Tau gene mutation in familial progressive subcortical gliosis

Familial forms of frontotemporal dementias are associated with mutations in the tau gene. A kindred affected by progressive subcortical gliosis (PSG), a rare form of presenile dementia, has genetic linkage to chromosome 17q21-22. This kindred (PSG-1) is included in the 'frontotemporal dementias and Parkinsonism linked to chromosome 17' group along with kindreds affected by apparently different forms of atypical dementias. Some of these kindreds have mutations in the tau gene. We report here that PSG-1 has a tau mutation at position +16 of the intron after exon 10. The mutation destabilizes a predicted stem-loop structure and leads to an over-representation of the soluble four-repeat tau isoforms, which assemble into wide, twisted, ribbon-like filaments and ultimately result in abundant neuronal and glial tau pathology. The mutations associated with PSG and other atypical dementias can be subdivided into three groups according to their tau gene locations and effects on tau. The existence of tau mutations with distinct pathogenetic mechanisms may explain the phenotypic heterogeneity of atypical dementias that previously led to their classification into separate disease entities.

Seasonal variation in stroke mortality rates

OBJECTIVE

To identify possible contributors to the seasonal variation in stroke mortality.

BACKGROUND

Stroke and respiratory disease mortality rates were calculated from vital statistics and census data for the United States from 1938 to 1988. State-specific average temperatures by month were derived from data obtained from the National Climatic Data Center for 1938 to 1987.

METHODS

Each time series was decomposed into a trend, a seasonal effect, and a residual effect. Multiple regression was used to fit both a trend and a seasonal harmonic series. Cross-correlation was used to assess the relationship between the residual time series.

RESULTS

There is a strong and consistent seasonal pattern of high stroke and respiratory disease mortality in the colder winter months. Stroke mortality was significantly and independently both positively associated with respiratory disease mortality and inversely associated with temperature. The sharp initial increases in both respiratory disease and stroke mortality in the late fall and early winter are synchronous, and the amplitudes are strongly associated, except for a saturation effect with extreme respiratory disease amplitudes.

CONCLUSIONS

Seasonal change in stroke mortality is associated with seasonal variation in both respiratory disease and temperature. Respiratory disease and temperature may influence stroke mortality nonspuriously by affecting stroke case fatality, incidence, or both.

[History of the reflex hammer]

The knee jerk was first described by Erb and Westphal in 1875. In subsequent years neurologists used direct finger taps and light-weight chest percussion hammers, but these proved to be inadequate for eliciting muscle stretch reflexes. The first hammer specially designed for eliciting such reflexes was the triangular reflex hammer introduced by John Madison Taylor in 1888. Over the next 25 years several popular reflex hammers were designed, some of which are still in use. These include the Babinski hammer with a round head fixed perpendicular to the shaft, and Rabiner's modification where the head can also be attached parallel to the shaft.

Stroke and intracranial venous thrombosis during pregnancy and puerperium

OBJECTIVES

To determine nationally representative estimates of the incidence of stroke and intracranial venous thrombosis during pregnancy and the puerperium, and to identify potential risk factors for these conditions.

METHODS

National Hospital Discharge Survey data were analyzed for the period 1979 to 1991. Nationally representative estimates of risk were calculated by age, race, presence of pregnancy-related hypertension, census region, hospital ownership, and number of hospital beds. Multivariate models were developed using logistic regression.

RESULTS

There were an estimated 8,918 cases of stroke and 5,723 cases of intracranial venous thrombosis during pregnancy and the puerperium in the United States among 50,264,631 deliveries, giving risks of 17.7 cases of stroke and 11.4 cases of intracranial venous thrombosis per 100,000 deliveries. In the multivariate models, stroke was associated strongly with pregnancy-related hypertension, larger hospital size, and proprietary hospital ownership, and inversely associated with living in the South. Intracranial venous thrombosis was associated with maternal age.

CONCLUSIONS

Stroke and intracranial venous thrombosis are relatively common complications of pregnancy and the puerperium. Collectively, rates for these conditions are about 50% greater for the entire period of pregnancy and the puerperium than for the immediate peripartum period.

The role of clinical pathways in reducing the economic burden of stroke

Clinical pathways are a potentially beneficial, but largely untested, management strategy for both improving healthcare efficiency and decreasing costs while also maintaining or improving quality of care. Although relatively few clinical pathways for stroke have been described in the medical literature and although the reported benefits have been mixed, more and more hospitals are adopting clinical pathways as a management strategy for patients with stroke. In published clinical pathways for acute stroke, the following benefits have been reported: (i) reduced use of expensive diagnostic studies; (ii) fewer complications (particularly the frequency of urinary tract infections and aspiration pneumonia); (iii) reduced duration of hospital stay; (iv) reduced patient charges; and (v) lower mortality. However, these reported benefits are not consistent across all studies and some outcomes are highly correlated. Despite potential benefits, many clinical pathway programmes fail because of inadequate planning and shortcomings of implementation. Effective implementation of clinical pathways requires strong administrative and medical staff leadership, active participation of all clinical disciplines involved in the care of patients on the pathway, provision of regular feedback to clinicians, sufficient resources, improved documentation, incorporation of the entire episode of care into the pathway, integration with ongoing quality and utilisation management programmes, and periodic evaluation and modification.

In-hospital mortality following carotid endarterectomy

OBJECTIVES

To determine population-based estimates of in-hospital mortality following carotid endarterectomy (CEA) and identify potential risk factors for in-hospital death.

METHODS

Data from the Healthcare Cost and Utilization Project (HCUP-3) were analyzed for the year 1993. Nationally representative estimates of risk were calculated by age, sex, race, income, census region, hospital location (urban versus rural), teaching status of hospital, number of hospital beds, hospital ownership, third-party payer, principal procedure, and presence of surgical complications. Multivariate models were developed using stepwise logistic regression and a logit model fit by generalized estimating equations.

RESULTS

There were 228 deaths among 18,510 CEAs performed in 17 states of the United States in 1993, yielding an estimated in-hospital mortality rate of 1.2%. Multivariate analysis showed that age, principal procedure, and presence of any surgical complication were significant predictors of in-hospital mortality. Mortality increased with increasing age (from 0.9% in those younger than 65 years to 1.7% in those age 75 and older) and was markedly higher with CEA performed as a secondary procedure (6.1% versus 0.9%) or with any surgical complication (5.9% versus 0.9%).

CONCLUSIONS

Increasing age, CEA performed as a secondary procedure, and surgical complications are important predictors of in-hospital mortality following CEA.

The mad cow problem in the UK: risk perceptions, risk management, and health policy development

Mad cow disease or bovine spongiform encephalopathy (BSE) is a fatal neurological disease of cattle first recognized in the United Kingdom (UK) in 1986. Until recently, the UK government considered the chance of a human becoming infected with the BSE agent to be extremely remote. As a result of new developments, alarmist media attention, bureaucratic mishandling of the issues, scientific uncertainty, bickering among technical experts, and a dearth of easily assimilated and balanced information on the problem, widespread fears that affected cattle could enter the human food supply and transmit the disease to humans have periodically erupted, causing social, economic, and political consequences of tremendous magnitude. Better management of the mad cow problem could have minimized the magnitude of the epidemic among cattle, the risk to humans, and the public outrage. Trust in the British government was seriously eroded, an entire industry crippled, and international relations severely tried. Although the scientific data concerning BSE and its transmissibility to humans are still not conclusive, a growing body of (still largely circumstantial) evidence suggests that BSE may be transmissible to humans. Unfortunately, policy decisions cannot wait for a final scientific answer. Therefore, high-stakes decisions must be made in the face of this uncertainty. Such decisions should be made with the primary purpose of protecting the public, and not preferentially the economics of an industry, political alliances, or other considerations. Given that the risk to humans from BSE was (and still is) unknown and may be high, and that the perceived risk among the British public was (and still is) extraordinarily high, policies should support more aggressive interventions. Of necessity, such interventions will be preventive, as there is presently no available treatment. Such policies should be modified as necessary as the developing scientific data warrants.

Late-onset sporadic progressive subcortical gliosis

We report two sporadic cases of progressive subcortical gliosis (PSG) with onset after age 60. The presentation included slowly progressive dementia with memory loss, geographic disorientation, and personality change. Both were diagnosed clinically as Alzheimer's disease (AD) and both met NINCDS-ADRDA criteria for probable AD. Autopsy revealed generalized atrophy, predominantly involving the white matter of the frontal and temporal lobes. Microscopically, prominent fibrillary astrocytosis was present in the subcortical white matter and in the subpial and deep layers of the overlying cerebral cortex. Mild cortical neuron loss accompanied the gliosis, but no myelin loss was evident. Amyloid deposits and neuronal cytoskeletal inclusions were absent.

Dementia mortality in the United States. Results of the 1986 National Mortality Followback Survey

This study sought to determine nationally representative estimates of mortality from or with dementia in the United States, to compare rates derived from various sources of ascertainment, and to estimate the contribution of dementia to morbidity and facility usage in the last year of life. National Mortality Followback Survey (NMFS) data were analyzed. The NMFS is based on a nationwide probability sample of persons aged 25 and over who died in the United States in 1986. For sampled decedents, information was obtained from death certificates, detailed questionnaires and interviews of family members, and from abstracted records of health facilities that provided care during the last year of life. Rates varied by age, race, and source of ascertainment. Rates based on death certificate diagnoses were generally an order of magnitude smaller than rates based on other sources. Alzheimer's disease was the most frequently reported cause of dementia. In the last year of life, most demented patients required assistance with multiple basic activities of daily living, had severe impairments in cognitive functioning, and received some care in general medical-surgical hospitals. Dementia is an extremely common cause of morbidity and mortality. Rates vary widely depending on the method of ascertainment; in particular, ascertainment based on death certificates grossly underestimates the magnitude of the problem.

The geographic distribution of Parkinson's disease mortality in the United States

PURPOSE

This study examines geographic variation in reporting of Parkinson's disease mortality in the U.S.

METHODS

National Center for Health Statistics and Bureau of the Census data were used to map age-adjusted, race- and race-gender-specific Parkinson's disease mortality rates in the U.S. for 1988.

RESULTS

Among whites, high underlying-cause rates predominated in the North and low rates predominated in the South, whereas high contributing and all-cause rates were concentrated in the northeastern U.S. Strong north-to-south decreasing gradients were present for both underlying- and all-cause rates for whites, regardless of gender, whereas a clear west-to-east gradient could not be demonstrated. Geographic variation in contributing- and all-cause rates was partially explained by variation in tendency to report contributing causes of death. Reported rates among blacks were significantly lower than among whites. There was no latitudinal or longitudinal gradient of underlying-cause rates for blacks, but there was a relatively weak north-to-south decreasing gradient of all-cause rates for blacks, regardless of gender.

CONCLUSIONS

The large-scale pattern of underlying-cause Parkinson's disease mortality among whites has persisted for over three decades.

Benign paroxysmal positioning vertigo: classic descriptions, origins of the provocative positioning technique, and conceptual developments

The original description of benign paroxysmal positioning vertigo (BPPV) has been variously attributed to Bárány, Adler, and others. In addition, the proper eponymic designation for the provocative positioning test used to diagnose BPPV has been unclear, because authors use a variety of different terms, including Bárány, Nylén-Bárány, Nylén, Hallpike, Hallpike-Dix, and Dix-Hallpike to refer to the procedure in current use. Based on a review of the extant medical literature, Bárány was the first to describe the condition in detail, and Dix and Hallpike were the first to clearly describe both the currently used provocative positioning technique and the essential clinical manifestations of benign paroxysmal positioning vertigo elicited by that technique. Nevertheless, despite their important contributions, neither Bárány nor Dix and Hallpike understood the pathophysiology of BPPV nor did they appreciate that the positioning techniques they used actually demonstrated pathology in the semicircular canals rather than the utricle. The modern understanding of the pathophysiology of BPPV began with Schuknecht's proposal that the dysfunction resulted from the gravity-dependent movement of loose or fixed dense material within the posterior semicircular canal ("cupulolithiasis"). Although Schuknecht's formulations were not consistent with all clinical features of the disease, they led to the modern "canalolithiasis theory" and highly effective canalith repositioning or "liberatory" maneuvers for BPPV.

Peripartum stroke and intracranial venous thrombosis in the National Hospital Discharge Survey

OBJECTIVES

To determine nationally representative estimates of the incidence of peripartum stroke and intracranial venous thrombosis and to identify potential risk factors for these conditions.

METHODS

We analyzed National Hospital Discharge Survey data for the period 1979-1991. Nationally representative estimates of risk were calculated by age, race, method of delivery, presence of pregnancy-related hypertension, census region, hospital ownership, and number of hospital beds. Multivariate models were developed using logistic and Poisson regression.

RESULTS

There were an estimated 5484 cases of peripartum stroke and 4454 cases of intracranial venous thrombosis in the United States among 50,110,949 deliveries (risk, 10.3 cases of peripartum stroke and 8.9 cases of intracranial venous thrombosis per 100,000 deliveries). In both univariate and multivariate models, peripartum stroke was associated strongly with cesarean delivery, pregnancy-related hypertension, proprietary hospital ownership, and larger hospital size. Intracranial venous thrombosis was strongly associated with cesarean delivery and less strongly with smaller hospital size.

CONCLUSIONS

Peripartum stroke and intracranial venous thrombosis are common complications of pregnancy. Although the associations identified in this study are plausible, further studies are required to confirm these associations and elucidate the underlying mechanisms.

Geographic distribution of stroke mortality among immigrants to the United States

BACKGROUND AND PURPOSE

This study examines the geographic distribution of stroke mortality among immigrants and natives of the United States.

METHODS

National Center for Health Statistics and Bureau of the Census data were used to determine the geographic distribution of age-adjusted, race-, and race/sex-specific stroke mortality rates among immigrants and natives of the United States for 1979 to 1981.

RESULTS

For whites and blacks and for each of the respective race/sex groups, immigrants had markedly and highly statistically significantly lower age-adjusted stroke mortality rates than either the entire US-born resident population or the US-born interregional migrant population. The spatial pattern of immigrant rates did not parallel the patterns for US-born populations. Immigrant rates were highest in the West and lowest in the Midwest for whites and highest in the Midwest and lowest in the Northeast for blacks, whereas for both US-born whites and blacks, resident and native rates were highest in the South and lowest in the Midwest. With few exceptions, region-specific immigrant rates for whites and blacks were significantly lower than rates for either US-born regional residents, US-born migrants to the regions, or US-born natives of the regions. In contrast, white immigrants to the West had significantly higher rates than US-born groups in that region.

CONCLUSIONS

Selection factors strongly influence stroke mortality rates among immigrants to the United States. The aberrantly high rates among white immigrants to the West may in part reflect a bias due to large census undercounts of this population.

Comparison of utilization of Sinemet and Parkinson's disease mortality as surrogate indicators of Parkinson's disease in the United States

OBJECTIVE

To compare two surrogate indicators of population disease burden for Parkinson's disease: utilization of Sinemet and Parkinson's disease mortality.

DESIGN

National Center for Health Statistics data were used to tabulate Parkinson's disease mortality in the United States by state for 1987-1989. Sinemet sales data by state were obtained from Merck & Co., Inc. for 1988. Least squares regression analyses were used to assess the relationship between Sinemet utilization and Parkinson's disease mortality.

SETTING

United States.

RESULTS

Regression analyses showed extraordinarily strong associations between state-level Parkinson's disease mortality and Sinemet utilization (underlying-cause model r2 = 0.969, p = 0.0001; multiple-cause model r2 = 0.980, p = 0.0001).

CONCLUSIONS

Sinemet utilization very closely parallels Parkinson's disease mortality, suggesting that Sinemet utilization and Parkinson's disease mortality are both useful indices of the population burden of Parkinson's disease for large-scale epidemiological studies.

Stages in the recognition of epidemic pellagra in the United States: 1865-1960

Recognition of the U.S. pellagra "epidemic" in the early part of this century occurred in stages. The recognition process distorted impressions of magnitude, rate of spread, and virulence. Unrecognized cases: Endemic pellagra developed from dietary deficiencies after the Civil War. Initially, cases were misdiagnosed as other more traditional disorders. Tradition and authority inhibited recognition. Recognition of severe cases: Beginning in 1907, outbreaks were reported in asylums. Existing severe cases came rapidly to medical attention, inflating the apparent rate of spread. Recognized cases had a fulminant course and a high case fatality. Expanded spectrum: Milder cases were increasingly recognized, leading to an exaggerated rate of increase in number of cases and a decrease in case fatality and apparent virulence. Greater sensitivity resulted largely from a shift in diagnostic thresholds, with loss of specificity and increase in false positive diagnoses. Standardization of diagnosis: Although no suitable diagnostic marker test was developed, diagnosis was ultimately standardized by development of a workable case definition and by assessment of response to an effective therapy (nicotinic acid) applied to presumptive cases.

Interobserver variability in the classification of neonatal seizures based on medical record data

This population-based, retrospective cohort study of neonatal seizures included all 16,428 neonates born to residents of Fayette County, Kentucky, from 1985 to 1989. Eighty potential cases were ascertained by computer search of hospital-based medical record systems, birth certificate data files, and multiple-cause-of-death mortality data files. Medical records for potential cases were abstracted, and relevant portions were reviewed independently by three neurologists using prospectively determined criteria. Both unweighted and weighted kappa statistics were used to measure agreement between each pair of observers in the classification of potential cases as seizures, possible seizures, or not seizures, adjusting for the proportion of agreement expected by chance. Agreement in the classification of potential cases was excellent (kappa = 0.72-0.79, average = 0.76; weighted kappa = 0.85-0.88, average = 0.87). The kappa extension statistic of Kraemer was used to assess agreement in the classification of seizure types by a simplification of the classification scheme of Volpe. This documented excellent agreement between raters in the classification of seizure types (kappa e = 0.72). Experienced raters can reliably classify potential cases of neonatal seizures using seizure descriptions transcribed from medical records.

Comparison of additive and multiplicative models of regional variation in the decline of stroke mortality in the United States

BACKGROUND AND PURPOSE

Although previous studies have shown that geographic variation in the decline of stroke mortality rates may be an important contributor to the changing geographic distribution of stroke mortality in the United States, some concern has been raised that this phenomenon may be model dependent. This study examines the geographic variation in the decline of stroke mortality rates in the United States with the use of both additive and multiplicative models.

METHODS

National Center for Health Statistics and Bureau of the Census data were used to assess regional-level temporal trends of underlying-cause stroke mortality rates in the United States for 1979 through 1989. Both additive and multiplicative models were fit to the data.

RESULTS

Underlying-cause stroke mortality rates have declined fairly steadily in all regions of the United States and for all race-sex groups, although there was significant regional variation in the rate of decline during the period 1979 through 1989. The South, which initially had the highest rates, had the most rapid decline for all race-sex groups when either additive or multiplicative models were used.

CONCLUSIONS

From 1979 through 1989 there was significant geographic variation in the rate of decline of stroke mortality rates, with the most rapid rates of decline in the South. As a result, there has been a decrease in interregional variation in stroke mortality rates.

Results of a computerized screening of stroke patients for unjustified hospital stay

BACKGROUND AND PURPOSE

Effective methods to monitor length of stay can help reduce unnecessary hospital stay without adversely affecting the quality of care. In this study a clinical algorithm for assessing unjustified hospital stay in stroke patients was computerized and tested.

METHODS

An algorithm was developed by the authors to estimate the number of medically justified and unjustified hospital days for patients admitted with a primary diagnosis of ischemic stroke. Data for the algorithm were obtained from 177 stroke patients from an acute-care teaching hospital. The performance of the algorithm was evaluated on a subset of 46 patients by comparing the number of medically unjustified hospital days determined by the algorithm with the consensus determination of two neurologists.

RESULTS

The algorithm classified 68% of the 177 patients as having some unjustified hospital days and 41% of all hospital days as unjustified. With the neurologists as the gold standard, the sensitivity of the algorithm was .89 and the specificity was .91. The correlation between the number of unjustified days determined by the algorithm and the neurologists was .76.

CONCLUSIONS

There is considerable unjustified length of stay for stroke patients. Physicians can develop simple clinical algorithms for detecting unjustified hospital stay in stroke patients that provide a reasonable approximation of complex clinical judgment.

Neonatal seizures in the United States: results of the National Hospital Discharge Survey, 1980-1991

We present nationally representative estimates of neonatal seizure risk by gender, race and geographic region of the United States. National Hospital Discharge Survey data were analyzed for the period 1980-1991. Birth-weight-adjusted risks of neonatal seizures were calculated by the direct method for each gender or race group and for each census region by 4-year intervals. The overall risk of neonatal seizures was 2.84 per 1,000 live births. Risk estimates were consistently higher in low-birth-weight infants (relative risk 3.9). Unadjusted risks were similar across race and gender groups; birth weight adjustment had very little effect. No clear temporal trend was apparent over the 12-year study period. National Hospital Discharge Survey data provide reasonable, although conservative, estimates of neonatal seizure risks nationwide. Underascertainment of neonatal seizures, particularly among sick low-birth-weight infants, is likely due to data collection limitations of the National Hospital Discharge Survey.

Geographic variation in reporting of stroke deaths to underlying or contributing causes in the United States

BACKGROUND AND PURPOSE

This study examines the geographic variation in the reporting of deaths with stroke as the underlying or contributing cause in the United States.

METHODS

Data from the National Center for Health Statistics and Bureau of the Census were used to map the geographic distribution of race- and race/sex-specific, underlying-, contributing-, and multiple-cause age-adjusted stroke mortality rates in the United States by state for 1979 through 1981.

RESULTS

Underlying-, contributing-, and multiple-cause age-adjusted stroke mortality rates were significantly clustered for both whites and blacks. However, the spatial distributions of underlying- and contributing-cause rates differed; there was no association between underlying- and contributing-cause rates for either racial group or for the various race/sex groups. There was no association between nonstroke mortality and stroke mortality rates. There was also very little spatial variation and no spatial clustering of the median number of contributing causes reported.

CONCLUSIONS

The overall large-scale spatial distribution of resident underlying-cause stroke mortality rates cannot be explained by geographic variation in the selection of the underlying cause of death from among all causes reported on the death certificate, by different area-dependent tendencies for mortality generally, or by different tendencies to consider stroke as the cause of death when death occurs. Geographic variation in contributing-cause rates is not explained by variation in tendency to report contributing causes of death.

Geographic variation in the decline of stroke mortality in the United States

BACKGROUND AND PURPOSE

This study examines the geographic variation in the decline of stroke mortality rates in the United States.

METHODS

National Center for Health Statistics and Bureau of the Census data were used to assess regional and state level temporal trends of stroke mortality in the United States for 1970 to 1989.

RESULTS

Underlying- and multiple-cause stroke mortality rates have declined fairly steadily in all regions of the United States and for all race/sex groups, although the rates of decline were greater during 1970 to 1978 than during 1979 to 1989. The declines in underlying-cause rates could not be attributed to a shift toward reporting stroke as a contributing rather than underlying cause of death, since both underlying- and multiple-cause rates declined similarly. There was significant regional variation in the rate of decline, particularly during 1979 to 1989. The South initially had the highest rates, but it experienced the most rapid decline, so that by 1989 the South no longer had the highest rates. States with the most rapid rates of decline were significantly clustered in the South and particularly the Southeast. Most of the decline in overall stroke mortality was due to declines in ischemic stroke mortality.

CONCLUSIONS

During 1970 to 1989 there was significant geographic variation in the rate of decline of stroke mortality rates, with the most rapid rates of decline concentrated in the high-rate areas of the South and particularly the Southeast. As a result, there has been a decrease in interregional and interstate variation in stroke mortality rates, which is apparently not due to an artifact of changing reporting patterns.

Familial progressive subcortical gliosis: presence of prions and linkage to chromosome 17

Progressive subcortical gliosis (PSG) is a sporadic and familial dementing disease characterized pathologically by astrogliosis at the cortex-white matter junction, a feature present in some prion diseases. With immunocytochemical and Western blot analyses, we investigated the presence of deposits of the prion protein (PrP) and of the protease-resistant PrP isoform, the hallmarks of prion diseases, in six affected members of two large kindreds with PSG. The coding region of the PrP gene was sequenced and chromosomal linkage determined. We demonstrated "diffuse" PrP plaques in the cerebral cortex of two subjects from one kindred and protease-resistant PrP fragments in four of the five subjects examined. We found no mutation in the coding region of the PrP gene. Moreover, the disease was linked to chromosome 17 and not to chromosome 20, where the PrP gene resides. The familial form of PSG is the first human genetic disease characterized by the presence of protease-resistant PrP that lacks a mutation in the coding region of the PrP gene. The linkage to chromosome 17 suggests that other genes are involved in the PrP metabolism. Whether the protease-resistant PrP plays a primary or secondary role in the pathogenesis of this form of PSG remains to be determined.

Effects of interstate migration on the geographic distribution of stroke mortality in the United States

BACKGROUND AND PURPOSE

This study examines the effects of lifetime net interstate migration on the geographic distribution of stroke mortality in the United States.

METHODS

National Center for Health Statistics and Bureau of the Census data were used to map the geographic distribution of age-adjusted, race-, and race/sex-specific stroke mortality rates by interstate migration status for natives, outmigrants, nonmigrants, inmigrants, and residents in the United States for 1979 to 1981.

RESULTS

High age-adjusted stroke mortality rates were significantly clustered in the southeastern United States for both whites and blacks; in addition, for whites, low-rate states were concentrated in some Mountain and northeastern states. Migrant status did not change this large-scale pattern, but individual states showed significant migration effects, which varied in magnitude and direction. Among whites, states that benefited from migration, with markedly lower stroke mortality rates among residents than natives, included Arizona, Colorado, District of Columbia, and Florida, whereas states that suffered from migration included California, Idaho, Montana, North Dakota, Nevada, and Oklahoma. Among blacks, only Colorado showed an apparent large benefit from migration, whereas 21 states suffered from migration.

CONCLUSIONS

Although the overall large-scale spatial distribution of resident stroke mortality rates cannot be explained by migration effects, some individual states had rates that were strongly influenced by migration. Patterns of mortality among migrant groups in Sun Belt retirement destination states probably result from differential selection effects for retirement migration in older adults. Patterns of mortality for black migrants to the North are probably influenced by "carryover" effects from their origin states.

A population-based study of neonatal seizures in Fayette County, Kentucky

This population-based, retrospective cohort study of neonatal seizures included all neonates born to residents of Fayette County, Kentucky, from 1985 to 1989. We ascertained potential cases by computer search of hospital-based medical record systems, Kentucky Center for Health Statistics birth certificate data files, and National Center for Health Statistics multiple-cause-of-death mortality data files. Medical records for potential cases were abstracted, and relevant portions were reviewed independently by three neurologists using prospectively determined case-selection criteria. Seizures occurred in 58 of 16,428 neonates (3.5/1,000 live births). An additional 15 neonates had possible seizures, for a combined risk of 4.4/1,000 live births. Neonatal seizure risk varied inversely with birth weight: 57.5/1,000 live births among very low birth weight infants (< 1,500 grams) compared with 4.4/1,000 for infants with moderately low birth weight (1,500 to 2,499 grams), 2.8/1,000 for those with normal birth weight (2,500 to 3,999 grams), and 2.0/1,000 for those with high birth weight (4,000 or more grams). Risk varied among the four hospitals in the county with obstetric units, the university hospital having the highest risk. Risk did not differ by race or gender. A Cox proportional hazards model confirmed the results of the simpler univariate analyses. Differences in birth weight of the subpopulations served by each hospital accounted for much but not all the differences in hospital-specific risk.

A population-based study of neonatal seizures in Fayette County, Kentucky: comparison of ascertainment using different health data systems

Based on a population-based, retrospective cohort study of neonatal seizures in Fayette County, Kentucky, from 1985 to 1989, estimates of neonatal seizure risk were calculated from computerized databases including hospital medical records, birth certificates, and death certificates. Computerized tabulations of hospital discharge diagnoses identified 97% of cases with a positive predictive value of 75%. Birth certificates had poor sensitivity for neonatal seizures overall (37%), but identified 67% of infants who seized on the first day of life. However, careless completion of the birth certificate produced a high number of false positives. Death certificates identified no infants with neonatal seizures.

Length of hospital stay for cerebrovascular disease in the United States: Professional Activity Study, 1963-1991

OBJECTIVE

To assess the temporal and spatial variation in length of hospital stay for cerebrovascular disease in the United States over three decades.

DESIGN

Age-, region-, and stroke type-specific length-of-hospital-stay data for nearly 4 million patients admitted with cerebrovascular disease were obtained for the Professional Activity Study of the Commission on Professional and Hospital Activities for the period 1963-1991.

MAIN OUTCOME MEASURE

Weighted averages and standard errors of length of stay were calculated for aggregate diagnosis groups within the category of cerebrovascular disease. Averages were age-adjusted by the direct method.

RESULTS

Average length of hospital stay declined from a peak of 18 days in 1967 to 8 days in 1991. The decline accelerated sharply from 1982 to 1986 coincident with implementation of the Medicare prospective payment system. Similar declines were observed within each age group, each cerebrovascular disease diagnosis group, and each census region. There were marked and persistent differences in average length of stay between regions, with longer stays in the Northeast and shorter stays in the West. The large interregional variation was not explained by differences in age or cerebrovascular disease diagnoses.

CONCLUSIONS

Implementation of the Medicare prospective payment system produced a marked decline in length of hospital stay for cerebrovascular disease, which was superimposed on a preexisting, but slower, decline. Much of the marked persistent interregional variation probably results from persistent widespread variation in patient management.

Familial progressive subcortical gliosis

We report clinical and pathologic findings from two kindreds afflicted with a familial form of progressive subcortical gliosis. The disorder segregated as an autosomal dominant trait. Onset was in the presenium and the course was slowly progressive. Affected individuals initially manifested personality change, degeneration of social ability, disinhibition, psychotic symptoms, memory impairment, or depression. Later, all developed progressive dementia, frequently associated with verbal stereotypy, decreased speech output, echolalia, or manifestations of the human Klüver-Bucy syndrome. Terminal clinical manifestations included profound dementia, frequently with mutism, dysphagia, and extrapyramidal signs. Autopsy of seven end-stage patients revealed generalized cerebral atrophy, predominantly involving the white matter of the frontal and temporal lobes. Microscopically, prominent fibrillary astrocytosis was present in the subcortical white matter and in the subpial and deep layers of the overlying cerebral cortex. These changes were most pronounced in the frontal and temporal lobes, especially in the cingulate gyri and insulae. Mild cortical neuronal loss accompanied the gliosis, but no myelin loss was evident. The claustra and substantia nigra also showed severe astrocytosis and degenerative changes. Amyloid deposits and neuronal cytoskeletal inclusions were absent.

Geographic distribution of hospitalization rates, case fatality, and mortality from stroke in the United States

We analyzed state-specific stroke-hospitalization, case-fatality, and mortality rates for the US Medicare population for 1989, using national data resources of the Health Care Financing Administration (HCFA), the National Center for Health Statistics, and the Bureau of the Census. State-specific hospital admission rates for stroke ranged from 0.66 to 1.26%, compared with the national value of 0.94%. Both hospital-usage rates and deviations of observed rates from predicted values (based on statistical models of the HCFA) showed significant spatial autocorrelation, with high rates clustered in the southeastern United States and low rates clustered in the Mountain census division of the West and also somewhat in the Northeast. Case-fatality rates increased nationally from 14.9% at 15 days after hospital admission to 31.2% at 180 days after hospital admission. State-level case-fatality rates showed relatively little interstate variation and no clear or consistent spatial pattern, although there was statistically significant spatial autocorrelation at several intervals after hospital admission. Admission rates and case-fatality rates were not significantly associated at any interval after admission to 180 days, suggesting that variation in case-fatality rates was not simply a result of differences in severity-of-illness thresholds for hospital admission. State-specific stroke-mortality rates ranged from 294.5 to 523.5 per 100,000 population, compared with the national value of 415.3 per 100,000 population. State-specific mortality rates for stroke showed significant spatial autocorrelation, with high rates clustered in the South and low rates clustered in the Northeast and the Mountain census division of the West. The spatial distribution of stroke-mortality rates strongly resembled the spatial distribution of hospitalization rates but did not resemble the spatial distribution of case-fatality rates at any interval from 15 to 180 days after hospital admission. Indeed, in univariate spatial-regression models fitted to the data using a maximum likelihood procedure and weighted for non-constant variances, the best predictor of state-level stroke-mortality rates was the hospital-utilization rate for stroke; attempts to improve the model by including case fatality at various intervals and interaction terms did not yield a significant improvement. These data suggest that factors determining stroke occurrence and hospital utilization are more important than factors determining case fatality in terms of explaining the long-standing distribution of stroke mortality in the United States. Factors affecting only case fatality but not hospitalization, such as the quality of medical care provided in the hospital, cannot explain the geographic distribution of stroke mortality in the United States.

Klüver-Bucy syndrome in juvenile neuronal ceroid lipofuscinosis

Although Klüver-Bucy syndrome in adults is commonly associated with neurodegenerative conditions, Klüver-Bucy syndrome in children has been recognized almost exclusively in association with acute bitemporal injury or dysfunction. We report a child with juvenile neuronal ceroid lipofuscinosis, who developed dementia, childhood-onset autistic disorder, and Klüver-Bucy syndrome. The behavioral features of this case are compared with those of previously reported cases of juvenile neuronal ceroid lipofuscinosis and with previous reports of Klüver-Bucy syndrome in children and adults.

Geographic distribution of stroke mortality in the United States: 1939-1941 to 1979-1981

I used data from the National Center for Health Statistics to map the geographic distribution of age-adjusted, race- and gender-specific stroke mortality rates in the United States from 1939-1941 to 1979-1981. Over this interval, stroke mortality rates declined dramatically with convergence of age-adjusted, state-specific stroke rates both within and between the various race-gender groups. For each race-gender group, high age-adjusted stroke mortality rates were significantly clustered in the southeastern United States, particularly in the South Atlantic census division, with persistent extreme rates in Georgia and the Carolinas. For whites, low-rate states were concentrated in the Mountain census division and along the northern Atlantic coast. The nonrandom distribution of stroke mortality across the United States, the large magnitude of the difference between high- and low-rate areas, the persistence of the pattern over more than four decades, the similarity of the distribution for different race-gender groups, the lack of delimitation by administrative or political boundaries, and results of national cooperative studies completed in the late 1960s and early 1970s together suggest that the pattern of excess stroke mortality is not an artifact of different diagnostic and reporting practices. Some of the observed geographic variation may be due to both the effects of selective migration and variations in the distributions of stroke risk factors.