Does frequent use of an exoskeletal upper limb robot improve motor function in stroke patients?

PURPOSE: To determine how differences in frequency of the single-joint hybrid assistive limb (HAL-SJ) use affect the improvement of upper limb motor function and activities of daily living (ADL) in stroke patients. MATERIALS AND METHODS: Subacute stroke patients were divided into the high or low frequency of HAL-SJ use groups. The two groups were matched by propensity score, and the degree of changes 30 days after initiating HAL-SJ use was compared. A logistic regression analysis was performed to examine whether frequent use would increase the number of subjects experiencing the efficacy of more than the minimal clinically important difference (MCID) of Fugl-Meyer assessment (FMA). RESULTS: Twenty-five stroke patients were matched by propensity score, and nine pairs were matched. The high-frequency group showed a significantly superior increase to total FMA shoulder, elbow, forearm, and Barthel index compared with the low-frequency group. Logistic regression analysis revealed no significant associations between frequent use and MCID. CONCLUSIONS: The frequency of HAL-SJ use may affect the improvement of motor function and ADL ability of the upper limb with exception of the fingers and wrist. However, the frequency of intervention was not effective enough to further increase the number of subjects with clinically meaningful changes in upper limb motor function.IMPLICATIONS FOR REHABILITATIONThe current study aimed to clarify how differences in the frequency of single-joint hybrid assistive limb (HAL-SJ) use can affect the improvement of upper-limb motor functions and ADL in subacute stroke patients.Our results implied that the frequency of HAL-SJ use may influence the recovery of upper limb function.However, even if HAL-SJ is used frequently, it does not mean that more patients will achieve clinically meaningful recovery.

Early Initiation of Exoskeletal Robotic Gait Training Improves Functional Outcomes in the Patients with Stroke: A Retrospective Observational Study.

INTRODUCTION: The effect of early initiation of gait training using hybrid assistive limb (HAL) remains unclear. This observational study aimed to investigate whether early initiation of gait training using HAL improves functional outcomes in patients with stroke. METHODS: We retrospectively analyzed patients with acute stroke admitted to our facility. HAL was used for exoskeletal robotic gait training. Study participants were median split into an early group and a late group based on the days from stroke onset to initiation of gait training using HAL. The functional outcomes, defined by the Brunnstrom recovery stage (BRS), modified Rankin Scale (mRS), and Functional Independence Measure (FIM) at discharge, were compared using propensity score-matched analysis. RESULTS: We performed a propensity score-matched analysis in 63 patients with stroke (31 from the early group and 32 from the late group), and 17 pairs were matched. There were no significant differences in discharge in the BRS of the upper limb and finger in the post-matched cohort. On the other hand, the BRS of the lower limb in the early group was significantly higher than that in the late group. In addition, the mRS, but not FIM scores, was significantly better in the early group than that in the late group. CONCLUSIONS: In conclusion, early initiation of gait training using HAL might improve the motor function of the paralyzed lower limb and disability in patients with stroke.

Recent Declining Trend of Incidence Rate of Subarachnoid Hemorrhage in Shimane, Japan: The Japan Incidence of Subarachnoid Hemorrhage (JIS) Study.

The "Izumo Study" revealed the incidence rate of subarachnoid hemorrhage (SAH) in Izumo City, Shimane Prefecture, Japan, from 1980 to 1998. However, no study has been published regarding the incidence of SAH in Shimane Prefecture after 1998. Most studies reporting the incidence of SAH in Japan have been conducted before 2000, although a few have been reported after 2000. This study aimed to assess the estimated age-adjusted incidence rate (AAIR) of SAH in Shimane Prefecture after 1998, following the Izumo Study. A retrospective study was conducted to identify the estimated AAIR of SAH in Shimane Prefecture, using the age-adjusted SAH mortality rate for this population from 1999 to 2017 and assuming that the case-fatality rate of SAH decreased by 0.7% annually from 45% in 1999 to 32.4% in 2017. We used linear regression analysis for trend to the estimated AAIR of SAH. Sensitivity analyses were also conducted by various case-fatality rates of SAH using assuming case-fatality rate based on previous reports. The estimated AAIR of SAH in Shimane Prefecture declined from 33.6 (95% confidence interval [CI]: 29.7-37.9) per 100,000 person-years in 1999, by 26.5%, to 24.7 (95% CI: 21.4-28.5) in 2017 (p < 0.01, r = 0.58). Declining trend of incidence rate of SAH in Shimane Prefecture from 1999 to 2017 was confirmed in this study.

Clinical Prediction Rule for Identifying the Stroke Patients who will Obtain Clinically Important Improvement of Upper Limb Motor Function by Robot-Assisted Upper Limb.

BACKGROUND: The number of studies on the characteristics of patients with stroke who would benefit from robot-assisted upper limb rehabilitation is limited, and there are no clear criteria for determining which individuals should receive such treatment. The current study aimed to develop a clinical prediction rule using machine learning to identify the characteristics of patients with stroke who can the achieve minimal clinically important difference of the Fugl-Meyer Upper Extremity Evaluation (FMA-UE) after single-joint hybrid assistive limb (HAL-SJ) rehabilitation. METHODS: This study included 71 patients with subacute stroke who received HAL-SJ rehabilitation. The chi-square automatic interaction detector (CHAID) model was applied to predict improvement in upper limb motor function. Based the analysis using CHAID, age, sex, days from stroke onset to the initiation of HAL-SJ rehabilitation, and upper limb motor and cognitive functions were used as independent variables. Improvement in upper limb motor function was determined based on the minimal clinically important difference of the FMA-UE, which was used as a dependent variable. RESULTS: According to the CHAID model, the FMA-UE score during the initiation of HAL-SJ rehabilitation was the most significant predictive factor for patients who are likely to respond to the intervention. Interestingly, this therapy was more effective in patients with moderate upper limb motor dysfunction and early initiation of HAL-SJ rehabilitation. The accuracy of the CHAID model was 0.89 (95% confidence interval: 0.81-0.96). CONCLUSION: We developed a clinical prediction rule for identifying the characteristics of patients with stroke whose upper limb motor function can improve with HAL-SJ rehabilitation.

Prevalence of cerebral aneurysms in autopsy studies: a review of the literature.

Cerebral aneurysms (CAs) are one of the most important causes of stroke, but details of their prevalence remain under-researched. Autopsy data for CAs were reviewed using standard search engines. Based on previously published autopsy and clinical studies, the prevalence of CAs with respect to age, gender, and aneurysm site, size, and multiplicity was investigated, and the natural course of CA prevalence was estimated. In autopsy studies, the prevalence of CAs across all age groups was 0.3-4.0% for unruptured cerebral aneurysms (UCAs) and 1.3-7.6% for CAs including UCAs and ruptured cerebral aneurysms (RCAs). Patients with UCAs were generally older than those with RCAs. Middle cerebral artery aneurysms were more predominant in autopsy studies than in clinical studies. UCAs tended to be smaller than RCAs, and minute UCAs (< 2 mm), diagnosed microscopically at autopsy and thought to be in the very early stages of formation, were present in 10-20% of the general population. Taking into consideration the clinical data for UCAs and RCAs, 10% of minute UCAs enlarge to major UCAs (≥ 2 mm) detectable by conventional imaging techniques, and 10% of major UCAs eventually rupture within 10 years. The high prevalence of UCAs and RCAs in the elderly and women can be attributed to the more frequent occurrence of minute UCAs in these populations. Minute UCAs occur at a high rate, but only a few enlarge to become major UCAs and rupture. Further advances in diagnostic technology are essential for revealing the true natural course of CA prevalence.

Comparison of Supervised Machine Learning Algorithms for Classifying of Home Discharge Possibility in Convalescent Stroke Patients: A Secondary Analysis.

OBJECTIVES: Classifying the possibility of home discharge is important during stroke rehabilitation to support decision-making. There have been several studies on supervised machine learning algorithms, but only a few have compared the performance of different algorithms based on the same dataset for the classification of home discharge possibility. Therefore, we aimed to evaluate five supervised machine learning algorithms for the classification of home discharge possibility in stroke patients. MATERIALS AND METHODS: This was a secondary analysis based on the data of 481 stroke patients from the database of our institution. Five models developed by supervised machine learning algorithms, including decision tree (DT), linear discriminant analysis (LDA), k-nearest neighbors (k-NN), support vector machine (SVM), and random forest (RF) were compared by constructing a classification system based on the same dataset. Several parameters including classification accuracy, area under the curve (AUC), and F1 score (a weighted average of precision and recall) were used for model evaluation. RESULTS: The k-NN model had the best classification accuracy (84.0%) with a moderate AUC (0.88) and F1 score (87.8). The SVM model also showed high classification accuracy (82.6%) along with the highest AUC (0.91), sensitivity (94.4), negative predictive value (87.5), and negative likelihood ratio (0.088). The DT, LDA, and RF models had high classification accuracies (≥ 79.9%) with moderate AUCs (≥ 0.84) and F1 scores (≥ 83.8). CONCLUSIONS: Regarding model performance, the k-NN and SVM seemed the best candidate algorithms for classifying the possibility of home discharge in stroke patients.

Machine Learning Algorithm Identifies the Importance of Environmental Factors for Hospital Discharge to Home of Stroke Patients using Wheelchair after Discharge.

BACKGROUND AND PURPOSE: Physical environmental factors are generally likely to become barriers for discharge to home of wheelchair users, compared with non-wheelchair users. However, the importance of environmental factors has not been investigated adequately. Application of machine learning technology might efficiently identify the most influential factors, although it is not easy to interpret and integrate various information including individual and environmental factors in clinical stroke rehabilitation. This study aimed to identify the influential factors affecting home discharge in the stroke patients who use a wheelchair after discharge by using machine learning technology. METHODS: This study used the rehabilitation database of our facility, which includes all stroke patients admitted into the convalescence rehabilitation ward. The chi-squared automatic interaction detection (CHAID) algorithm was used to develop a model to classify wheelchair-using stroke patients discharged to home or not-to-home. RESULTS: Among the variables, including basic information, motor functional factor, activities of daily living ability factor, and environmental factors, the CHAID model identified house renovation and the existence of sloping roads around the house as the first and second discriminators for home discharge. CONCLUSIONS: Our present results could scientifically clarify that the clinician need to focus on the physical environmental factors for achieving home discharge in the patients who use a wheelchair after discharge.

Decision Tree Algorithm Identifies Stroke Patients Likely Discharge Home After Rehabilitation Using Functional and Environmental Predictors.

BACKGROUND AND PURPOSE: The importance of environmental factors for stroke patients to achieve home discharge was not scientifically proven. There are limited studies on the application of the decision tree algorithm with various functional and environmental variables to identify stroke patients with a high possibility of home discharge. The present study aimed to identify the factors, including functional and environmental factors, affecting home discharge after stroke inpatient rehabilitation using the machine learning method. METHOD: This was a cohort study on data from the maintained database of all patients with stroke who were admitted to the convalescence rehabilitation ward of our facility. In total, 1125 stroke patients were investigated. We developed three classification and regression tree (CART) models to identify the possibility of home discharge after inpatient rehabilitation. RESULTS: Among three models, CART model incorporating basic information, functional factor, and environmental factor variables achieved the highest accuracy for identification of home discharge. This model identified FIM dressing of the upper body (score of ≤2 or >2) as the first single discriminator for home discharge. Performing house renovation was associated with a high possibility of home discharge even in patients with stroke who had a poor FIM score in the ability to dress the upper body (≤2) at admission into the convalescence rehabilitation ward. Interestingly, many patients who performed house renovation have achieved home discharge regardless of the degree of lower limb paralysis. CONCLUSION: We identified the influential factors for realizing home discharge using the decision tree algorithm, including environmental factors, in patients with convalescent stroke.

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

BACKGROUND: The etiology and background factors which cause decreases in the size of ruptured intracranial aneurysms remain unclear. OBJECTIVE: To clarify the age- and sex-related differences in aneurysmal subarachnoid hemorrhage (SAH) based on a 35-year-old hospital database and demographic data. METHODS: A 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. RESULTS: Altogether, 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. CONCLUSION: We 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.

Development and Validation of Machine Learning-Based Prediction for Dependence in the Activities of Daily Living after Stroke Inpatient Rehabilitation: A Decision-Tree Analysis.

BACKGROUND AND PURPOSE: Accurate prediction using simple and changeable variables is clinically meaningful because some known-predictors, such as stroke severity and patients age cannot be modified with rehabilitative treatment. There are limited clinical prediction rules (CPRs) that have been established using only changeable variables to predict the activities of daily living (ADL) dependence of stroke patients. This study aimed to develop and assess the CPRs using machine learning-based methods to identify ADL dependence in stroke patients. METHODS: In total, 1125 stroke patients were investigated. We used a maintained database of all stroke patients who were admitted to the convalescence rehabilitation ward of our facility. The classification and regression tree (CART) methodology with only the FIM subscores was used to predict the ADL dependence. RESULTS: The CART method identified FIM transfer (bed, chair, and wheelchair) (score ≤ 4.0 or > 4.0) as the best single discriminator for ADL dependence. Among those with FIM transfer (bed, chair, and wheelchair) score > 4.0, the next best predictor was FIM bathing (score ≤ 2.0 or > 2.0). Among those with FIM transfer (bed, chair, and wheelchair) score ≤ 4.0, the next predictor was FIM transfer toilet (score ≤ 3 or > 3). The accuracy of the CART model was 0.830 (95% confidence interval, 0.804-0.856). CONCLUSION: Machine learning-based CPRs with moderate predictive ability for the identification of ADL dependence in the stroke patients were developed.

Combination of Exoskeletal Upper Limb Robot and Occupational Therapy Improve Activities of Daily Living Function in Acute Stroke Patients.

PURPOSE: Previous studies have suggested that upper limb rehabilitation using therapeutic robots improves motor function of stroke patients. However, the effect of upper limb robotic rehabilitation on improving functioning in activities of daily living (ADL) remains unclear. The present study aimed to determine whether upper limb rehabilitation using single joint Hybrid Assistive Limb (HAL-SJ) affects ADL function and the use of a hemiparetic arm in ADLs of acute stroke patients. MATERIALS AND METHODS: Twelve acute stroke patients participated in the study and were randomly divided into group A or group B. The patients in group A followed an A-B-A-B design and those in group B followed a B-A-B-A design. The patients received combination HAL-SJ and occupational therapy during A and conventional occupational therapy during B. RESULTS: Upper limb motor function and ADLs, in particular, dressing the upper body, were improved during combination HAL-SJ and occupational therapy. Interestingly, the use of a hemiparetic arm in daily life evaluated using the motor activity log was also significantly improved during A in group A. CONCLUSIONS: Combination HAL-SJ and occupational therapy affects ADL function and real use of a hemiparetic arm in the daily life of acute stroke patients.

A Comparison of Computed Tomography-Based Scales with and without Consideration of the Presence or Absence of Intraventricular Hemorrhage in Patients with Aneurysmal Subarachnoid Hemorrhage.

OBJECTIVE: There has been controversy as to whether intraventricular hemorrhage (IVH) after aneurysmal subarachnoid hemorrhage (SAH) contributes to angiographic cerebral vasospasm (aCV) and delayed cerebral ischemia (DCI). Computed tomography-based SAH scales that did and did not consider IVH were compared in terms of ability to predict aCV, DCI, and outcome. METHODS: We reviewed 390 patients with ruptured aneurysms who had been treated surgically by day 3 by the same surgeon (T.I.). aCV was graded as 0-4. Outcome at 6 months was classified using the Glasgow Outcome Scale. Inagawa SAH grades and scores, for which only SAH was evaluated, were compared with scales that evaluated both SAH and IVH (Fisher, Claassen, and Frontera grades, and Hijdra score). The area under the receiver operating characteristic curve was calculated to compare severe aCV (grade 3-4), DCI, or poor outcome (Glasgow Outcome Scale score 1-3). RESULTS: The Inagawa grade showed constant and significant intergrade differences in both aCV and DCI. The Inagawa grade area under the receiver operating characteristic curve values were highest among the scales examined. In the Fisher, Claassen, and Frontera grades, IVH was unlikely to be related to aCV and DCI. There was no significant difference in aCV grade or DCI occurrence between the Inagawa and Hijdra scores. In contrast, the presence of IVH was significantly associated with poor outcome. CONCLUSIONS: In patients with aneurysmal SAH, IVH is an important factor affecting patient outcome, whereas computed tomography-based SAH scales that do not consider IVH are superior to scales that do consider it for prediction of aCV or DCI.

[A Case Report of Stereotactic Craniotomy for the Cerebral Cavernous Angioma].

A 59-year-old woman presented with right sensory loss and right hemiparesis. In February 2013, she was admitted to Araki Neurosurgical Hospital. A magnetic resonance imaging was performed that revealed a left temporal lobe hemorrhage. The image also showed a chronic stereotype hematoma. After 14 days of hospitalization, she underwent a stereotactic craniotomy. Subsequently, by postoperative pathological evaluation, the hematoma was diagnosed as a cavernous angioma. She had no postoperative complications. She was provided rehabilitation support and was discharged 28 days after the admission following which she rejoined work. A stereotactic craniotomy device is very useful in surgeries involving deep lesions. We present a case of stereotactic craniotomy and a few investigation reports.

Risk Factors for Cerebral Vasospasm Following Aneurysmal Subarachnoid Hemorrhage: A Review of the Literature.

OBJECTIVE: To examine the literature on risk factors for cerebral vasospasm (CV), one of the most serious complications following aneurysmal subarachnoid hemorrhage (SAH), with special reference to the definition of CV. METHODS: Using standard search engines, including PubMed, the medical literature on risk factors for CV after SAH was reviewed, and the best definition representative of CV was searched. RESULTS: Severe SAH evident on computed tomography scan was the only consistent risk factor for CV after SAH. Effects of risk factors on CV, including age, clinical grade, rebleeding, intraventricular or intracerebral hemorrhage on computed tomography scan, acute hydrocephalus, aneurysm site and size, leukocytosis, interleukin-6 level, and cardiac abnormalities, appeared to be associated with the severity of SAH rather than each having a direct effect. Cigarette smoking, hypertension, and left ventricular hypertrophy on electrocardiogram were associated with CV without any relationship to SAH severity. With regard to parameters representative of CV, the grade of angiographic vasospasm (i.e., the degree of arterial narrowing evident on angiography) was the most adequate. Nevertheless, few reports on the risk factors associated with angiographic vasospasm grade have been reported to date. CONCLUSIONS: Severe SAH evident on computed tomography scan appears to be a definite risk factor for CV after SAH, followed by cigarette smoking, hypertension, and left ventricular hypertrophy on electrocardiogram. To understand the pathogenesis of CV, further studies on the relationships between risk factors, especially factors not related to the severity of SAH, and angiographic vasospasm grade are necessary.

Prediction of motor outcomes and activities of daily living function using diffusion tensor tractography in acute hemiparetic stroke patients.

[Purpose] The efficacy of diffusion tensor imaging in the prediction of motor outcomes and activities of daily living function remains unclear. We evaluated the most appropriate diffusion tensor parameters and methodology to determine whether the region of interest- or tractography-based method was more useful for predicting motor outcomes and activities of daily living function in stroke patients. [Subjects and Methods] Diffusion tensor imaging data within 10 days after stroke onset were collected and analyzed for 25 patients. The corticospinal tract was analyzed. Fractional anisotropy, number of fibers, and apparent diffusion coefficient were used as diffusion tensor parameters. Motor outcomes and activities of daily living function were evaluated on the same day as diffusion tensor imaging and at 1 month post-onset. [Results] The fractional anisotropy value of the affected corticospinal tract significantly correlated with the motor outcome and activities of daily living function within 10 days post-onset and at 1 month post-onset. Tthere were no significant correlations between other diffusion tensor parameters and motor outcomes or activities of daily living function. [Conclusion] The fractional anisotropy value of the affected corticospinal tract obtained using the tractography-based method was useful for predicting motor outcomes and activities of daily living function in stroke patients.

Risk factors associated with cerebral vasospasm following aneurysmal subarachnoid hemorrhage.

We studied the risk factors associated with cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH). The subjects were 370 patients with ruptured aneurysms who fulfilled all of the following criteria: admission by day 2 after onset, operation performed by day 3 by the same surgeon (T.I.), Hunt-Hess grade I-IV, availability of bilateral carotid angiograms acquired by day 2 and repeated between days 7 and 9. The demographic, clinical, radiographic, surgical, laboratory, and electrocardiographic data were analyzed for angiographic vasospasm (AV), symptomatic vasospasm (SV), and cerebral infarction on computed tomography (CT) scan. Both CT-evident SAH and AV were graded as 0-IV. Among the 370 patients, AV grade III-IV, SV, and cerebral infarction occurred in 26%, 24%, and 20%, respectively. Univariate analysis showed that Hunt-Hess grade III-IV, SAH grade III-IV, intracerebral or/and intraventricular hemorrhage, rebleeding, cigarette smoking, hypertension, alcohol intake, leukocytosis, hyperglycemia, and electrocardiographic QTc prolongation, left ventricular hypertrophy (LVH), and ST depression were significantly related to at least one of AV grade III-IV, SV, or cerebral infarction. Multivariate analysis showed that SAH grade III-IV was the most important risk factor for vasospasm followed by LVH on electrocardiogram, cigarette smoking, and hypertension. AV grade III-IV, SV, and cerebral infarction occurred in 57%, 54%, and 39% of the 46 smokers with LVH, and in 43%, 49%, and 35% of the 68 patients who had both LVH and hypertension, respectively. CT-evident SAH, LVH, cigarette smoking, and hypertension are associated with vasospasm. In smokers or hypertensive patients, premorbid LVH appears to predict much more severe vasospasm.

Delayed diagnosis of aneurysmal subarachnoid hemorrhage in patients: a community-based study.

OBJECT: A community-based study was conducted to estimate the frequency of and evaluate the clinical features related to delayed diagnosis of aneurysmal subarachnoid hemorrhage (SAH). METHODS: Between 1980 and 1998, 358 patients with aneurysmal SAH underwent treatment in Izumo, Japan. The diagnosis of SAH was delayed in 76 patients (21%) and was early in 282 (79%). Among the 76 patients whose diagnosis was delayed, the condition was misdiagnosed by clinicians in 46 cases (Subgroup A), and in the remaining 30 the patients were unaware that SAH had occurred and failed to seek prompt treatment (Subgroup B). RESULTS: The proportion of Subgroup A patients decreased significantly from 18% (30 of 170 patients) between 1980 and 1989 to 9% (16 of 188 patients) between 1990 and 1998 (p = 0.0098), whereas the proportion of Subgroup B patients during the same periods was 8% (13 of 170 patients) and 9% (17 of 188 patients), respectively (p = 0.6341). With regard to Subgroup A, the misdiagnosis rate in private clinics decreased from 14% (23 of 170 patients) between 1980 and 1989 to 5% (10 of 188 patients) between 1990 and 1998 (p = 0.0073), whereas the misdiagnosis rate in hospitals during the same periods was 4% (7 of 170 patients) and 3% (6 of 188 patients), respectively (p = 0.6399). Multivariate analysis revealed that World Federation of Neurosurgical Societies Grade I or II was the main risk factor for delayed diagnosis of SAH (OR 3.97 [95% CI 1.69-10.37]), and that the timing of SAH onset, that is, between 12:00 a.m. and 6:00 a.m., was an important reason for the condition in Subgroup B patients (OR 9.29 [95% CI 2.66-33.93]). Rebleeding before admission occurred in 26% of the patients in whom diagnosis was delayed, and in 3% of those who were diagnosed early (p < 0.0001). CONCLUSIONS: Although the rate of SAH misdiagnosis seems to be decreasing, failure of patients to present for prompt treatment is unlikely to decrease unless the public becomes better educated about SAH and the importance of getting prompt medical attention, even in the middle of the night.

Size of ruptured intracranial saccular aneurysms in patients in Izumo City, Japan.

BACKGROUND: A community-based study was conducted to evaluate the factors related to the size of ruptured aneurysms and the effects of aneurysm size on clinical features. METHODS: Data from 358 patients with subarachnoid hemorrhage (SAH) treated between 1980 and 1998 in Izumo, Japan, were reviewed. In 285 of these patients, the sizes of the ruptured aneurysms were determined. RESULTS: Aneurysm diameter was less than 5 mm in 68 patients, at least 5 to less than 10 mm in 137 patients, and 10 mm or more in 80 patients. Aneurysm size tended to increase with patient age. Age (≥60 years of age) and cigarette smoking were independently associated with aneurysms of 5 mm or more in diameter. Multiple aneurysms were positively and anterior cerebral artery aneurysms were inversely related to aneurysms of 10 mm or more in diameter. The larger the aneurysm, the worse was the World Federation of Neurosurgical Societies grade. The risk of rebleeding was higher in patients with larger (≥10 mm) aneurysms than in those with smaller (<10 mm) aneurysms. The incidences of diffuse severe SAH on computed tomographic scans in patients with SAH alone, symptomatic vasospasm, and hydrocephalus were higher in patients with larger (≥5 mm) aneurysms than in those with smaller (<5 mm) aneurysms. The larger the aneurysm, the worse was either functional outcome or the 6-month and 2-year survival rates. CONCLUSION: Age, cigarette smoking, multiple aneurysms, and aneurysm site appear to be related to the size of ruptured aneurysms. Patients with larger aneurysms seem to have a worse clinical condition and more severe SAH, resulting in higher incidences of rebleeding, symptomatic vasospasm and hydrocephalus, and a worse outcome.

Risk factors for the formation and rupture of intracranial saccular aneurysms in Shimane, Japan.

BACKGROUND: Prevention of aneurysmal subarachnoid hemorrhage (SAH) can be achieved by reducing risk factors, which include those for aneurysm formation and aneurysm rupture. However, neither of these 2 factors has been discussed separately so far. A case control study was undertaken in Shimane, Japan, to identify modifiable risk factors for the formation and rupture of aneurysms. METHODS: This study included 858 patients with ruptured aneurysms, 285 patients with unruptured aneurysms without a history of SAH, and 798 control subjects. Hypertension, diabetes mellitus, heart disease, hypercholesterolemia, cigarette smoking, and alcohol consumption were assessed as risk factors by using conditional logistic regression. RESULTS: After adjustment for other risk factors, hypertension was the most powerful risk factor for aneurysm formation, regardless of age and sex, followed by hypercholesterolemia, heart disease, and cigarette smoking, whereas diabetes mellitus and daily drinking were insignificant for aneurysm formation. Hypertension and daily drinking were not related to the risk of aneurysm rupture, regardless of age and sex, whereas cigarette smoking was associated with an increased risk of aneurysm rupture in patients 60 years or older and in men. In contrast, hypercholesterolemia was strongly associated with a decreased risk of rupture, regardless of age and sex, and in patients with small aneurysms (<5 mm). Diabetes mellitus and heart disease were also related to a decreased risk of rupture in patients 60 years or older and in women. CONCLUSION: Identification of risk factors for aneurysm formation and rupture separately seems to be pivotal for reducing the incidence of SAH.

Site of ruptured intracranial saccular aneurysms in patients in Izumo City, Japan.

BACKGROUND AND PURPOSE: A community-based study was conducted to estimate the site distribution of ruptured intracranial aneurysms and to evaluate clinical features related to aneurysm site. METHODS: The author reviewed data from 358 patients with aneurysmal subarachnoid hemorrhage (SAH) treated between 1980 and 1998 in Izumo, Japan. In 291 of these patients, the sites of the ruptured aneurysms were confirmed. RESULTS: The aneurysm arose from the anterior communicating artery (AcoA) in 101 patients, the distal anterior cerebral artery (ACA) in 24, the internal carotid artery (ICA) in 70, the middle cerebral artery (MCA) in 77, and the vertebrobasilar artery (VBA) in 19. Regardless of age, ACoA aneurysms were more frequent in men, whereas ICA aneurysms were more common in women. Intracerebral hemorrhage was more frequent in patients with MCA aneurysms, whereas intraventricular hemorrhage was more common in those with VBA, ACoA and distal ACA aneurysms. While the incidence of symptomatic vasospasm was not related to aneurysm site, the patients who died due to vasospasm harbored an ACoA or ICA aneurysm. The incidence of hydrocephalus was relatively high in patients with ACoA, ICA and VBA aneurysms, and low in those with MCA aneurysms. The overall outcome was best in patients with MCA aneurysms, followed by those with aneurysms of the ACA, including ACoA and distal ACA, ICA and VBA; these results were in good agreement with the admission grades. CONCLUSIONS: The roughly estimated proportions of the sites of aneurysm rupture were 40% for the ACA, including ACoA and distal ACA, 25% for the ICA, 25% for the MCA, and 10% for the VBA. The clinical features showed significant differences according to aneurysm site.