Cerebral emboli as a potential cause of Alzheimer's disease and vascular dementia: case-control study

OBJECTIVE

To compare the occurrence of spontaneous cerebral emboli and venous to arterial circulation shunts in patients with Alzheimer's disease or vascular dementia and controls without dementia.

DESIGN

Cross sectional case-control study.

SETTING

Secondary care old age psychiatry services, Manchester.

PARTICIPANTS

170 patients with dementia (85 with Alzheimer's disease, 85 with vascular dementia) and 150 age and sex matched controls. Patients on anticoagulant treatment, patients with severe dementia, and controls with marked cognitive impairment were excluded.

MAIN OUTCOME MEASURES

Frequencies of detection of spontaneous cerebral emboli during one hour monitoring of the middle cerebral arteries with transcranial Doppler and venous to arterial circulation shunts by a transcranial Doppler technique using intravenous microbubbles as an ultrasound contrast.

RESULTS

Spontaneous cerebral emboli were detected in 32 (40%) of patients with Alzheimer's disease and 31 (37%) of those with vascular dementia compared with just 12 each (15% and 14%) of their controls, giving significant odds ratios adjusted for vascular risk factors of 2.70 (95% confidence interval 1.18 to 6.21) for Alzheimer's disease and 5.36 (1.24 to 23.18) for vascular dementia. These spontaneous cerebral emboli were not caused by carotid disease, which was equally frequent in dementia patients and their controls. A venous to arterial circulation shunt indicative of patent foramen ovale was found in 27 (32%) Alzheimer's disease patients and 25 (29%) vascular dementia patients compared with 19 (22%) and 17 (20%) controls, giving non-significant odds ratios of 1.57 (0.80 to 3.07) and 1.67 (0.81 to 3.41).

CONCLUSION

Spontaneous cerebral emboli were significantly associated with both Alzheimer's disease and vascular dementia. They may represent a potentially preventable or treatable cause of dementia.

Apolipoprotein E epsilon4 allele frequency and age at onset of Alzheimer's disease

The age distribution of the epsilon4 allelic form of the apolipoprotein E gene (APOE) was investigated in 630 patients with Alzheimer's disease (AD) with onset age ranging from 35 to 90 years. Overall, mean age at onset in APOE epsilon4 allele bearers was significantly later than that in nonbearers. However, when stratified into early onset AD (EOAD) and late onset (LOAD) groups, mean age at onset in EOAD cases bearing APOE epsilon4 allele was later than that in those EOAD cases without epsilon4 allele, whereas in LOAD mean age at onset in cases bearing APOE epsilon4 allele was earlier than in those without epsilon4 allele. When analysed by decade, it was observed that 37% of the total number of APOE epsilon4 allele bearers, and 43% of total number of cases with APOE epsilon4/epsilon4 genotype fell into the 60-69 years age class. Hence, APOE epsilon4 allele frequency, at 0.44, was highest in the 60-69 years age class, progressively decreasing either side of this age group. APOE epsilon4 allele therefore has its maximum impact between onset ages of between 60 and 70 years.

Apolipoprotein E epsilon4 allele frequency in vascular dementia

AIM

The aim of the study was to investigate whether possession of the epsilon4 allelic form of the apolipoprotein E (APOE) gene increases the risk of developing vascular dementia (VaD).

METHODS

APOE allele and genotype frequencies were determined by PCR in 89 patients with possible and probable VaD and compared with those in 97 patients with possible and probable Alzheimer's disease (AD) of similar age of disease onset and ethnic background, and with 766 control subjects drawn from the same geographical region.

RESULTS

The APOE epsilon4 allele frequency in all 97 patients with possible and probable AD was significantly higher (p < 0.001) than that in control subjects. However, the APOE epsilon4 allele frequency in all 89 patients with possible and probable VaD was also significantly higher (p < 0.001) than that in control subjects, but not significantly different from that in AD. The APOE epsilon4 allele frequency was similarly, and still significantly (p < 0.001), increased when only those patients with probable AD or probable VaD were considered.

CONCLUSION

Possession of APOE epsilon4 allele increases the risk of VaD.

Genetic associations between cathepsin D exon 2 C-->T polymorphism and Alzheimer's disease, and pathological correlations with genotype

Genetic variations represent major risk factors for Alzheimer's disease (AD). While familial early onset AD is associated with mutations in the amyloid precursor protein and presenilin genes, only the e4 allele of the apolipoprotein E (APOE) gene has so far been established as a genetic risk factor for late onset familial and sporadic AD. It has been suggested that the C-->T (224Ala-->Val) transition within exon 2 of the cathepsin D gene (CTSD) might represent a risk factor for late onset AD. The objective of this study was to investigate whether possession of the CTSD exon 2 T allele increases the risk of developing AD, and to determine whether this modulates the amyloid pathology of the disease in conjunction with, or independent of, the APOE e4 allele. Blood samples were obtained from 412 patients with possible or probable AD and brain tissues from a further 148 patients with AD confirmed by postmortem examination. CTSD and APOE genotyping were performed by PCR on DNA extracted from blood, or from frontal cortex or cerebellum in the postmortem cases. Pathological measures of amyloid beta protein (Abeta), as plaque Abeta40 and Abeta42(3) load and degree of cerebral amyloid angiopathy were made by image analysis or semiquantitative rating, respectively. CTSD genotype frequencies in AD were not significantly different from those in control subjects, nor did these differ between cases of early or late onset AD or between younger and older controls. There was no gene interaction between the CTSD T and APOE e4 alleles. The amount of plaque Abeta40 was greater in patients carrying the CTSD T allele than in non-carriers, and in patients bearing APOE e4 allele compared with non-carriers. Possession of both these alleles acted synergistically to increase levels of plaque Abeta40, especially in those individuals who were homozygous for the APOE e4 allele. Possession of the CTSD T allele had no effect on plaque Abeta42(3) load or degree of CAA. Possession of the CTSD T allele does not increase the risk of developing AD per se, but has a modulating effect on the pathogenesis of the disorder by increasing, in concert with the APOE e4 allele, the amount of Abeta deposited as senile plaques in the brain in the form of Abeta40.

Deletion/Insertion Polymorphism of the Angiotensin-Converting Enzyme Gene and White Matter Hyperintensities in Dementia: A Pilot Study

OBJECTIVES

To examine the association between the angiotensin-converting enzyme (ACE) deletion/insertion (D/I) polymorphism and white matter hyperintensities (WMHs) in patients with dementia.

DESIGN

Observational pilot study with adjustment for potential confounders using analysis of covariance.

SETTING

Secondary care old-age psychiatry services in greater Manchester, United Kingdom.

PARTICIPANTS

Ninety-seven patients with dementia: 49 with Alzheimer's disease (AD, National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer's Disease and Related Disorders Association criteria) and 48 with vascular dementia (VaD, National Institute of Neurological Disorders and Stroke/Association Internationale pour la Recherche et l'Enseignement en Neurosciences criteria).

MEASUREMENTS

The ACE D/I polymorphism, WMHs (deep WMHs (DWMHs) and periventricular hyperintensities (PVHs)) on T2-weighted magnetic resonance imaging, and potential cardiovascular confounders.

RESULTS

The D/D polymorphism of the ACE genotype was associated with severity of DWMH (P = .005) but not PVH (P = .34), corrected for age, cardiovascular risk factors, and type of dementia. Post hoc analyses were limited by statistical power but suggested an interaction with the apolipoprotein E epsilon4 allele.

CONCLUSION

The results support previous observations that genetic factors influence the development of WMHs in dementia. The involvement of the ACE D/I polymorphism in the pathogenesis of DWMHs in dementia (AD and VaD), by a mechanism that is independent of its association with cardiovascular risk factors, should be confirmed in a large population-based sample.

Asymptomatic spontaneous cerebral emboli and cognitive decline in a cohort of older people: a prospective study

BACKGROUND

Asymptomatic spontaneous cerebral emboli (SCE) are common in dementia and are associated with cognitive decline in dementia. The significance of their presence in older people is unknown.

METHOD

We included 96 participants (mean (SD) age 76.8 (6.7) years, 46% female) who were the control group in a case-control study to evaluate SCE in dementia. Cognitive functioning was assessed prospectively over 2.5 years, using the MMSE and CAMCOG.

RESULTS

The mean (SD) MMSE score was 28.7 (1.4) at baseline with an average (SD) drop of 0.79 (0.91) per year. The presence of SCE was not related to the annual drop in MMSE score, nor to the CAMCOG score at follow-up (p = 0.88 and p = 0.41, respectively). Linear regression analyses identified higher age in years (beta = 0.29, p = 0.003), history of stroke (beta = 0.31, p = 0.001) and carotid stenosis (beta = 0.28, p = 0.003) as independent predictors of cognitive decline.

CONCLUSION

We found no association between the presence of SCE and subsequent cognitive decline in older people without dementia.

Ten steps to successful poster presentation

Receiving a letter confirming acceptance for you to present a poster at a conference can evoke mixed emotions. Joy, panic, fear and dread are among the many possible emotions and this is not exclusive to first time presenters. Developing an effective poster presentation is a skill that you can learn and can provide a rewarding way to present your work in a manner less intimidating than oral presentation (Shelledy, 2004). The key to successful poster presentation is meticulous, timely, well informed preparation. This article outlines ten steps to help guide you through the process to maximize your success.

Cerebral emboli and depressive symptoms in dementia

BACKGROUND

The vascular depression hypothesis and our recent findings of increased frequency of spontaneous cerebral emboli in dementia suggest that such emboli may be involved in the causation of depressive symptoms in dementia.

AIMS

To evaluate the association between spontaneous cerebral emboli and depressive symptoms in Alzheimer's disease and vascular dementia.

METHOD

In a cohort of 142 patients with dementia (72 with Alzheimer's disease and 70 with vascular dementia), the association between spontaneous cerebral emboli and clinically relevant depressive symptoms was examined using multiple logistic regression analyses.

RESULTS

Spontaneous cerebral emboli were significantly more frequent in the patients with clinically relevant depressive symptoms (66 v. 37%, P=0.03). After adjustment for age, gender, Mini-Mental State Examination score, type of dementia and significant cardiovascular risk factors, the relationship remained significant (OR=3.47, 95% CI 1.10-10.97).

CONCLUSIONS

Spontaneous cerebral emboli are associated with clinically relevant depressive symptoms in dementia, and further research is needed to explore the nature of this relationship.

Ten steps to successful conference presentations

Delivering an oral presentation at a conference can be a demanding yet exhilarating experience. It can create a variety of emotions such as excitement, joy and achievement--but for many the overriding emotions are those of anxiety, fear and dread. A certain amount of nervousness can enhance your performance but how can you avoid pre-presentation nerves developing into full-blown anxiety and fear. The key to successful conference presentation is meticulous preparation and practise. This article guides you through ten steps to help maximize your success and enjoyment.

An overview of research ethics and learning from the past

This article has introduced the reader to research ethics. In order to to show the development of the codes of ethics and guidelines in use today, it has briefly reviewed the most infamous unethical research studies. Learning from these traumatic and often cruel moments i history gave impetus to the development of international ethical guidelines, driving research conduct and protecting the rights and safety of those participating in studies today. Research within the NHS would not exist without the hundreds of thousands of patients who volunteer their time and indeed their 'selves' to research . Researchers have a duty to those patients, to treat them with the dignity, respect and care they would afford any patient. In addition to serving as researchers, they must also act as patient advocates to ensure that every stage of the research process embraces all elements of ethical codes and frameworks and patients should expect nothing less.

Ten steps to convert your assignment into a journal article

Nurses spend a great deal of time and effort in constructing a variety of assignments and dissertations as part of courses, both at undergraduate and postgraduate levels. It is not uncommon to read comments from lecturers such as 'this requires only minimal work to be published'. It might be assumed that many assignments and dissertations would therefore go on to appear in print; however it is questionable just how many of them ever do materialize in journals. The reality is that this transition can be a challenging process. This is highlighted when a search of the literature for use in preparation for this article the authors discovered a dearth of advice to help potential authors make the transition from good quality assignment to published article. With this in mind we will try to guide you through a process that will assist you in converting your academic work into an article fit for publication.

Embedding the 6 Cs into clinical research practice and management

The White Paper, Equity and Excellence:liberating the NHS (DH, 2010) emphasises the promotion and conduct of research as a core NHS role. The updated NHS Constitution(DH, 2013) outlines its commitment to innovation and also to the promotion and conduct of research to improve the current and future health and social care of the population.Furthermore, NHS England (2013) in its guidance, Everyone Counts: planning for patients 2014/15 to 2018/19, identified research as one of the essential elements for a successful and sustainable health economy recommending research and evaluation be embedded across the whole patient pathway.The 6 Cs were launched in 2012 to drive the Compassion in Practice vision with calls for every nurse, midwife and member of the care team to implement them into practice (NHS Commissioning Board, 2013). The 6 Cs can be embedded into the world of clinical research so that research patients are afforded the same levels of compassionate care by all members of the research workforce and, indeed, to drive compassion in practice for the researchers themselves. It is suggested that this will result in high quality, compassionate personalised care for all and that the biggest voices will be those of the patients themselves.

Ten steps to developing an abstract for conferences

There is an increasing importance being placed on the dissemination of research and other high quality evidence. This article is the first in a series of three that will assist you in ensuring that your work is presented in the best light at the conference of your choice. In this first article we guide you through the ten steps you need to take to ensure that you submit the best possible abstract to the scientific committee. We also will guide you through the process of selection.

Ten steps to getting your paper published in a professional journal

There is an increasing expectation that nurses, whether they work in clinical practice management, education or research, will publish. At the same time there remains a mystique about the best way to go about this. This article provides a simple commentary suggesting ten steps to help you publish in a professional journal.

Meeting the needs of families of patients in intensive care units

Anyone entering an intensive care unit (ICU) can feel bombarded by the huge array of sensory stimuli. Family members in ICU are typically in a state of fear and shock. Studies have shown that caring for the families of patients who are critically ill is believed to be an essential component of the nurse's role. However, despite the fact that the critical care nurse is cited as the one who is responsible for meeting the needs of such families, little is known about how nurses view this role. This article discusses the ICU environment and its potential effect on families and nursing staff.

Meeting the requirements for becoming a nurse lecturer

Career planning is essential for nurses considering a change in role, as it provides direction and enables them to use time and money efficiently. This article describes a survey of 25 universities in which each participating institution was asked to comment on the required characteristics of nurse lecturers. The results should be useful to nurses who are planning to become nurse lecturers in the future.

Nurses' experiences of caring for the relatives of patients in ICU

To date there have been no published qualitative studies looking solely at the experiences of nurses caring for the relatives of patients who are critically ill. This small-scale phenomenological study explores such experiences. Three intensive care units in North West England were included; the nine participants were D grade or above, with a minimum of three months' ICU experience. Each nurse attended a tape-recorded, unstructured interview to discuss caring for relatives. A thematic analysis of the nurses' comments was then performed. Although many of the nurses understood the benefits of performing the care-giver role to families, some nurses felt inadequately prepared. There were also issues about whether they felt supported by colleagues in undertaking this role.

An exploration of the role of the research nurse and its impact

Nurses, midwives and allied health professionals (AHPs) are multiskilled with a variety of career options available to them. As nurses develop they can specialize in many areas, performing many different and diverse roles. One of these roles is within the world of research. This paper is a basic exploration of the role of the research nurse or practitioner and how crucial this is in the development and management of research. A series of papers will follow outlining important areas of the research process offering a comprehensive set of developmental areas for both novice and experienced researchers. The term 'nurse' will also refer to midwives and AHPs.

Supporting failing students in practice. 1: Assessment

This two-part unit examines the issue of nursing students who fail in clinical practice. Part 1 explores reasons for failure, assessment and the emotional challenges mentors may face when supporting failing students.

Supporting failing students in practice 2: management

This two-part unit examines the issue of students who fail in clinical practice. Part 1 explored reasons for failure, assessment and emotional challenges mentors may face when supporting underperforming students. This part, part 2, discusses the management of failing students.