Heterogeneity Of Alzheimer S Disease

The term "Alzheimer's disease" is currently used to refer to senile and also presenile dementia, but the heterogeneity of this disorder is demonstrated in many of its aspects. This is of great theoretical interest, and with the appearance of new therapeutic interventions, it may well also start to have very significant practical importance. To shed some light on the debate, the Fondation Ipsen organized an international symposium which took place on April 6, 1992. This volume contains the proceedings of this meeting, which was attended by researchers in epidemiology, clinical neurology and geriatrics, neuropsychology, neuropathology, molecular biology, and genetics.

Currently, approximately 50 million individuals have dementia, and this number is expected to rise due to increased life expectancy. Responsible for approximately 70% of dementia cases, Alzheimer’s disease (AD) is the leading cause of dementia. AD is caused by accumulation of amyloid plaques and tau tangles in the brain, resulting in neuronal death and cognitive impairment. AD has several stages: first, there is a long preclinical period, followed by a prodromal or mild cognitive impairment (MCI) stage, which finally results in an AD-type clinical dementia stage wherein the affected individual ultimately can no longer live independently. Until recently, a diagnosis of AD relied on clinical criteria. However, pathological studies showed that clinical symptoms do not always accurately reflect the underlying pathology. The current research framework definition of AD now requires biomarkers that reflect amyloid and tau pathology, regardless of cognitive state. Such biomarkers include cerebrospinal fluid (CSF) levels of amyloid-beta 1-42 (amyloid), phosphorylated tau (p-tau) and total tau (t-tau). While amyloid and tau are important in diagnosing AD, an unresolved issue is that despite many clinical trials targeting amyloid and tau proteins, no disease-modifying treatments are available. The limited success of clinical trials targeting amyloid and tau may reflect that AD pathophysiology is heterogeneous, with patients differing in the precise underlying causes. The first studies that analysed biological heterogeneity focussed on the core AD biomarkers, and showed subgroups of individuals with AD dementia with different tau levels. It remains largely unknown if tau subgroups also exist in earlier clinical stages of AD, and if they differ in other biological processes. Another approach to study biological heterogeneity in AD is with new CSF proteomic technologies, which can analyse large numbers of proteins simultaneously.

The management of Alzheimer's Disease and the related dementias is one of the major challenges to health care professionals and American society-at-large for the coming decade and the coming millennium. The rapid growth of the over-eighty-five population, the group which, as recent studies have confirmed and as many of us clinicians have long suspected, has an even higher prevalence than previously quoted of dementing disorders, is the major cause of this. We are thus challenged by, as Bernard Issacs used to call it, "the survival of the unfittest," as well as the oPtimistic approach of "bringing life to years," as John F. Kennedy said. The fact is that we, as a society, tend to confuse "treatment" and "cure" (and "prevention"). As the proceedings of the conference which this book represents emphasize, there is considerable work going on about the potential prevention of, or at least the reduction of, symptomatology in these illnesses by interventions genetically, chemIcally, and so forth. However, the more we find out, the more complicated it becomes, and the more heterogeneous Alzheimer's and the related disorders appear to be, not only in their manifestations (as clinicians have long recognized) but also in the individual initiating and underlying processes. For these reasons, absolute preventive techniques or the likelihood of an intervention which will reverse the process in a high proportion of patients, do not appear to be just around the corner.

Published in 1996: Alzheimer's disease is characterized by memory disturbances and changes in personality and is associated with aging, although it can occur in people under 65. It is a progressive disease, painful to witness as the patient's health declines. Alzheimer's Disease: Cause(s), Diagnosis, and Care, with its complete and authoritative discussions, will help you understand all facets of this complex disease. This book addresses a broad spectrum of topics ranging from diagnosis, causes, treatment, epidemiology, genetics, risk factors, and care and management. Alzheimer's Disease: Cause(s), Diagnosis, and Care is intended for a diverse audience, including practitioners and students, family members, and everyone who is concerned about this disease.

"Cerebrovascular and Alzheimer disease often occur together, but are usually studied apart. This book offers a timely integrated approach to both diseases. Beginning with a section on epidemiology and neuropsychology, this volume goes on to discuss and explore the neuropathological and neurophysiological mechanisms of these disorders. This book then develops a novel concept of an Alzheimer disease/vascular dementia spectrum. Sections on neuroimaging, as well as treatments and interventions follow. The editors have succeeded in gathering an impressive group of clinicians and scientists, who are well qualified by their achievements and leadership to make important contributions to this new integrated approach to dementing disorders. This important book should have broad appeal to anyone studying or caring for patients with dementing disorders, as it is comprehensive, yet focused on a unitary, complementary and pragmatic approach"--

This up-to-date, superbly illustrated book is a practical guide to the effective use of neuroimaging in the patient with cognitive decline. It sets out the key clinical and imaging features of the various causes of dementia and directs the reader from clinical presentation to neuroimaging and on to an accurate diagnosis whenever possible. After an introductory chapter on the clinical background, the available "toolbox" of structural and functional neuroimaging techniques is reviewed in detail, including CT, MRI and advanced MR techniques, SPECT and PET, and image analysis methods. The imaging findings in normal ageing are then discussed, followed by a series of chapters that carefully present and analyze the key findings in patients with dementias. Throughout, a practical approach is adopted, geared specifically to the needs of clinicians (neurologists, radiologists, psychiatrists, geriatricians) working in the field of dementia, for whom this book will prove an invaluable resource.