Citations

A 15-year follow-up of 140 patients who had transient cerebral ischemic attacks and were first seen at the Mayo Clinic for this complaint in 1950 through 1954 is reported. There was no significant difference in mortality related to sex or location of residence. Patients hypertensive at onset of symptoms had no significant increase in mortality compared to normotensive patients but the survival trend favored normotensive patients. Probability of surviving 15 years was significantly less than expected for patients less than 65 years old. Patients who were 65 or older at their first attack had a survival similar to that of the standard population. The difference between the expected and observed 15-year survivals for patients with primarily motor symptoms was about the same as that difference for patients with primarily sensory symptoms. Information concerning stroke occurrence was incomplete but 37% of local residents are known to have had a stroke, a higher rate than expected. Among patients who died during this study, 50% died of a cardiac cause and 36% died of a stroke.

The records of the Mayo Clinic have been used as the primary basis for the study of stroke in the population of Rochester, Minnesota, from 1945 through 1954. The incidence rate for first stroke of all types was 1947/100,000/year. The rates increased with age, and at age 65 to 74 years, about 1% of the population was affected annually. No significant differences were noted between men and women. The rate for cerebral thrombosis was 146/l00,000/year for all ages. Cerebral hemorrhage represented less than 10% of all strokes and occurred in less than 15% of those who died; this is contrary to what is published in the U.S. Mortality Statistics . The prevalence rate was 547/100,000 on January 1, 1955. Twenty-one percent of these persons who had previously had a stroke were functioning with no incapacity on the date of prevalence determination and only 3% were bedridden. Death certificates were reviewed for all those who died after a stroke. Among those who died within a month after a stroke, some type of stroke was noted as the underlying or an associated cause of death in 91%. However, among those who died more than a month after a stroke, only 54% had such a diagnosis recorded. Probability of surviving after each type of stroke was determined and compared with survival in a normal population. The curve showing probability of surviving from cerebral thrombosis diverges throughout its course from that of the expected survival but diverges more sharply in the first several months. Among those patients with stroke who died, 41% died of causes related to the acute stroke and 10% died of a subsequent stroke. Heart disease was the cause of nearly twice as many deaths as was a subsequent stroke among those who survived the initial stroke. Autopsies were performed on approximately 50% of those persons who died following a stroke, and information from these studies confirmed the high degree of accuracy of the clinical appraisals.

The purposes of this study were to determine the trend in stroke recurrence over time and the effect of the prestroke blood pressure and management of hypertension on stroke recurrence in 1,680 incidence cases of stroke in residents of Rochester, Minnesota. Recurrent, primarily ischemic, stroke occurred in 267 cases. Stroke recurrence rates did not change during the 30-year period 1950-1979, in contrast to the decline in initial stroke incidence rates during this time. The overall stroke recurrence rates were less than 5%/yr, with cumulative rates of 5.7%, 19.3%, and 28.8% at 1, 5, and 10 years, respectively. Neither level of blood pressure before the first stroke nor management of hypertension had any apparent effect on stroke recurrence rates throughout the follow-up.

Background and Purpose —There is scant population-based information on incidence and risk factors for ischemic stroke subtypes. Methods —We identified all 454 residents of Rochester, Minn, with a first ischemic stroke between 1985 and 1989 from the Rochester Epidemiology Project medical records linkage system. We used Stroke Data Bank criteria to assign infarct subtypes after reviewing medical records and brain imaging. We adjusted average annual incidence rates by age and sex to the US 1990 population and compared the age-adjusted frequency of stroke risk factors across ischemic stroke subtypes. Results —Age- and sex-adjusted incidence rates (per 100 000 population) were as follows: large-vessel cervical or intracranial atherosclerosis with >50% stenosis, 27; cardioembolic, 40; lacuna, 25; uncertain cause, 52; other or uncommon cause, 4. Sex differences in incidence rates were detected only for atherosclerosis with stenosis (47 [95% CI, 34 to 61] for men; 12 [95% CI, 7 to 17] for women). There was no difference in prior transient ischemic attack and hypertension among subtypes, and diabetes was not more common among patients with lacunar infarction than other common subtypes. Conclusions —The age-adjusted incidence rate of stroke due to stenosis of the large cervicocephalic vessels is nearly 4 times higher for men than for women. There is no association between preceding transient ischemic attack and stroke mechanism. Diabetes and hypertension are not more common among patients with lacunae. Age- and sex-adjusted incidence rates for ischemic stroke subtypes in this population can be compared with similarly determined rates from other populations.

Background Criteria for the clinical diagnosis of Alzheimer's disease (AD) were established in 1984. A broad consensus now exists that these criteria should be revised to incorporate state‐of‐the‐art scientific knowledge. Methods The National Institute on Aging (NIA) and the Alzheimer's Association sponsored a series of advisory round table meetings in 2009 whose purpose was to establish a process for revising diagnostic and research criteria for AD. The recommendation from these advisory meetings was that three separate work groups should be formed with each assigned the task of formulating diagnostic criteria for one phase of the disease: the dementia phase; the symptomatic, pre‐dementia phase; and the asymptomatic, preclinical phase of AD. Results Two notable differences from the AD criteria published in 1984 are incorporation of biomarkers of the underlying disease state and formalization of different stages of disease in the diagnostic criteria. There was a broad consensus within all three workgroups that much additional work is needed to validate the application of biomarkers for diagnostic purposes. In the revised NIA‐Alzheimer's Association criteria, a semantic and conceptual distinction is made between AD pathophysiological processes and clinically observable syndromes that result, whereas this distinction was blurred in the 1984 criteria. Conclusions The new criteria for AD are presented in three documents. The core clinical criteria of the recommendations regarding AD dementia and MCI due to AD are intended to guide diagnosis in the clinical setting. However, the recommendations of the preclinical AD workgroup are intended purely for research purposes.

The National Institute on Aging and the Alzheimer's Association charged a workgroup with the task of revising the 1984 criteria for Alzheimer's disease (AD) dementia. The workgroup sought to ensure that the revised criteria would be flexible enough to be used by both general healthcare providers without access to neuropsychological testing, advanced imaging, and cerebrospinal fluid measures, and specialized investigators involved in research or in clinical trial studies who would have these tools available. We present criteria for all‐cause dementia and for AD dementia. We retained the general framework of probable AD dementia from the 1984 criteria. On the basis of the past 27 years of experience, we made several changes in the clinical criteria for the diagnosis. We also retained the term possible AD dementia, but redefined it in a manner more focused than before. Biomarker evidence was also integrated into the diagnostic formulations for probable and possible AD dementia for use in research settings. The core clinical criteria for AD dementia will continue to be the cornerstone of the diagnosis in clinical practice, but biomarker evidence is expected to enhance the pathophysiological specificity of the diagnosis of AD dementia. Much work lies ahead for validating the biomarker diagnosis of AD dementia.

The pathophysiological process of Alzheimer's disease (AD) is thought to begin many years before the diagnosis of AD dementia. This long “preclinical” phase of AD would provide a critical opportunity for therapeutic intervention; however, we need to further elucidate the link between the pathological cascade of AD and the emergence of clinical symptoms. The National Institute on Aging and the Alzheimer's Association convened an international workgroup to review the biomarker, epidemiological, and neuropsychological evidence, and to develop recommendations to determine the factors which best predict the risk of progression from “normal” cognition to mild cognitive impairment and AD dementia. We propose a conceptual framework and operational research criteria, based on the prevailing scientific evidence to date, to test and refine these models with longitudinal clinical research studies. These recommendations are solely intended for research purposes and do not have any clinical implications at this time. It is hoped that these recommendations will provide a common rubric to advance the study of preclinical AD, and ultimately, aid the field in moving toward earlier intervention at a stage of AD when some disease‐modifying therapies may be most efficacious.