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Biomedical subjects

L T Kurland

Publications and source records attributed to L T Kurland.

At least 19 recordsLinked to original sources

Incidence and natural history of primary systemic amyloidosis in Olmsted County, Minnesota, 1950 through 1989.

No reports of the incidence rates for primary systemic amyloidosis (AL) have come to our attention. Records of all residents of Olmstead County, Minnesota, with a diagnosis of amyloidosis were obtained from the Mayo Clinic and its affiliated hospitals, as well as other medical groups that might have seen local patients for the period January 1, 1950 to December 31, 1989. Twenty-one patients fulfilled the criteria for the diagnosis of AL. The median age was 73.5 years, and 62% were men. In all but one patient the diagnosis was made ante mortem. The clinical data of the 21 patients were similar to those referral patients with AL seen at Mayo Clinic. Immunohistochemical stains were positive for monoclonal light chains in the amyloid deposits in 15 of the 21 cases. In six cases, tissue was not available for immunohistochemical studies. Three of the six patients without immunohistochemical stains had a free monoclonal lambda light chain in the urine, and the other three had a monoclonal serum protein. Immunoelectrophoresis/immunofixation detected a monoclonal (M)-protein in the serum of 16 of 17 patients tested. A monoclonal light chain was found in the urine of 10 of 15 patients. The overall sex- and age-adjusted rate per million person-years was 6.1 from 1950 to 1969 and 10.5 from 1970 to 1989. The similarity of these rates suggests no significant increase over time.

Aged

Mechanical trauma as a risk factor in classic amyotrophic lateral sclerosis: lack of epidemiologic evidence.

We have examined the relationship between mechanical injuries and the subsequent development of classic amyotrophic lateral sclerosis (ALS) through a critical review of the literature. Only prospective evaluation of a large cohort of trauma victims can provide an unbiased answer to this controversy. However, such an evaluation would be prohibitively expensive, and the results would not be available in our lifetime. The results of retrospective case-control studies are conflicting in part because of biases in the selection of patients and controls, poor definition of the nature and extent of the trauma and its chronological relationship to the onset of ALS, and a non-uniform approach to the collection of antecedent information. More rigorously designed studies show no association of ALS to antecedent trauma. The existing data thus do not suggest that mechanical trauma is a risk factor for ALS. Future case-control studies should conform to a standardized methodology. The critical analysis presented here of the research on the purported connection between mechanical injury and ALS may serve as a model for the evaluation of the role of trauma in other chronic diseases. Application of these methodological principles may bring increased scientific rigor to assessing the frequently litigated question of what constitutes a true trauma sequela.

Adult

Conditions associated with carpal tunnel syndrome.

With use of a comprehensive medical records-linkage system, we identified the comorbid conditions and risk factors in the residents of Rochester, Minnesota, who had a diagnosis of carpal tunnel syndrome during 1961 through 1980. In 43.2% of the 1,016 patients, no associated conditions were found on review of the medical records, whereas associated conditions were documented in 56.8%. The most frequent of these conditions were Colles' fracture, rheumatoid arthritis, hormonal agents or oophorectomy (or both), diabetes mellitus, and, among men, occupations that involved excessive use of the hands. Rheumatoid arthritis, diabetes mellitus, and pregnancy were significantly more frequent among the study patients with carpal tunnel syndrome than in the general population of Rochester, Minnesota. The standardized morbidity ratio was 3.6 for rheumatoid arthritis, 2.3 for diabetes mellitus, and 2.5 for pregnancy. The population attributable risk for pregnancy among women 15 to 44 years old was 7.0%. The standardized morbidity ratio for polymyalgia rheumatica was not significantly increased.

Adolescent

Reye's syndrome in Olmsted County, Minnesota: did it exist before 1963?

In this study, our goals were to determine whether Reye's syndrome existed before the first published report of this entity in 1963 and to describe the long-term incidence and trend of this syndrome. Medical and pathologic records and pathologic specimens for Mayo Clinic patients, including those who were residents of Olmsted County, Minnesota, were reviewed through the facilities of the Rochester Epidemiology Project. On review, 12 cases were identified for the period 1920 through 1962; 2 of these cases were in Olmsted County residents. Of the 12 cases identified before 1963, 10 were in patients younger than 5 years of age. In addition to the aforementioned two cases, five others in Olmsted County were diagnosed between 1963 and 1989. Incidence rates were computed for the Olmsted County population. The number of cases and rates per 100,000 persons younger than 18 years of age in that population were 2 cases (0.3) for 1920 through 1962, 4 cases (0.7) for 1963 through 1980, and 1 case (0.4) for 1981 through 1989. Although cases found during the earlier periods may have included disorders that mimic Reye's syndrome, the recommended criteria from the Centers for Disease Control were applied to review of medical records and supported by pathologic findings in the liver. The data showed an age distribution tending toward young patients and no seasonality of occurrence. The incidence rates in Olmsted County, Minnesota, showed an increase for 1963 through 1980 over previous decades, followed by a decrease. The small numbers preclude any conclusion about trends in the incidence rates.

Child

Fracture risk in patients with parkinsonism: a population-based study in Olmsted County, Minnesota.

In this population-based retrospective cohort study, the 138 Olmsted County, Minnesota residents first diagnosed with Parkinson's disease during 1967-79 were matched by age and sex to an equal number of control subjects from the community. Fractures were assessed through review of each subject's complete (inpatient and outpatient) medical records. At the time of diagnosis, County residents with parkinsonism were no more likely to have a history of selected fractures than control subjects (32% in each group). Subsequently, 33% of cases and 20% of controls experienced one or more new fractures during 696 person-years of follow-up (p = 0.008). The greatest increase in risk was seen for proximal femur fractures, confirming previous case-control studies. By 10 years after diagnosis, an estimated 27% of the parkinsonism cohort had experienced a new hip fracture. The pattern of fractures that was observed suggested that the increased risk was due more to specific types of falls than to disuse osteoporosis.

Aged

Lack of association between Alzheimer's disease and education, occupation, marital status, or living arrangement.

Using the resources of the Rochester Epidemiology Project, we conducted a case-control study of sociodemographic characteristics using the incidence cohort of patients with Alzheimer's disease (AD). During the conduct of ongoing studies of AD in Rochester, we identified new cases of AD as they occurred during 1975-1979 (N = 241). We selected one age- and sex-matched control from among all registrations for care in this community during the year of onset for each case. There was little difference between cases and controls for educational attainment, marital status, type of dwelling, living arrangement, or occupation. We were unable to confirm low educational level as a risk factor for AD in this population. Future attempts to identify etiologic risk factors for dementing illness should probably move toward other areas of research.

Aged

Reassessment of the association between Guillain-Barré syndrome and receipt of swine influenza vaccine in 1976-1977: results of a two-state study. Expert Neurology Group.

Although the original Centers for Disease Control study of the relation between A/New Jersey/8/76 (swine flu) vaccine and Guillain-Barré syndrome (polyradiculoneuritis) demonstrated a statistical association and suggested a causal relation between the two events, controversy has persisted. To reassess this association, the authors obtained medical records of all previously reported adult patients with Guillain-Barré syndrome in Michigan and Minnesota from October 1, 1976 through January 31, 1977. To identify previously unreported hospitalized cases with onset of symptoms during this period, the authors surveyed medical care facilities. A group of expert neurologists formulated diagnostic criteria for Guillain-Barré syndrome and then reviewed the clinical records in a blinded fashion. Of the 98 adult patients from the original Centers for Disease Control study eligible for consideration, three were found to have been misclassified by date of onset and were excluded. Of the remaining 95, the 28 (29%) who did not meet the diagnostic criteria were equally distributed between the vaccinated group (18 of 60, 30%) and the unvaccinated group (10 of 35, 29%). In addition to the 67 remaining cases who met the diagnostic criteria, six previously unreported cases (three of whom had been vaccinated) were found and included in this analysis. The relative risk of developing Guillain-Barré syndrome in the vaccinated population of these two states during the 6 weeks following vaccination was 7.10, comparable to the relative risk of 7.60 found in the original study. These findings suggest that there was an increased risk of developing Guillain-Barré syndrome during the 6 weeks following vaccination in adults. The excess cases of Guillain-Barré syndrome during the first 6 weeks attributed to the vaccine was 8.6 per million vaccinees in Michigan and 9.7 per million vaccinees in Minnesota. No increase in relative risk for Guillain-Barré syndrome was noted beyond 6 weeks after vaccination.

Causality

Antecedent medical diseases in patients with amyotrophic lateral sclerosis. A population-based case-controlled study in Rochester, Minn, 1925 through 1987.

Odds ratios (ORs) were estimated for the prevalence of antecedent endocrine, metabolic, or vascular diseases among 45 patients with amyotrophic lateral sclerosis from the Rochester, Minn, population compared with 90 control subjects matched for sex, year of birth, period of observation, and residence. Hypertension occurred less frequently in male patients with amyotrophic lateral sclerosis (4%) than in control subjects (30%; OR = .10). Because of small population size, no conclusions can be drawn with respect to the following antecedent conditions: thyroid disease (OR = 1.61), coronary artery disease (OR = .58), obesity (OR = .52), diabetes (OR = 1.00), cerebrovascular disease (OR = .21), and peripheral vascular disease (OR = 1.23). The heterogeneity of antecedent thyroid disease makes it highly unlikely that any specific thyroid lesion is causally associated with most cases of amyotrophic lateral sclerosis. Hypertension may be a marker for protective factors against the development of amyotrophic lateral sclerosis in men.

Aged

Tuberous sclerosis complex in Olmsted County, Minnesota, 1950-1989.

The incidence of tuberous sclerosis complex in Olmsted County, Minnesota, was 0.28 per 100,000 person-years from 1950 through 1989, the point prevalence on December 31, 1989, was 6.9 per 100,000 persons, and the incidence at birth was 6.0 per 100,000 live births. The incidence was 0.13 per 100,000 person-years from 1950 through 1974 and 0.46 per 100,000 person-years from 1975 through 1989. The higher rate of diagnosis during the later period is believed to be due to the use of computed tomography. Of the 12 patients considered in this study, one patient presented with seizures and severe intellectual disability, six patients presented with seizures, three patients presented with multiple facial angiofibroma, and two patients were asymptomatic.

Female

The incidence of Peyronie's disease in Rochester, Minnesota, 1950 through 1984.

Peyronie's disease was diagnosed in 101 male residents of Rochester, Minnesota between 1950 and 1984. Mean patient age at diagnosis was 53 years. The average age-adjusted annual incidence rate of 25.7 and a prevalence rate of 388.6 per 100,000 male population were noted. The steady increase in incidence with time may reflect an increasing tendency to obtain medical help. However, the possibility of a true increase in the incidence rate cannot be ruled out. An effort was made to identify possible risk factors and other disease associations. Rheumatoid arthritis and hypertension were more common among the patients compared to the Rochester population. In contrast, no excess of diabetes mellitus was observed among patients with Peyronie's disease.

Adult

Malignant potential of the cryptorchid testis.

A follow-up study of 224 male patients from Rochester, Minnesota, diagnosed with cryptorchidism during the period from 1935 through 1974 was conducted to assess the frequency of subsequent testicular neoplasms. Age-specific rates for testicular neoplasm in this community were used to estimate an expected number for comparison with that observed. Two malignant testicular neoplasms have occurred in this cohort; thus, the standardized morbidity ratio was 11.4 (95% confidence interval, 1.4 to 41.1). Of the 158 patients born in the community, 11% were known to have birth weights of less than 2,500 g, approximately twice the expected occurrence. Increased risks were also noted for inguinal hernia, hypospadias, Down's syndrome, cleft lip or palate (or both), clubfoot, and congenital heart disease, for which the standardized morbidity ratios were 3.6, 4.7, 17.8, 11.3, 11.7, and 2.7, respectively. The increased risk for malignant neoplasms observed in this cohort of patients with cryptorchidism is consistent with that found in earlier studies.

Abnormalities, Multiple

Incidence and prognosis of brain abscess in a defined population: Olmsted County, Minnesota, 1935-1981.

The incidence of brain abscess was studied on all cases occurring in residents of Olmsted County, Minn., from 1935 through 1981. Thirty-eight cases (9 cases first diagnosed at autopsy) were identified and followed through the Rochester Olmsted County medical record-linkage system at the Mayo Clinic. The incidence rate was 1.3/100,000 person-years (PY), 1.9 in males and 0.6 in females. Incidence decreased from 2.7 in 1935-44 to 0.9 in 1965-81. Rates were higher in children 5-9 years old (2.4) and after age 60 (2.6 PY). An etiologic agent was identified in 29 cases (76%) with streptococci being the most frequently isolated. Case-fatality ratio was 38% (11/29), stable over time. Concurrent bacterial meningitis was the strongest predictor of death. Neurologic sequelae were observed in 8 (44%) of the 18 surviving patients including epilepsy (5 cases), deafness and motor impairment.

Brain Abscess

Psychologic and adaptational difficulties anteceding amyotrophic lateral sclerosis: Rochester, Minnesota, 1925-1987.

Comprehensive medical records of 45 amyotrophic lateral sclerosis (ALS) patients and 90 controls from the same community, matched by age, gender, and period of observation, were reviewed. Three (13%) of 23 men with ALS, 15 (33%) of 46 control men, 10 (45%) of 22 women with ALS, and 19 (43%) of 44 control women had antecedent psychologic or adaptational difficulties. The proportions of long-standing or serious conditions were comparable in all four groups. However, no man in whom ALS developed had a record of mild antecedent difficulties alone, whereas 3 would have been expected (p = 0.024).

Adaptation, Psychological

Incidence and clinical features of glossopharyngeal neuralgia, Rochester, Minnesota, 1945-1984.

The annual crude incidence rate of glossopharyngeal neuralgia per 100,000 population in Rochester, Minn., for 1945 through 1984, was 0.7 for both sexes combined, suggesting that glossopharyngeal neuralgia is a rare disease. There were no significant differences between the sexes (p greater than 0.10) in the overall age-adjusted (to the total 1980 US population) rates: 1.1 for men and 0.5 for women. Overall age-specific crude rates increased slightly with age. Our results and conclusions, achieved by comparing our data with a large referral study at Mayo Clinic, suggest that glossopharyngeal neuralgia is generally a mild disease, since mild attacks are not uncommon, the average annual recurrence rate for a second episode is low (3.6%), and only one fourth of the cases had to have surgery for relief of symptoms. Bilaterality is not uncommon; it was observed in one fourth of the patients, all of whom had mild disease.

Adult

Epidemiology and clinical features of idiopathic trigeminal neuralgia and glossopharyngeal neuralgia: similarities and differences, Rochester, Minnesota, 1945-1984.

A comparison of epidemiological and clinical features of trigeminal neuralgia (TN) and glossopharyngeal neuralgia (GN) in Rochester, Minn., reveals several differences. The overall age- and sex-adjusted annual incidence rates were significantly higher for TN than for GN (4.7 vs. 0.8 per 100,000 population). The TN:GN ratio was increased for both men and women and was 5.9:1 for both sexes combined. This ratio is greater than reported in previous non-population-based studies. GN is a milder disease than TN, as indicated by the number of episodes, treatment, and characterization of pain. The right side is affected more often with TN than with GN. Bilaterality was noted less often in TN than in GN cases.

Adult

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.

Adolescent

Brain injury and neurologic sequelae: a cohort study of dementia, parkinsonism, and amyotrophic lateral sclerosis.

We reviewed the medical records of 821 Olmsted County residents who had suffered head trauma with presumed brain injury between 1935 and 1974 and were more than 40 years old at the time of their last medical assessment. These patients were followed over 15,000 person-years for dementia and other degenerative neurologic diseases. The standardized morbidity ratio (SMR) for dementia was 1.06, and the SMR for dementia of the Alzheimer type was 1.00. These values are not significantly elevated and are inconsistent with studies that suggest that head trauma is a risk factor for Alzheimer's disease. In addition, the SMRs for parkinsonism (1.04), Parkinson's disease (0.94), and amyotrophic lateral sclerosis (1.05) were not significantly elevated, providing no evidence that head trauma is a risk factor for these disorders. However, these latter results are based on smaller total case numbers.

Alzheimer Disease