Biomedical subjects

W A Rocca

Publications and source records attributed to W A Rocca.

At least 73 records · Page 4Linked to original sources

PubMed1996

Dementia and adult-onset unprovoked seizures.

OBJECTIVE: We tested the hypothesis that dementia increases the risk of unprovoked seizure among adults. Partial- and generalized-onset seizures were considered together and separately. Additionally, we explored whether the increased risk was restricted to Alzheimer's disease (AD), as previously shown. DESIGN: Subjects in this population-based case-control study were 145 incident cases of first unprovoked seizure (without prior stroke, CNS infection, brain tumor, head trauma, mental retardation, or cerebral palsy) aged 55 years or older and 290 controls matched to cases on age, gender, and duration of medical follow-up. Using the records-linkage system of the Rochester Epidemiology Project, we obtained, for both cases and matched controls, information on dementia prior to onset of unprovoked seizure. Subjects were classified as having dementia if they met ad hoc criteria equivalent to those in the DSM-III. AD was distinguished from other dementias. RESULTS: Both a diagnosis of AD and a diagnosis of other dementia were associated with at least a six-fold increased risk of unprovoked seizure when controlling for age, sex, and length of medical follow-up in Rochester. There was no difference in risk when comparing generalized-onset seizures with partial-onset seizures. CONCLUSIONS: In the absence of other prior neurologic insult, both AD and other dementias increase the risk of generalized- and partial-onset unprovoked seizures.

Age of Onset↗

PubMed1996

Anticipation in familial Parkinson's disease: a reanalysis of 13 United Kingdom kindreds.

Several authors reported anticipation for age at onset in familial Parkinson's disease (PD) and postulated the involvement of an unstable trinucleotide repeat gene. We reanalyzed 13 previously reported multiple generation kindreds with familial PD to investigate anticipation and related biases. Although initial review of 33 informative parent-child and aunt/uncle-niece/nephew pairs revealed a mean anticipation interval of 9.3 years (p = 0.0001), exclusion of probands, in an effort to limit referral bias, reduced this to 4.1 years (p = 0.09). This reduced figure is still an overestimate of the true anticipation interval because of residual referral bias and because of incomplete information on the most recent generation. Our analyses did not demonstrate the effects of recall bias or of reduced fertility. We conclude that the observed anticipation in familial PD may partly or completely result from referral and other biases. Caution should be exercised in assuming an unstable trinucleotide repeat gene as the cause of familial PD.

Adolescent↗

PubMed1996

Causes of epilepsy: contributions of the Rochester epidemiology project.

The contributions of the Rochester (Minnesota) Epidemiology Project and Mayo Clinic studies in the evaluation of the causes of epilepsy are summarized. The development of the unique population-based medical records-linkage resource is chronicled, and the measures of occurrence and association used in epidemiologic study designs to assess the causes of epilepsy are presented. The historical cohort design is optimal for the study of the relationship between common central nervous system insults and seizures, and case-control studies are best used for analysis of relatively rare seizure disorders. The major findings about the etiologic roles of traumatic brain injuries, central nervous system infections, cerebrovascular disease, brain tumors, neurodegenerative diseases, developmental disabilities, perinatal insults, and familial factors are discussed. The role of genetic factors in epilepsy has been controversial, perhaps because of the numerous causes of seizures and their episodic nature. Both potential environmental and genetic causes will continue to be assessed.

Epidemiologic Methods↗

PubMed1996

Descriptive epidemiology of epilepsy: contributions of population-based studies from Rochester, Minnesota.

Studies based on the Rochester Epidemiology Project medical records-linkage system have provided important insights into the epidemiology of epilepsy. The incidence of all convulsive disorders in Rochester, Minnesota, during a 50-year period exceeded 130 per 100,000 person-years. The age-adjusted incidence of epilepsy was 44 per 100,000 person-years; of a first unprovoked seizure, 61; and of acute symptomatic seizures excluding febrile convulsions, 31. In addition, 2% of the population experienced a febrile convulsion before the age of 5 years. The cumulative incidence of epilepsy through age 74 years was 3.0%, of all unprovoked seizures was 4.1%, and of any convulsive disorder approached 10%. For epilepsy, single unprovoked seizures, and acute symptomatic seizures, the incidence was significantly higher in males than in females, and it was high in the first year of life but highest in those age 75 years or older. For epilepsy alone, approximately 60% of incidence cases experienced partial seizures, and two-thirds had no clearly identified antecedent. Cerebrovascular disease was the most commonly identified antecedent of epilepsy, accounting for 11% of cases. Over time, the incidence of epilepsy and of unprovoked seizures decreased in children and increased in the elderly population. The age-adjusted prevalence of active epilepsy on Jan. 1, 1980, was 6.8 per 1,000 residents. Prevalence was low in the first decade of life, increased to a plateau in the adult years, and further increased in the elderly population. Almost 1.5% of the population older than 75 years of age had active epilepsy. About 25% of prevalence cases had an identified cause; 60% experienced partial epilepsy.

Age Distribution↗

PubMed1995

Incidence of acute symptomatic seizures in Rochester, Minnesota, 1935-1984.

We determined the incidence of seizures due to acute CNS insults for residents of Rochester, Minnesota, U.S.A., from 1935 through 1984. The age-adjusted incidence rates for 1955-1984, the period of most complete case ascertainment, was 39.0/100,000 person-years (United States 1970 population as standard). The age-adjusted incidence was considerably higher in men: 52.0 as compared with 29.5 in women. The 3.6% risk of experiencing an acute symptomatic seizure in an 80-year lifespan approaches that of developing epilepsy. The major causes of acute symptomatic seizures were traumatic brain injury, cerebrovascular disease, drug withdrawal, and CNS infections. Each type of acute symptomatic seizure has age, gender, and time period patterns that reflect the occurrence of the underlying cause.

Adolescent↗

PubMed1995

Secular trends and birth cohort effects in unprovoked seizures: Rochester, Minnesota 1935-1984.

The incidence of idiopathic/cryptogenic epilepsy and isolated unprovoked seizures has been relatively stable in the population of Rochester, Minnesota, for the 50-year period 1935 through 1984. In each decade, the age-specific rates exhibited a consistent U-shaped pattern of decreasing rates from infancy to age 40-49 and a progressive increase thereafter to a second peak at age 70 years. Males had a 15% higher incidence of cryptogenic unprovoked seizures than females. The most pronounced secular trend was a decrease in the incidence in children aged < 10 years for the first 4 decades of the study; however, this trend was interrupted by a slight rebound in the decade 1975-1984. There has been a progressive decrease in the incidence of cryptogenic unprovoked seizures in individuals aged > or = 50 from 1965 through 1984. This decrease paralleled the decrease in cerebrovascular disease in the community. The decrease in idiopathic unprovoked seizures may be related to a concurrent trend in "silent stroke." Plots and Poisson regression analysis did not show patterns in the incidence of idiopathic unprovoked seizures related to successive birth cohorts. However, significantly lower incidence rates were observed for the 1930-1934 birth cohort, about half that of all others, between the ages of 5 and 54 years.

Adult↗

PubMed1995

Education and occupation as risk factors for dementia: a population-based case-control study.

To further investigate the putative associations between education and dementia and between occupation and dementia, we conducted a population-based case-control study. Cases were all subjects affected by dementia ascertained through a prevalence survey conducted in the municipality of Appignano, Macerata Province, Italy. For each case (n = 48), we randomly selected 2 population controls residing in the same municipality and matched for age and sex (n = 96). Information regarding exposures was collected by nonmedical personnel during the first contact for the prevalence survey. Although we found a striking trend toward decreasing prevalence with increasing education, this association was suggestive but not significant after age and sex adjustment at case-control analyses (odds ratio for illiterates = 1.4; 95% CI 0.6-3.1). In contrast, we found a significant association between manual principal lifetime occupation and dementia using both unadjusted and adjusted analyses (odds ratio = 2.9; 95% CI 1.2-7.4). Our findings suggest that, although education and occupation are related, occupation is a stronger indicator of risk than education.

Aged↗

PubMed1995

Prevalence of Alzheimer's disease and other dementing disorders in Pamplona, Spain.

We investigated the prevalence of dementing disorders in the city of Pamplona, Spain, using a door-to-door two-phase approach. We first administered the Cambridge Examination of Mental Disorders of the Elderly (CAMDEX) to all survivors, as of March 1, 1991, of a probability sample of the total population identified in 1989 (n = 1,127). Using specified diagnostic criteria, the study neurologists extensively investigated those subjects who screened positive on CAMDEX. We found 194 subjects affected by dementia, 119 had Alzheimer's disease; 51 vascular or mixed dementia, and 16 secondary dementia. The prevalence of both dementia and Alzheimer's disease increased steeply with advancing age and was consistently higher in women. The prevalence of combined vascular and mixed dementia increased less rapidly with age, and was generally higher in men. Alzheimer's disease was the most common type of dementia. Our prevalence figures for dementia and Alzheimer's disease are similar to those previously reported in Europe.

Age Factors↗

PubMed1994

Attrition and use of proxy respondents and auxiliary information in the Sicilian Neuroepidemiologic Study.

Two-phase prevalence surveys with screening (phase 1) and examination (phase 2) are useful for some chronic diseases. Attrition, which may bias estimates, occurs in either phase because some eligible subjects die before contact, some refuse to cooperate, some are incapacitated, and some are unreachable. This investigation relates to a survey of neurologic diseases conducted in three municipalities of Sicily (prevalence date, November 1, 1987) and considers the attrition experienced and the use of proxy respondents in phase 1 and auxiliary information in phase 2 to offset, in part, this attrition. Regarding case finding, the salvage effort was more productive for decreased and incapacitated subjects. The age, sex, and household size of the subject were related to phase 1 attrition, but only age was related for all four attrition groups--deceased, refusing, incapacitated, and unreachable subjects. On the basis of information from proxy respondents, the educational levels of refusing and unreachable subjects were compared with those of subjects screened directly. Refusing subjects were less educated, and unreachable subjects were more educated. The proxy respondent performance, as indicated by "don't know" responses, was better with screening items concerning facial paralysis and mouth drooping (and not limb sensory abnormalities or impaired consciousness), better with younger subjects, and worse with refusing or incapacitated subjects.

Adolescent↗

PubMed1994

Interaction between genetic and environmental risk factors for Alzheimer's disease: a reanalysis of case-control studies.

To study the interaction among genetic and environmental risk factors, a reanalysis of case-control studies of Alzheimer's disease (AD) was conducted based on the original data of all studies carried out to January 1, 1990. Seven studies were included in the present analysis, comprising a total of 814 AD patients and 894 control subjects. When comparing those with a positive and negative family history of dementia, similar odds ratio were found for late maternal age [1.7; 95% confidence interval (0.6-4.8) vs. 2.0 (1.1-3.5)], head trauma [1.7 (0.7-4.2) vs. 1.9 (1.1-3.2)], and history of depression [2.0 (0.2-19.8) vs. 2.1 (0.8-1.7)]. This suggests a model in which these risk factors increase the risk for AD independent of family history of dementia. Among those with a positive family history of dementia, the odds ratios for family history of Down's syndrome [4.2 (0.9-20.0)] and of Parkinson's disease [3.3 (0.4-28.2)] tended to be higher than among those with a negative family history of dementia [2.6 (0.8-8.5) and 2.4 (0.8-7.0), respectively]. However, for both disorders the difference in odds ratio was not statistically significant. For history of cigarette smoking, there was no association to AD for those with no first degree relatives with dementia and an inverse relation with AD for those with a positive family history. Although in all analyses, family history of dementia remained significantly associated with AD in the absence of other factors, the odds ratio associated with family history of dementia tended to be lower for those with a positive smoking history, particularly for those with two or more affected relatives. These findings suggest that smoking may interact specifically with a genetically determined process.

Aged↗

PubMed1994

Early treatment of stroke with monosialoganglioside GM-1. Efficacy and safety results of the Early Stroke Trial.

BACKGROUND AND PURPOSE: The Early Stroke Trial (EST) is a randomized, double-blind, placebo-controlled trial to assess the effect of monosialoganglioside GM-1 in improving recovery in patients who experienced an ischemic supratentorial stroke. METHODS: Sixteen clinical centers recruited 805 patients, of whom 792 were confirmed to be eligible. Treatment, consisting of a first dose of either 200 mg GM-1 or placebo, was initiated within 5 hours of the onset of stroke; a second dose of either 100 mg GM-1 or placebo was administered 12 hours later. Thereafter, patients received a daily injection of 100 mg GM-1 or placebo intravenously from day 2 through 10 and intramuscularly from day 11 through 21. Patients were followed up for a total of 4 months. RESULTS: Survival was similar in the two treatment groups. Improvement in neurological status, as measured by the change in Canadian Neurological Scale score between baseline and 4-month assessments, was greater in the group receiving GM-1; the observed difference between treatment groups was 0.22 (P = .06). A post hoc analysis in the subgroup of patients treated within 4 hours showed a statistically significant difference, with Canadian Neurological Scale mean improvement of 0.41 (P = .016). GM-1 use was not associated with differences in frequency, nature, or severity of adverse experiences. CONCLUSIONS: These findings suggest that GM-1 is safe in the dose and treatment schedule used and that its efficacy in ischemic stroke is greater when given soon after onset of stroke.

Adult↗

PubMed1994

Prevalence of essential tremor: a door-to-door survey in Terrasini, Sicily. Sicilian Neuro-Epidemiologic Study Group.

As part of a door-to-door neuroepidemiologic survey, we investigated the frequency and distribution of essential tremor (ET) in a Sicilian municipality. During phase 1, we administered a screening instrument for tremor to 7,653 persons residing in Terrasini (Palermo province). During phase 2, neurologists evaluated those subjects who had screened positive. The diagnoses, based on specified clinical criteria, were reviewed to increase reliability across neurologists. We found 31 subjects affected by ET (17 men, 14 women); 11 patients (35.5%) reported a familial aggregation. The prevalence of ET as of November 1, 1987, was 405.1 per 100,000 for the total population, and 1,074.9 per 100,000 for those 40 years old or older. The prevalence increased with advancing age for both sexes and was slightly but consistently higher in men. Comparison with other studies suggests striking geographic variation, which may reflect genetic differences.

Adolescent↗

PubMed1994

Frequency, distribution, and risk factors for Alzheimer's disease.

Both prevalence and incidence of AD increase steeply with advancing age in all populations investigated thus far. In general, women have higher prevalence and incidence; however, there are exceptions to this pattern. When considering only methodologically comparable surveys, and taking age into account, there are no major geographic differences in either prevalence or incidence. Data on incidence are unfortunately limited worldwide. There are no major time trends in either prevalence or incidence. The only definite risk factors for AD are age and familial aggregation. Putative risk factors are familial aggregation of Down's syndrome, familial aggregation of Parkinson's disease, late maternal age, head trauma, history of depression, and history of hypothyroidism. Cigarette smoking was found to be less common in the history of patients with AD than in that of controls. This association is probably spurious, however. Unfortunately, current knowledge about risk factors for AD does not justify the conduct of preventive trials or the introduction of large-scale interventions.

Aged↗

PubMed1993

Prevalence of diabetic neuropathy with somatic symptoms: a door-to-door survey in two Sicilian municipalities. Sicilian Neuro-Epidemiologic Study (SNES) Group.

In a door-to-door survey conducted in two municipalities of Sicily, we ascertained the prevalence of diabetic neuropathy. Our case-finding was restricted to subjects with somatic symptoms. During phase 1, we administered a screening instrument for peripheral neuropathy to 14,540 persons residing in Santa Teresa di Riva (Messina Province) and Terrasini (Palermo Province). During phase 2, neurologists evaluated those subjects who had screened positive. Diagnoses were based on clinical criteria only, and were reviewed by an adjudication panel. We found 39 persons (27 women, 12 men) affected by diabetic neuropathy. The crude prevalence, as of November 1, 1987, was 268.2 cases per 100,000 population. The prevalence increased with advancing age for both sexes and was consistently higher in women. The most common type was distal symmetric polyneuropathy. The median time between diagnosis of diabetes mellitus and onset of diabetic neuropathy was 8 years, and almost all identified persons with diabetic neuropathy were under treatment for diabetes mellitus.

Adult↗

PubMed1992

Validating screening instruments for neuroepidemiologic surveys: experience in Sicily. Sicilian Neuro-Epidemiologic Study (SNES) Group.

In a hospital setting in Sicily, we assessed a screening instrument developed for a prevalence survey of parkinsonism, peripheral neuropathies, stroke, and epilepsy. The subjects consisted of (1) hospital patients with any of the above-mentioned diseases, to investigate sensitivity; and (2) hospital visitors free of all these diseases, to investigate specificity. The standard for comparison was a clinical evaluation based on specified criteria. Trained interviewers administered the screening instrument, asking subjects to answer symptom questions and to perform simple physical tasks. For the questions and tasks together, the sensitivity estimates were 100% for parkinsonism (n = 21), 96% for peripheral neuropathies (n = 22), 96% for stroke (n = 22), and 96% for epilepsy (n = 22), while the specificity estimate was 86% (n = 21). Analogous estimates were computed for the set of questions, for the set of tasks, and for each question and task individually. Despite limitations in our approach, we concluded that the screening instrument would be adequate for its intended use.

Adult↗

PubMed1992

Validation of the Hodkinson abbreviated mental test as a screening instrument for dementia in an Italian population.

We investigated the accuracy of the Hodkinson abbreviated mental test (AMT) as a screening instrument for dementia in an Italian population. The AMT was administered by nonmedical personnel to 124 subjects > 59 years old. Each subject independently underwent a clinical evaluation for dementia (DSM-III criteria), and scores on the AMT were compared to corresponding clinical diagnoses (standard for comparison). Twenty of the 124 subjects were found to be affected by dementia upon clinical investigation. Although a score of 6 on the AMT showed the best combination of sensitivity (90%) and specificity (89%), only a score of 7 yielded 100% sensitivity (71% specificity). Specificity was higher in men, younger, and more educated subjects.

Aged↗

PubMed1992

Design and baseline results of the monosialoganglioside early stroke trial. The EST Study Group.

BACKGROUND AND PURPOSE: The Early Stroke Trial is a randomized, placebo-controlled, double-masked, multicenter study to assess the safety and efficacy of monosialoganglioside in patients who have suffered an ischemic stroke of the cerebral hemispheres. METHODS: Only patients who could be evaluated and treated within 5 hours after the onset of stroke were considered; within each center, subjects were stratified by age, sex, and clinical severity. Patients were randomly allocated to receive a specified sequence of intravenous and intramuscular doses of either monosialoganglioside or identical-appearing placebo for 21 days. Patients were followed up for 4 months after randomization. Neurological status was measured primarily by using the Canadian Neurological Scale. After assessing the effect of treatment on survival, the principal measure of efficacy will be the change in neurological status between baseline and the 4-month follow-up among survivors. RESULTS: Sixteen clinical centers, 15 in Europe and one in North America, entered a total of 792 eligible patients during a 36-month recruitment period (from May 1987 to April 1990). In our series there were more men than women, and the relative frequency of patients increased with advancing age. The most frequently associated cardiovascular conditions were hypertension, atrial fibrillation, and peripheral vascular disease. Approximately 46% of the patients were admitted to a hospital within 1 hour and 81%, within 2 hours after the onset of stroke. About 22% first received the study treatment within 3 hours and 57%, within 4 hours. CONCLUSIONS: This study demonstrates the feasibility of large-scale trials with the onset of treatment within 5 hours after an ischemic stroke.

Adult↗

PubMed1992

Prevalence of Parkinson's disease and other types of parkinsonism: a door-to-door survey in three Sicilian municipalities. The Sicilian Neuro-Epidemiologic Study (SNES) Group.

We investigated the prevalence of Parkinson's disease and other types of parkinsonism in a Sicilian population using a door-to-door two-phase approach. This design called for the administration of a brief screening instrument to all subjects who, on November 1, 1987, were residents of Terrasini (Palermo Province), Santa Teresa di Riva (Messina Province), and Riposto (Catania Province), Sicily (N = 24,496). Study neurologists using specified diagnostic criteria extensively investigated those subjects who screened positive. We found 63 subjects affected by Parkinson's disease, 21 with secondary parkinsonism, and seven with unspecified parkinsonism. The crude prevalence per 100,000 population was 371.5 for all types of parkinsonism and 257.2 for Parkinson's disease; for both entities, prevalence increased steeply with age and showed an inconsistent sex pattern. Our prevalence figures for Parkinson's disease are higher than those previously reported in Italy or elsewhere, which may be due, in part, to more complete case-ascertainment.

Female↗