Incidence and prevalence of tuberous sclerosis in Rochester, Minnesota, 1950 through 1982

The incidence of tuberous sclerosis in Rochester, MN, was 0.56 per 100,000 person-years in 1950 through 1982, and point prevalence on December 31, 1980, was 10.6 per 100,000 persons. The true incidence and prevalence may be even higher, because cases with hypomelanotic macules and no other clinical manifestations are often unrecognized. Pertinent clinical observations in the eight cases identified included familial occurrence in two; hypomelanotic macules in all eight; seizures with onset before age 2 in four, of whom two were mentally retarded; and no neurologic abnormalities in those free of seizures.     

Incidence of unprovoked seizures and epilepsy in Iceland and assessment of the epilepsy syndrome classification: a prospective study

BACKGROUND: No population-based incidence studies of epilepsy have studied syndrome classification from the outset. We prospectively studied the incidence of a single unprovoked seizure and epilepsy in the population of Iceland, and applied the syndrome classification endorsed by the International League Against Epilepsy to this population. METHODS: We used a nationwide surveillance system to prospectively identify all residents of Iceland who presented with a first diagnosis of a single unprovoked seizure or epilepsy between December 1995 and February 1999. All cases were classified by seizure type, cause or risk factors, and epilepsy syndrome. RESULTS: The mean annual incidence of first unprovoked seizures was 56.8 per 100,000 person-years, 23.5 per 100,000 person-years for single unprovoked seizures, and 33.3 per 100,000 person-years for epilepsy (recurrent unprovoked seizures). Incidence was similar in males and females. Partial seizures occurred in 40% and a putative cause was identified in 33%. Age-specific incidence was highest in the first year of life (130 per 100,000 person-years) and in those 65 years and older (110.5 per 100,000 person-years). Using strict diagnostic criteria for epilepsy syndromes, 58% of cases fell into non-informative categories. Idiopathic epilepsy syndromes were identified in 14% of all cases. INTERPRETATION: Findings are consistent with incidence studies from developed countries. Although the epilepsy syndrome classification might be useful in tertiary epilepsy centers, it has limited practicality in population studies and for use by general neurologists.     

Incidence of Epilepsy and Unprovoked Seizures in Rochester, Minnesota: 1935–1984

Summary: The incidence of epilepsy and of all unprovoked seizures was determined for residents of Rochester, Minnesota U.S.A. from 1935 through 1984. Ageadjusted incidence of epilepsy was 44 per 100,000 personyears. Incidence in males was significantly higher than in females and was high in the first year of life but highest in persons aged ≥75years. Sixty percent of new cases had epilepsy manifested by partial seizures, and two thirds had no clearly identified antecedent. Cerebrovascular disease was the most commonly identified antecedent, accounting for 11% of cases. Neurologic deficits from birth, mental retardation and/or cerebral palsy, observed in 8% of cases, was the next most frequently identified preexisting condition. The cumulative incidence of epilepsy through age 74 years was 3.1%. The age-adjusted incidence of all unprovoked seizures was 61 per 100,000 person-years. Age-and gender-specific incidence trends were similar to those of epilepsy, but a higher proportion of cases was of unknown etiology and was characterized by generalized onset seizures. The cumulative incidence of all unprovoked seizures was 4.1% through age 74 years. With time, the incidence of epilepsy and of unprovoked seizures decreased in children and increased in the elderly.     

50-year trends in the incidence of anorexia nervosa in Rochester, Minn.: a population-based study

OBJECTIVE: The aim of the study was to determine incidence and prevalence rates and long-term trends in incidence of anorexia nervosa by identifying all persons residing in the community of Rochester, Minn., during the 50-year period 1935 through 1984 who had the disorder. METHOD: From a community-based epidemiologic resource, 13,559 medical records with diagnoses of amenorrhea, starvation, weight loss, anorexia nervosa, or other conditions were screened to identify true cases of anorexia nervosa determined by using standard diagnostic criteria. RESULTS: One hundred eighty-one residents (166 female and 15 male) fulfilled the diagnostic criteria for anorexia nervosa; these were the incidence cases. Due to a quadratic trend in the rates for girls 10-19 years old, the incidence rate among female residents fell from 16.6 per 100,000 person-years in the 1935-1939 period to a low of 7.0 in 1950-1954 and increased to 26.3 in 1980-1984. The incidence rates for women 20 years old and older and for males remained constant. For females 15-24 years old, there was a linear increase. The overall age-adjusted incidence rate per 100,000 person-years was 14.6 for females and 1.8 for males. The prevalence rate per 100,000 population was 269.9 for females and 22.5 for males. CONCLUSIONS: Anorexia nervosa is more common than previously recognized. Among girls 15-19 years old it is a very common chronic illness. Its incidence has increased among females 15-24 years old but not among older women or among males.     

Incidence and effectiveness of cerebrospinal fluid shunts in Olmsted County, Minnesota, 1956-1981

In the period 1956 through 1981, 129 cerebrospinal fluid (CSF) shunt operations were performed on 50 patients who were residents of Olmsted County, Minn. The overall average annual age- and sex-adjusted incidence of initial CSF shunts during this 26-year period was 2.3 per 100,000 person-years. Within 5-year calendar time intervals, the average annual incidence rates per 100,000 person-years ranged from 0.8 (1956-1960) to 4.6 (1971-1975). There were 4 shunt-related deaths, 1 due to a CSF shunt infection and 3 due to acute increases in intracranial pressure. In this analysis of shunt procedures in a defined population, the diagnostic indications and changes over time in CSF shunting devices are also described.     

Incidence and prevalence of amyotrophic lateral sclerosis in Harris County, Texas, 1985-1988

The incidence of amyotrophic lateral sclerosis was determined in Harris County, Texas, for the period 1985 through 1988. Amyotrophic lateral sclerosis cases were ascertained from four sources: area neurologists, hospitals, death certificates, and the Muscular Dystrophy Association. The age-adjusted incidences of 1.27 per 100,000 person-years in males and 1.03 per 100,000 person-years in females were lower than recent rates in the northern US, Canadian, and northern European studies but higher than rates in southern European studies. Comparisons with other recent incidence studies show less uniformity in occurrence of amyotrophic lateral sclerosis, in both the overall rates and in the age- and sex-specific patterns, than was suggested by mortality studies. The incidence of amyotrophic lateral sclerosis among blacks and whites was similar. Hispanic males had incidences similar to white males, although a deficit of female Hispanic cases was found in Harris County. The prevalence of amyotrophic lateral sclerosis peaked in the 65- to 74-year age group at 33 per 100,000 population among males and 19 per 100,000 population for females.     

Incidence of schizophrenia in a nationwide cohort of patients with type 1 diabetes mellitus

CONTEXT: Patients with schizophrenia have an increased risk of type 2 diabetes mellitus. However, very few studies have dealt with the association of type 1 diabetes and schizophrenia. Preliminary evidence points to a possible inverse association. OBJECTIVE: To investigate the incidence of schizophrenia in a nationwide cohort of patients with type 1 diabetes born in 1950 through 1959 in Finland. DESIGN: A cohort study of individuals born in 1950 through 1959 with a follow-up of 1969 through 1991. SETTING: Finland. PATIENTS: All individuals born in 1950 through 1959 with type 1 diabetes were identified through nationwide registers. The incidence of schizophrenia until 1992 among the total 1950-1959 cohort and in individuals with type 1 diabetes was calculated using information from 3 health care registers. MAIN OUTCOME MEASURE: Incidence of schizophrenia. RESULTS: The incidence of schizophrenia was 0.21 per 10 000 person-years in the group with type 1 diabetes and 0.56 per 10 000 person-years in the group without type 1 diabetes (P < .001). CONCLUSION: The incidence of schizophrenia is decreased in patients with type 1 diabetes.     

Epidemiological study of motor neuron disease in Hokkaido island--its incidence, prevalence and regional distributions--ALS Study Group]

The incidence, prevalence and regional distributions of sporadic motor neuron disease (MND) from 1980 through 1989 were evaluated in collaboration with multiple neurological institutes in Hokkaido island. Patients with sporadic MND were collected from three sources: 1) neurologist practicing in Hokkaido island, 2) sending inquiries to 620 major hospitals, 3) notification file of MND provided by Japanese Ministry of Welfare and Health. Three hundred and eighty-nine patients with sporadic MND were ascertained for this study. Of 389 patients, 238 patients were men and 151 patients were women, and the ratio of men to women was 1.6:1. The mean age of onset was 58.2 +/- 10.3 years old, 57.7 +/- 10.4 for men and 58.9 +/- 10.0 for women. Their clinical presentations were 303 patients with ALS, 52 patients were PBP and 34 patients were SPMA. The crude incidence rate for both sexes combined for 1980 through 1989 was estimated as 0.69 per 100,000 person-year. The age- and sex-adjusted incidence for men was 0.86 per 100,000 person-year (95% CI, 0.75 to 0.97) and that is higher than 0.53 per 100,000 person-year (95% CI, 0.45 to 0.61) for women. The average, crude prevalence rate from 1985 through 1989 was estimated as 2.25 per 100,000 person-year. There are no overall trends of changing the pattern in incidence and prevalence of MND in Hokkaido island, however the geographic distributions of the incidence of MND according to towns and cities disclosed the presence of some relative clustering areas.(ABSTRACT TRUNCATED AT 250 WORDS)     

The incidence of first provoked and unprovoked seizure in pediatric patients with and without psychiatric diagnoses

PURPOSE: To estimate the rate of new-onset afebrile provoked and unprovoked seizure in a general pediatric population and subgroups of patients with and without psychiatric diagnoses other than attention deficit hyperactivity disorder (ADHD). METHODS: A retrospective cohort study of 133,440 pediatric patients, between the ages of 6 and 17 years, and without history of seizure or prior use of anticonvulsant medications, with follow-up during 2003. The data source for this study was Ingenix's research database containing pharmacy and medical claims for members of a large US-based managed care organization. The main outcome measure was new-onset nonfebrile seizure. Incidence rates of seizure and 95% confidence intervals (CI) were calculated and expressed as rates per 100,000 person-years. RESULTS: There were 132 new-onset provoked and unprovoked seizures in 78,423 person-years of follow-up among the general pediatric population sample. The incidence rate of seizure among the general pediatric population was 168 per 100,000 p-y (95% CI 141-200). The incidence rate of seizure among patients without psychiatric diagnoses was 149 per 100,000 p-y (95% CI 122-180). The incidence rate of seizure among patients with psychiatric diagnoses other than ADHD was 513 per 100,000 p-y (95% CI 273-878). There were increases in the incidence rates of seizure in all of the seizure risk factor groups, but this was more pronounced among males ages 6-12 with psychiatric diagnoses. CONCLUSIONS: The results of this study are consistent with previous reports showing that pediatric patients with psychiatric disorders have a higher incidence rate of seizure than the general pediatric population.     

Incidence of migraine headache: a population-based study in Olmsted County, Minnesota.

To determine the incidence of clinically detected migraine headache in the defined population of Olmsted County, MN, 1979-1981, we screened over 6,400 patient records from several diagnostic rubrics using the unique resources of the Rochester Epidemiology Project for population-based studies. We identified 629 Olmsted County residents who fulfilled the International Headache Society's 1988 criteria for newly diagnosed migraine headache between 1979 and 1981. The overall age-adjusted incidence was 137 per 100,000 person-years for males and 294 per 100,000 person-years for females. The highest incidence in females was among those aged 20 to 24 years (689 per 100,000 person-years), and in males, the highest incidence was among those aged 10 to 14 years (246 per 100,000 person-years). From 1979 to 1981, there was a striking increase in the age-adjusted incidence in those under 45 years of age: the incidence increased 34% in women and 100% for men. This is the first population-based study of migraine incidence across all ages.     

Incidence and prevalence of motor neuron disease in Coastal and Mountainous Regions,Croatia, 1984–1993. A preliminary survey

In the period 1984–1993, we carried out an incidence and prevalence study of motor neuron disease in Coastal and Mountainous Regions, Croatia. This was the first epidemiological study on motor neuron disease in Croatia. A total of 22 incident cases were identified. The crude annual incidence rate was 0.68 (95% confidence interval 0.43-1.03) per 100,000 person-years; 0.95 (95% confidence interval 0.60-1.43) per 100,000 person-years for men and 0.42 (95% confidence interval 0.26-0.63) per 100,000 person-years for women. The rate adjusted to the European population was 0.63 (95% confidence interval 0.39-0.95) per 100,000 person-years. The age-adjusted incidence in our population is similar to the rates, standardized to the European population, observed in Italy, but lower than recent rates in the US and northern European studies. On 31st December 1993, there were 18 prevalent cases. The prevalence adjusted to the European population was 5.24 (95% confidence interval 3.10-8.28) per 100,000 population.     

Incidence of newly diagnosed epileptic seizures in a French South Indian Ocean Island, La Réunion (EPIREUN)

Purpose:   To assess the incidence of newly diagnosed epileptic seizures in the population of La Réunion.
Methods:   From July 1, 2004 to June 30, 2005, we conducted a prospective, observational, and multicenter epidemiologic study to identify patients with newly diagnosed epileptic seizures. Febrile and neonatal seizures were excluded.
Results:   Seven hundred sixty-six patients were included. The standardized (2000 U.S. population) incidence rate of all suspected cases of newly diagnosed (provoked and unprovoked) epileptic seizures was 115.4/100.000 person-years [95% confidence interval (CI) 106.7–124.0]. We observed a bimodal distribution: The crude incidence was 99.5/100,000 in the group aged 0–14 years and 330.8/100,000 in those older than 65 years. One hundred thirty-five cases were classified as provoked seizures (17.6%; incidence 17.7/100,000). Alcohol consumption, cranial trauma, and cerebrovascular disease were the most frequent causes (27.4%, 11.1%, and 10.4%, respectively). Six hundred twenty cases were classified as unprovoked seizures (single and recurrent) (80.9%; incidence, 81.2/100,000). Two hundred sixty cases of seizures were due to stable neurologic conditions (incidence, 34.1/100,000) and the most common causes were cerebrovascular disease (46.2%), alcoholism (20.4%), and cranial trauma (5.4%). Evolutive neurologic conditions contributed to 23 cases (incidence, 3.0/100,000). Lastly, unprovoked seizures with unknown etiology were 337 (incidence, 44.2/100,000).
Conclusions:   The global incidence rate of newly diagnosed epileptic seizures in La Réunion was clearly higher than those observed in industrialized countries and similar to those observed in developing countries. The major risk factors were represented by cerebrovascular disease, alcohol consumption, and cranial trauma. Surprisingly, there were few infections.     

Incidence and prevalence of ALS in Ireland, 1995-1997: a population-based study

BACKGROUND: We conducted a prospective, population-based study of ALS in the Republic of Ireland for the 3-year period 1995 to 1997. METHODS: To ensure complete case ascertainment, multiple sources of information were used, including consultant neurologists, neurophysiologists, primary care physicians, and the Irish Motor Neuron Disease Association. The El Escorial diagnostic criteria for ALS were applied to all cases enrolled on the register and each patient was regularly followed up during his or her illness. RESULTS: Between January 1, 1995, and December 31, 1997, 231 patients were diagnosed with possible, probable, or definite ALS, including 133 men (57.6%) and 98 women (42.4%). The average annual incidence rate was 2.1 per 100,000 person-years (95% CI, 1.8 to 2.4), and 2.8 per 100,000 person-years for the population older than 15 years (95% CI, 2.4 to 3.1). The incidence rate was higher for men, being 2.5 per 100,000 person-years (95% CI, 2.0 to 2.9), than for women, at 1.8 per 100,000 person-years (95% CI, 1.5 to 2.2), and increased with age for both sexes. The median age at onset was 64.2 years for men and 67.8 years for women. On December 31, 1996, the crude prevalence was 4.7 per 100,000 of the total population (95% CI, 4.0 to 5.5), and 6.2 per 100,000 for the population older than 15 years (95% CI, 5.3 to 7.1). Adjusting to the 1996 Irish population as standard, the incidence of ALS in Ireland during the 3-year study period is the third highest reported to date. CONCLUSIONS: There was a trend toward a higher incidence of ALS in the northwestern region of Ireland, although the numbers of cases involved were small and further study is required.     

The trends in incidence of primary brain tumors in the population of rochester,minnesota

A number of reports have suggested an increasing incidence of primary brain tumors, especially malignant astrocytomas, in the elderly population. To investigate this issue, we analyzed the incidence and temporal trends of primary intracranial neoplasms diagnosed in the population of Rochester, Minnesota, over the 40 years between 1950 and 1990. The incidence of symptomatic primary brain tumors (excluding patients diagnosed incidentally at autopsy and by neuroimaging studies) increased from 9.5 per 100,000 population per year in 1950 to 1969 to 12.5 per 100,000 per year in 1970 to 1989; this change was not statistically significant (χ² trend, 1.89; p = 0.17). While the incidence of pituitary adenomas increased significantly between the two periods (χ² trend, 4.44;p = 0.04), the incidence trends of all gliomas, malignant astrocytomas, and meningiomas showed no change among persons younger than 65 years as well as those 65 years and older. The number of patients incidentally found to have neoplasms by neuroimaging studies increased in the recent 20-year period (χ² trend, 4.08;p = 0.04). The average age- and sex-adjusted incidence rates per 100,000 per year during the study period in the population of Roshester, Minnesota, for symptomatic tumors were 5.0 for all gliomas, 3.3 for malignant astrocytomas, 2.0 for meningiomas, and 2.4 for pituitary adenomas. In conclusion, our data indicate that the reported increase in the incidence of primary brain tumors is an artifact of improvement in diagnostic technology and practice.     

Trends in head injury incidence in New Zealand: a hospital-based study from 1997/1998 to 2003/2004

Traumatic brain injury (TBI) is a leading cause of disability and death in young adults. Globally, the incidence of TBI hospitalizations is estimated at 200-300 people per 100,000 annually. Using a national health database, we examined the incidence of TBI-related hospital discharges (including 1-day stays) to New Zealand Hospitals from 1997/1998 to 2003/2004. Crude annual hospital-based incidence rates for the total population ranged from 226.9 per 100,000 in 1998/1999 to a high rate of 349.2 in 2002/2003. There was a noticeable increase in rates with the change from ICD-9 to ICD-10 diagnostic codes and there was also disparity in incidence rates according to ethnicity, age and gender. Crude annual hospital-based incidence rates for males and females in Maori (689/100,000 and 302.8/100,000 person-years) and Pacific Island populations (582.6/100,000 and 217.6/100,000 person-years) were much higher than those for the remaining population (435.4/100,000 and 200.9/100,000 person-years), particularly for males. The overall age-standardized hospital- based incidence rate for 2003/2004 was 342 per 100,000 per year (95% CI = 337-349/100,000), and 458 per 100,000 per year for Maori (95% CI = 438-479/100,000) with Maori males experiencing a peak in incidence between 30 and 34 years of age that was not evidenced for the wider population. Standardized hospital-based incidence rates for the total population and for Maori by age, gender and ICD-10 diagnostic codes are also examined.     

Incidence of adult epilepsy in Estonia

PURPOSE: To estimate the main incidence-related characteristics of epilepsy in an adult population in Estonia. Epidemiologic data about epilepsy from central and eastern Europe is controversial. METHODS: All existing databases and lists in the area were reviewed to identify all persons with newly diagnosed epilepsy aged > or =20 years during 3 years. Special attention was paid to extensive adoption of definitions and criteria proposed by Guidelines for epidemiologic studies. RESULTS: Crude and age-adjusted incidence rates were 35 per 100,000 person-years. The age-specific rates tended to increase with advancing age. Of the seizure types, partial seizures had highest rates, 27 per 100,000. The largest syndromic categories were localization-related epilepsies. Risk factors for epilepsy were identified in 55.5% cases. CONCLUSIONS: Incidence-related characteristics in the adult population of Tartu was comparable with those reported from the developed countries. The predominance of localization-related syndromes and partial seizures is the result of age distribution of the study.     

Incidence and prognosis of stroke in young adults: a population-based study in Ferrara, Italy

The reported annual incidence of juvenile stroke ranges from 9 to 47 cases per 100,000 inhabitants. We sought to estimate the incidence of first-ever stroke in young adults through a population-based stroke registry in a well-defined and stable population. We planned to collect all cases of new stroke in people aged 15–44 years in Ferrara, Italy, over the period 2002–2007. During the surveillance period, a first-ever stroke was diagnosed in 39 patients, giving a mean annual crude incidence rate of 12.1 cases per 100,000 person-years (95% CI 8.6–16.5), 9.1 when adjusted to the European population. The overall 30-day case fatality rate was 7.7, 21.4% for hemorrhagic stroke. The incidence rate was in the range of estimates detected in western countries. The case-fatality rate was lower than that reported in less recent studies. The stroke subtype predicted the probability of death and the outcome.     

Incidence and Clinical Characterization of Unprovoked Seizures in Adults: A Prospective Population-Based Study

In a population-based prospective study of epileptic seizures in adults aged ≥17 years, we identified 563 patients with possible seizures in a period of 34 months. Seizures were unprovoked in 160 patients, an incidence of 56 in 100,000 person-years. There was no difference in incidence between sexes. Age-specific incidences of unprovoked seizures increased sharply in men from age 60 years and in women from age 70 years. The incidence of unprovoked seizures in those aged ≥65 years was 139 (men 166, women 116). The cumulative incidence of unprovoked seizures between the ages of 17 and 84 years was 4.6%. The proportion with an identified presumptive cause for unprovoked seizures increased with advancing age. A presumed etiology was identified in 77% of persons aged ≥60 years. Stroke was the most common etiology, detected in 30% (incidence 16) and in 45% at ages ≥60 years. Tumors were detected in 11% (incidence 6) and Alzheimer's disease was detected in 7% (incidence 4). Eighteen percent of patients were demented. Unprovoked seizures were partial in 68% of cases (incidence 38), and generalized in 16% (incidence 9). Another 13% of patients had generalized seizures, but seizure onset was not witnessed (incidence 7). In 16%, there was a delay of ≥1 year from the first unprovoked seizure to initial diagnosis.     

Incidence of amyotrophic lateral sclerosis and of the parkinsonism-dementia complex of Guam, 1950-1989

Studies representing the accumulated information from the first 30 years of research effort on Guam (1950-1979) have demonstrated a varying degree of decline in the incidence of amyotrophic lateral sclerosis (ALS) and the parkinsonism-dementia complex (PDC) of Guam. Analysis with more complete information for the period 1980-1989 provides more valid estimates of the later patterns in the incidence of ALS and PDC and affords a more extensive assessment of trends over a 40-year period. The annual age-adjusted incidence of ALS was 7/100,000 and the annual age-adjusted incidence of PDC was 22/100,000 in 1989. The incidence was much higher for the period 1980-1989 than suggested in previous reports. These findings provide compelling evidence that this spectrum of neurodegenerative diseases continues to have a significant impact on the health of the Chamorro people of Guam.     

Suicide risk in placebo vs active treatment in placebo-controlled trials for schizophrenia

BACKGROUND: If there is an increased risk of suicide in the placebo arms of placebo-controlled studies in patients with schizophrenia, it would be a strong ethical argument against the conduct of placebo-controlled studies in this patient population. We tested whether the risk of suicide and attempted suicide in the placebo arms of placebo-controlled studies among patients with schizophrenia is higher than in the active treatment arms of such studies. METHODS: All placebo-controlled double-blind studies that were part of a registration dossier for the indication schizophrenia, and that were submitted to the regulatory authority of the Netherlands from January 1, 1992, through December 31, 2002, were reviewed for suicide and attempted suicide. RESULTS: In 31 studies, 7152 patients were included: 1888 in placebo groups (398.2 person-years) and 5264 in active compound groups (981.3 person-years). One suicide occurred in the placebo groups (0.05%, or an incidence rate of 251 per 100,000 years of exposure) and 1 in the active compound groups (0.02%, or an incidence rate of 102 per 100,000 years of exposure). This difference was not statistically significant. Two attempted suicides occurred in the placebo groups (0.11%, or an incidence rate of 502 per 100,000 years of exposure) and 11 in the active compound groups (0.21%, or an incidence rate of 1121 per 100,000 years of exposure). This difference was also not statistically significant. CONCLUSION: Concern about increased risk of suicide or attempted suicide in the placebo group should not be an argument against the conduct of placebo-controlled trials in schizophrenia, provided that appropriate precautions are taken.