Prevalence of intracranial saccular aneurysms in a Japanese community based on a consecutive autopsy series during a 30-year observation period. The Hisayama study

Morphological Risk Factors for Rupture of Small (<7 mm) Posterior Communicating Artery Aneurysms

BACKGROUND

The management of small, unruptured intracranial aneurysms is still controversial. Given the distinctive natural history of aneurysm at different locations, location-specific analysis might be a reasonable approach. This study aimed to investigate morphological discriminators for rupture status by focusing on only posterior communicating artery (PcomA) aneurysms smaller than 7 mm.

METHODS

In 108 small PcomA aneurysms (68 ruptured, 40 unruptured), clinical and morphological characteristics were compared between the ruptured and unruptured groups. Multivariate logistic regression analysis was performed to determine the independent predictors for the rupture status of small PcomA aneurysms.

RESULTS

None of the clinical characteristics were significantly different between the ruptured and unruptured groups (P > 0.05). The ruptured group revealed a significantly larger size (P = 0.009), aspect ratio (P = 0.009), size ratio (P = 0.002), dome-to-neck ratio (P = 0.002), inflow angle (P < 0.001), and proportion of bleb formation (P = 0.039). Bottleneck factor (P = 0.154), diameter of PcomA (P = 0.302), and fetal-type PcomA (P = 0.832) showed no significance. With multivariate analyses, size ratio (P = 0.012) and inflow angle (P = 0.001) were shown to be independently associated with the rupture status of small PcomA aneurysms.

CONCLUSIONS

Morphological characteristics were closely related with the rupture status of small PcomA aneurysms. Size ratio and inflow angle were independent risk factors for rupture and might be useful in clinical risk stratification of small PcomA aneurysms.

Prediction model for 3-year rupture risk of unruptured cerebral aneurysms in Japanese patients

OBJECTIVE

To build a prediction model that estimates the 3-year rupture risk of unruptured saccular cerebral aneurysms.

METHODS

Survival analysis was done using each aneurysm as the unit for analysis. Derivation data were from the Unruptured Cerebral Aneurysm Study (UCAS) in Japan. It consists of patients with unruptured cerebral aneurysms enrolled between 2000 and 2004 at neurosurgical departments at tertiary care hospitals in Japan. The model was presented as a scoring system, and aneurysms were classified into 4 risk grades by predicted 3-year rupture risk: I, < 1%; II, 1 to 3%; III, 3 to 9%, and IV, >9%. The discrimination property and calibration plot of the model were evaluated with external validation data. They were a combination of 3 Japanese cohort studies: UCAS II, the Small Unruptured Intracranial Aneurysm Verification study, and the study at Jikei University School of Medicine.

RESULTS

The derivation data include 6,606 unruptured cerebral aneurysms in 5,651 patients. During the 11,482 aneurysm-year follow-up period, 107 ruptures were observed. The predictors chosen for the scoring system were patient age, sex, and hypertension, along with aneurysm size, location, and the presence of a daughter sac. The 3-year risk of rupture ranged from <1% to >15% depending on the individual characteristics of patients and aneurysms. External validation indicated good discrimination and calibration properties.

INTERPRETATION

A simple scoring system that only needs easily available patient and aneurysmal information was constructed. This can be used in clinical decision making regarding management of unruptured cerebral aneurysms.

3D contrast enhancement-MR angiography for imaging of unruptured cerebral aneurysms: a hospital-based prevalence study

Background and Purpose

Contrast enhanced MRA (CE-MRA) can help to overcome the limitations of other techniques to clearly display the details of cerebral aneurysms at 1.5-T MR system. We investigated the prevalence of unruptured cerebral aneurysms (UCAs) using three dimensional (3D) CE-MRA in a tertiary comprehensive hospital in China.

Materials and Methods

The cases were prospectively recorded at our hospital between February 2009 and October 2010. 3D CE-MRA, interpreted by 2 observers blinded to the participants’ information, was used to identify the location and size of UCAs and to estimate the overall, age-specific, and sex-specific prevalence.

Results

Of the 3993 patients (men: women = 2159∶1834), 408 UCAs were found in 350 patients (men: women = 151∶199). The prevalence was 8.8% overall (95% CI, 8.0–10.0%), with 7.0% for men (CI, 6.0–8.0%) and 10.9% for women (CI, 9.0–12.0%). The overall prevalence of UCAs was higher in women than in men (P<0.001) and increased with age both in men and women. Prevalence peaked at age group 75–80 years. Forty-two patients (11.7%) had multiple aneurysms, including 10 (2.9%) male patients and 32 (9.1%) female patients. The most common site of aneurysm was the carotid siphon, and most lesions (71.3%) had a maximum diameter of 3−5 mm.

Conclusion

This hospital-based prevalence study suggested a high prevalence (8.8%) of UCAs and most lesions (71.3%) had a maximum diameter of 3–5 mm observed by 3D CE-MRA. Because the rupture of small cerebral aneurysms was not uncommon, an appropriate follow-up care strategy must be formulated.

Exacerbation of intracranial aneurysm and aortic dissection in hypertensive rat treated with the prostaglandin F-receptor antagonist AS604872

Intracranial aneurysm (IA) and aortic dissection are both complications of hypertension and characterized by degeneration of the media. Given the involvement of prostaglandin F2α and its receptor, FP, in extracellular matrix remodeling in a mouse model of pulmonary fibrosis, here we induced hypertension and IA in rats by salt loading and hemi-lateral ligation of renal and carotid arteries and examined effects of a selective FP antagonist, AS604872, on these vascular events. AS604872 significantly accelerated degeneration of the media in both cerebral artery and aorta as evidenced by thinning of the media and disruption of the elastic lamina and promoted IA and aortic dissection. Notably, AS604872 induced expression of pro-inflammatory genes such as E-selectin in lesions and significantly enhanced macrophage infiltration. Suppression of surface expression of E-selectin with cimetidine prevented macrophage infiltration and aortic dissection. Thus, AS604872 exacerbates vascular inflammation in hypertensive rats and facilitates IA and aortic dissection. These results demonstrate that both IA and aortic dissection are caused by chronic inflammation of the arterial wall, which is worsened by AS604872, cautioning that other FP antagonists may share such deleterious actions in vascular homeostasis and suggesting that AS604872 can be used to make models of these vascular diseases with extensive degeneration.

Incidental Saccular Aneurysms on Head MR Angiography: 5 Years' Experience at a Single Large-Volume Center

Background and Purpose

The diagnostic accuracy for unruptured intracranial aneurysms has increased, and incidental asymptomatic aneurysms have come to represent a substantial clinical burden because of their controversial natural history. However, their prevalence may be attributable to variations in evaluation methods and demographics. We therefore describe the prevalence and magnetic resonance angiography (MRA) findings of incidental intracranial saccular aneurysms over a 5-year period at a single large-volume center.

Methods

MRA images from 18,237 patients obtained between January 2001 and December 2005 were retrieved from the radiology report database. Patients diagnosed with incidental intracranial saccular aneurysms were identified and their MRA data were reviewed. Imaging and clinical follow-up data were evaluated.

Results

During the study period, 366 incidental intracranial saccular aneurysms were identified in 330 patients (prevalence, 1.8%; 95% confidence interval, 1.63%-2.01%; 115 men and 215 women; age range, 22-82 years; median age, 63 years). The prevalence was higher in women (215/8,112) than in men (115/10,125; P=0.02). The prevalence increased with age in women (P<0.01), but not in men (P=0.30). Aneurysm size ranged from 1.5 mm to 13 mm, with a median size of 4 mm. The most common location was the bifurcation of the middle cerebral artery (131/366; 35.8%).

Conclusions

Our real world experience indicated a slightly lower overall prevalence of incidental intracranial saccular aneurysms than previously reported. The prevalence increased with age in women but not in men.

Female sex as a risk factor for the growth of asymptomatic unruptured cerebral saccular aneurysms in elderly patients

Object

The prevalence of patients with asymptomatic unruptured intracranial aneurysms (UIAs) increases with the advancing age of the general population. The goal of the present study was to identify risk factors for the growth of UIAs detected with serial MR angiography (MRA) in patients 70 years of age or older.

Methods

This prospective study enrolled 79 patients (age range 70–84 years) with 98 UIAs. Patients were followed up every 4 months, including an assessment of the aneurysm diameter and morphological changes on MRA, neurological status, and other medical conditions. Aneurysm growth was categorized into two different patterns on the basis of the MRA findings: 1) maximum increase in aneurysm diameter of 2 mm or more; and 2) obvious morphological change, such as the appearance of a bleb.

Results

The mean duration of follow-up was 38.5 months (250.2 patient-years). Aneurysm rupture did not occur, but aneurysm growth was observed in 8 aneurysms (8 patients) during the study period. Univariate analysis showed that female sex, patient age ≥ 75 years, and an aneurysm location in the internal carotid artery (ICA) or middle cerebral artery (MCA) were associated with aneurysm growth (p = 0.04, p = 0.04, and p < 0.001, respectively). Multivariate analysis demonstrated that female sex was the only independent predictor of aneurysm growth (p = 0.0313, OR 2.3, 95% CI 1.3–30.2).

Conclusions

Female sex is an independent risk factor for the growth of UIAs in elderly patients. In addition, an age ≥ 75 years and aneurysm location in the ICA or MCA are characteristics that may warrant additional attention during follow-up imaging.

The impact of atherosclerotic factors on cerebral aneurysm is location dependent: aneurysms in stroke patients and healthy controls

Previous studies have indicated that cerebrovascular diseases (CVDs) seem to increase the occurrence of unruptured intracranial aneurysms (UIAs). However, this maybe explained by the fact that CVDs and UIAs share common risk factors, such as hypertension (HT) and smoking. To clarify the impact of atherosclerotic risk factors on cerebral aneurysmal formation, we explored the incidence of UIAs and their locations in healthy controls and patients with CVD, who frequently have atherosclerotic risk factors. This study included consecutive 283 asymptomatic healthy adults and 173 acute stroke patients, from patients diagnosed with acute cerebral hemorrhage or cerebral infarction and admitted to our hospital. The incidence, maximum diameter, and location of UIAs were evaluated, and we also investigated the following factors: age, gender, current smoking, HT, diabetes mellitus (DM), and dyslipidemia. UIAs were found in 19 of the total 456 subjects (4.2%), 11 of 283 healthy subjects (3.9%), and 8 of 173 stroke patients (4.6%). These differences are not statically significant. The incidence of middle cerebral artery (MCA) aneurysms was significantly higher in the CVD patients than in the healthy controls (P = .03), and the incidence of paraclinoid aneurysms was significantly higher in the healthy controls than in the CVD patients (P = .03). Moreover, higher incidences of HTs and CVDs in the MCA aneurysms than in the other locations of UIAs were observed. These results indicate that the impact of atherosclerotic factors on cerebral aneurysmal formation depends on their location and that there is a stronger impact on MCA aneurysms than on paraclinoid aneurysms.

Prevalence of unruptured intracranial aneurysms in healthy asymptomatic Japanese adults: differences in gender and age

BACKGROUND

We aimed to assess the prevalence of unruptured intracranial aneurysms (UIAs) in healthy asymptomatic adults, and investigate the differences in incidence due to gender and age in Japan.

METHODS

Magnetic resonance angiography (MRA) results of healthy asymptomatic adults who underwent the procedure for examination of the brain, from April 2010 to March 2012, were retrospectively examined. Patients with a history of ruptured aneurysm and UIAs were excluded. UIAs greater than 2.0 mm in size were counted. In accordance with these criteria, 8,696 people with a mean age of 52.2±9.5 years were examined, and 37.4 % of these individuals were women.

RESULTS

The overall prevalence of UIAs was 3.2 %. The prevalence in women was higher than that in men (4.4 % versus 2.5 %, OR, 1.81; 95% CI, 1.4 to 2.31). The prevalence increased with age in both genders. In under 49 years, the prevalence in women and men were 2.7 % and 1.9 %, respectively, with no significant differences (OR, 1.47; CI, 0.91 to 2.37). In over 50 years, the prevalence in women was higher than that in men (5.4 % versus 2.8 %, OR, 2.01; CI, 1.52–2.67). There were significant differences in the locations of UIAs by gender (P <0.001); Internal carotid artery was more frequent in women, whereas anterior cerebral artery and middle cerebral artery were more common inmen.

CONCLUSIONS

This study provides etiological data on the prevalence of UIAs in healthy asymptomatic Japanese adults, and may be useful in determining therapeutic managements for UIAs.

Endovascular methods for the treatment of intracranial cerebral aneurysms

This article briefly discusses the clinical features, natural history, and epidemiology of intracranial cerebral aneurysms, along with current diagnostic imaging techniques for their detection. The main focus is on the basic techniques used in endovascular coiling of ruptured and nonruptured saccular intracranial cerebral aneurysms. After a discussion of each technique, a short review of the results of each form of treatment is given, concentrating on reported large case series. Specific complications related to the endovascular treatment of saccular intracranial aneurysms are then discussed.

Temporal trends in sudden unexpected death in a general population: the Hisayama study

BACKGROUND

Studies addressing the temporal trends in the prevalence of sudden unexpected death (SUD) and its underlying causes in the general population are limited.

METHODS

Among a total of 1934 residents aged ≥20 years of the town of Hisayama, Japan, who died of endogenous causes of death and underwent autopsy examination (autopsy rate 78.5%) from 1962 to 2009, 204 were determined to be cases of SUD within 24 hours.

RESULTS

The trend in the age- and sex-adjusted prevalence of SUD among all autopsy subjects was stable over four 12-year periods (13.1% in 1962-1973, 13.4% in 1974-1985, 15.0% in 1986-1997, and 14.6% in 1998-2009; P for trend = .80). Regarding causes of death, the prevalence of SUD from stroke significantly declined with time (8.0%, 5.0%, 2.3%, and 2.1%, respectively; P for trend < .001), whereas significant increments were observed in the prevalence of SUD from heart disease (4.0%, 6.2%, 8.6%, and 9.7%; P for trend = .02) and from aortic aneurysm and dissection (0.2%, 1.2%, 2.9%, and 2.8%; P for trend = .01). In particular, the prevalence of ischemic heart disease increased 3-fold from 2.1% in 1962-1973 to 6.6% in 1998-2009 (P = .04). Reflecting the increment of ischemic heart disease, SUD within 1 hour increased significantly from 2.5% to 7.6% during this period (P = .01).

CONCLUSIONS

The trend in the prevalence of SUD was stable across a half century in a general Japanese population. Despite the decrement in the prevalence of SUD from stroke, that from heart disease, especially ischemic heart disease, increased significantly with time.

The expression of SPARC in human intracranial aneurysms and its relationship with MMP-2/-9

Objective

SPARC is a key determinant of invasion and metastasis in some tumors, such as gliomas, melanomas and prostate tumors. SPARC can change the composition and structure of the matrix and promote angiogenesis; these effects are closely related to clinical stage and the prognosis of tumors such as meningiomas. However, little is known about the expression of SPARC in intracranial aneurysms. The goal of this study was to establish the role of SPARC in human intracranial aneurysms.

Methods

Thirty-one intracranial aneurysms were immunohistochemically stained for SPARC, MMP-2 and MMP-9. As controls, normal Circle of Willis arteries were similarly immunostained. All specimens were retrieved during autopsies and were embedded in paraffin. To evaluate the expression levels of SPARC, MMP-2 and MMP-9, western blotting was also performed in three available intracranial aneurysm specimens. The limited availability of fresh intracranial aneurysm tissue was the result of the majority of patients choosing endovascular embolization.

Results

The results showed that SPARC, MMP-2 and MMP-9 were strongly expressed in intracranial aneurysm tissues; however, these proteins were expressed minimally or not at all in normal Circle of Willis arteries. The western blot results showed that the expression levels of SPARC, MMP-2 and MMP-9 were significantly up-regulated in intracranial aneurysms relative to the expression levels in the normal Circle of Willis arteries. Data analysis showed that SPARC was significantly correlated with MMP-2 and MMP-9, also with age and risk factors but not with the Hunt-Hess grade or with sex.

Conclusion

The results indicate that SPARC is widely expressed in human intracranial aneurysms, and its expression correlates with MMP-2 and MMP-9 expression, age and risk factors but not with the Hunt-Hess grade. The results of this study suggest that SPARC has a pathogenic role in the alteration of the extracellular matrix of intracranial arteries during aneurysm formation.

Is type I alpha 2 collagen gene responsible for intracranial aneurysm in Northeast China?

In this study, we investigated whether a single nucleotide polymorphism (rs42524 G > C) in the type I alpha 2 collagen gene was associated with sporadic ruptured intracranial aneurysm or its clinical characteristics in patients from Northeast China. Genotyping of the rs42524 G > C polymorphism was carried out using a polymerase chain reaction-restriction fragment length polymorphism assay. The data showed that the frequency of the rs42524 GC + CC genotype was significantly higher than the GG genotype among intracranial aneurysm patients whose Hunt and Hess grading scale was > 3. In addition, the rs42524 G > C genotype was found to have a statistically significant association with intracranial aneurysm risk. These findings indicate that the type I alpha 2 collagen gene gene may be involved in a predisposition to intracranial aneurysm in the Northeast Chinese population. Crucially, the rs42524 C allele may be an important risk factor for increased severity of the condition in patients with ruptured intracranial aneurysms.

Epidemiology and genetics of intracranial aneurysms

Intracranial aneurysms are acquired lesions (5-10% of the population), a fraction of which rupture leading to subarachnoid hemorrhage with devastating consequences. Until now, the exact etiology of intracranial aneurysms formation remains unclear. The low incidence of subarachnoid hemorrhage in comparison with the prevalence of unruptured IAs suggests that the vast majority of intracranial aneurysms do not rupture and that identifying those at highest risk is important in defining the optimal management. The most important factors predicting rupture are aneurysm size and site. In addition to ambiental factors (smoking, excessive alcohol consumption and hypertension), epidemiological studies have demonstrated a familiar influence contributing to the pathogenesis of intracranial aneurysms, with increased frequency in first- and second-degree relatives of people with subarachnoid hemorrhage. In comparison to sporadic aneurysms, familial aneurysms tend to be larger, more often located at the middle cerebral artery, and more likely to be multiple. Other than familiar occurrence, there are several heritable conditions associated with intracranial aneurysm formation, including autosomal dominant polycystic kidney disease, neurofibromatosis type I, Marfan syndrome, multiple endocrine neoplasia type I, pseudoxanthoma elasticum, hereditary hemorrhagic telangiectasia, and Ehlers-Danlos syndrome type II and IV. The familial occurrence and the association with heritable conditions indicate that genetic factors may play a role in the development of intracranial aneurysms. Genome-wide linkage studies in families and sib pairs with intracranial aneurysms have identified several loci on chromosomes showing suggestive evidence of linkage, particularly on chromosomes 1p34.3-p36.13, 7q11, 19q13.3, and Xp22. For the loci on 1p34.3-p36.13 and 7q11, a moderate positive association with positional candidate genes has been demonstrated (perlecan gene, elastin gene, collagen type 1 A2 gene). Moreover, 3 of the polymorphisms analyzed in 2 genes (endothelial nitric oxide synthase T786C, interleukin-6 G572C, and interleukin-6 G174C) were found to be significantly associated with ruptured/unruptured aneurysms: the endothelial nitric oxide synthase gene single-nucleotide polymorphisms increased the risk, while IL-6 G174C seemed protective. More recently, two genomic loci (endothelin receptor A and cyclin-dependent kinase inhibitor 2BAS) have been found to be significantly associated with intracranial aneurysms in the Japanese population; endothelin-1 is a potent vasoconstrictor produced by the endothelial cells. Until now, there are no diagnostic tests for specific genetic risk factors to identify patients who are at a high risk of developing intracranial aneurysms. Knowledge of the genetic determinants may be useful in order to allow clues on stopping aneurysm formation and obtain diagnostic tools for identifying individuals at increased risk. Further multicenter studies have to be carried out.

Prevalence of asymptomatic incidental aneurysms: a review of 2,685 computed tomographic angiograms

OBJECTIVE

Intracranial aneurysms are a public health issue with a potential for rupturing, causing significant morbidity/mortality. The prevalence of unruptured intracranial aneurysms, including those that are asymptomatic, varies widely, as it has been determined through autopsy studies as well as conventional angiography. However, computed tomography angiography, a less invasive procedure, has replaced the use of conventional angiography in the recent decades. The objective of the present study is to determine the prevalence of incidental aneurysms.

METHODS

The present study reviews all computed tomography angiography cases within the past decade at a single institution.

RESULTS

Of 2195 cases included in the study, 39 (1.8%) were found to have asymptomatic unruptured aneurysms.

CONCLUSIONS

The numbers of asymptomatic incidental aneurysms have increased.

Morphological and clinical risk factors for the rupture of anterior communicating artery aneurysms

OBJECT

Patients with ruptured anterior communicating artery (ACoA) aneurysms have historically been observed to have poor neuropsychological outcomes, and ACoA aneurysms have accounted for a higher proportion of ruptured than unruptured aneurysms. Authors of this study aimed to investigate the morphological and clinical characteristics predisposing to ACoA aneurysm rupture.

METHODS

Data from 140 consecutive patients with ACoA aneurysms managed at the authors' facility between July 2003 and November 2011 were retrospectively reviewed. Patients with (78) and without (62) aneurysm rupture were divided into groups, and morphological and clinical characteristics were compared. Morphological characteristics were evaluated based on 3D CT angiography and included aneurysm location, dominance of the A1 portion of the anterior cerebral artery, direction of the aneurysm dome around the ACoA, aneurysm bleb(s), size of the aneurysm and its neck, aneurysm-parent artery angle, and existence of other intracranial unruptured aneurysms.

RESULTS

Patients with ruptured ACoA aneurysms were significantly younger (a higher proportion were younger than 60 years of age) than those with unruptured lesions, and a significantly smaller proportion had hypercholesterolemia. A significantly larger proportion of patients with ruptured aneurysms showed an anterior direction of the aneurysm dome around the ACoA, had a bleb(s), and/or had an aneurysm size ≥ 5 mm. Multivariate logistic regression analysis showed that an anterior direction of the aneurysm dome around the ACoA (OR 6.0, p = 0.0012), the presence of a bleb(s) (OR 22, p < 0.0001), and an aneurysm size ≥ 5 mm (OR 3.16, p = 0.035) were significantly associated with ACoA aneurysm rupture.

CONCLUSIONS

Findings in the present study demonstrated that the anterior projection of an ACoA aneurysm may be related to rupturing. The authors would perhaps recommend treatment to patients with unruptured ACoA aneurysms that have an anterior dome projection, a bleb(s), and a size ≥ 5 mm.

Fatal subarachnoid hemorrhage during sexual activity: a case report

In this article, a case of sudden and unexpected death of a homeless 45-year-old woman is described. The woman suddenly died following sexual intercourse. When her partner described the circumstances surrounding her death, he reported that it was about 1:00 PM and they were on the beach lying under a boat. Shortly after intercourse,the woman had severe dyspnea and rigidity of the body. Medical assistance was immediately called to the place but despite attempts of resuscitation,the woman died. A complete medico-legal autopsy was performed.The external examination was unremarkable; no signs of injuries or trauma were observed. However, the sectioning of the skull showed a massive subarachnoid hemorrhage because of a rupture of the aneurysmatic basilar artery. This case demonstrates that subarachnoid hemorrhage secondary to a cerebral artery rupture is still an important cause of death despite steady advances in diagnosis and treatment.

Prevalence and risk factors for myopic retinopathy in a Japanese population: the Hisayama Study

PURPOSE

To examine the prevalence of myopic retinopathy and its risk factors in a general Japanese population.

DESIGN

Population-based, cross-sectional study.

PARTICIPANTS

In 2005, a total of 1969 Hisayama residents aged ≥ 40 years consented to participate in this study. Of these, 1892 subjects with adequate data were enrolled.

METHODS

Each participant underwent comprehensive physical and eye examinations that included measurements of refractive error, axial lengths, and color fundus photography. Myopic retinopathy was defined as the presence of diffuse chorioretinal atrophy, patchy chorioretinal atrophy, lacquer cracks, or macular atrophy.

MAIN OUTCOME MEASURES

Prevalence of myopic retinopathy.

RESULTS

Thirty-three participants had myopic retinopathy and the prevalence was 1.7% (2.2% in women and 1.2% in men). The prevalence of myopic retinopathy increased significantly with advancing age. Diffuse chorioretinal atrophy, patchy chorioretinal atrophy, lacquer cracks, and macular atrophy were present in 1.7%, 0.4%, 0.2%, and 0.4% of subjects, respectively. In multivariate analysis, myopic retinopathy was significantly associated with older age (per 1 year: odds ratio [OR], 1.12; 95% confidence interval [CI], 1.07-1.18), female gender (OR, 3.29; 95% CI, 1.09-9.92), and longer axial length (per 1 mm: OR, 4.20; 95% CI, 3.03-5.83).

CONCLUSIONS

The prevalence of myopic retinopathy was 1.7% in a general Japanese population. Older age, female gender, and longer axial length were significant risk factors for myopic retinopathy.

Ocular symptomatology, management, and clinical outcome of a giant intracranial aneurysm

Giant aneurysms of the anterior intracranial circulation are rare, slowly progressive vascular abnormalities, often presenting with neuro-ophthalmological symptoms before they rupture. This is a case of a 55-year-old woman with a double aneurysm of the anterior intracranial circulation, part of which was giant, diagnosed exclusively on the basis of ocular manifestations. We also describe successful management of the case throughout a long follow-up period.

Elderly patients with aneurysmal subarachnoid hemorrhage: Coils but also clips

The ageing of the population in good health or without severe morbidity expose them to the occurrence of a subarachnoid hemorrhage (SAH) and requires effective management. Currently, the pertinence of cerebral aneurysm treatment by clipping or coiling is accepted for patients in the 8th or 9th decade of life, and the risk of postoperative morbidity induced by our therapeutic alternative must be carefully assessed. In these decades, the female/male sex ratio for aneurysmal SAH was greater in female who had a 1.6 times higher ratio than in male. The initial clinical status did not appear worse with age despite the frequent severity of bleeding observed on CT scan probably due to the large subarachnoid space. The aneurysm distribution and size were similar to those classically reported in the global population. The endovascular (EV) coiling appears as the first option with a favorable outcome rate estimated at 48% to 63%. Nevertheless, the benefit of EV coiling compared to microsurgical clipping for treatment of ruptured aneurysm in the elderly has not been demonstrated in a large randomized study. This is the reason why the vascular section of the French Society of Neurosurgery developed a prospective and randomized study of the aneurysmal SAH (PHRC 2007-042/HP) on the elderly patients.

Management of incidentally discovered intracranial vascular abnormalities

With the widespread use of brain imaging studies, neurosurgeons have seen a marked increase in the number of incidental intracranial lesions, including vascular abnormalities. Specifically, the detection of incidentally discovered aneurysms, arteriovenous malformations, cavernous angiomas, developmental venous anomalies, and capillary telangiectasias has increased. The best management strategy for most of these lesions is controversial. Treatment options include observation, open surgery, endovascular procedures, and radiosurgery. Multiple factors should be taken into account when discussing treatment indications, including the natural history of the disease and the risk of the treatment. In this article, the authors focus on the natural history of these lesions and the risk of the treatment, and they give recommendations regarding the most appropriate management strategy based on the current evidence in the literature and their experience with intracranial vascular abnormalities.

Fatal subarachnoid hemorrhage during sexual anal self-stimulation in a female: a case report

Sudden death after sexual activity is a well-known entity, but it is rare in females. Herein we present a case of fatal, massive subarachnoid hemorrhage from a ruptured berry-shaped aneurysm, during sexual anal self-stimulation. A 39-year-old woman was found dead on a couch, with the wooden handle of a spring twirl whisk inserted inside her anus and rectum as a dildo-like object. External examination was unremarkable with no signs of injuries. Intracranial examination showed a massive subarachnoid hemorrhage, up to 6 mm in thickness, especially around the brainstem and the inferior side of the brain. After removing the blood clots, the saccular aneurysm was found at the site of the bifurcation of the left internal carotid. In this case study, we underline the utility of forensic autopsy, as well as death scene investigation, in reconstructing the mechanism of death, as well as the dynamics of the event.

What bone part is important to remove in accessing the suprachiasmatic region with less frontal lobe retraction in frontotemporal craniotomies

BACKGROUND

The anterolateral approach is one of the main routes for accessing suprachiasmatic lesions involving the anterior communicating artery (AComA) complex. Pterional (PT) craniotomy and its alternatives, including orbitozygomatic, orbitopterional, and mini-supraorbital craniotomies, have been developed as tailored frontotemporal craniotomies. One of the main differences between PT craniotomy and its alternatives is the removal of the orbital bone along with the sphenoid wing. However, which bone part is the most important to remove has not been discussed in relation to frontal lobe retraction. We have evaluated how the removal of the supraorbital bar versus the removal of the lateral orbital wall along with the sphenoid wing affects the relationship between the levels of frontal lobe retraction and area of exposure (AOE) in the suprachiasmatic region.

METHODS

We performed three types of craniotomies: PT craniotomy, PT craniotomy with the removal of the supraorbital bar (PT-SO craniotomy), and PT craniotomy with the removal of the lateral orbital wall along with the sphenoid wing, i.e., the frontal process of the zygomatic bone and the orbital and cerebral faces of the greater sphenoid wing (PT-LO-SW craniotomy). For each craniotomy, the AOE around the suprachiasmatic region was measured at four different levels of frontal lobe retraction, namely, 5, 10, 15, and 20 mm, from the cranial base.

RESULTS

At 5-mm retraction, PT-LO-SW craniotomy was the only craniotomy in which the AComA complex was visible. At 10-mm retraction, PT-LO-SW craniotomy afforded the greatest AOE among the three craniotomies, and the AOE was significantly greater than that of PT craniotomy (P = 0.025). At 15- and 20-mm retraction, there were no significant differences among the three craniotomies.

CONCLUSIONS

Treatment of lesions in the suprachiasmatic region via an anterolateral route involving a frontotemporal craniotomy requires sufficient removal of the lateral orbital wall along with the greater sphenoid wing so that brain retraction is minimized.

Intracranial aneurysms: optimized diagnostic tools call for thorough interdisciplinary treatment strategies

OBJECTIVE

Intracranial aneurysms (IAs) require deliberately selected treatment strategies as they are incrementally found prior to rupture and deleterious subarachnoid haemorrhage (SAH). Multiple and recurrent aneurysms necessitate both neurointerventionalists and neurosurgeons to optimize aneurysmal occlusion in an interdisciplinary effort. The present study was conducted to condense essential strategies from a single neurovascular centre with regard to the lessons learned.

METHOD

Medical charts of 321 consecutive patients treated for IAs at our centre from September 2008 until December 2010 were retrospectively analysed for clinical presentation of the aneurysms, multiplicity and treatment pathways. In addition, a selective Medline search was performed.

RESULTS

A total of 321 patients with 492 aneurysms underwent occlusion of their symptomatic aneurysm: 132 (41.1%) individuals were treated surgically, 189 (58.2%) interventionally; 138 patients presented with a SAH, of these 44.2% were clipped and 55.8% were coiled. Aneurysms of the middle cerebral artery were primarily occluded surgically (88), whereas most of the aneurysms of the internal carotid artery and anterior communicating artery (114) were treated endovascularly. Multiple aneurysms (range 2-5 aneurysms/individual) were diagnosed in 98 patients (30.2%). During the study period 12 patients with recurrent aneurysms were allocated to another treatment modality (previously clip to coil and vice versa).

CONCLUSIONS

Our data show that successful interdisciplinary occlusion of IAs is based on both neurosurgical and neurointerventional therapy. In particular, multiple and recurrent aneurysms require tailored individual approaches to aneurysmal occlusion. This is achieved by a consequent interdisciplinary pondering of the optimal strategy to occlude IAs in order to prevent SAH.

Prevalence of unruptured intracranial aneurysm on MR angiography

Objective

To evaluate the prevalence of incidentally found unruptured intracranial aneurysms (UIAs) on the brain MR angiography (MRA) from a community-based general hospital.

Materials and Methods

This was a prospectively collected retrospective study, carried out from January 2004 to December 2004. The subjects included 3049 persons from a community-based hospital in whom MRA was performed according to a standardized protocol in an outpatient setting. Age- and sex-specific prevalence of UIAs was calculated. The results by MRA were compared with intra-arterial digital subtraction angiography (DSA) findings.

Results

Unruptured intracranial aneurysms were found in 137 (5%) of the 3049 patients (M:F = 43:94; mean age, 60.2 years). The prevalence of UIAs was 5% (n = 94) in women and 4% (n = 43) in men, respectively (p = 0.2046) and showed no age-related increase. The most common site of aneurysm was at the distal internal carotid artery (n = 64, 39%), followed by the middle cerebral artery (n = 40, 24%). In total, 99% of aneurysms measured less than 12 mm, and 93% of aneurysms measured less than 7 mm. Direct comparisons between MRA and DSA were available in 70 patients with 83 UIAs; the results revealed two false positive and two false negative results.

Conclusion

This community-hospital based study suggested a higher prevalence of UIAs observed by MRA than previously reported. These findings should be anticipated in the design and use of neuroimaging in clinical practice.

Intracranial aneurysms: review of current treatment options and outcomes

Intracranial aneurysms are present in roughly 5% of the population, yet most are often asymptomatic and never detected. Development of an aneurysm typically occurs during adulthood, while formation and growth are associated with risk factors such as age, hypertension, pre-existing familial conditions, and smoking. Subarachnoid hemorrhage, the most common presentation due to aneurysm rupture, represents a serious medical condition often leading to severe neurological deficit or death. Recent technological advances in imaging modalities, along with increased understanding of natural history and prevalence of aneurysms, have increased detection of asymptomatic unruptured intracranial aneurysms (UIA). Studies reporting on the risk of rupture and outcomes have provided much insight, but the debate remains of how and when unruptured aneurysms should be managed. Treatment methods include two major intervention options: clipping of the aneurysm and endovascular methods such as coiling, stent-assisted coiling, and flow diversion stents. The studies reviewed here support the generalized notion that endovascular treatment of UIA provides a safe and effective alternative to surgical treatment. The risks associated with endovascular repair are lower and incur shorter hospital stays for appropriately selected patients. The endovascular treatment option should be considered based on factors such as aneurysm size, location, patient medical history, and operator experience.

Endovascular treatment for unruptured intracranial aneurysms in elderly patients: single-center report

BACKGROUND AND PURPOSE

The optimal management of patients with unruptured intracranial aneurysms remains controversial in elderly populations. The aim of this study was to evaluate technical results and clinical outcomes in a single center of consecutive elderly patients with unruptured intracranial aneurysms treated with endovascular embolization.

MATERIALS AND METHODS

Between May 2003 and February 2010, 96 patients older than 70 years (men, 16 patients; women, 80 patients; mean age, 73 years) with 122 saccular unruptured intracranial aneurysms were treated in our hospital with an endovascular approach. The endovascular procedures and technique, angiographic follow-up, and complications were evaluated.

RESULTS

Successful embolizations without complications were completed in 95.9%. Five patients had procedure-related events, including thromboembolism in 1 patient, aneurysm perforation during the procedure in 1, and 3 postoperative transient minor symptoms (headache, otalgia, and trigeminal pain) in 3. The degree of occlusion of the treated aneurysm was complete in 46.7%; there was a small neck remnant in 40.9% and residual filling in 12.2%. Imaging (MR angiography) follow-up was performed in 68.7% of the patients. The mean follow-up duration was 19.4 months (range, 5-57 months). Fifty-five patients (93.9%) showed no interval change of the residual neck. Four (6%) demonstrated recanalizations, all of which were successfully recoiled.

CONCLUSIONS

Endovascular treatment of unruptured intracranial aneurysms in patients older than 70 years of age appears to be safe. Favorable outcomes with low morbidities may replace surgery or conservative treatment as an active management alternative.

Branching pattern of middle cerebral artery in an African population

Branching pattern of middle cerebral artery influences frequency of its aneurysms, and is of potential value in their surgical repair and diagnosis of stroke. This pattern shows inter-population variations but there is paucity of data from Africans. This study aimed at describing branching pattern among black Kenyans. Middle cerebral arteries numbering 288 from 144 formalin fixed brains obtained during dissection and autopsy at Department of Human Anatomy, University of Nairobi, Kenya were studied. Origin of the middle cerebral artery was identified at base of brain and its stem followed by gently separating the fronto-parietal and temporal lobes. Pattern of early cortical, lenticulostriate, and terminal branching was recorded and macrographs taken. Results were analyzed using SPSS version 13.0 for windows and presented using macrographs. All the brains had bilateral middle cerebral arteries which were continuations of the internal carotid artery. Variations of the artery observed included duplication (1.7%), early bifurcation (5.2%), and early cortical branching (47%), predominantly temporal (63.9%). Lenticulostriate arteries arose predominantly from the pre-bifurcation segment as single branches (64.6%), and as common trunks (35.4%). Modes of termination were bifurcation (82.3%), trifurcation (10.8%), primary trunks (6.2%), and quadrifurcation (0.7%). Cortical branching pattern of the middle cerebral artery resembles that of Caucasian and Indian populations suggesting equal vulnerability to aneurysms and stroke. Pattern of origin of lenticulostriate arteries, predominantly from the pre-bifurcation segment and higher percentage of common trunks implies that the population is more prone to ischemia after aneurysm repair. Extra diligence during operation on proximal middle cerebral artery is called for.

Neuroform Stent-Assisted Embolization of Incidental Anterior Communicating Artery Aneurysms: Long-term Clinical and Angiographic Follow-up

BACKGROUND:

Anterior communicating artery (A-comm) aneurysm is one of the most common intracranial aneurysms. Treatments include neurosurgical clipping or endovascular embolization.

OBJECTIVE:

To retrospectively examine the long-term results of Neuroform stent-assisted coil embolization of incidental A-comms, with a focus on stent-associated stenosis, long-term angiographic aneurysm occlusion outcome, delayed stent-related thromboembolus, subsequent subarachnoid hemorrhage from the treated aneurysm, and procedural complications.

METHODS:

Between January 7, 2003 and June 16, 2009, 44 Neuroform stents were placed as an adjunct to embolization of A-comms. Patient charts were reviewed retrospectively. Angiographic follow-up of at least 3 months (up to 6.5 years, mean 65 weeks) was available for 33 patients. Aneurysm occlusion success was determined using the Raymond classification for aneurysm remnants.

RESULTS:

Referencing the last angiogram in the follow-up course, complete occlusion, dog-ear residual, residual neck, and residual aneurysm were found in 24, 2, 3, and 4 patients, respectively. Stenosis (45% and asymptomatic) of the artery where the stent had been placed was found in 1 patient. One patient had delayed transient ischemic attack after dual antiplatelet therapy was stopped prematurely. Retreatment based on the presence of residual aneurysm was performed or recommended in 2 patients. In 2 patients with residual or recurrent aneurysm filling, their age or clinical condition did not warrant retreatment.

CONCLUSION:

Neuroform stent-assisted embolization provides long-term control of A-comms with a low incidence of aneurysm growth after treatment. The need for retreatment is uncommon, and retreatment is safe if performed. Subsequent bleeding from treated aneurysms was not observed in this study.

Benefits of surgical treatment for unruptured intracranial aneurysms in elderly patients

OBJECTIVE

Due to longer life spans, patients newly diagnosed with unruptured intracranial aneurysms (UIAs) are increasing in number. This study aimed to evaluate how management of UIAs in patients age 65 years and older affects the clinical outcomes and post-procedural morbidity rates in these patients.

METHODS

We retrospectively reviewed 109 patients harboring 136 aneurysms across 12 years, between 1997 and 2009, at our institute. We obtained the following data from all patients : age, sex, location and size of the aneurysm(s), presence of symptoms, risk factors for stroke, treatment modality, and postoperative 1-year morbidity and mortality. We classified these patients into three groups : Group A (surgical clipping), Group B (coil embolization), and Group C (observation only).

RESULTS

Among the 109 patients, 56 (51.4%) underwent clipping treatment, 25 (23%) patients were treated with coiling, and 28 observation only. The overall morbidity and mortality rates were 2.46% and 0%, respectively. The morbidity rate was 1.78% for clipping and 4% for coiling. Factors such as hypertension, diabetes mellitus, hypercholesterolemia, smoking, and family history of stroke were correlated with unfavorable outcomes. Two in the observation group refused follow-up and died of intracranial ruptured aneurysms. The observation group had a 7% mortality rate.

CONCLUSION

Our results show acceptable favorable outcome of treatment-related morbidity comparing with the natural history of unruptured cerebral aneurysm. Surgical clipping did not lead to inferior outcomes in our study, although coil embolization is generally more popular for treating elderly patients. In the treatment of patients more than 65 years old, age is not the limiting factor.

Echocardiogram-gated computed tomographic and magnetic resonance angiographies for the detection of pulsatile expansion at the intracranial arterial bifurcation

OBJECTIVE

To identify the pulsatile small vascular lesion by echocardiogram (ECG)-gated computed tomographic (CT) and magnetic resonance (MR) angiographies.

METHODS

Seven patients who exhibited small evagination at the cerebral artery bifurcations on 3-dimensional (3D) time-of-flight MR angiogram were enrolled. They were examined by conventional/ECG-gated CT angiogram (n = 6) and ECG-gated MR angiogram (n = 5). Echocardiogram-gated MR angiogram was performed with 3D time of flight, triggered after each time window. From ECG-gated CT and MR angiograms, consecutive 10-phase images within a single cardiac cycle were obtained.

RESULTS

The pulsatile change of evagination was demonstrated on both ECG-gated CT angiogram (5 of 6 patients) and ECG-gated MR angiogram (all 5 patients). Flattening of the evagination during the diastolic phase was observed in 4 of 6 ECG-gated CT angiograms and 3 of 5 ECG-gated MR angiograms. Of note was a patient with a tiny evagination (<2 × 1 mm); pulsatile change was demonstrated only by ECG-gated MR angiogram.

CONCLUSION

The pulsatile expansion of evagination at the cerebral artery bifurcation can be demonstrated on ECG-gated CT/MR angiograms.

Cognitive function and anxiety before and after surgery for asymptomatic unruptured intracranial aneurysms in elderly patients

BACKGROUND

The prevalence of patients with asymptomatic unruptured intracranial aneurysms (UIAs) will likely increase as the general population ages. The goal of the present study was to prospectively assess cognitive function and anxiety before and after surgical repair of asymptomatic UIAs in patients ≥ 70 years.

METHODS

A total of 28 patients ≥ 70 years with UIAs underwent cognitive testing using the Wechsler Adult Intelligence Scale-Revised, Wechsler Memory Scale (WMS), and the Rey-Osterrieth Complex Figure test (ROCF) 1 month before and 1 month after surgery. All patients also underwent anxiety testing at these time points using the State-Trait Anxiety Inventory.

RESULTS

Group-rate analysis demonstrated that the performance intelligence quotient (IQ) and ROCF recall trial scores were significantly increased postoperatively, whereas there were no postoperative differences in verbal IQ, WMS, and ROCF copy trial scores. State anxiety scores were significantly decreased postoperatively, but there was no change in trait anxiety scores. Furthermore, a significant negative correlation was observed between changes in state anxiety scores and preoperative verbal IQ, performance IQ, and WMS. None of the patients developed postoperative cognitive functional impairments as demonstrated by event-rate analysis.

CONCLUSIONS

Surgical treatment of UIAs does not impair cognitive function and results in improvement in state anxiety in elderly patients.

Genome-wide association study of intracranial aneurysm identifies three new risk loci

Saccular intracranial aneurysms (IAs) are balloon-like dilations of the intracranial arterial wall; their hemorrhage commonly results in severe neurologic impairment and death. We report a second genome-wide association study with discovery and replication cohorts from Europe and Japan comprising 5,891 cases and 14,181 controls with ∼832,000 genotyped and imputed SNPs across discovery cohorts. We identified three new loci showing strong evidence for association with IA in the combined data set, including intervals near RBBP8 on 18q11.2 (OR=1.22, P=1.1×10^-12), STARD13/KL on 13q13.1 (OR=1.20, P=2.5×10^-9) and a gene-rich region on 10q24.32 (OR=1.29, P=1.2×10^-9). We also confirmed prior associations near SOX17 (8q11.23-q12.1; OR=1.28, P=1.3×10^-12) and CDKN2A/B (9p21.3; OR=1.31, P=1.5×10^-22). It is noteworthy that several putative risk genes play a role in cell-cycle progression, potentially affecting proliferation and senescence of progenitor cell populations that are responsible for vascular formation and repair.

Incidence and risk factors for multiple intracranial saccular aneurysms in patients with subarachnoid hemorrhage in Izumo City, Japan

BACKGROUND

A community-based study was conducted to estimate the incidence rates of multiple aneurysms and to investigate the factors related to multiplicity.

METHOD

The subjects were 291 patients with ruptured saccular aneurysms treated between 1980 and 1998, in Izumo, Japan. There were 403 aneurysms in total, and 78 patients (27%) had multiple aneurysms.

FINDINGS

Both the crude and the age- and sex-adjusted annual incidence rates per 100,000 population for multiple and single aneurysms were five and 14 for all ages, respectively, and were higher in women than in men. The age-specific incidence rates of both multiple and single aneurysms showed a tendency to increase with age. Of the 190 patients who underwent four-vessel studies, 26% (49) had multiple aneurysms. The frequencies of multiple aneurysms in patients with ruptured aneurysms > or =10 and <10 mm in diameter were 41% and 21%, respectively (p = 0.0081). In patients with multiple aneurysms, the number of aneurysms was greater in those with large ruptured aneurysms, and the unruptured aneurysms tended to be larger in patients with large ruptured aneurysms. The size of the ruptured aneurysms was positively associated with multiplicity, whereas hypertension had an inverse association. Age, sex, aneurysm site and risk factors other than hypertension were not predictive.

CONCLUSIONS

This study is the first to provide annual incidence rates for multiple aneurysms in a defined population. It appears that multiplicity of aneurysms is associated with larger ruptured aneurysms and that patients with larger ruptured aneurysms have a higher number of aneurysms as well as larger unruptured aneurysms.

Polymorphism rs42524 of COL1A2 and sporadic intracranial aneurysms in the Chinese population

Object

The COL1A2 gene at 7q22.1 has been shown to be associated with familial intracranial aneurysms (IAs) in the Japanese population. In the present study, the authors investigated the correlation between the presence of the rs42524 polymorphism in COL1A2 and the occurrence of sporadic IAs in Chinese patients.

Methods

The polymorphism rs42524 of the COL1A2 gene was identified by polymerase chain reaction–based restriction analysis in genomic DNA from 226 patients with sporadic IAs (mean age 51.49 ± 11.47 years) and 326 control participants (mean age 52.33 ± 10.50 years). Neurological assessments were performed using the Hunt and Hess grading system, and differences in allelic and genotypic frequencies between the patient and control groups were evaluated with the chi-square test.

Results

There was a significant difference in either the genotype distribution (χ2 = 11.99, p = 0.002) or allelic frequencies (χ2 = 11.96, p = 0.001, odds ratio 2.579, 95% confidence interval 1.486–4.476) between patients with IAs and patients in the control group.

Conclusions

The rs42524 polymorphism of COL1A2 could be a genetic risk factor for sporadic IAs among individuals of Chinese Han ethnicity. This study is the first to confirm the association between COL1A2 and IAs.

The influence of genetics on intracranial aneurysm formation and rupture: current knowledge and its possible impact on future treatment

The etiology of intracranial aneurysm formation and rupture remains mostly unknown, but lately several studies have increasingly supported the role of genetic factors. In reports so far, genome-wide linkage studies suggest several susceptibility loci that may contain one or more predisposing genes. Depending on the examined ethnic population, several different non-matching chromosomal regions have been found. Studies of several candidate genes report association with intracranial aneurysms. To date, no single gene has been identified as responsible for intracranial aneurysm formation or rupture. In addition to the well-published environmental factors, such as alcohol intake, hypertension and smoking, only the recent progress in molecular genetics enables us to investigate the possible genetic determinants of this disease. Although a familial predisposition is the strongest risk factor for the development of intracranial aneurysms, the mode of Mendelian inheritance is uncertain in most families. Therefore, multiple genetic susceptibilities in conjunction with the environmental factors are considered to act together in the disease's etiology. Accordingly, researchers performed linkage studies and case-control association studies for the genetic analysis and have identified several genes to be susceptible to intracranial aneurysms. The identification of susceptible genes may lead to the understanding of the mechanism of formation and rupture and possibly lead to the development of a pharmacological therapy. Furthermore, should it be possible to identify a genetic marker associated with an increased risk of formation and rupture of an intracranial aneurysm, the necessity for screening and urgency of treatment could be determined more easily. In this review we summarize the current knowledge of intracranial aneurysm genetics and also discuss the method to detect the causalities. In view of the recent advances made in this field, we also give an outlook on possible future genetically engineered therapies, whose development are well underway.

Endothelial injury and inflammatory response induced by hemodynamic changes preceding intracranial aneurysm formation: experimental study in rats

OBJECT

Intracranial aneurysms are the leading cause of subarachnoid hemorrhage, which is associated with high morbidity and mortality rates. Despite advances in the microsurgical and endovascular treatment of intracranial aneurysms, little is known about the mechanisms by which they originate, grow, and rupture. To clarify the series of early events leading to formation of intracranial aneurysms, the authors compared aneurysmal morphological changes on vascular corrosion casts with parallel pathological changes in the cerebral arteries of rats.

METHODS

The authors induced cerebral aneurysms by renal hypertension and right common carotid artery ligation in 40 male Sprague-Dawley rats; 10 intact rats served as the controls. The anterior cerebral artery-olfactory artery bifurcation was assessed morphologically by using vascular corrosion casts of Batson plastic reagent and immunohistochemically by using antibodies against endothelial nitric oxide synthase, alpha-smooth muscle actin, macrophages, and matrix metalloproteinase-9.

RESULTS

Surgically treated rats manifested different degrees of aneurysmal changes. Based on these staged changes, the authors propose that the formation of intracranial aneurysms starts with endothelial injury at the apical intimal pad (Stage I); this leads to the formation of an inflammatory zone (Stage II), followed by a partial tear or defect in the inflammatory zone. Expansion of this defect forms the nidus of the intracranial aneurysm (Stage III).

CONCLUSIONS

This is the first study to demonstrate the in vivo mechanisms of intracranial aneurysm formation. The inflammatory response that follows endothelial injury is the basic step in the pathogenesis of these lesions. In this study the investigators have expanded the understanding of the origin of intracranial aneurysms and have contributed to the further development of measures to prevent and treat aneurysms.

Prehypertension increases the risk for renal arteriosclerosis in autopsies: the Hisayama Study

Information regarding the association between prehypertension BP level and renal arteriosclerosis is limited. In 652 consecutive population-based autopsy samples without hypertension treatment before death, the relationship between the severity of renal arteriosclerosis and BP levels classified according to the criteria of the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure was examined. The age- and gender-adjusted frequencies of renal arteriosclerosis linearly increased with elevating BP levels; both hypertensive and prehypertensive subjects had significantly higher frequencies of renal arteriosclerosis than subjects with normal BP (normal 11.9%; prehypertension 28.5%; stage 1 hypertension 32.9%; stage 2 hypertension 58.2%; all P < 0.01 versus normal). In a logistic regression model, prehypertension was significantly associated with renal arteriosclerosis after adjustment for other cardiovascular risk factors (prehypertension multivariate-adjusted odds ratio [mOR] 5.99 [95% confidence interval (CI) 2.20 to 15.97]; stage 1 hypertension mOR 6.99 [95% CI 2.61 to 18.72]; stage 2 hypertension mOR 22.21 [95% CI 8.35 to 59.08]). This significant association was observed for all renal arterial sizes. The similar association was also observed for arteriolar hyalinosis. When the subjects were divided into those with and those without target organ damage, the impact of prehypertension on renal arteriosclerosis was similar for both groups (subjects without target organ damage mOR 5.04 [95% CI 1.36 to 18.62]; subjects with target organ damage mOR 6.42 [95% CI 1.29 to 32.04]). These findings suggest that both hypertension and prehypertension are associated significantly with the severity of renal arteriosclerosis, regardless of the presence or absence of target organ damage.

Intracranial infectious aneurysm: presentation, management and outcome

BACKGROUND

Intracranial infectious aneurysms (IA) are infrequent, but can be fatal.

OBJECTIVES

To compare the clinical profile of IAs associated with intravascular/systemic infection like infective endocarditis with that associated with local infections like meningitis, orbital cellulitis and cavernous sinus thrombosis.

METHODS

We analysed all cases of IA, treated in this Institute from 1976 to 2003, in order to identify prognostic factors.

RESULTS

There were 25 persons (mean age 24.8+/-17.3 years, males 17) with 29 IA (carotid circulation 19, vertebrobasilar circulation 10). Headache (83%) and fever (67%) were the most common presenting symptoms. In contrast to noninfectious aneurysms, intracerebral haemorrhage (60%) and focal signs were more common than subarachnoid haemorrhage (7%) with IA. Sources of infection were cardiac (10), meningitis (12), orbital cellulitis (2) or uncertain (1). Infective agents included bacteria (18), fungi (4), and tubercle bacilli (3). Fifteen IA were distal and 14 were proximal. IAs associated with meningitis were proximal (75%) while those associated with cardiac diseases preferentially involved carotid territory and were distal (p=0.013). The overall mortality was 32%. Survivors were younger than those who expired (p=0.015). Of the sixteen patients treated medically, seven recovered (44%), others (56%) had treatment failure (three died and six required surgery later). Another five patients underwent early surgery (one died). Mortality of IA was significantly higher with meningitis, fungal aetiology and vertebrobasilar location.

CONCLUSIONS

IAs associated with local infections like meningitis had different clinical profile as compared to IAs associated with intravascular/systemic infections like infective endocarditis.

Causes of sudden death related to sexual activity: results of a medicolegal postmortem study from 2001 to 2005

Sexual activity (SA), combined with organic heart disease, may cause sudden death (SD). However, the causes of SD related to SA are not known well. The aim of this study was to assess the causes of SD related to SA. From August 2001 to November 2005, all autopsies (n=1,379) performed at Kyungpook National University were prospectively searched for SD cases related to SA. Fourteen cases (46+/-11 yr old, 9 males) of SD related to SA were found. All were heterosexual. The toxicologic study was negative in all. Ten cases were witnessed; during SA in 4 cases, just after SA in another 4 cases, 2 and 5 hr after in 1 each case. In 4 unwitnessed cases the victims were found dead less than 12 hr from the end of their SA. The partners were steady extramarital partners (n=8), prostitutes (n=2), marital partner (n=1) and unknown (n=3). The causes of the SD were as follows; coronary artery disease in 6, subarachnoid hemorrhage with ruptured berry aneurysm in 4, fibromuscular dysplasia of the atrioventricular nodal artery in 2, and unknown in 2. Coronary artery disease and subarachnoid hemorrhage with ruptured berry aneurysm were important as causes of SD related to SA.

The genetics of intracranial aneurysms

The rupture of an intracranial aneurysm (IA) leads to a subarachnoid hemorrhage, a sudden onset disease that can lead to severe disability and death. Several risk factors such as smoking, hypertension and excessive alcohol intake are associated with subarachnoid hemorrhage. IAs, ruptured or unruptured, can be treated either surgically via a craniotomy (through an opening in the skull) or endovascularly by placing coils through a catheter in the femoral artery. Even though the etiology of IA formation is mostly unknown, several studies support a certain role of genetic factors. In reports so far, genome-wide linkage studies suggest several susceptibility loci that may contain one or more predisposing genes. Studies of several candidate genes report association with IAs. To date, no single gene has been identified as responsible for IA formation or rupture. The identification of susceptible genes may lead to the understanding of the mechanism of formation and rupture and possibly lead to the development of a pharmacological therapy.

A haplotype spanning two genes, ELN and LIMK1, decreases their transcripts and confers susceptibility to intracranial aneurysms

The rupture of an intracranial aneurysm (IA) results in subarachnoid hemorrhage, a catastrophic neurological condition with high morbidity and mortality. Following-up on our previous genome-wide linkage study in Japanese population, we extensively analyzed a 4.6 Mb linkage region around D7S2472 on 7q11 by genotyping 168 single nucleotide polymorphisms (SNPs). SNP association and window scan haplotype-based association studies revealed a susceptibility locus for IA on a single LD block covering the 3'-untranslated region (3'-UTR) of ELN and the entire region of LIMK1. An association study with 404 IA patients and 458 non-IA controls revealed that the ELN 3'-UTR G(+659)C SNP has the strongest association to IA (P=0.000002) and constitutes a tag-SNP for an at-risk haplotype, which contains two functional SNPs, the ELN 3'-UTR (+502) A insertion and the LIMK1 promoter C(-187)T SNP. These allelic and haplotype-based associations were confirmed in a Korean population. Ex vivo and in vitro analyses demonstrate that the functional impact of both SNPs is the decrease of transcript levels, either through accelerated ELN mRNA degradation or through decreased LIMK1 promoter activity. Elastin and LIMK1 protein are involved in the same actin depolymerization signaling pathway; therefore, these lines of evidence suggest a combined effect of the SNPs in the at-risk haplotype possibly by weakening the vascular wall and promoting the development of IA.

Quantitative anatomic study of three surgical approaches to the anterior communicating artery complex

OBJECTIVE

To compare the angles of approach and area of exposure to the anterior communicating artery (AComA) complex associated with pterional (PT), orbitopterional (OPT), and orbitozygomatic (OZ) craniotomies before and after gyrus rectus resection.

METHODS

PT, OPT, and OZ craniotomies were performed on both sides of four heads, and the angles of approach and area of exposure to the AComA complex were measured before and after resection of the gyrus rectus.

RESULTS

The vertical angle of approach increased significantly among the PT and OPT (P = 0.001), PT and OZ (P = 0.001), and OPT and OZ approaches (P = 0.005). The horizontal angle of approach was significantly larger between the PT to OPT (P = 0.001) and PT to OZ (P = 0.001) approaches but not between the OPT and OZ approaches (P = 0.757). After gyrus rectus resection, the vertical and horizontal angles of approach increased significantly for the PT approach but not for the OPT and OZ approaches. The area of exposure to the AComA complex increased progressively from the PT to OPT to OZ approach but did not reach statistical significance (P = 0.124). Resection of the gyrus rectus resulted in significant relative gains in the area of exposure for the PT (P = 0.01) and OPT (P = 0.04) approaches but not for the OZ approach (P = 0.88).

CONCLUSION

The vertical and horizontal angles of approach to the AComA complex are significantly larger for the OPT and OZ approaches compared with the PT approach. Use of the OZ approach may decrease the need for frontal lobe retraction and resection of the gyrus rectus.

Higher Burden of Hemorrhagic Stroke among Women

The aim of this study was to verify the gender difference in sudden cardiovascular death, mainly comparing brain infarction and hemorrhagic stroke. We analyzed 970 autopsy cases from a total of 3,802 nonviolent deaths (448 considered as sudden deaths, 296 undetermined, and 226 non-sudden deaths) including patients aged 30-69 years. All cardiovascular diseases were responsible for 69% of sudden deaths, and all types of stroke for only 14%. The proportions of sudden death for all cardiovascular diseases, coronary heart disease and ischemic stroke deaths were similar for both sexes. However, sudden deaths due to all types of stroke (women 20.0%; men 11.1%; p = 0.012) and hemorrhagic stroke (women 15.6%; men 7.9%; p = 0.019) were significantly more frequent among women when compared to men, the main cause being subarachnoid hemorrhage (women 5.6%; men 1.0%; p = 0.011). Hemorrhagic stroke deaths were usually sudden deaths among women.

Stroke subtypes and lesion sites in Akita, Japan

Stroke patients who underwent computed tomography (CT) were enrolled in a stroke registry in Akita, Japan, which comprised 7288 first-ever stroke cases during 1999 to 2001. Differences in age and sex were evaluated with respect to type-specific incidences and lesion sites. The incidence increased with age, except for subarachnoid hemorrhage (SAH) in men after age 40. The incidence of intracerebral hemorrhage (IH) and cerebral infarction (CI) was higher in men than in women, whereas that for SAH was lower. The mean age of putaminal hemorrhage was lower than that of thalamic hemorrhage, and the mean age of cortical infarction was higher than that of CI in perforator regions, the cerebellum, and the pons. In subjects age 70 years and older, the proportion of thalamic hemorrhage in IH was larger in women than in men; for those age 50 years and older, the proportion of cortical infarction in CI was larger in men than in women. The proportions of anterior communicating artery aneurysms in men and internal carotid artery aneurysms in women were largest in SAH for all age groups. In conclusion, thalamic hemorrhage was most common in elderly women and cortical infarction was most common in middle-aged and elderly men. The feature of SAH occurring at a higher incidence in women than in men, with a sexual difference in aneurysmal distribution, was also observed.