Psychiatric symptoms in cases of clinically diagnosed Alzheimer's disease

All incident cases of clinically diagnosed Alzheimer's disease were identified through the unique record linkage system of the Mayo Clinic. Thirty-nine (32%) of the sample of 122 had a psychiatric history that preceded the onset of CDAD by at least 3 years. Twenty-five percent of the study population had had an episode of delirium within 2 years of the onset of CDAD. Eighty-four percent of the cases had psychiatric symptoms in the course of CDAD that were documented in their medical records. Specific symptom patterns included agitation, combativeness, confusion and disorientation, depression, psychosis, and wandering. These symptoms occurred more frequently in clusters than singularly.

Familial aggregation of Alzheimer's disease and related disorders: a collaborative re-analysis of case-control studies

Case-control studies of Alzheimer's disease were re-analysed to examine the association of Alzheimer's disease with family history in first degree relatives of dementia, Down's syndrome and Parkinson's disease. Overall, the relative risk of Alzheimer's disease for those with at least one first degree relative with dementia was 3.5 (95% confidence interval 2.6-4.6). Stratification according to age of onset of Alzheimer's disease showed that the relative risk decreased with increasing onset age. However, among patients with an onset of disease after 80 years, there were still significantly more subjects with one or more first degree relatives with dementia as compared to controls (relative risk 2.6; 95% confidence interval 1.3-5.2). The relative risk of Alzheimer's disease was significantly lower in patients who had one first degree relative with dementia (relative risk 2.6; 95% confidence interval 2.0-3.5) as compared to those who had two or more affected relatives (relative risk 7.5; 95% confidence interval 3.3-16.7). Furthermore, the re-analysis showed a significant association between Alzheimer's disease and family history of Down's syndrome (relative risk 2.7; 95% confidence interval 1.2-5.7), which was strongest in those patients who had a positive family history of dementia. The relative risk of Alzheimer's disease for those with a positive family history of Parkinson's disease was 2.4 (95% confidence interval 1.0-5.8).

Psychiatric history and related exposures as risk factors for Alzheimer's disease: a collaborative re-analysis of case-control studies. EURODEM Risk Factors Research Group

Data from case-control studies of Alzheimer's disease (AD) were pooled to examine the possible roles of history of depression, anti-depressant treatment and adverse life events as risk factors. History of depression was found to be associated with AD, although the effect was confined to late onset cases. The association held for episodes of depression more than 10 years before AD onset, as well as for episodes occurring within a decade of onset. No association was found with anti-depressant treatment. However, data were only available from two studies, limiting the power of the analysis. Also, no association was found with the three major life events considered in the pooled analysis: death of spouse, death of a child and divorce.

Prevalence survey of headache in a rural Mexican village

Prevalence of headache was studied by house-to-house survey of a small remote Mexican village where the population was characterized by a low income and high rate of illiteracy. Severe headache was found in 8.9% of the male population and in 10.6% of the females. Approximately half of these individuals gave a history suggestive of headache with aura, but reinterview by a neurologist revealed that in one third of such histories the visual phenomena were probably not true aurae. Only in the over 35-year age-group was headache more prevalent in females. 'Incapacitating' headache was usually equated with 'severe' headache and was 10 times as frequent in the over 55-year age-group as in younger people. Sophisticated interviewers (neurologists) obtained different results from less trained interviewers.

Head trauma as a risk factor for Alzheimer's disease: a collaborative re-analysis of case-control studies. EURODEM Risk Factors Research Group

A re-analysis of the data from 11 case-control studies was performed to investigate the association between head trauma and Alzheimer's disease (AD). To increase comparability of studies, exposures were limited to head trauma with loss of consciousness (hereafter referred to as 'head trauma') and comparisons were restricted to community (versus hospital) controls. Test for heterogeneity across studies was negative; consequently, data were pooled in subsequent analyses. The pooled relative risk for head trauma was 1.82 (95% confidence interval: 1.26-2.67). Stratified analyses showed stronger associations in cases without a positive family history of dementia and in males (versus females). Adjustment of the pooled relative risk for family history of dementia, education and alcohol consumption did not alter significantly the association between head trauma and AD. There was no interaction effect between head trauma and family history of dementia, suggesting that these risk factors operate independently. Mean age of onset was not significantly different in cases with a history of head trauma compared to cases without such a history. The findings of the pooled analysis support an association between reported head trauma and AD.

Alcohol and tobacco consumption as risk factors for Alzheimer's disease: a collaborative re-analysis of case-control studies. EURODEM Risk Factors Research Group

A meta-analysis, involving the secondary analysis of original data from 11 case-control studies of Alzheimer's disease, is presented for alcohol consumption and cigarette smoking. Five studies included in the meta-analysis of alcohol consumption. Alcohol consumption was computed in terms of average weekly intake, measured in ounces of 'pure alcohol'. This variable was categorized into tertiles to represent low, medium and high intake. Analyses showed no excess estimated risk of Alzheimer's disease for any level of alcohol intake. Smoking was analysed in three different manners: (1) lifetime prevalence of smoking (ever/never)--this included eight studies; (2) amount smoked (less than or equal to one pack per day versus more than one pack per day)--this included seven studies; and (3) pack-years--including four studies. A statistically significant inverse association between smoking and Alzheimer's disease was observed at all levels of analysis, with a trend towards decreasing risk with increasing consumption (p(trend) = 0.0003). A propensity towards a stronger inverse relation was observed among patients with a positive family history of dementia, but the difference between this group and the group with no such history was not statistically significant. Although the observed disturbance in nicotinic receptor function in Alzheimer's disease may provide an explanation for these findings, possible biases related to the selection or survival of study subjects cannot be fully ruled out at this time. Prospective, community-based studies of incident cases of Alzheimer's disease are needed to document in detail the smoking history, age of onset of disease and survival of patients and cognitively intact people by smoking status.

Medical history and the risk of Alzheimer's disease: a collaborative re-analysis of case-control studies. EURODEM Risk Factors Research Group

In a re-analysis of eight case-control studies on Alzheimer's disease we explored several medical conditions that had previously been suggested as possible risk factors for Alzheimer's disease. History of hypothyroidism was increased in cases as compared to controls (relative risk 2.3; 95% confidence interval 1.0-5.4). Severe headaches and migraine were inversely related to Alzheimer's disease (relative risk 0.7; 95% confidence interval 0.5-1.0). More cases than controls reported epilepsy before onset of Alzheimer's disease (relative risk 1.6; 95% confidence interval 0.7-3.5), especially for epilepsy with an onset within 10 years of onset of dementia. Neurotropic viruses, allergic conditions, general anaesthesia and blood transfusions were not associated with Alzheimer's disease.

Maternal age and Alzheimer's disease: a collaborative re-analysis of case-control studies. EURODEM Risk Factors Research Group

To investigate the possible association between Alzheimer's disease and late maternal age at index birth, we conducted a collaborative re-analysis of existing case-control data sets. Of the 11 studies participating in the EURODEM project, four were included in the analyses regarding maternal age. In all four studies, cases were matched to controls by age and gender, and only population controls were considered. Analyses were conducted on the individual data sets, on the pooled sample, and on subgroups defined by gender, age at onset, and familial aggregation of dementia. Maternal age of 40 years and over was found to be suggestively associated with a higher risk of Alzheimer's disease (overall relative risk = 1.7; 95% confidence intervals: 1.0-2.9). In subgroup analyses, the association was statistically significant for women and for sporadic cases. Adjustments for education or analyses restricted to case-control pairs matched by type of respondent did not modify these results noticeably. The association was confirmed by a test of consistency with the Down's syndrome risk model; results of this test were again more definite for sporadic Alzheimer's disease. In addition, three of the four studies also suggested an increased risk for maternal age at index birth between 15 and 19 years (overall relative risk = 1.5; 95% confidence intervals: 0.8-3.0). Although consistency across studies was not always complete, only some of the increased relative risks reached statistical significance, and information regarding maternal age obtained through a next-of-kin interview may have limitations, our study suggests that both early and late maternal age should be further investigated as possible risk factors for Alzheimer's disease.

Occupational exposures to solvents and lead as risk factors for Alzheimer's disease: a collaborative re-analysis of case-control studies. EURODEM Risk Factors Research Group

A meta-analysis, involving the secondary analysis of original data from 11 case-control studies of Alzheimer's disease, is presented for occupational exposures to solvents and lead. Three studies had data on occupational exposure to solvents. Among cases, 21.3% were reported to have been exposed; among controls, this figure was comparable (20.9%). This yielded a pooled matched relative risk of 0.76 (95% CI: 0.47-1.23). Four studies had data on exposure to lead. Exposure frequencies were 6.1% in cases and 8.3% in controls. This resulted in a pooled matched relative risk of 0.71 (95% CI: 0.36-1.41). The meta-analysis was particularly useful in validating negative results from individual studies and in increasing the statistical power for the analysis of lead exposure, where stratum-specific cell sizes were frequently smaller than five in individual studies. However, since exposure in the various studies was ascertained in a rather broad manner, prospective studies are recommended which focus on high-risk occupational populations and which determine the incidence of Alzheimer's disease in these and comparable unexposed populations.

Pilot study of the prevalence of major neurologic disorders in a rural population of India

A study of the prevalence of major neurologic diseases will be carried out in a rural population near Ballabgarh. India, using the World Health Organization protocol for epidemiologic studies of neurologic disorders and other internationally standardized survey techniques, screening procedures, and diagnostic criteria. Before applying any protocol developed in one population to another population, it must be intensively tested. Here, we describe the adaptation of the WHO protocol to the local conditions in rural Ballabgarh, and the findings of the pilot study conducted to test the protocol.

Head trauma with loss of consciousness as a risk factor for Alzheimer's disease

We identified all incident cases of clinically diagnosed Alzheimer's disease among the population of Rochester, MN, with onset from 1965 through 1974. A control (selected from the same community) was matched to each case by age, race, sex, and length of stay in Rochester. We studied 274 case-control pairs. Using the records linkage system available for residents of this community, we abstracted information on the occurrence of head trauma with loss of consciousness (LOC) from the medical records of both cases and controls. There were 5 pairs in which the case suffered an episode of head trauma with LOC but the control did not, and 4 pairs in which the control suffered an episode of head trauma with LOC but the case did not. We failed to detect a statistically significant difference between the 2 groups. This study overcomes many problems encountered in previous case-control studies reporting this association. The sample size was large; severity of head injury was documented in high-quality medical records; data about head injury were recorded before the onset of dementia: equal quality of data were available for cases and controls; and, since the study was population-based, there was no selection bias for cases or controls.

Ciprofloxacin versus amoxycillin/clavulanic acid in the treatment of urinary tract infections in general practice

An open, randomized general practice study was performed to assess the comparative efficacy and tolerability of ciprofloxacin and amoxycillin/clavulanic acid in the treatment of uncomplicated urinary tract infection. One hundred and eighty nine patients were recruited into the study. In comparison of pre- and post-treatment urine cultures and symptomatology, ciprofloxacin was significantly more effective (P less than 0.01) than amoxycillin/clavulanic acid. Both drugs were well tolerated with minimal adverse side effects. Ciprofloxacin is an effective and safe treatment for uncomplicated urinary tract infection in general practice.

Inheritance of Alzheimer's disease: epidemiologic evidence

The available evidence suggests that there may be two subtypes of AD-- inherited and noninherited. Inherited AD may have certain characteristics, e.g. younger age at onset and some clinical signs or symptoms, which distinguish them from noninherited cases. It is possible that the noninherited type of AD may also have a similar genetic defect as the inherited kind, the only difference being that in one case the defect is inherited from the parents and in the other the defect arises de novo during embryogenesis. An environmental factor operating during embryogenesis may be responsible for causing a genetic defect which later manifests as noninherited AD. Currently, however, there is no precise way to separate these two subtypes. The exact proportion of all cases of AD which are inherited on a genetic basis is not known, but it must be small. The mode of inheritance of genetic AD is not known. It must be emphasized that the subtypes of inherited and noninherited AD are not synonymous with the older categorization of AD into presenile and senile AD.

Patterns of mortality from hereditary ataxias in the United States, 1971 and 1973-1978

Mortality rates for deaths 'due to' and 'with' hereditary ataxias are presented for the first time. Age-adjusted mortality rates were higher for whites than for nonwhites of either sex, and for men in both racial groups. Age-specific mortality rates for whites showed a peak for 'hereditary spinal ataxia' in the 20-29 age group. For the other types of ataxias they were low until age 40 and increased thereafter. Heart diseases were a frequent cause of death in people dying 'with' hereditary ataxias. The median survival (from birth) for hereditary spinal ataxia in whites was 35 years.

Conditions associated at death with specific types of completed stroke in patients with and without hypertension: a case-control study

Potential risk factors for various types of stroke were studied using a case-control study design. All 1978 US death certificates for which the registered underlying cause of death was subarachnoid hemorrhage (SAH), cerebral hemorrhage (CH), or cerebral infarction (CI) were identified. The frequency with which other conditions appeared on the death certificates of cases with and without hypertension was compared with controls. These data provide new information, such as the occurrence of peripheral vascular disease in association with SAH, the risk of CH in epileptic and cirrhotic patients, and the association of benign neoplasms of the nervous system, motor neuron disease, and 'paralysis agitans' with CI.

Trends in incidence of dementing illness in Rochester, Minnesota, in three quinquennial periods, 1960-1974

We ascertained the incidence of dementias of all causes between 1960 and 1975 among citizens of Rochester, Minnesota. Study of all medical records yielded incidence rates for the quinquennial periods of 1960-1964, 1965-1969, and 1970-1974. In the population at risk (30 years or older), the age-adjusted rates (per 100,000 population/year) for Alzheimer's disease (clinically diagnosed or pathologically confirmed, or both) in the three periods were: 104.9, 80.8, and 96.6. The rates for dementia of all causes were: 160.6, 122.0, and 136.8. Calculation of 95% confidence intervals showed that the incidence rate for dementia or Alzheimer's disease has not changed in this 15-year period in Rochester, Minnesota. Assuming no demented patients younger than 29 years, the incidence rates in the three quinquennial periods for all dements were 79.4, 60.3, and 67.7; for Alzheimer's disease they were 51.9, 40.0, and 47.8.

Case-control study of associated conditions at the time of death in patients with epilepsy

Analysis of mortality data based on underlying cause of death in epileptic patients is of limited value in view of the low case-fatality ratio of epilepsy. Recently the National Center for Health Statistics has made available all conditions mentioned on each death certificate for the entire US population. Using a case-control study design, we have analyzed all the associated conditions at the time of death in patients with epilepsy for the year 1978. Association between epilepsy and the following conditions reached statistical significance: mental retardation, cerebral palsy, cerebrovascular disease, myocardial ischemia, dementia, foreign body in pharynx and larynx, pneumonia, alcoholism and cirrhosis of liver. Early recognition and proper management of some of these factors could significantly reduce the mortality and morbidity in epileptic patients.

Case-control study of late onset "probable Alzheimer's disease"

A case-control study was conducted on 64 cases of "probable Alzheimer's disease" with late onset of illness (after age 70 years) and 64 controls matched by age (+/- 3 years), race, and sex. Information was obtained on birth order, lifetime medical and surgical history, personal characteristics, exposure to toxins and animals, and a family history of various illnesses. None of the variables studied, including family history of dementia, reached statistical significance. An antecedent history of head trauma with loss of consciousness, though not statistically significant, was more frequently found in cases than in controls.

Motor neuron disease in the United States, 1971 and 1973-1978: patterns of mortality and associated conditions at the time of death

Mortality rates for deaths "due to" and "with" motor neuron disease are presented for the first time. Age-specific mortality rates increase with age until 70 to 74 years and then decline. There appear to be no major differences by race in the age-adjusted mortality rates, but these rates are higher for males both white and nonwhite. A case-control study of all deaths with amyotrophic lateral sclerosis (ALS) was conducted for deaths due to ALS in the year 1971. Conditions associated with ALS at the time of death include pneumonia and bronchopneumonia, symptoms referable to respiratory system, superficial injury to shoulder and upper arm, essential benign hypertension, chronic skin ulcer, and malnutrition. No association was found between ALS and malignancies, Parkinson's disease, or dementia.

A prevalence survey of 'incapacitating headache' in the People's Republic of China

Two Chinese populations over age 15 were surveyed as to the point prevalence of "incapacitating" headaches in an urban population of 1,525 persons and a rural one of 1,203. Personal interviews were carried out by a team of instructed interviewers; there was 100% cooperation. In both populations, prevalence in women was twice that in men except in the urban population in the youngest age group. Prevalence in the urban was almost exactly twice that of the rural population, with the highest figure occurring in traders.

Conditions associated with Alzheimer's disease at death: case-control study

To determine which conditions may be associated with reduced survival in patients with Alzheimer's disease, we studied all death certificates in the United States for 1978 on which senile and presenile dementia (ICDA 290, N = 7,195) was mentioned. Each case was compared with two control deaths. Differences in the frequency of listing on the death certificates for the following conditions reached statistical significance: infections, trauma, nutritional deficiency, chronic ulcer of skin, foreign body in pharynx, cataract, glaucoma, blindness, deafness, Parkinson's disease, and epilepsy. There seem to be many preventable and treatable disorders in patients with senile and presenile dementia.

Patterns of mortality from types of dementia in the United States, 1971 and 1973-1978

In the first analysis of US mortality data for different types of dementia, we searched all death certificates for the years 1971 and 1973 through 1978 for the diagnosis of senile and presenile dementia and for senility. The age-adjusted mortality rates for both types of dementia were higher for deaths with these conditions than due to them. Other diseases were listed as the underlying cause of death in most patients who died with dementia. Mortality rates were generally higher in men for both types of dementia; higher for whites for senile and presenile dementia, but higher for nonwhites for senility. Between 1971 and 1978, there was an increase in the age-adjusted mortality rates for senile and presenile dementia and a decline for senility. Age-specific mortality rates for both types of dementia increased exponentially with age, with no evidence of bimodality.