of dementia

Reversible dementia due to vitamin B12 deficiency in a lung cancer patient: Relevance of preoperative evaluation

OBJECTIVE

Cognitive dysfunction has a negative effect on cancer treatment; however, in a cancer setting, specific treatments can restore cognitive function. Such conditions are known as reversible dementia, with one of these being vitamin B12 (VB12) deficiency. However, there have been no reports of VB12 deficiency identified by preoperative evaluation in cancer patients.

METHOD

We studied a patient who was referred to the Department of Psycho-oncology on suspicion of cognitive decline prior to lung cancer surgery. Preoperative evaluation revealed VB12 deficiency.

RESULTS

The patient was an 82-year-old woman diagnosed with lung cancer. She also presented with cognitive decline and, therefore, was referred to the Department of Psycho-oncology for preoperative evaluation. The patient scored 19 points on a Mini-Mental State Examination (MMSE), which is indicative of cognitive decline. As the onset of symptoms occurred several months previously and they were subacute, the possibility of reversible dementia was considered. Extensive examination revealed VB12 deficiency, and VB12 replacement therapy normalized the MMSE score to 25 points before surgery.

SIGNIFICANCE OF THE RESULTS

When cognitive decline is observed in cancer patients, it is necessary to actively evaluate the serum levels of some B vitamins, including VB12.

The Role of Neuroimaging in the Assessment of the Cognitively Impaired Elderly

This article reviews the current diagnostic tools that are available for structural, functional, and molecular imaging of the brain, summarizing some of the key findings that have been reported in individuals diagnosed with Alzheimer disease, mild cognitive impairment, prodromal AD, or other prevalent dementias. Given recent advances in the development of amyloid PET tracers, current guidelines for the use of amyloid PET imaging in patients with cognitive complaints are reviewed. In addition, data addressing the potential value of amyloid PET imaging in the clinical setting are highlighted.

Under-diagnosis of common chronic diseases: prevalence and impact on human health

AIMS

The disability-adjusted life years (DALY) and its components, namely the years lived with disability and the years of life lost, are measures of the impact of disease on human health. Our impression was that several common chronic diseases responsible for many DALYs are frequently under-diagnosed.

METHODS

We attempted to summarise data regarding the under-diagnosis of common chronic diseases of the developed world, which are associated with considerable mortality and/or disability. We searched PubMed and Current Contents to identify relevant studies (1980-2005). Two reviewers extracted data concerning DALYs and prevalence of under-diagnosis of common chronic diseases.

RESULTS

Studies regarding the first 15 diseases (or group of diseases) based on DALYs were reviewed. The under-diagnosis of common chronic diseases in the developed world ranges from about 20% for dementia and cirrhosis to 90% for depression and osteoarthritis. The delay in the prompt diagnosis and initiation of treatment is associated with increased morbidity and mortality for most of the reviewed diseases.

CONCLUSION

The available evidence suggests that the prevalence of under-diagnosis of common chronic diseases is considerable. Physicians should be aware of the prevalence of under-diagnosis of chronic diseases and its impact on human health.

Evaluation of factors of importance for clinical dementia diagnosis

Diagnosing clinical dementia is based on an assessment of different variables, such as the patient's medical history, known risk factors, and biochemical features. Partial least squares discriminant analysis was used to evaluate variables of importance for diagnosing dementia in a clinical dementia population. Polymorphism for genotypes of glutathione S-transferase (GST) and sulfotransferase 1A1, hypothetically of importance in dementia disorders, was also included in the analysis. The study population consisted of 73 patients with Alzheimer's disease (AD), 14 with mixed dementia, 75 patients with vascular dementia, and 28 control cases. We found that several of the variables, such as the presence of ApoE4 allele, high cerebrospinal fluid levels of total tau protein, low levels of beta-amyloid((1-42)), and a low score on the Mini-Mental State Examination, facilitated a discrimination between the diagnoses compared with the controls. The different diagnoses overlapped. There were indications that genotypes of GSTs contributed to a subgrouping within AD.

The effect of dementia on outcomes and process of care for Medicare beneficiaries admitted with acute myocardial infarction

OBJECTIVES

To determine differences in mortality after admission for acute myocardial infarction (AMI) and in use of noninvasive and invasive treatments for AMI between patients with and without dementia.

DESIGN

Retrospective chart review.

SETTING

Cooperative Cardiovascular Project.

PATIENTS

Medicare patients admitted for AMI (N=129,092) in 1994 and 1995.

MEASUREMENTS

Dementia noted on medical chart as history of dementia, Alzheimer's disease, chronic confusion, or senility. Outcome measures included mortality at 30 days and 1-year postadmission; use of aspirin, beta-blocker, angiotensin-converting enzyme (ACE) inhibitor, thrombolytic therapy, cardiac catheterization, coronary angioplasty, and cardiac bypass surgery compared by dementia status.

RESULTS

Dementia was associated with higher mortality at 30 days (relative risk (RR)=1.16, 95% confidence interval (CI)=1.09-1.22) and at 1-year postadmission (RR=1.18, 95% CI=1.13-1.23). There were few to no differences in the use of aspirin and beta-blockers between patients with and without a history of dementia. Patients with a history of dementia were less likely to receive ACE inhibitors during the stay (RR=0.89, 95% CI=0.86-0.93) or at discharge (RR=0.90, 95% CI=0.86-0.95), thrombolytic therapy (RR=0.82, 95% CI=0.74-0.90), catheterization (RR=0.51, 95% CI=0.47-0.55), coronary angioplasty (RR=0.58, 95% CI=0.51-0.66), and cardiac bypass surgery (RR=0.41, 95% CI=0.33-0.50) than patients without a history of dementia.

CONCLUSION

The results imply that the presence of dementia had a major effect on mortality and care patterns for this condition.

Application of capture-recapture methodology to estimate the prevalence of dementia in South Carolina

PURPOSE

The purpose of this study was to estimate the prevalence of dementia in individuals 65 years of age and older in the state of South Carolina using capture-recapture methodology.

METHODS

We linked data from the Department of Mental Health admissions, inpatient admissions, and emergency room visits. Separate log-linear models were used to obtain estimates of the underascertainment-corrected prevalence of dementia in twelve age-gender-race subgroups, which were summed to estimate the prevalence of dementia in the total population.

RESULTS

We found an overall prevalence of dementia of 14% in South Carolina for persons 65 years of age and older using capture-recapture methodology. This estimate of persons with dementia is 25% higher than the identified cases of dementia in the South Carolina Alzheimer's Disease Registry (10.5%).

CONCLUSIONS

Although capture-recapture methods are prone to limitations, they can be used to more accurately estimate the prevalence of dementia in a geographic area.