Aneurysmal subarachnoid hemorrhage in Izumo City and Shimane Prefecture of Japan. Outcome

The overall outcome of patients with aneurysmal subarachnoid hemorrhage was investigated in Izumo City and Shimane Prefecture. Of the patients from Izumo City, the clinical grade on admission was Grade I or II in 41% and Grade IV or V in 31%. Of those from Shimane Prefecture, 49% were graded as Grade I or II and 24% as Grade IV or V. The overall mortality rates 1 year after subarachnoid hemorrhage were 46% for Izumo City and 35% for Shimane Prefecture, while the surgical mortality rates were 18 and 15%, respectively. The mortality rates were particularly high among the elderly over the age of 70 years and among unoperated cases. The leading cause of death in these cases was the effect of aneurysm rupture itself, followed by rebleeding and vasospasm. The 5-year survival probabilities according to life table analysis were 50% for Izumo City and 59% for Shimane Prefecture, and a significant difference was observed in survival curves between Izumo City and Shimane Prefecture. It is concluded that the smaller the community studied, the less favorable the overall outcome, mainly because of poorer clinical conditions on admission.     

Has there been a decline in subarachnoid hemorrhage mortality?

We studied subarachnoid hemorrhage in the population of Rochester, Minnesota, for the 40-year period from 1945 through 1984. The average annual incidence rate of subarachnoid hemorrhage in Rochester has remained constant at approximately 11 per 100,000 population. Age-specific incidence rates increased with age. However, the average annual mortality rate for subarachnoid hemorrhage in Rochester has shown a decreasing trend, from 6.8 per 100,000 population in 1955-1964 to 4.3 in 1975-1984. It is likely that this is due to a decrease in case-fatality rates from 57% in 1945-1974 to 42% in 1975-1984 (p = 0.10). This decreasing trend was also evident in annual mortality rates from subarachnoid hemorrhage for US white men and women. The reason for the improved case-fatality rate is unclear, but it may be related to changes in management. The interval from onset of subarachnoid hemorrhage to surgery decreased from a median of 12 days in 1975-1979 to 2 days in 1980-1984, and of those who survived to receive medical attention, more patients received some form of medical treatment in 1980-1984. Whether either or both of these changes have led to the decrease in the case-fatality rate is uncertain.     

Aging Changes of Aneurysmal Subarachnoid Hemorrhage: A 35-year,Hospital-Based Study

BackgroundThe etiology and background factors which cause decreases in the size of ruptured intracranial aneurysms remain unclear.ObjectiveTo clarify the age- and sex-related differences in aneurysmal subarachnoid hemorrhage (SAH) based on a 35-year-old hospital database and demographic data.MethodsA database of patients admitted to our hospital with aneurysmal SAH from 1983 to 2017 was split into 5-year intervals and analyzed. Demographic data of the general population were also analyzed for reference.ResultsAltogether, 1,523 aneurysmal SAH events were enrolled in the analysis. Age (p<0.001), proportion of elderly patients ≥ 65 years old (p<0.001), female sex (p=0.005), very small aneurysms less than 5 mm (p<0.001), and the yearly-averaged number of fatal events showed increasing trends. The proportion of aneurysm size of 10 mm or more (p = 0.011) and the yearly-averaged population of Shimane prefecture (p < 0.001) showed declining trends. In the subgroup analyses, the proportion of very small aneurysms was found to increase significantly in the non-elderly male and elderly female subgroups. The proportion of large aneurysms (10 mm or more) decreased in the non-elderly subgroup (p<0.05). As for the elderly subgroups, the yearly-averaged number of events did not show a significant tendency, although the yearly-averaged population of Shimane prefecture showed an increasing trend.ConclusionWe found an increasing trend in the prevalence of very small aneurysms in elderly females. Recent aging may contribute to this trend. The number of aneurysmal SAH events was confirmed to not increase, despite the increased aging population of Shimane prefecture.     

Incidence rate of Aneurysmal SAH in Gwangju City and Jeollanamdo Province in 2007

Objective

The incidence of subarachnoid hemorrhage (SAH) worldwide varies considerably. In spite of many reports about the incidence of SAH, there has been no report about the incidence of SAH on the basis of the Korean population. The purpose of this hospital-based study was to assess the actual incidence rates of aneurysmal SAH in Gwangju city and Jeollanamdo province.

Methods

All cases of SAH confirmed by computerized tomography (CT) between January 2007 and December 2007 were selected for analysis. For the data collection, three major training hospital and ten general hospitals working the CT in Gwangju city and four major general hospitals in Jeollanamdo province participate in this study.

Results

According to the official census of Korea, the population was 1,413,444 in Gwangju city and 1,929,836 in Jeollanamdo province in 2007. There were 163 patients in Gwangju city and 266 patients in Jeollanamdo province confirmed SAH by CT in 2007. The crude and the age- and sex-adjusted annual incidence rates per 100,000 population for all ages in Gwangju city were 11.5 and 12.4 for aneurysmal SAH and in Jeollanamdo province were 13.8 and 10.8. The incidence was higher in women and increased with age. The gender distribution varied with age. At young ages, the incidence was higher in men while after the age of 40 years, the incidence was higher in women.

Conclusion

In the present study, the age- and sex-adjusted annual incidence rates is 11.8 in Gwangju city and Jeollanamdo province. The incidence was higher in women and increased with age.     

Subarachnoid hemorrhage in an isolated population. Incidence on the Faroes during the period 1962-1975

In a retrospective study of a 14-year period (1962-1975) the annual incidence of subarachnoid hemorrhage (SAH) was found to be 7.4 per 100,000 in an isolated population of about 40,000. The age-specific incidences in the age groups from 15-25 to 60 years are on the same level as found in Sweden, Rochester USA, England, and Iceland, but lower than the findings in Finland. The age-specific incidence among persons over 60 years of age was far lower than in Sweden, Rochester USA, and Finland. The possible causes of the lower incidence in all age groups than reported in the above-mentioned studies are discussed. Forty patients had a history of SAH. Two months after the episode 38% had died and at the end of 5 years 53%. The recurrence rate at 5 years was 24%.     

The Incidence of Aneurysmal Subarachnoid Hemorrhage in Youngdong District, Korea

Objective

The purpose of this study is to investigate the incidence of aneurysmal subarachnoid hemorrhage (SAH) in Youngdong district for 10 years.

Methods

From Jan. 1997 to Dec. 2006, 732 patients (327 males, 405 females, mean age: 54.8±13.1 years) with spontaneous SAH were admitted to our hospital. We reviewed the medical records and radiological findings regarding to the ictus of SAH, location and size of the ruptured aneurysms, Hunt-Hess grade and Fisher grade on admission, personal details such as address, age, and sex, and previous history of medical diseases.

Results

In these 732 patients, 672 cases were confirmed as aneurysmal SAH. Among them, 611 patients (262 males, 349 females, mean age: 54.9±13.2 years) came from Youngdong district. The average crude annual incidence of aneurysmal SAH for men, women, and both sexes combined in Youngdong district was 7.8±1.7, 10.5±2.7, and 9.1±2.1 per 100,000 population, respectively. Because of the problems related to the observation period and geographical confinement, it was suspected that the representative incidence of aneurysmal SAH in Youngdong district should be made during the later eight years in six coastal regions. Therefore, the average age-adjusted annual incidence for men, women, and both sexes combined was 8.8±1.4, 11.2±1.3 and 10.0±1.0, respectively in the coastal regions of Youngdong district from 1999 to 2006.

Conclusion

In overall, our results on the incidence of aneurysmal SAH was not very different from previous observations from other studies.     

Trends in surgical and management outcomes in patients with aneurysmal subarachnoid hemorrhage in Izumo city, Japan, between 1980-1989 and 1990-1998

BACKGROUND AND PURPOSE: The purpose of this community-based study was to evaluate temporal changes in surgical and management outcomes in patients with aneurysmal subarachnoid hemorrhage (SAH). METHODS: The subjects were 358 patients with aneurysmal SAH who were treated during the 19-year period from 1980 to 1998 in Izumo City, Japan. We compared data during the 9-year period 1990-1998 (period B; 188 patients) with those during the 10-year period 1980-1989 (period A; 170 patients). RESULTS: The proportion of patients 80 years of age or older or those with World Federation of Neurosurgical Societies grade V increased significantly (period A, 5 and 25%; period B, 18 and 35%, respectively). The operability rate did not change for patients 69 years of age or younger, whereas it increased significantly for those 70-79 years of age (period A, 48%; period B, 72%). The 6-month and 2-year case fatality rates in surgically treated patients decreased significantly (period A, 12 and 20%; period B, 2 and 8%, respectively), whereas they were virtually unchanged for overall management (period A, 41 and 46%; period B, 38 and 42%, respectively). In patients who underwent surgery, the incidence of permanent symptomatic vasospasm decreased from 21% during period A to 11% during period B, and there was no death from vasospasm in the later period. However, no significant difference was found in the functional outcome between the two periods, regardless of whether surgery was performed. The most important determinants of 6-month and 2-year survival rates were grade on admission, rebleeding and the site of the ruptured aneurysms. Age was also a significant predictor of the 6-month case fatality rate. CONCLUSIONS: For patients with SAH who underwent surgery, there were trends towards decreases in the case fatality rate and in the incidence of permanent symptomatic vasospasm. Nevertheless, the overall management outcome was still unsatisfactory, mainly because of increasing numbers of very elderly and/or high-risk patients. .     

动脉瘤性蛛网膜下腔出血后脑血管痉挛的脑血流动力学改变

目的探讨动脉瘤性蛛网膜下腔出血（aSAH）后脑血管痉挛（CVS）的血流动力学改变。方法对337例（382枚动脉瘤）aSAH患者临床资料进行回顾性分析,均经数字减影血管造影（DSA）和／或CT血管造影（CTA）检查证实为动脉瘤（An）,其中动脉瘤颈夹闭术297例,瘤颈夹闭及载瘤动脉塑形术29例,动脉瘤孤立术8例及包裹术3例。术后给予尼莫地平持续泵入扩血管、脑脊液引流、3H疗法等治疗,并于SAH1—3d．4～7d,8～14d、15～20d进行床边经颅超声多普勒（TCD）检测,主要观察MCA平均血流速度（VmMcA）、计算Lindegaard指数,即同侧MCA与颅外段ICAVm之比（LI）,观察CVS及颅内压（ICP）等脑血流动力学变化。结果SAH患者不同程度的存在CVS,25％的患者1—3d就出现CVS,8～14d达高峰;Hunt-Hess分级与CVS的变化成正相关;102例患者（102／337,30．3％）出现不同程度的颅内压增高;17例（17／337,5％）出现延迟性缺血性神经功能障碍（DIND）,颅内压增高且有CVS者预后较差。结论TCD可以床边、动态监测aSAH患者的脑血流动力学改变,具有无创、简单易行的特点。TCD检测的脑血流速度、Lindegaard指数和频谱形态相结合对临床和血管造影诊断CVS有价值。     

Cerebrovascular disease in infants and children: a study of incidence, clinical features, and survival

A 10-year review of the Mayo Clinic experience with childhood cerebrovascular disease unrelated to birth, intracranial infection, or trauma identified 69 patients (38 with ischemic stroke, and 31 with subarachnoid or intracerebral hemorrhage). Although children with cerebral infarction had better survival, they experienced more residual disability than children with cerebral hemorrhage. The medical records-linkage system for Rochester, Minnesota residents made it possible for the first time to study cerebrovascular disease in a well-defined childhood population. Records from all medical facilities serving this population (average of 15,834 resident children) showed four strokes over 10 years (average annual incidence rate of 2.52 cases per 100,000 per year).     

Epidemiology of cerebrovascular disease in Tartu, Estonia, USSR, 1970 through 1973.

This study was undertaken to establish the incidence and mortality for various types of cerebrovascular disease in the population of Tartu. All medical records for this population were reviewed for the period 1970 through 1973, and those with a diagnosis of brain infarction, transient ischemic attacks, cerebral hemorrhage or subarachnoid hemorrhage were identified. Only the first stroke was considered when determining incidence. A total of 786 cases were included in the study. Without cases of transient ischemic attacks, the number was 667 (e.g., cases of stroke). Cerebral infarction accounted for 80% of all strokes, cerebral hemorrhage for 13.5% and subarachnoid hemorrhage for 6.5%. The incidence rate for stroke was higher for men than for women and significantly increased in each older age group. The rate for all persons was 184 per 100,000 population per year. The incidence of transient ischemic attacks was 33 per 100,000 population per year. The mortality rate for stroke for this population was 98/100,000 per year. The data on incidence of stroke and its type, its dependence on age and sex, and mortality rate are close to the corresponding data reported from other countries.     

动脉瘤性蛛网膜下腔出血形态分析

目的 探讨动脉瘤性蛛网膜下腔出血计算机断层扫描（computed tomography,CT）形态特征,根据CT出血形态预判颅内动脉瘤的部位。方法 回顾性分析82例动脉瘤性蛛网膜下腔出血患者CT出血形态及全脑血管造影结果,总结不同部位动脉瘤破裂出血CT形态特征。结果 大脑前动脉、前交通动脉、大脑中动脉动脉瘤出血CT形态特异,为单纯前纵裂、外侧裂出血,蛛网膜下腔出血伴前纵裂、额叶、外侧裂血肿;颈内动脉、后交通动脉瘤出血CT形态多样,特异性较差,但常见形态为一侧鞍上池、外侧裂出血,波及其他脑池,前纵裂出血少或无出血;大脑后动脉、椎动脉、基底动脉、小脑后下动脉等后循环动脉瘤出血CT形态较典型,为脚间池、桥前池、环池、四叠体池、小脑延髓外侧池、小脑幕上下出血,但与脑干周围非动脉瘤性蛛网膜下腔出血鉴别困难。结论 根据特异性CT出血形态能够预判部分大脑前动脉、前交通动脉、大脑中动脉动脉瘤,预判颅内后循环动脉瘤时与脑干周围非动脉瘤性蛛网膜下腔出血鉴别困难,预判颈内动脉、后交通动脉瘤特异性差。     

Impact of unruptured intracranial aneurysms on public health in the United States.

BACKGROUND AND PURPOSE: Unruptured intracranial aneurysms constitute a significant public health problem that has not been quantified. The purpose of this study is to document the magnitude of this problem in the United States. METHODS: National Hospital Discharge Survey data from 1979, 1984, and 1989 served as the basis for calculating patient numbers and frequency distributions. Cost estimates included the direct costs of hospitalization and surgery for those who had surgery, disability and lost income from morbidity, and lost income from mortality. RESULTS: The estimated lifetime cost (including hospitalization, surgery, morbidity, and mortality) for annual cases of patients hospitalized with unruptured intracranial aneurysms in the United States is $522,500,000 compared with $1,755,600,000 for patients with aneurysmal subarachnoid hemorrhage. CONCLUSIONS: These data underscore the need to better understand unruptured intracranial aneurysm as a risk factor for subarachnoid hemorrhage, to define other subarachnoid hemorrhage risk factors, and to optimize the management of patients with these conditions.     

Incidence and prognosis of subarachnoid hemorrhage in a Japanese rural community

Twenty-six first episodes of subarachnoid hemorrhage occurred among 1,621 Hisayama residents aged greater than or equal to 40 years during the 22-year follow-up of a prospective study. Subarachnoid hemorrhage was confirmed by both clinical and autopsy findings. The average annual incidence (96.1/100,000 population) was 3-13 times higher than any previously reported and steeply increased with age in both sexes, being 2.3 times higher for women than for men after adjusting for age. Nine patients (35%) died less than or equal to 8 hours after the onset of subarachnoid hemorrhage. None was correctly diagnosed on the death certificates, and four of the nine (44%) were misdiagnosed as intracerebral hemorrhage. We found the survival rate of patients suffering subarachnoid hemorrhage to be much lower than previously reported because we detected a large number of sudden deaths due to subarachnoid hemorrhage through the high rate of autopsy in our cohort (81.4%).     

Cerebral vascular complications in the population of Dijon. Incidence-breakdown-mortality

Since 1985, a stroke registry has registered every stroke in this town, of about 140,000 inhabitants. A CT Scan and numerous sources of information have allowed to achieve an exhaustive survey. The annual incidence of stroke has been 145/100,000. The annual specific incidence for age is 170/100,000 in men, 126/100,000 in women. The annual specific incidence for age and sex has shown a female preponderance until 30 and a male preponderance after this age. At 80, the rates became equal. Sixty-eight per cent of stroke were due to an infarct, 12 p. 100 to lacunae, 5 p. 100 to subarachnoid hemorrhage and 15% to cerebral hemorrhage. A preponderance of young people was found in subarachnoid hemorrhage, of the fifth decade in cerebral hemorrhage, while infarct rose up with age in the 2 sexes. Infarcts appeared predominantly during winter, while transient ischemic attacks appeared more often during summer. Cerebral hemorrhage had a constant incidence over the year. Mortality was high, mainly during the first month with 12.5 p. 100 during the first week, 21.5 p. 100 during the first month, and 30 p. 100 the first year. Our results appear to set in the mean of white occidental countries as opposed to Japan. They emphasize the important and underestimated place of lacunae and the seasonal variations of several causal varieties of stroke.     

Radiological Evaluation of Cerebral Aneurysms in Selected Clinical Presentations

BACKGROUND AND PURPOSE: Cerebral aneurysms have different presenting features and, to some extent, a variable clinical course based on the pattern of subarachnoid hemorrhage, the circumstance of their discovery, and the anatomy. Thus, the neuroimaging workup must be tailored accordingly to provide accurate diagnosis and optimal follow-up. METHOD: The authors suggest neuroradiological evaluation of patients in the emergency room and in cases of perimesencephalic subarachnoid hemorrhage, aneurysmal pattern of subarachnoid hemorrhage with normal angiography, vascular infundibula, unruptured/incidental aneurysms, infectious aneurysms, dissecting aneurysms, dolichoectatic/fusiform aneurysms, intracavernous aneurysms, and traumatic aneurysms. CONCLUSION: Recent neuroimaging advances have contributed to improvement in diagnostic safety and accuracy, allowing a more diligent patient follow-up, improved patient outcome, and enhanced physician perception and clinical judgment.     

Incidence of Convexal Subarachnoid Hemorrhage in the Elderly: The Mayo Clinic Study of Aging

ObjectivesNontraumatic convexal subarachnoid hemorrhages in the elderly can be a manifestation of cerebral amyloid angiopathy associated with a high risk of future intracerebral hemorrhage. The incidence in the elderly population is unknown. Our objectives were to: 1) determine the incidence of convexal subarachnoid hemorrhage in a population-based study, and, 2) to compare apopolipoprotein-E genotype and amyloid positron emission tomographic (PET) imaging for those with versus without hemorrhage.MethodsBetween 11/29/2004 and 3/11/2017, 4462 individuals without hemorrhage at baseline participated in the population-based Mayo Clinic Study of Aging. We used the Rochester Epidemiology Project medical records-linkage system to identify intracerebral hemorrhages. Records and images were reviewed to identify convexal subarachnoid hemorrhage. Neuroimaging characteristics, demographics, medications, and apopolipoprotein-E genotype were recorded.ResultsFour cases were identified. The incidence of convexal subarachnoid hemorrhage was 14.1 per 100,000 person years. Three occurred in women, median age, 79 (range: 71-84). One patient had coexisting cerebral microbleeds. Two participants developed a subsequent lobar intracerebral hemorrhage at a median of 4.75 years after convexal subarachnoid hemorrhage. The apopolipoprotein-E -allele combinations of the 4 were: 3/3, 3/3, 2/2, and 2/3. On Pittsburgh Compound B-PET imaging, median standardized uptake value ratio with convexal subarachnoid hemorrhage was 1.86 (range: 1.38-2.34).ConclusionsConvexal subarachnoid hemorrhage is rare in the older population, occurring with an incidence of about 14 per 100,000 person years. Yet, when present, it may be associated with a high risk of future intracerebral hemorrhage.     

Clinical characteristics of ruptured distal middle cerebral artery aneurysms: Review of the literature

Middle cerebral artery (MCA) aneurysms usually arise at the primary MCA bifurcation or trifurcation. Distal MCA aneurysms are rarely considered as sources of aneurysmal subarachnoid hemorrhage (SAH). It has been reported that ruptured distal MCA aneurysms are associated with head trauma, neoplastic emboli, arterial dissection, or bacterial infection. We experienced five cases of ruptured distal MCA aneurysms and evaluated their clinical characteristics. Retrospective analysis of aneurysmal SAH at Kobayashi Neurosurgical Neurological Hospital was performed from January, 2004 to December, 2014. Clinical characteristics of ruptured distal MCA aneurysms were analyzed using our database. Among 191 aneurysmal SAH patients, there were five ruptured distal MCA aneurysms. All patients did not have any specific medical problems such as infectious disease, head trauma, or cardiac disorders. The incidence of ruptured distal MCA aneurysm was higher than expected and was equivalent to 9.4% of the total ruptured MCA aneurysms. Strong male predominance (80%) and M2–3 junction aneurysm preponderance (80%) were observed. In addition, there were only two patients (40%) with intracerebral hematoma in our study. We reported five cases of ruptured distal MCA aneurysms. Although ruptured distal MCA aneurysms are thought to be rare as sources of aneurysmal SAH, the incidence of ruptured distal MCA aneurysm was 9.4% of all ruptured MCA aneurysms in our study. Ruptured distal MCA aneurysms should be considered as sources of aneurysmal SAH without intracerebral hematoma.     

Cost-effectiveness analysis of screening for asymptomatic, unruptured intracranial aneurysms. A mathematical model.

BACKGROUND AND PURPOSE: Subarachnoid hemorrhage (SAH) due to aneurysmal rupture is a major cause of cerebrovascular disease-related death. This problem could be eliminated by diagnosis and successful treatment of aneurysms before rupture. Recent developments in high-resolution imaging technology have made screening for unruptured aneurysms possible in the general population. Such screening has become widespread in Japan ("No Dokku, " or brain checkup). As a result, unruptured aneurysms are being identified with increasing frequency. However, the economic implications of treatment decisions for unruptured aneurysms have not been analyzed. Therefore, we performed such an analysis. METHODS: We used a Markov model to evaluate the cost-effectiveness of screening for asymptomatic, unruptured intracranial aneurysms. The model involved a set of variables describing discrete health states. Each state was assigned a quality of life score and an associated medical cost. A comparison of the expected outcomes was then made between 2 hypothetical cohorts, one receiving screening and the other no screening. A sensitivity analysis was performed by altering the input values within clinically reasonable ranges to reflect uncertainty in the baseline analysis and then assessing the effects on outcomes. RESULTS: Combining the incremental cost and effectiveness data revealed a cost per quality-adjusted life-year of $7760 for an annual rate of subarachnoid hemorrhage due to unruptured aneurysms (rupture rate) of 0.02; this cost was $39 450 for a rupture rate of 0.01. There was no benefit (negative quality-adjusted life-year benefit) for a rupture rate of 0.005, the rupture rate found in a recently published international cooperative study. The risks of surgery for unruptured aneurysms and the discounting ratio used to assess the impact of timing of costs and benefits on future outcomes also had significant effects on the results. Other variables had little impact on cost-effectiveness. CONCLUSIONS: The cost-effectiveness of screening for an unruptured aneurysm is highly sensitive to the annual rate of subarachnoid hemorrhage due to unruptured aneurysms. The low annual rupture rate seen in the recent large international cooperative study implies that screening asymptomatic populations to identify and treat unruptured aneurysms would not be cost cost-effective.     

The clinical course of perimesencephalic nonaneurysmal subarachnoid hemorrhage

We studied the early clinical course of 65 patients with perimesencephalic (nonaneurysmal) subarachnoid hemorrhage. None of the patients rebled; none had delayed cerebral ischemia; and only 3 patients (5%) developed clinical signs of acute hydrocephalus, 2 requiring ventricular shunting. Hyponatremia and electrocardiographic changes were found in the same proportions as in patients with aneurysmal rupture. All patients had a good outcome after 3 months. To control for the influence of the relatively small amount of cisternal blood in perimesencephalic hemorrhage on the absence of delayed cerebral ischemia, we compared these 65 patients with 49 patients who had aneurysmal subarachnoid hemorrhage. This control group with aneurysms was selected according to a similar amount of cisternal blood, a comparable level of consciousness on admission, and absence of other factors known to increase the risk for delayed cerebral ischemia. We found that 4 of the 49 patients with aneurysmal hemorrhage developed delayed cerebral ischemia (Fisher's exact test, p = 0.03); therefore the relatively small amount of blood does not account for the absence of delayed cerebral ischemia in perimesencephalic hemorrhage. Patients with a perimesencephalic pattern of hemorrhage and a normal angiogram should be considered to have a distinct subset of subarachnoid hemorrhage and should be excluded from future treatment trials of patients with subarachnoid hemorrhage.     

Epidemiological aspects of spontaneous subarachnoid haemorrhage in Queensland, Australia.

AIMS: To examine the epidemiology of spontaneous subarachnoid haemorrhage (SAH) within the population of Queensland, Australia in 2002. METHODS: A retrospective population and hospital-based survey of all cases of spontaneous SAH occurring within the population of Queensland (3.7 million) during the calendar year 2002 was performed. Cases were identified from hospital separation coding data and the register of births, deaths and marriages. Standard demographic data was recorded for each case identified. RESULTS: The annual incidence of SAH in our population was 9.4 cases per 100,000. There was a steady increase in the incidence of SAH with increasing age, with the incidence rising to 38.8 per 100,000 in those aged greater than 80. The overall mortality rate was 33.1%, with 6% of all cases dying before reaching hospital care. The annual incidence in the indigenous population of Queensland was 8.9 /100,000.