Shifts in Diagnostic Testing for Headache in the Emergency Department, 2015 to 2021.

Importance: Subarachnoid hemorrhage is typically diagnosed by noncontrast head computed tomography (CT); lumbar puncture is recommended if computed tomography is nondiagnostic, although CT cerebral angiography has been promoted as an alternative to lumbar puncture in this diagnostic pathway. The outcomes of this debate in practice have not been studied. Objective: To determine whether CT cerebral angiography use has increased in lieu of lumbar puncture among emergency department (ED) patients with headache, with an increase in unruptured intracranial aneurysm detection. Design, Setting, and Participants: This retrospective cohort study took place in 21 community EDs of an integrated health care system in Northern California between 2015 and 2021. Participants were adult (aged >17 years) health plan members with a chief concern of headache. Exclusions were prior diagnoses of subarachnoid hemorrhage, unruptured intracranial aneurysm, cerebral arteriovenous malformation, or cerebrospinal fluid shunt. Data were analyzed from October to November 2023. Exposures: CT cerebral angiography and/or lumbar puncture during the ED encounter. Main Outcomes and Measures: Primary and secondary outcomes were 14-day and 90-day unruptured intracranial aneurysm detection, respectively. Safety outcomes were missed diagnoses of subarachnoid hemorrhage or bacterial meningitis. The annual incidence of unruptured intracranial aneurysm detection was normalized to the incidence of subarachnoid hemorrhage (UIA:SAH ratio). Average annualized percentage changes were quantified using joinpoint regression analysis. Results: Among 198 109 included ED encounters, the mean (SD) age was 47.5 (18.4) years; 140 001 patients (70.7%) were female; 29 035 (14.7%) were Black or African American, 59 896 (30.2%) were Hispanic or Latino, and 75 602 (38.2%) were White. Per year, CT cerebral angiography use increased (18.8%; 95% CI, 17.7% to 20.3%) and lumbar punctures decreased (-11.1%; 95% CI, -12.0% to -10.4%), with a corresponding increase in the 14-day UIA:SAH ratio (3.5%; 95% CI, 0.9% to 7.4%). Overall, computed tomography cerebral angiography use increased 6-fold relative to lumbar puncture, with a 33% increase in the detection of UIA. Results were similar at 90 days and robust to sensitivity analyses. Subarachnoid hemorrhage (1004 cases) and bacterial meningitis (118 cases) were misdiagnosed in 5% and 18% of cases, respectively, with no annual trends (P = .34; z1003 = .95 and P = .74; z117 = -.34, respectively). Conclusions and Relevance: In this cohort study of ED patients with headache, increases in CT cerebral angiography use were associated with fewer lumbar punctures and higher detection of unruptured intracranial aneurysms, with no significant change in missed diagnoses of subarachnoid hemorrhage or bacterial meningitis. While this shift in diagnostic strategy appeared safe in the short-term, the long-term consequences remain unclear.

Prevention and Correction of Dysnatremia After Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Dysnatremia occurs commonly in patients with aneurysmal subarachnoid hemorrhage (aSAH). The mechanisms for development of sodium dyshomeostasis are complex, including the cerebral salt-wasting syndrome, the syndrome of inappropriate secretion of antidiuretic hormone, diabetes insipidus. Iatrogenic occurrence of altered sodium levels plays a role, as sodium homeostasis is tightly linked to fluid and volume management. METHODS: Narrative review of the literature. RESULTS: Many studies have aimed to identify factors predictive of the development of dysnatremia, but data on associations between dysnatremia and demographic and clinical variables are variable. Furthermore, although a clear relationship between serum sodium serum concentrations and outcomes has not been established-poor outcomes have been associated with both hyponatremia and hypernatremia in the immediate period following aSAH and set the basis for seeking interventions to correct dysnatremia. While sodium supplementation and mineralocorticoids are frequently administered to prevent or counter natriuresis and hyponatremia, evidence to date is insufficient to gauge the effect of such treatment on outcomes. CONCLUSIONS: In this article, we reviewed available data and provide a practical interpretation of these data as a complement to the newly issued guidelines for management of aSAH. Gaps in knowledge and future directions are discussed.

Effect of combined fenestration of lamina terminalis and Liliequist membrane during surgical clipping on the incidence of chronic hydrocephalus in patients with anterior circulation ruptured aneurysms.

PURPOSE: To explore the effects of combined fenestration of lamina terminalis and Liliequist membrane during surgical clipping on the occurrence of chronic hydrocephalus in patients with ruptured anterior circulation aneurysm. METHODS: Clinical data of 78 patients with anterior circulation ruptured aneurysms who were treated between June 2018 and January 2021 were retrospectively analyzed. Based on the surgical treatment, patients were divided into 3 groups: clipping group (26 cases); fenestration group (lamina terminalis fenestration combined with clipping, 28 cases); and combination group (lamina terminalis fenestration and Liliequist membrane opening combined with clipping, 24 cases). The incidence of postoperative chronic hydrocephalus, the postoperative hydrocephalus shunt rate, and the Glasgow prognostic score (GOS) were evaluated. RESULTS: The incidence of postoperative chronic hydrocephalus in the combined group (16.6 %, 4/24) was significantly lower than that in the clipping group (46.1 %, 12/26) and the fenestration group (35.7 %, 10/28; P < 0.05). The shunt rate of chronic hydrocephalus in the combined group (4.1 %, 1/24) was significantly lower than that in the clipping group (30.7 %, 8/26) and the fenestration group (17.8 %, 5/28; P < 0.05). The rate of postoperative GOS score of 5 in the combined group (75.0 %, 18/24) was significantly higher than that in the clipping group (23.0 %, 6/26) and the fenestration group (57.1 %, 16/28; P < 0.05). CONCLUSION: Aneurysm clipping combined with lamina terminalis fenestration and Liliequist membrane opening can reduce the occurrence of chronic hydrocephalus and the rate of chronic hydrocephalus shunt surgery, thereby improving the prognosis of patients.

Treatment and outcomes of non-aneurysmal perimesencephalic subarachnoid haemorrhage: A 5 year retrospective study in a tertiary care centre.

PURPOSE: Perimesencephalic Subarachnoid Haemorrhage (PMSAH) is an uncommon type of SAH. Severity of PMSAH can be graded by the presence of blood in the Sylvian fissure. No study compares the outcomes from PMSAH with blood present or absent in the Sylvian fissure. Furthermore, the use of Nimodipine lacks evidence base in PMSAH. We investigated whether continuing Nimodipine to 21 days in PMSAH with or without blood in the Sylvian fissure made any significant difference to patient outcome. METHODS: Retrospective study of 93 cases admitted to tertiary centre from 2016 to 2020. We compared prevalence of cases with blood in Sylvian fissure, and analysed outcomes including complications and changes to patient modified rankin scale (MRS). We also audited use of Nimodipine in these cases and analysed whether Nimodipine made any significant difference in preventing complications. RESULTS: 91 % of PMSAH were grade 1, 24 cases (26 %) had blood in the Sylvian fissure. Sylvian fissure positive (Sylvian-positive) cases were statistically significantly more likely to have higher rates of complication compared to Sylvian fissure negative (Sylvian-negative) cases. Our centre stopped Nimodipine 56 % of the time in Sylvian-negative cases and 45 % of the time in Sylvian-positive cases. There was no statistically significant difference in outcomes when Nimodipine was continued to 21 days or ceased after negative angiogram; this result extended to both Sylvian-positive and Sylvian-negative subgroups when directly comparing Sylvian-positive cases with each other and Sylvian-negative cases likewise. DISCUSSION: Sylvian-positive cases have a significantly higher rate of complication, as well as an increase in MRS. This may be because of the inflammatory properties of haemoglobin in the subarachnoid space post-bleed. Furthermore, acknowledging the limitations of our retrospective data, we did not find a statistically significant difference in continuing Nimodipine to 21 days with relation to PMSAH outcomes in all subgroups.

Exploration of Medical Trajectories of Stroke Patients Based on Group-Based Trajectory Modeling.

A high mortality rate is an issue with acute cerebrovascular disease (ACVD), as it often leads to a high medical expenditure, and in particular to high costs of treatment for emergency medical conditions and critical care. In this study, we used group-based trajectory modeling (GBTM) to study the characteristics of various groups of patients hospitalized with ACVD. In this research, the patient data were derived from the 1 million sampled cases in the National Health Insurance Research Database (NHIRD) in Taiwan. Cases who had been admitted to hospitals fewer than four times or more than eight times were excluded. Characteristics of the ACVD patients were collected, including age, mortality rate, medical expenditure, and length of hospital stay for each admission. We then performed GBTM to examine hospitalization patterns in patients who had been hospitalized more than four times and fewer than or equal to eight times. The patients were divided into three groups according to medical expenditure: high, medium, and low groups, split at the 33rd and 66th percentiles. After exclusion of unqualified patients, a total of 27,264 cases (male/female = 15,972/11,392) were included. Analysis of the characteristics of the ACVD patients showed that there were significant differences between the two gender groups in terms of age, mortality rate, medical expenditure, and total length of hospital stay. In addition, the data were compared between two admissions, which included interval, outpatient department (OPD) visit after discharge, OPD visit after hospital discharge, and OPD cost. Finally, the differences in medical expenditure between genders and between patients with different types of stroke-ischemic stroke, spontaneous intracerebral hemorrhage (sICH), and subarachnoid hemorrhage (SAH)-were examined using GBTM. Overall, this study employed GBTM to examine the trends in medical expenditure for different groups of stroke patients at different admissions, and some important results were obtained. Our results demonstrated that the time interval between subsequent hospitalizations decreased in the ACVD patients, and there were significant differences between genders and between patients with different types of stroke. It is often difficult to decide when the time has been reached at which further treatment will not improve the condition of ACVD patients, and the findings of our study may be used as a reference for assessing outcomes and quality of care for stroke patients. Because of the characteristics of NHIRD, this study had some limitations; for example, the number of cases for some diseases was not sufficient for effective statistical analysis.

Impact of Early Versus Late Intravenous Followed by Oral Nimodipine Treatment on the Occurrence of Delayed Cerebral Ischemia Among Patients With Aneurysm Subarachnoid Hemorrhage.

BACKGROUND: Guidelines for aneurysm subarachnoid hemorrhage (aSAH) management recommend treatment with nimodipine to all patients to reduce delayed cerebral ischemia (DCI) and poor clinical outcome. However, it did not give the most beneficial time to start therapy and route of administration. OBJECTIVES: To compare the DCI occurrence and clinical outcome among aSAH patients who received nimodipine treatment at different times. METHODS: A retrospective cohort study was conducted by collecting data from medical chart reviews between August 30, 2010, and October 31, 2015, at Prasart Neurological Institute, Thailand. Patients were classified into 2 groups by time to receive nimodipine: early group and late group (<96 and >96 hours, respectively). All patients received intravenous (IV) followed by oral nimodipine to complete treatment course. Clinical outcome was graded using the Glasgow Outcome Scale at 21 days. The factors related to DCI were analyzed using multivariate logistic regression. RESULTS: A total of 149 patients were recruited: early (n = 97) and late (n = 52). No difference in baseline characteristics between groups was observed. The occurrence of DCI was not statistically significantly different between groups (early group, 18.60%, vs late group, 20.80%; P = 0.74). The World Federation of Neurosurgical Societies IV to V was associated with DCI occurrence. The proportion of patients with good outcome, poor outcome, or death did not show any difference between groups. CONCLUSIONS AND RELEVANCE: Receiving IV nimodipine 3 to 7 days following oral therapy after bleeding can be the alternative regimen in patients who did not start nimodipine within 96 hours.

Coffee Consumption and Incidence of Subarachnoid Hemorrhage: The Jichi Medical School Cohort Study.

BACKGROUND: Previous studies on the association between coffee consumption and subarachnoid hemorrhage (SAH) have provided inconsistent results. We examine the risk of SAH from coffee consumption in a Japanese population. METHODS: Our analyses were based on the Jichi Medical School Cohort Study, a large-scale population-based prospective cohort study. A total of 9941 participants (3868 men and 6073 women; mean age 55 years) with no history of cardiovascular disease or carcinoma were examined. Participants were asked to choose one of five options to indicate their daily coffee consumption: none, less than 1 cup a day, 1-2 cups a day, 3-4 cups a day, or 5 or more cups a day. The incidence of SAH was assessed independently by a diagnostic committee. Cox proportional hazards models were used to calculate hazard ratios (HRs) and their 95% confidence intervals (CI) after adjustment for age and sex (HR1) and for additional potential confounders (HR2). RESULTS: During 10.7 years of follow-up, SAH occurred in 47 participants. When compared with the participants who consumed less than 1 cup of coffee a day, the HR of SAH was significantly higher in the group who consumed 5 or more cups a day in both models (HR1 4.49; 95% CI, 1.44-14.00; HR2 3.79; 95% CI, 1.19-12.05). CONCLUSIONS: The present community-based cohort study showed that heavy coffee consumption was associated with an increased incidence of SAH after adjusting for age, sex, and multiple potential cardiovascular confounders.

Continuous selective intra-arterial application of nimodipine in refractory cerebral vasospasm due to aneurysmal subarachnoid hemorrhage.

BACKGROUND: Cerebral vasospasm is one of the leading courses for disability in aneurysmal subarachnoid hemorrhage. Effective treatment of vasospasm is therefore one of the main priorities for these patients. We report about a case series of continuous intra-arterial infusion of the calcium channel antagonist nimodipine for 1-5 days on the intensive care unit. METHODS: In thirty patients with aneurysmal subarachnoid hemorrhage and refractory vasospasm continuous infusion of nimodipine was started on the neurosurgical intensive care unit. The effect of nimodipine on brain perfusion, cerebral blood flow, brain tissue oxygenation, and blood flow velocity in cerebral arteries was monitored. RESULTS: Based on Hunt & Hess grades on admission, 83% survived in a good clinical condition and 23% recovered without an apparent neurological deficit. Persistent ischemic areas were seen in 100% of patients with GOS 1-3 and in 69% of GOS 4-5 patients. Regional cerebral blood flow and computed tomography perfusion scanning showed adequate correlation with nimodipine application and angiographic vasospasm. Transcranial Doppler turned out to be unreliable with interexaminer variance and failure of detecting vasospasm or missing the improvement. CONCLUSION: Local continuous intra-arterial nimodipine treatment for refractory cerebral vasospasm after aSAH can be recommended as a low-risk treatment in addition to established endovascular therapies.

Trends in the incidence of subarachnoid hemorrhage in South Korea from 2006-2009: an ecological study.

OBJECTIVE: The purpose of this study is to investigate trends in the incidence of subarachnoid hemorrhage (SAH) in South Korea from 2006-2009. METHODS: We used the national health claim database managed by Health Insurance Review and Assessment Service, which contains all hospital records of every Korean citizen. Patients with SAH were defined as International Classification of Diseases-10 codes with a hospitalization period of ≥ 14 days or death within 14 days of hospitalization. We evaluated trends in the incidence of SAH during a 4-year period using the Cochran-Armitage trend test. RESULTS: We identified 35,263 patients with SAH among adult patients (≥ 18 years old) from 2005-2009. Age-adjusted SAH incidence rates decreased from 13.4 in 2006 to 12.4 in 2009/100,000 men (P = 0.0025) and women also showed a decrease from 19.4-17.3/100,000 (P < 0.0001). However, this decreasing pattern was not shown in patients less than 50 years of age. SAH incidence showed gender differences dependent on age; men who were 40 years old or less had a higher incidence than women. CONCLUSIONS: The age-adjusted incidence rates of SAH were slightly decreased in South Korea. Further research should be conducted to identify the clinical risk factors to reduce SAH incidence rates even more, especially in younger people.

Dietary intake of key nutrients and subarachnoid hemorrhage: a population-based case-control study in Australasia.

BACKGROUND: A healthy, balanced diet can prevent stroke, but little is known about dietary risk factors for subarachnoid hemorrhage (SAH). We aimed to determine the relationship between common dietary habits and risk of SAH. METHODS: In a population-based, case-control study of SAH undertaken across 4 Australasian cities, a standardized questionnaire was used to obtain information on the frequency of consumption of 15 common food items and alcohol in incident cases (n = 383) and frequency-matched community controls (n = 473). Logistic regression models were used to estimate the independent effects of these dietary factors, after adjusting for conventional risk factors for SAH. Data are reported with odds ratios (OR) and 95% confidence intervals (CI). RESULTS: The risk of SAH rose with increasing consumption of fat or skin on meat (p trend = 0.04), being highest in those with consumption >4 times weekly compared with no fat or skin on meat (adjusted OR 1.70, 95% CI 1.09-2.66), while use of skim or reduced-fat milk (p trend = 0.01) and fruit (p trend = 0.04) was associated with a reduced risk of SAH compared with rare use. Among people with a history of hypertension, frequently adding salt to food was associated with an increased risk of SAH, irrespective of whether they were (OR 2.58, 95% CI 1.29-5.13) or were not (OR 2.88, 95% CI 1.46-5.70) currently taking antihypertensive treatment. CONCLUSIONS: Frequent intake of fat appears to be associated with an increased risk of SAH, particularly in people with hypertension, while frequent use of skim or reduced-fat milk and fruit appears protective for SAH.

Coffee consumption and risk of stroke in women.

BACKGROUND AND PURPOSE: Coffee consumption has been inconsistently associated with stroke incidence and mortality in previous studies. We investigated the association between coffee consumption and stroke incidence in the Swedish Mammography Cohort. METHODS: We prospectively followed of 34,670 women without a history of cardiovascular disease or cancer at baseline in 1997. Coffee consumption was assessed in 1997 using a self-administered questionnaire. Incident stroke cases were ascertained from the Swedish Hospital Discharge Registry. RESULTS: During a mean follow-up of 10.4 years, we ascertained 1680 stroke events, including 1310 cerebral infarctions, 154 intracerebral hemorrhages, 79 subarachnoid hemorrhages, and 137 unspecified strokes. After adjustment for other risk factors, coffee consumption was associated with a statistically significant lower risk of total stroke, cerebral infarction, and subarachnoid hemorrhage but not intracerebral hemorrhage. The multivariable relative risks of total stroke across categories of coffee consumption (<1 cup/day, 1 to 2 cups/day, 3 to 4 cups/day, and ≥5 cups/day) were 1.00, 0.78 (95% CI, 0.66 to 0.91), 0.75 (95% CI, 0.64 to 0.88), and 0.77 (95% CI, 0.63 to 0.92, respectively; P for trend=0.02). The association between coffee consumption and cerebral infarction was not modified by smoking status, body mass index, history of diabetes or hypertension, or alcohol consumption. CONCLUSIONS: These findings suggest that low or no coffee consumption is associated with an increased risk of stroke in women.

Habitual green tea consumption and risk of an aneurysmal rupture subarachnoid hemorrhage: a case-control study in Nagoya, Japan.

BACKGROUND: Green tea, a popular beverage in Japan, contains many polyphenolic antioxidants, which might prevent cardiovascular disease. This study is designed to determine whether the consumption of green tea is associated with a reduced risk for subarachnoid hemorrhage (SAH) using a case-control study. METHODS: Incident SAH cases (n=201) were identified and individually matched by age (+/-2 years) and gender to hospital (n=201) and community controls (n=201) from April 1992 to March 1997. Habitual regular tea consumption was assessed with a structured questionnaire. Conditional logistic regression models were used to compute odds ratios adjusted for smoking, history of hypertension, and educational levels. RESULTS: The proportion of the consumption of one time or more of tea per day was higher in controls (70.9%) than in SAH patients (60.3%). Multivariate analyses showed that green tea consumption was inversely associated with SAH risk. Subjects consuming <1, and >or=1 time per day had adjusted ORs of 0.74 (CI: 0.34-1.58), and 0.56 (CI: 0.32-0.98) in comparison with non daily green tea drinkers, respectively (p-trend <0.001). CONCLUSION: In a case-control study in Japan, we found that habitual green tea consumption may be strongly associated with a reduced risk for SAH. Our findings will be useful in targeting individuals and populations for the primary prevention of SAH.

Postintervention effect of alpha tocopherol and beta carotene on different strokes: a 6-year follow-up of the Alpha Tocopherol, Beta Carotene Cancer Prevention Study.

BACKGROUND AND PURPOSE: In the Alpha Tocopherol, Beta Carotene Cancer Prevention Study, alpha tocopherol supplementation decreased risk of cerebral infarction by 14% (95% CI, -25% to -1%), and beta carotene increased risk of intracerebral hemorrhage by 62% (95% CI, 10% to 132%). We report here the 6-year postintervention effects of alpha tocopherol and beta carotene supplementation on stroke and its subtypes. METHODS: A total of 29,133 male smokers, aged 50 to 69 years, were randomized to receive 50 mg of alpha tocopherol, 20 mg of beta carotene, both, or placebo daily for 5 to 8 years. At the beginning of the post-trial follow-up, 24 382 men were still at risk for first-ever stroke. During the post-trial follow-up, 1327 men experienced a stroke: 1087 cerebral infarctions, 148 intracerebral hemorrhages, 64 subarachnoid hemorrhages, and 28 unspecified strokes. RESULTS: Post-trial risk for cerebral infarction was elevated among those who had received alpha tocopherol compared with those who had not (relative risk [RR], 1.13; 95% CI, 1.00 to 1.27), whereas beta carotene had no effect (RR, 0.97; 95% CI, 0.86 to 1.09). Alpha tocopherol supplementation was associated with a postintervention RR of 1.01 (95% CI, 0.73 to 1.39) for intracerebral hemorrhage and 1.38 (95% CI, 0.84 to 2.26) for subarachnoid hemorrhage. The corresponding RRs associated with beta carotene supplementation were 1.38 (95% CI, 0.99 to 1.91) and 1.09 (95% CI, 0.67 to 1.77), respectively. CONCLUSIONS: Neither alpha tocopherol nor beta carotene supplementation had any postintervention preventive effects on stroke. The post-trial increase in cerebral infarction risk among recipients of alpha tocopherol may present a rebound of the reduced risk of cerebral infarction during the intervention.

Factors associated with the development of vasospasm after planned surgical treatment of aneurysmal subarachnoid hemorrhage.

OBJECT: The goal of this study was to determine factors associated with the development of symptomatic vasospasm among patients with aneurysmal subarachnoid hemorrhage (SAH) who participated in the randomized, double-blind, placebo-controlled trials of tirilazad between 1991 and 1997. METHODS: Data obtained from 3567 patients entered into trials of tirilazad were analyzed using uni- and multivariate logistic regression to determine factors that predict the development of symptomatic vasospasm. Symptomatic vasospasm was defined by clinical criteria accompanied by laboratory- and radiologically determined exclusion of other causes of neurological deterioration. Transcranial Doppler ultrasonographic and/or angiographic confirmation was not required. In these patients, the aneurysms were scheduled to be treated surgically, and no patient undergoing endovascular treatment was included. A multivariate analysis showed that factors significantly associated with vasospasm were age 40 to 59 years, history of hypertension, worse neurological grade, thicker blood clot on the cranial computerized tomography (CT) scan obtained on hospital admission, larger aneurysm size, presence of intraventricular hemorrhage (IVH), prophylactic use of induced hypertension, and not participating in the first European tirilazad study. CONCLUSIONS: Symptomatic vasospasm was associated with the amount of SAH on the CT scan, the presence of IVH, and the patient's neurological grade. The association with patient age may reflect alterations in vessel reactivity associated with age. A history of hypertension may render the brain more susceptible to symptoms from vasospasm. The explanation for the relationships with aneurysm size, use of prophylactic induced hypertension, and the particular study is unclear.

Controlled trial of alpha-tocopherol and beta-carotene supplements on stroke incidence and mortality in male smokers.

Observational data suggest that diets rich in fruits and vegetables and with high serum levels of antioxidants are associated with decreased incidence and mortality of stroke. We studied the effects of alpha-tocopherol and beta-carotene supplementation. The incidence and mortality of stroke were examined in 28 519 male cigarette smokers aged 50 to 69 years without history of stroke who participated in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (ATBC Study). The daily supplementation was 50 mg alpha-tocopherol, 20 mg beta-carotene, both, or placebo. The median follow-up was 6.0 years. A total of 1057 men suffered from incident stroke: 85 men had subarachnoid hemorrhage; 112, intracerebral hemorrhage; 807, cerebral infarction; and 53, unspecified stroke. Deaths due to stroke within 3 months numbered 38, 50, 65, and 7, respectively (total 160). alpha-Tocopherol supplementation increased the risk of subarachnoid hemorrhage 50% (95% CI -3% to 132%, P=0.07) but decreased that of cerebral infarction 14% (95% CI -25% to -1%, P=0.03), whereas beta-carotene supplementation increased the risk of intracerebral hemorrhage 62% (95% CI 10% to 136%, P=0.01). alpha-Tocopherol supplementation also increased the risk of fatal subarachnoid hemorrhage 181% (95% CI 37% to 479%, P=0.01). The overall net effects of either supplementation on the incidence and mortality from total stroke were nonsignificant. alpha-Tocopherol supplementation increases the risk of fatal hemorrhagic strokes but prevents cerebral infarction. The effects may be due to the antiplatelet actions of alpha-tocopherol. beta-Carotene supplementation increases the risk of intracerebral hemorrhage, but no obvious mechanism is available.

Different risk factors for different stroke subtypes: association of blood pressure, cholesterol, and antioxidants.

BACKGROUND AND PURPOSE: Blood pressure is an important risk factor for stroke, but the roles of serum total and HDL cholesterol, alpha-tocopherol, and beta-carotene are poorly established. We studied these factors in relation to stroke subtypes. METHODS: Male smokers (n=28 519) aged 50 to 69 years without a history of stroke participated in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, a controlled trial to test the effect of alpha-tocopherol and beta-carotene supplementation on cancer. From 1985 to 1993, a total of 1057 men suffered from primary stroke: 85 had subarachnoid hemorrhage; 112, intracerebral hemorrhage; 807, cerebral infarction; and 53, unspecified stroke. RESULTS: Systolic blood pressure > or = 160 mm Hg increased the risk of all stroke subtypes 2.5 to 4-fold. Serum total cholesterol was inversely associated with the risk of intracerebral hemorrhage, whereas the risk of cerebral infarction was raised at concentrations > or = 7.0 mmol/L. The risks of subarachnoid hemorrhage and cerebral infarction were lowered with serum HDL cholesterol levels > or = 0.85 mmol/L. Pretrial high serum alpha-tocopherol decreased the risk of intracerebral hemorrhage by half and cerebral infarction by one third, whereas high serum beta-carotene doubled the risk of subarachnoid hemorrhage and decreased that of cerebral infarction by one fifth. CONCLUSIONS: The risk factor profiles of stroke subtypes differ, reflecting different etiopathology. Because reducing atherosclerotic diseases, including ischemic stroke, by lowering high serum cholesterol is one of the main targets in public health care, further studies are needed to distinguish subjects with risk of hemorrhagic stroke. The performance of antioxidants needs confirmation from clinical trials.

Validation of stroke diagnosis in the National Hospital Discharge Register and the Register of Causes of Death in Finland.

The validity of stroke diagnosis in the National Hospital Discharge Register and the Register of Causes of Death was examined among 546 middle-aged men in Finland. The subjects were cases of cerebrovascular diseases of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study and identified by record linkage to the registers. In all, 375 events with cerebrovascular disease as hospital discharge diagnosis and 218 events with cerebrovascular disease as the underlying cause of death were reviewed using specific criteria modified from the classifications of the National Survey of Stroke and the WHO MONICA Study. For hospital stroke diagnoses, there was agreement on diagnosis for all strokes in 90%, for subarachnoid hemorrhage in 79%, intracerebral hemorrhage in 82%, and cerebral infarction in 90%. The respective agreement rates for stroke as the underlying cause of death were 97%, 95%, 91%, and 92%. The data were insufficient for review in 1% and 3% of the stroke events, respectively. Age, observation year and trial supplementation with alphatocopherol or beta-carotene had no effect on validity. In conclusion, the validity of stroke diagnosis was good in registers of hospital diagnoses and causes of death justifying their use for endpoint assessment in epidemiological studies.