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Objective: In the absence of clear guidelines and consistent natural history data, the decision to treat unruptured intracranial aneurysms (UIAs) is a matter of some controversy. Currently, decisions are often guided by a consensus of cerebrovascular specialist teams and patient preferences. It is unclear how paradigm-shifting developments in the detection and treatment of UIAs have affected the size of the UIAs that are selected for treatment. Herein, the authors aimed to study potential changes in the average size of the UIAs that were treated over time. They hypothesized that the average size of UIAs that are treated is decreasing over time., Methods: A systematic search of the literature was performed to identify all studies describing the size of UIAs that were treated using any modality. Scatter diagrams with trend lines were used to plot the size of the aneurysms treated over time and assess for the presence of a potentially significant trend via statistical correlation tests. Subgroup analyses based on type of treatment, country of study, and specialty of the authors were performed., Results: A total of 240 studies including 35,150 UIAs treated between 1987 and 2021 met all eligibility criteria and were entered in the analysis. The mean age of patients was 55.5 years, and 70.7% of the patients were females. There was a significant decrease in the size of treated UIAs over time (Spearman's r = -0.186, p < 0.001), with a 0.71-mm decrease in the average size of treated UIAs every 5 years since 1987 and an annual mean dropping below 7 mm in 2012. This decreasing trend was present in surgically and endovascularly treated UIAs (p < 0.001 for both), in more developed and developing countries (p < 0.001 for both), within neurosurgical and non-neurosurgical specialties (p < 0.001 for both), most prominently in the US (Spearman's r = -0.482, p < 0.001), and less prominently in Europe (Spearman's r = -0.221, p < 0.001) and was not detected in East Asia., Conclusions: The present study indicates that based on the treated UIA size data published in the literature over the past 35 years, smaller UIAs are being treated over time. This trend is likely driven by safer treatments. However, future studies should elucidate the cost-effectiveness of treating smaller UIAs as well as the possible real-world contribution of this trend in preventing aneurysmal subarachnoid hemorrhage.

Objective: The natural history of cavernous carotid aneurysms (CCAs) is not fully understood. For robust clinical decision-making, the behavior of CCAs needs to be fully understood. The objective of this paper was to calculate the mortality and morbidity rates of patients with diagnosed but untreated CCAs from a relatively large single-center cohort., Methods: The authors identified 250 patients with 276 CCAs from August 1946 to August 2017 from an aneurysm database including 12,000 intracranial aneurysm patients. Patient and aneurysm characteristics were extracted for further analysis., Results: The cumulative patient follow-up was 1560 years, with a mean of 6.3 years. For patients presenting with a cranial nerve deficit caused by a CCA, those with a ruptured CCA, and patients who received treatment for a CCA, the cumulative patient follow-up was 121 years, with a mean of 1.3 years. For patients with symptom-free or conservatively treated CCAs, the cumulative patient follow-up was 1093 years, with a mean of 7.2 years. Of the 276 aneurysms, 57 (21%) caused cranial nerve deficits and 18 (6.5%) other symptoms, while 201 (73%) remained symptom free. A total of 264 (96%) of the CCAs remained unruptured, and 2 were considered possibly ruptured. Ten (3.6%) ruptures of the CCAs were found. However, none of the ruptured aneurysms caused subarachnoid hemorrhage or death of the patient. Of the CCAs, 51 were multiple, and 131 patients had ≥ 1 intradural aneurysm. The CCAs were analyzed separately., Conclusions: The majority of the CCAs were asymptomatic during follow-up, and none caused the death of the patient. The incidence of symptoms increased with aneurysm size. Because CCAs have a benign natural course, treatment should be considered mainly if the CCA is symptomatic or grows during follow-up.

Objective: Treatment indications in unruptured intracranial aneurysms (UIAs) are challenging because of the lack of prospective natural history studies without treatment selection and the decreasing incidence of aneurysm rupture. The purpose of this study was to test whether the population, hypertension, age, size of aneurysm, earlier aneurysm rupture, site of aneurysm (PHASES) score obtained from an individual-based meta-analysis could predict the long-term rupture risk of UIAs., Methods: The series included 142 patients of working age with UIAs diagnosed before 1979, when these were not treated but were followed up until the first rupture, death, or the last contact. PHASES scores were recorded for all patients by using the baseline variables and compared with the new treatment score obtained from a recent cohort, consisting of age, smoking status, and aneurysm size and location., Results: Of the 142 patients, 34 had an aneurysm rupture during a total follow-up of 3064 person-years. The median time between diagnosis and an aneurysm rupture was 10.6 years. The PHASES score at baseline was higher in those with an aneurysm rupture than in the others (5.3 ± 2.3 vs 4.2 ± 2.2, p = 0.012), and the difference relative to the new treatment score was 5.3 ± 2.4 versus 3.0 ± 2.2 (p < 0.001). The receiver operating characteristic curve of the PHASES score for predicting rupture showed a fair area under the curve (0.674, 95% CI 0.558-0.790) where the optimal cutoff point was obtained at ≥ 6 versus < 6 points for sensitivity (0.500) and specificity (0.811). The area under the curve of the new score was 0.755 (95% CI 0.657-0.853), with the optimal cutoff point at ≥ 5 versus < 5 points for sensitivity (0.607) and specificity (0.789)., Conclusions: The PHASES and the new scores predicted the long-term aneurysm rupture risk moderately well, with the latter, which also included smoking, being slightly better and easier in clinical practice. The findings suggest that treatment decisions about UIAs in patients of working age can be done with an improved cost-effectiveness.

The authors used computer simulation to investigate the hemodynamics in 36 unruptured aneurysms on the first day the lesions were discovered; 12 of them later ruptured. Knowledge about any differences in hemodynamics at this early stage improves predictions about which patients will get a subarachnoid hemorrhage-a dangerous bleeding in the brain-and helps decide which patients should be treated in advance to avoid the bleeding.

Objective: Clinical trials forming the basis of current guidelines for the management of intracranial aneurysms have relied on patient-reported modified Rankin Scale (mRS) scores to assess functional outcome. The effect of patient demographics on perception of disability and, by extension, patient-reported mRS score, is not well understood., Methods: A consecutive series of patients with a previously treated or untreated unruptured intracranial aneurysm (UIA) prospectively underwent a structured interview with a trained nurse. At the conclusion of this interview, the patients were assigned an mRS score in accordance with their degree of disability. During the same visit, patients were also required to grade themselves on a paper sheet containing the mRS and corresponding information. Data on patient and aneurysm characteristics were also collected during the same visit. Agreement between patient- and nurse-reported mRS scores was assessed using Cohen's kappa coefficient. The effect of patient demographics on the frequency of higher patient- than nurse-reported mRS scores was assessed using the Pearson's chi-square and Fisher's exact tests., Results: A total of 209 patients with a UIA were included in the study, 38 of whom (18.2%) had undergone previous treatment. The majority of patients were female (161/209, 77.0%), and the mean age of the cohort was 60.2 years (SD 13.7 years). Agreement between patient- and nurse-reported mRS scores occurred in 72.7% of cases (95% CI 66.3%-78.3%), with a kappa coefficient of 0.58 (95% CI 0.49-0.67). Patients younger than 75 years were more likely to report a higher mRS score than the nurse (19.4% vs 3.4%, p = 0.034). Among female patients, those without a college degree were more likely to report a higher mRS score than the nurse (22.5% vs 9.5%, p = 0.035)., Conclusions: The results suggest that patient demographics may influence perception of disability. These findings should be considered when using patient-reported mRS scores to determine functional outcome.

OBJECTIVE Pathophysiological differences that underlie the development and subsequent growth of multiple aneurysms may exist. In this study, the authors assessed the factors associated with the occurrence of multiple aneurysms in patients presenting with aneurysmal subarachnoid hemorrhage (SAH). METHODS Consecutive patients presenting with aneurysmal SAH between 1996 and 2012 were prospectively enrolled in the Subarachnoid Hemorrhage Outcome Project. Patients harboring 1, 2, or 3 or more aneurysms were stratified into groups, and the clinical and radiological characteristics of each group were compared using multivariate logistic regression. RESULTS Of 1277 patients with ruptured intracranial aneurysms, 890 had 1 aneurysm, 267 had 2 aneurysms, and 120 had 3 or more aneurysms. On multinomial regression using the single-aneurysm cohort as base case, risk factors for patients presenting with 2 aneurysms were female sex (relative risk ratio [RRR] 1.80, p < 0.001), higher body mass index (BMI) (RRR 1.02, p = 0.003), more years of smoking (RRR = 1.01, p = 0.004), and black race (RRR 1.83, p = 0.001). The risk factors for patients presenting with 3 or more aneurysms were female sex (RRR 3.10, p < 0.001), higher BMI (RRR 1.03, p < 0.001), aneurysm in the posterior circulation (RRR 2.59, p < 0.001), and black race (RRR 2.15, p = 0.001). Female sex, longer smoking history, aneurysms in the posterior circulation, BMI, and black race were independently associated with the development of multiple aneurysms in our adjusted multivariate multinomial model. CONCLUSIONS Significant demographic and clinical differences are found between patients presenting with single and multiple aneurysms in the setting of aneurysmal SAH. These predictors of multiple aneurysms likely reflect a predisposition toward inflammation and endothelial injury.

OBJECTIVE Dissection of the carotid and vertebral arteries can result in the development of aneurysmal dilations. These dissecting pseudoaneurysms can enlarge and cause symptoms. The objective of this study is to provide insight into the progression of dissecting pseudoaneurysms and the treatments required to manage them. METHODS A review of the electronic medical records was conducted to detect patients with carotid and vertebral artery dissection. An imaging review was conducted to identify patients with dissecting pseudoaneurysms. One hundred twelve patients with 120 dissecting pseudoaneurysms were identified. Univariate and multivariate analyses were conducted to assess the factors associated with undergoing further interventions other than medical treatment, pseudoaneurysm enlargement, pseudoaneurysms resulting in ischemic and nonischemic symptoms, and clinical outcome. RESULTS Overall, 18.3% of pseudoaneurysms were intracranial and 81.7% were extracranial, and the average size was 7.3 mm. The mean follow-up time was 29.3 months; 3.3% of patients had a recurrent transient ischemic attack, no patients had a recurrent stroke, and 14.2% of patients had recurrence of nonischemic symptoms (headache, neck pain, Horner syndrome, or cranial nerve palsy). Follow-up imaging demonstrated that 13.8% of pseudoaneurysms had enlarged, 30.2% had healed, and 56% had remained stable. In total, 20.8% of patients had an intervention other than medical treatment. Interventions included stenting, coiling, flow diversion, and clipping. Predictors of intervention included increasing size, size > 10 mm, location in the C 2 (petrous) segment of the internal carotid artery (ICA), younger age, hyperlipidemia, pseudoaneurysm enlargement, and any symptom development. Significant predictors of enlargement included smoking, history of trauma, C 2 location, hyperlipidemia, and larger initial pseudoaneurysm size. Predictors of pseudoaneurysm resulting in recurrent ischemic and nonischemic symptoms included increasing size and location in the petrous segment of the ICA. Smoking was a predictor of unfavorable outcome. CONCLUSIONS Dissecting pseudoaneurysms have a benign course and most will not cause symptoms or enlarge on follow-up. Medical treatment can be a sufficient, initial treatment for dissecting pseudoaneurysms.

Objective: Seizures are relatively common after aneurysmal subarachnoid hemorrhage (aSAH). Seizure prophylaxis is controversial and is often based on risk stratification; middle cerebral artery (MCA) aneurysms, associated intracerebral hemorrhage (ICH), poor neurological grade, increased clot thickness, and cerebral infarction are considered highest risk for seizures. The purpose of this study was to evaluate the impact of recent cocaine use on seizure incidence following aSAH., Methods: Prospectively collected data from aSAH patients admitted to 2 institutional neuroscience critical care units between 1991 and 2009 were reviewed. The authors analyzed factors that potentially affected the incidence of seizures, including patient demographic characteristics, poor clinical grade (Hunt and Hess Grade IV or V), medical comorbidities, associated ICH, intraventricular hemorrhage (IVH), hydrocephalus, aneurysm location, surgical clipping and cocaine use. They further studied the impact of these factors on "early" and "late" seizures (defined, respectively, as occurring before and after clipping/coiling)., Results: Of 1134 aSAH patients studied, 182 (16%) had seizures; 81 patients (7.1%) had early and 127 (11.2%) late seizures, with 26 having both. The seizure rate was significantly higher in cocaine users (37 [26%] of 142 patients) than in non-cocaine users (151 [15.2%] of 992 patients, p = 0.001). Eighteen cocaine-positive patients (12.7%) had early seizures compared with 6.6% of cocaine-negative patients (p = 0.003); 27 cocaine users (19%) had late seizures compared with 10.5% non-cocaine users (p = 0.001). Factors that showed a significant association with increased risk for seizure (early or late) on univariate analysis included younger age (< 40 years) (p = 0.009), poor clinical grade (p = 0.029), associated ICH (p = 0.007), and MCA aneurysm location (p < 0.001); surgical clipping was associated with late seizures (p = 0.004). Following multivariate analysis, age < 40 years (OR 2.04, 95% CI 1.355-3.058, p = 0.001), poor clinical grade (OR 1.62, 95% CI 1.124-2.336, p = 0.01), ICH (OR 1.95, 95% CI 1.164-3.273, p = 0.011), MCA aneurysm location (OR 3.3, 95% CI 2.237-4.854, p < 0.001), and cocaine use (OR 2.06, 95% CI 1.330-3.175, p = 0.001) independently predicted seizures., Conclusions: Cocaine use confers a higher seizure risk following aSAH and should be considered during risk stratification for seizure prophylaxis and close neuromonitoring.

The pathophysiology of extracranial traumatic aneurysm formation has not been fully elucidated. Intraarterial optical coherence tomography (OCT), an imaging modality capable of micrometer cross-sectional resolution, was used to evaluate patients presenting with saccular traumatic aneurysms of the internal carotid artery (ICA). Two consecutive trauma patients diagnosed with saccular traumatic aneurysms of the cervical ICA, per the institutional screening protocol for traumatic cerebrovascular injury, underwent digital subtraction angiography (DSA) with OCT. Optical coherence tomography demonstrated disruption of the intima with preservation and stretching of the more peripheral layers. In 1 patient the traumatic aneurysm was associated with thrombus formation and a separate, more proximal dissection not visible on CT angiography (CTA) or DSA. Imaging with OCT indicates that saccular traumatic aneurysms may develop from disruption of the intima with at least partial preservation of the media and adventitia. This provides in vivo evidence that saccular traumatic aneurysms result from a partial arterial wall tear rather than complete disruption. Interestingly, OCT was also able to detect arterial injury and thrombi not visible on CTA or DSA.

Object: The present study aimed to investigate aneurysm locations and treatments for ruptured cerebral aneurysms associated with secondary normal-pressure hydrocephalus (sNPH) after subarachnoid hemorrhage (SAH) by using comprehensive data from the Japanese Stroke DataBank., Methods: Among 101,165 patients with acute stroke registered between 2000 and 2013, 4693 patients (1482 men, 3211 women) were registered as having had an SAH caused by a ruptured saccular aneurysm. Of them, 1448 patients (438 men and 1010 women; mean age 61.9 ± 13.4 years) who were confirmed to have or not have coexisting acute hydrocephalus and sNPH were included for statistical analyses. Locations of the ruptured aneurysms were subcategorized into 1 of the following 4 groups: middle cerebral artery (MCA; n = 354), anterior communicating artery and anterior cerebral artery (ACA; n = 496), internal carotid artery (ICA; n = 402), and posterior circulation (n = 130). Locations of 66 of the ruptured aneurysms were unknown/unrecorded. Treatments included craniotomy and clipping alone in 1073 patients, endovascular coil embolization alone in 285 patients, and a combination of coiling and clipping in 17 patients. The age-adjusted and multivariate odds ratios from logistic regression analyses were calculated after stratification using the Fisher CT scale to investigate the effects of the hematoma volume of SAH., Results: Acute hydrocephalus was confirmed in 593 patients, and 521 patients developed sNPH. Patients with a ruptured ACA aneurysm had twice the risk for sNPH over those with a ruptured MCA aneurysm. Those with an ACA aneurysm with Fisher Grade 3 SAH had a 9-fold-higher risk for sNPH than those with an MCA aneurysm with Fisher Grade 1 or 2 SAH. Patients with a ruptured posterior circulation aneurysm did not have any significant risk for sNPH. Clipping of the ruptured aneurysm resulted in twice the risk for sNPH over coil embolization alone., Conclusions: Patients with low-grade SAH caused by a ruptured MCA aneurysm had a low risk for the development of sNPH. In contrast, patients with high-grade SAH caused by a ruptured ACA aneurysm had a higher risk for sNPH. Endovascular coiling might confer a lower risk of developing sNPH than microsurgical clipping.

Object: Case fatality rates after aneurysmal subarachnoid hemorrhage (aSAH) have decreased over time, and many patients treated with modern paradigms return to a normal life. However, there is little information on predictors of excellent functional outcome after aSAH. In this study, the authors investigated predictors of excellent outcome in a modern consecutive series of patients with aSAH., Methods: A retrospective review was conducted of patients with aSAH admitted between 2001 and 2013. The primary outcome measure was excellent functional outcome, defined as modified Rankin Scale (mRS) score of 0 or 1 at last follow-up within 1 year of aSAH., Results: Three hundred seventy-three patients were identified with posthospital follow-up. Excellent outcome was noted in 236 patients (63.3%), including an mRS score of 0 in 122 (32.7%) and an mRS score of 1 in 114 (30.6%). On univariate analysis, the following factors were associated with an excellent outcome: indicators of less severe bleeding, such as better World Federation of Neurosurgical Societies grade at any of the times of assessment, better modified Fisher grade, and absence of intracerebral hemorrhage (ICH), intraventricular hemorrhage (IVH), and symptomatic hydrocephalus; aneurysm treatment with coil embolization; absence of symptomatic vasospasm, delayed cerebral ischemia, and radiological infarction; absence of in-hospital seizures; lack of need for CSF diversion; fewer hours with fever; less severe anemia; and absence of transfusion. On multivariable analysis, the 4 variables that were most strongly associated with excellent outcome were presence of good clinical grade after neurological resuscitation, absence of ICH on initial CT scan, blood transfusion during the hospitalization, and radiological infarctions on final brain imaging., Conclusions: Excellent outcomes (mRS score 0-1) can be achieved in the majority of patients with aSAH. The likelihood of excellent outcome is predicted by good clinical condition after resuscitation, absence of ICH on presentation, no evidence of infarction on brain imaging, and absence of blood transfusion during hospitalization.

Object: The yield of CT angiography (CTA) and MR angiography (MRA) in patients with subarachnoid hemorrhage (SAH) who have a negative initial catheter angiogram is currently not well understood. This study aims to determine the yield of CTA and MRA in a prospective cohort of patients with SAH and a negative initial catheter angiogram., Methods: From January 1, 2005, until September 1, 2010, the authors instituted a prospective protocol in which patients with SAH-as documented by noncontrast CT or CSF xanthochromia and a negative initial catheter angiogram- were evaluated using CTA and MRA to assess for causative cerebral aneurysms. Two neuroradiologists independently evaluated the noncontrast CT scans to determine the SAH pattern (perimesencephalic or not) and the CT and MR angiograms to assess for causative cerebral aneurysms., Results: Seventy-seven patients were included, with a mean age of 52.8 years (median 54 years, range 19-88 years). Fifty patients were female (64.9%) and 27 male (35.1%). Forty-three patients had nonperimesencephalic SAH (55.8%), 29 patients had perimesencephalic SAH (37.7%), and 5 patients had CSF xanthochromia (6.5%). Computed tomography angiography demonstrated a causative cerebral aneurysm in 4 patients (5.2% yield), all of whom had nonperimesencephalic SAH (9.3% yield). Mean aneurysm size was 2.6 mm (range 2.1-3.3 mm). Magnetic resonance angiography demonstrated only 1 of these aneurysms. No causative cerebral aneurysms were found in patients with perimesencephalic SAH or CSF xanthochromia., Conclusions: Computed tomography angiography is a valuable adjunct in the evaluation of patients with nonperimesencephalic SAH who have a negative initial catheter angiogram, demonstrating a causative cerebral aneurysm in 9.3% of patients.

Object: Investigators conducting the International Study of Unruptured Intracranial Aneurysms, sponsored by the National Institutes of Health, sought to evaluate predictors of future hemorrhage in patients who had unruptured mirror aneurysms. These paired aneurysms in bilateral arterial positions mirror each other; their natural history is unknown., Methods: Centers in the US, Canada, and Europe enrolled patients for prospective assessment of unruptured intracranial aneurysms. Central radiological review confirmed the presence or absence of mirror aneurysms in patients without a history of prior subarachnoid hemorrhage (SAH) (Group 1). Outcome at 1 and 5 years and aneurysm characteristics are compared., Results: Of 3120 patients with aneurysms treated in 61 centers, 376 (12%) had mirror aneurysms, which are more common in women than men (82% [n = 308] vs 73% [n = 1992], respectively; p <0.001) and in patients with a family history of aneurysm or SAH (p <0.001). Compared with patients with nonmirror saccular aneurysms, a greater percentage of patients with mirror aneurysms had larger (>10 mm) aneurysms (mean maximum diameter 11.7 vs 10.4 mm, respectively; p <0.001). The most common distribution for mirror aneurysms was the middle cerebral artery (34% [126 patients]) followed by noncavernous internal carotid artery (32% [121]), posterior communicating artery (16% [60]), cavernous internal carotid artery (13% [48]), anterior cerebral artery/anterior communicating artery (3% [13]), and vertebrobasilar circulation (2% [8]). When these patients were compared with patients without mirror aneurysms, no statistically significant differences were found in age (mean age 54 years in both groups), blood pressure, smoking history, or cardiac disease. Aneurysm rupture rates were similar (3.0% for patients with mirror aneurysms vs 2.8% for those without)., Conclusions: Overall, patients with mirror aneurysms were more likely to be women, to report a family history of aneurysmal SAH, and to have larger aneurysms. The presence of a mirror aneurysm was not an independent predictor of future SAHs.

Object: The use of flow-diverting stents has gained momentum as a curative approach in the treatment of complex proximal anterior circulation intracranial aneurysms. There have been some reported attempts of treating formidable lesions in the posterior circulation. Posterior circulation giant fusiform aneurysms have a particularly aggressive natural history. To date, no one approach has been shown to be comprehensively effective or low risk. The authors report the initial results, including the significant morbidity and mortality encountered, with flow diversion in the treatment of large or giant fusiform vertebrobasilar aneurysms at Millard Fillmore Gates Circle Hospital., Methods: The authors retrospectively reviewed their prospectively collected endovascular database to identify patients with intracranial aneurysms who underwent treatment with flow-diverting devices and determined that 7 patients had presented with symptomatic large or giant fusiform vertebrobasilar aneurysms. The outcomes of these patients, based on the modified Rankin Scale (mRS), were tabulated, as were the complications experienced., Results: Among the 7 patients, Pipeline devices were placed in 6 patients and Silk devices in 1 patient. At the last follow-up evaluation, 4 patients had died (mRS score of 6), all of whom were treated with the Pipeline device. The other 3 patients had mRS scores of 5 (severe disability), 1, and 0. The deaths included posttreatment aneurysm ruptures in 2 patients and lack of improvement in neurological status related to presenting brainstem infarcts and subsequent withdrawal of care in the other 2 patients., Conclusions: Whether flow diversion will be an effective strategy for treatment of large or giant fusiform vertebrobasilar aneurysms remains to be seen. The authors' initial experience suggests substantial morbidity and mortality associated with the treatment and with the natural history. As outcomes data slowly become available for patients receiving these devices for fusiform posterior circulation aneurysms, practitioners should use these devices judiciously.

Object: Subarachnoid hemorrhage (SAH) results in significant morbidity and mortality, even among patients who reach medical attention in good neurological condition. Many patients have neurological decline in the perioperative period, which contributes to long-term outcomes. The focus of this study is to characterize the incidence of, characteristics predictive of, and outcomes associated with acute postoperative neurological deterioration in patients undergoing surgery for ruptured intracranial aneurysm., Methods: The Intraoperative Hypothermia for Aneurysm Surgery Trial (IHAST) was a multicenter randomized clinical trial that enrolled 1001 patients and assesssed the efficacy of hypothermia as neuroprotection during surgery to secure a ruptured intracranial aneurysm. All patients had a radiographically confirmed SAH, were classified as World Federation of Neurosurgical Societies (WFNS) Grade I-III immediately prior to surgery, and underwent surgery to secure the ruptured aneurysm within 14 days of SAH. Neurological assessment with the National Institutes of Health Stroke Scale (NIHSS) was performed preoperatively, at 24 and 72 hours postoperatively, and at time of discharge. The primary outcome variable was a dichotomized scoring based on an IHAST version of the Glasgow Outcome Scale (GOS) in which a score of 1 represents a good outcome and a score > 1 a poor outcome, as assessed at 90-days' follow-up. Data from IHAST were analyzed for occurrence of a postoperative neurological deterioration. Preoperative and intraoperative variables were assessed for associations with occurrence of postoperative neurological deterioration. Differences in baseline, intraoperative, and postoperative variables and in outcomes between patients with and without postoperative neurological deterioration were compared with Fisher exact tests. The Wilcoxon rank-sum test was used to compare variables reported as means. Multiple logistic regression was used to adjust for covariates associated with occurrence of postoperative deficit., Results: Acute postoperative neurological deterioration was observed in 42.6% of the patients. New focal motor deficit accounted for 65% of postoperative neurological deterioration, while 60% was accounted for using the NIHSS total score change and 51% by Glasgow Coma Scale score change. Factors significantly associated with occurrence of postoperative neurological deterioration included: age, Fisher grade on admission, occurrence of a procedure prior to aneurysm surgery (ventriculostomy), timing of surgery, systolic blood pressure during surgery, ST segment depression during surgery, history of abnormality in cardiac valve function, use of intentional hypotension during surgery, duration of anterior cerebral artery occlusion, intraoperative blood loss, and difficulty of aneurysm exposure. Of the 426 patients with postoperative neurological deterioration at 24 hours after surgery, only 46.2% had a good outcome (GOS score of 1) at 3 months, while 77.7% of those without postoperative neurological deterioration at 24 hours had a good outcome (p < 0.05)., Conclusions: Neurological injury incurred perioperatively or in the acute postoperative period accounts for a large percentage of poor outcomes in patients with good admission WFNS grades undergoing surgery for aneurysmal SAH. Avoiding surgical factors associated with postoperative neurological deterioration and directing investigative efforts at developing improved neuroprotection for use in aneurysm surgery may significantly improve long-term neurological outcomes in patients with SAH.

Object: Because the risks are reduced, larger basilar apex aneurysms are usually treated endovascularly instead of with surgery. However, small basilar apex aneurysms are more common and an unfavorable shape may prevent definitive endovascular treatment. The goal of this study was to reevaluate the outcome of traditional surgery for small unruptured basilar apex aneurysms as an alternative to the currently more accepted endovascular treatment., Methods: The authors reviewed clinical data obtained in 21 patients who underwent surgery between 2000 and 2007 for unruptured basilar apex aneurysms < 7 mm., Results: The median age of the 21 patients was 52 years (range 29-74 years). All patients experienced a good outcome. Two patients harbored a small residual aneurysm (> 95% occlusion). Eight patients (38%) suffered a temporary third nerve paresis, which resolved in all cases., Conclusions: Surgical clip ligation remains an excellent treatment for small basilar apex aneurysms. The treatment is definitive and in experienced hands is associated with a low risk.

Object: The authors conducted a study to evaluate the advantages of a 3D volume-rendering technique (VRT) in follow-up digital subtraction (DS) angiography of coil-embolized intracranial aneurysms., Methods: One hundred nine patients with 121 intracranial aneurysms underwent endovascular coil embolization and at least 1 follow-up DS angiography session at the authors' institution. Two neuroradiologists independently evaluated the conventional 2D DS angiograms, rotational angiograms, and 3D VRT images obtained at the interventional procedures and DS angiography follow-up. If multiple follow-up sessions were performed, the final follow-up was mainly considered. The authors compared the 3 techniques for their ability to detect aneurysm remnants (including aneurysm neck and sac remnants) and parent artery stenosis based on the angiographic follow-up. The Kruskal-Wallis test was used for group comparisons, and the kappa test was used to measure interobserver agreement. Statistical analyses were performed using commercially available software., Results: There was a high statistical significance among 2D DS angiography, rotational angiography, and 3D VRT results (X(2) = 9.9613, p = 0.0069) when detecting an aneurysm remnant. Further comparisons disclosed a statistical significance between 3D VRT and rotational angiography (X(2) = 4.9754, p = 0.0257); a high statistical significance between 3D VRT and 2D DS angiography (X(2) = 8.9169, p = 0.0028); and no significant difference between rotational angiography and 2D DS angiography (X(2) = 0.5648, p = 0.4523). There was no statistical significance among the 3 techniques when detecting parent artery stenosis (X(2) = 2.5164, p = 0.2842). One case, in which parent artery stenosis was diagnosed by 2D DS angiography and rotational angiography, was excluded by 3D VRT following observations of multiple views. The kappa test showed good agreement between the 2 observers., Conclusions: The 3D VRT is more sensitive in detecting aneurysm remnants than 2D DS angiography and rotational angiography and is helpful for identifying parent artery stenosis. The authors recommend this technique for the angiographic follow-up of patients with coil-embolized aneurysms.

Object: The association of vitreous and/or subhyaloid hemorrhage with aneurysmal subarachnoid hemorrhage (SAH) has been frequently identified since the original description by Terson in 1900. In this prospective clinical study the authors examined the actual incidence of Terson hemorrhage in patients suffering aneurysmal SAH, they attempted to identify those parameters that could predispose its development, and they evaluated its prognostic significance in the overall patients' outcome., Methods: A total of 174 patients suffering aneurysmal SAH were included in this study. The admitting Glasgow Coma Scale scores (GCS), World Federation of Neurological Societies (WFNS) scale scores, Hunt and Hess grades, and Fisher grades were recorded. A careful ophthalmological evaluation was performed in all participants. The exact anatomical locations and the largest diameter of the dome of the ruptured aneurysms were also recorded. Surgical clipping or endovascular coiling was used in 165 patients. Clinical outcome was evaluated at discharge from the hospital by using the Glasgow Outcome Scale and the modified Rankin Scale. Periodic ophthalmological evaluations were performed for 2 years., Results: In this series, the observed incidence of Terson hemorrhage was 12.1%. Statistical analysis of our data demonstrated that patients with low GCS scores and high WFNS scores, Hunt and Hess grades, and Fisher grades had an increased incidence of Terson hemorrhage. The mortality rate for patients with Terson hemorrhage was 28.6%, whereas that for patients without Terson hemorrhage was 2.0%. Moreover, patients with Terson hemorrhage who survived had significantly worse outcomes than those in patients without Terson hemorrhage., Conclusions: Terson hemorrhage constitutes a common SAH-associated complication. Its incidence is increased in patients with low GCS and high WFNS scores, and high Hunt and Hess and Fisher grades. Its presence is associated with increased mortality and morbidity rates.

Object: The authors report the management protocol and successful outcomes in 6 patients with dissecting aneurysms of the posterior inferior cerebellar artery (PICA)., Methods: Medical records and neuroimaging studies of 6 patients who underwent surgical treatment of dissecting PICA aneurysms were reviewed. The mean follow-up duration was 1.8 years. No patient was lost to follow-up review., Results: Four patients presented with acute subarachnoid hemorrhage and 2 with PICA ischemia. All patients underwent surgery, which entailed proximal occlusion with distal revascularization in 3 cases and circumferential wrap/clip reconstruction in 3 cases. The revascularization techniques used were occipital artery-PICA bypass and PICA-PICA anastomosis. Delayed follow-up angiography was performed in all cases. In patients treated with proximal occlusion, delayed angiography showed minimal retrograde opacification of the dissected segments. The 3 patients treated with wrap/clip reconstruction showed unexpectedly significant normalization of their lesions on angiographic studies. Outcome was good in all cases., Conclusions: Dissecting PICA aneurysms are rare lesions with an apparent propensity for bleeding. Individualized management including distal revascularization with PICA sacrifice or circumferential wrap/clip reconstruction to reinforce the dissected segment produced good outcomes. Patients treated with aneurysm wrapping may show dramatic angiographic improvement of the dissected segment.

Object: Lenticulostriate artery (LSA) aneurysms are rarely reported in the literature, making management decisions challenging. Conservative, endovascular, and surgical treatments have been described primarily through case reports and reports of individual authors' experiences. The purpose of this study is to report neurological outcomes in a single-institution experience of ruptured lenticulostriate aneurysms treated surgically., Methods: The authors have conducted a retrospective review of all cases involving patients with ruptured LSA aneurysms who presented to the Mt. Sinai Hospital neurosurgical service between September 2001 and January 2007., Results: Over 5.4 years, the authors treated 6 patients with 7 LSA aneurysms-6 ruptured and 1 unruptured. The Hunt and Hess grade on admission ranged from I to IV, with subarachnoid hemorrhage in 5 of the 6 patients. Catheter angiography confirmed the presence of the aneurysms, and all patients underwent a pterional craniotomy and clipping or resection of the aneurysm, performed by a single surgeon. Associated risk factors in our series of patients included hypertension, cocaine abuse, and intracranial occlusive disease suggestive of moyamoya disease. Two types of LSA aneurysms were identified. The mean size of the 6 ruptured aneurysms was 3.2 mm. The LSA was preserved in 3 of 6 patients, but LSA preservation did not correlate with development of a postoperative infarct, clinically or radiologically. In patients with ruptured aneurysms, the mean modified Rankin Scale score at discharge was 1.7. The 3 patients in whom the LSA was sacrificed had good outcomes, suggesting that loss of the artery is clinically well tolerated., Conclusions: This case series demonstrates that surgical treatment of ruptured LSA aneurysms can be an appropriate, effective, and safe therapy.

Object: The most appropriate treatment for cerebral aneurysms, both ruptured and unruptured, is currently under debate, and updated guidelines have yet to be defined. The authors attempted to identify trends in therapy for cerebral aneurysms in the US as well as outcomes., Methods: The authors retrospectively reviewed data from the Nationwide Inpatient Sample hospital discharge database (Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality) for the period 1993-2003. Multiple variables were categorized and subjected to statistical analysis for International Classification of Diseases, 9th Revision, Clinical Modification codes related to subarachnoid hemorrhage (SAH), unruptured aneurysm, and clipping and endovascular treatment of cerebral aneurysm., Results: During the study period, the numbers of discharges remained stable for SAH but doubled for unruptured aneurysms. Concomitantly, the number of aneurysms treated with clip placement remained stable, and the number treated by means of endovascular procedures doubled. By the study's end, the mortality rates had decreased 20% for SAH and 50% for unruptured aneurysms. Increasing age was associated with increased mortality rates, mean length of hospital stay (LOS), and mean charges (p < 0.01). Endovascular treatment was used more often in older patients (p < 0.01). Teaching status and larger hospital size were associated with higher charges and longer hospital stays (although the association was not statistically significant) and with better outcomes (p < 0.05) and lower mortality rates (p < 0.05), especially in patients who underwent aneurysm clipping (p < 0.01). Endovascular treatment was associated with significantly higher mortality rates in small hospitals (p < 0.001) and steadily increasing morbidity rates (45%). Morbidity rates, mean LOS, and mean charges were higher for aneurysm clipping (p < 0.01)., Conclusions: From 1993 to 2003, endovascular techniques for aneurysm occlusion have been increasingly used, while the use of surgical clipping procedures has remained stable. Toward the end of the study period, better overall outcomes were observed in the treatment of cerebral aneurysms, both ruptured and unruptured. Large academic centers were associated with better results, particularly for surgical clip placement.

Object: The use of intracranial stents in stent-assisted coil embolization is now a current neurosurgical practice worldwide. The clinical utility of these stents in the sole stenting (SS) technique, however, has not been thoroughly described, and the published reports of this experience are scarce. This study was designed to evaluate SS treatment of dissecting and nondissecting aneurysms of the posterior circulation., Methods: This prospective and descriptive study was conducted in 20 consecutive patients who harbored single aneurysms of the posterior circulation and who were treated using the SS approach in the last 3 years. The clinical and radiological assessment and follow-up of the patients were evaluated using the modified Rankin scale as well as with computed tomography angiography and digital subtraction angiography at discharge and at 1, 3, 6, and 12 months., Results: Eleven of the 20 patients had subarachnoid hemorrhages, 3 presented with ischemia, 1 presented with brainstem compression, and the remaining 5 patients had incidentally discovered, asymptomatic lesions. Only 1 patient had a complication (occipital infarction) attributable to the SS procedure. One patient died of rebleeding 2 weeks after the procedure. At 1 month, 40% of the patients had a subtotal or total occlusion, which increased to 55% at 3 months and 85% at 6 months, with a final subtotal or total occlusion rate of 80% at 1 year. The SS procedure in 1 case was considered a failure at 6 months because no change had been noted since the 1-month follow-up. One case showed partial occlusion and 1 case showed recanalization., Conclusions: Use of SS for aneurysms in the posterior circulation complex is a safe and effective technique, demonstrating an occlusion rate of 80% at the 1-year follow up.

Object: Approximately 20% of patients with an intracranial saccular aneurysm report a family history of intracranial aneurysm (IA) or subarachnoid hemorrhage. A better understanding of predictors of aneurysm detection in familial IA may allow more targeted aneurysm screening strategies., Methods: The Familial Intracranial Aneurysm (FIA) study is a multicenter study, in which the primary objective is to define the susceptibility genes related to the formation of IA. First-degree relatives (FDRs) of those affected with IA are offered screening with magnetic resonance (MR) angiography if they were previously unaffected, are > or = 30 years of age, and have a history of smoking and/or hypertension. Independent predictors of aneurysm detection on MR angiography were determined using the generalized estimating equation version of logistic regression., Results: Among the first 303 patients screened with MR angiography, 58 (19.1%) had at least 1 IA, including 24% of women and 11.7% of men. Ten (17.2%) of 58 affected patients had multiple aneurysms. Independent predictors of aneurysm detection included female sex (odds ratio [OR] 2.46, p = 0.001), pack-years of cigarette smoking (OR 3.24 for 20 pack-years of cigarette smoking compared with never having smoked, p < 0.001), and duration of hypertension (OR 1.26 comparing those with 10 years of hypertension to those with no hypertension, p = 0.006)., Conclusions: In the FIA study, among the affected patients' FDRs who are > 30 years of age, those who are women or who have a history of smoking or hypertension are at increased risk of suffering an IA and should be strongly considered for screening.

Object: The introduction of the Neuroform microstent has facilitated the embolization of complex cerebral aneurysms, which were previously not amenable to endovascular therapy. Typically, the use of this stent necessitates the administration of dual antiplatelet therapy to minimize thromboembolic complications. Such therapy may increase the risk of hemorrhage in patients who require concurrent external ventricular drainage and/or subsequent permanent cerebrospinal fluid diversion., Methods: The authors' neurosurgical database was queried for all patients who underwent stent-assisted coil embolization for cerebral aneurysms and who required an external ventricular drain (EVD) or ventriculoperitoneal (VP) shunt placement for management of hydrocephalus., Results: Thirty-seven patients underwent stent-assisted coil embolization for intracranial aneurysms at the authors' institution over a recent 2-year period. Seven of these patients required placement of an EVD and/or a VP shunt. Three of the 7 patients suffered an immediate intraventricular hemorrhage (IVH) associated with placement or manipulation of an EVD; 1 experienced a delayed intraparenchymal hemorrhage and an IVH; 1 suffered an aneurysmal rehemorrhage; and the last patient had a subdural hematoma (SDH) that resulted from placement of a VP shunt. This patient required drainage of the SDH and exchange of the valve., Conclusions: The necessity of dual antiplatelet therapy in the use of stent-assisted coil embolization increases the risk of intracranial hemorrhage and possibly rebleeding from a ruptured aneurysm. This heightened risk must be recognized when contemplating the appropriate therapy for a cerebral aneurysm and when considering the placement or manipulation of a ventricular catheter in a patient receiving dual antiplatelet therapy. Further study of intracranial procedures in patients receiving dual antiplatelet therapy is indicated.

Object: The aim of this study was to assess the long-term results of intracranial aneurysms treated with Guglielmi detachable coils (GDCs) with the aid of contrast-enhanced magnetic resonance (MR) angiography., Methods: Between January 1998 and August 2001, 92 patients with 92 aneurysms treated by endovascular coiling with GDCs underwent contrast-enhanced MR angiography. These patients underwent long-term follow-up (range 32-78 months, mean 42.1 +/- 11.9 months [standard deviation]) after endovascular treatment. All images were compared with digital subtraction angiograms and contrast-enhanced MR angiograms that had been obtained during the short-term follow-up (range 5-25 months, mean 13 +/- 5.1 months after treatment). The MR angiograms were analyzed independently by 2 senior radiologists. Findings were assigned to 1 of 3 categories: complete obliteration (Class 1), residual neck (Class 2), or residual aneurysm (Class 3)., Results: Of 92 contrast-enhanced MR angiograms obtained at the long-term follow-up, complete obliteration of the aneurysm was noted in 57 patients (Class 1), a residual neck was seen in 22 (Class 2), and a residual aneurysm was observed in 13 (Class 3). One patient experienced aneurysm rehemorrhaging during the follow-up period. The comparison of short- and long-term follow-up angiograms demonstrated a change in aneurysm classification in 7 patients (7.6%), including 4 that progressed from Class 1 to Class 2 and 3 from Class 2 to Class 3. However, 4 (14.2%) of the 28 long-term recurrences were not detected on the short-term control images., Conclusions: Long-term follow-up with contrast-enhanced MR angiography after selective embolization of intracranial aneurysms can identify late aneurysm recanalization that is undetected at short-term follow-up.

Object: The purpose of this study was to determine whether cocaine use is a significant prognostic factor for outcome measures such as Hunt and Hess grade and Glasgow Outcome Scale (GOS) score among patients presenting with ruptured intracranial aneurysms (IAs)., Methods: The authors performed a MEDLINE/PubMed search for cases of ruptured IAs associated with cocaine use. Fourteen cases from the authors' experience were combined with 50 from a literature review, for a total of 64 cases associated with cocaine use. These 64 cases were compared with 65 cases without cocaine use (controls), which had been obtained from an aneurysm database. Logistic regression analysis was performed to determine significant prognostic factors for a poor Hunt and Hess grade and a poor GOS score, and a general linear model was applied to identify significant factors for these measures among cocaine users., Results: There were 40 women in each group. The mean age was 32.3 +/- 8.1 years in the cocaine group and 49.7 +/- 10.6 years in the control group; thus, patients in the cocaine group were significantly younger (p < 0.01). Cocaine was snorted in 21% of cases, smoked in 55%, and intravenously injected or taken in through a combination of routes in 24%. Fifty-one percent of cocaine users and 7.7% of nonusers presented with a poor GOS score (p < 0.01). Fifty-six percent had ictus during cocaine abuse. At the end of a 30-day follow-up, 51% of the patients in the cocaine group had a good GOS score compared with 92% in the control group (p < 0.01). Controlling for the effects of other significant factors, cocaine use had a significant effect on Hunt and Hess grade (p < 0.03) and GOS score (p < 0.01). The odds of having a poor Hunt and Hess grade among cocaine users were 4.2 times greater than those in nonusers, and the odds of having a poor GOS score among cocaine users were 38.8 times greater., Conclusions: Aneurysms were significantly smaller and ruptured at a younger age among cocaine users compared with nonusers. Although the poor clinical grade was not significantly different between the 2 groups, outcome was significantly worse in cocaine users.

The authors report the successful staged stenting and coil embolization of a large vertebral artery-posterior inferior cerebellar artery (VA-PICA) aneurysm using the contralateral VA for access. A 67-year-old woman presented with a large ruptured VA-PICA aneurysm. Initial attempts to stent the wide-necked aneurysm from the ipsilateral side failed, so coil embolization of the dome was performed. During a second endovascular session, the aneurysm neck was successfully stented from the contralateral VA into the PICA. Six weeks later, coils were inserted into the aneurysm from the ipsilateral side. The coil result was stable at the 3-month follow-up examination.

The authors describe a rare case of idiopathic distal lenticulostriate artery (LSA) aneurysm in a 5-year-old boy who presented in the emergency department with a sudden onset of headache. Admission computed tomography scans revealed an intracerebral hemorrhage in the left caudate nucleus with intraventricular extension. Angiographic studies demonstrated a left medial LSA aneurysm. The patient underwent a left parasagittal frontal craniotomy, the lateral ventricle was accessed via the anterior transcallosal approach, and the aneurysm was removed after sectioning of the parent vessel. The child left the hospital after 5 days; at that time he was asymptomatic and without motor impairment. The optimum treatment of aneurysms involving small perforating arteries is controversial and depends mainly on the causative factors. The pathogenesis and treatment of these unusual aneurysms are discussed.

Distal aneurysms of basilar perforating and circumferential arteries are exceedingly rare. The authors encountered one patient with a distal basilar perforating artery aneurysm and two with aneurysms arising from circumferential branches of the basilar artery (BA). The diagnostic features, microsurgical treatment, and outcomes in these three patients are described. The first patient, a 27-year-old man, presented with an angiogram-negative subarachnoid hemorrhage (SAH), and subsequent readmission for a new hemorrhage revealed a centrally thrombosed aneurysm arising from a basilar apex perforating artery. The second patient, a 68-year-old man, presented for follow-up evaluation 2 months after an angiogram-negative SAH, and an aneurysm was identified on a circumferential artery originating from the BA trunk. The third patient, a 2-year-old boy, presented with blunt head trauma and a pseudoaneurysm arising from a basilar apex circumferential artery. All three aneurysms were managed microsurgically with aneurysm trapping, via either an orbitozygomatic or an extended retrosigmoid approach. Occlusion of the distal perforating or circumferential artery was well tolerated in all cases, with no neurological sequelae resulting from surgery. Features common to all three aneurysms were dolichoectatic morphology, intraluminal thrombus, and SAH. These aneurysms may be difficult to diagnose given their small size and delayed filling on angiographic studies. Consequently, their presence in cases of angiogram-negative SAH may be underestimated. These aneurysms are not amenable to endovascular treatment, but excellent results can be obtained with microsurgical exposure and trapping.

Object: Digital subtraction (DS) angiography is the current gold standard of assessing intracranial aneurysms after coil placement. Magnetic resonance (MR) angiography offers a noninvasive, low-risk alternative, but its accuracy in delineating coil-treated aneurysms remains uncertain. The objective of this study, therefore, is to compare a high-resolution MR angiography protocol relative to DS angiography for the evaluation of coil-treated aneurysms., Methods: In 2003, the authors initiated a prospective protocol of following up patients with coil-treated brain aneurysms using both 1.5-tesla gadolinium-enhanced MR angiography and biplanar DS angiography. Using acquired images, the subject aneurysm was independently scored for degree of remnant identified (complete obliteration, residual neck, or residual aneurysm) and the surgeon's ability to visualize the parent vessel (excellent, fair, or poor)., Results: Thirty-seven patients with 42 coil-treated aneurysms were enrolled for a total of 44 paired MR angiography-DS angiography tests (median 9 days between tests). An excellent correlation was found between DS and MR angiography for assessing any residual aneurysm, but not for visualizing the parent vessel (K = 0.86 for residual aneurysm and 0.10 for parent vessel visualization). Paramagnetic artifact from the coil mass was minimal, and in some cases MR angiography identified contrast permeation into the coil mass not revealed by DS angiography. An intravascular microstent typically impeded proper visualization of the parent vessel on MR angiography., Conclusions: Magnetic resonance angiography is a noninvasive and safe means of follow-up review for patients with coil-treated brain aneurysms. Compared with DS angiography, MR angiography accurately delineates residual aneurysm necks and parent vessel patency (in the absence of a stent), and offers superior visualization of contrast filling within the coil mass. Use of MR angiography may obviate the need for routine diagnostic DS angiography in select patients.

The authors report the case of a 34-year-old woman who presented with increasing headaches. Neuroimaging revealed bilateral anomalous vessels arising at the level of each ophthalmic artery, coursing rostromedially to join the anterior communicating artery (ACA), which harbored an aneurysm. Intraoperatively, the authors identified an abnormal gyral segmentation of the frontoorbital region, with a median gyrus separated from the olfactory tracts on each side by the gyrus rectus. No interhemispheric fissure was observed in the exposed area. This is the first report in the literature of an abnormal gyral segmentation in association with an infraoptic course of an ACA. Recognition of this possible gyral abnormality in association with this vascular anomaly is relevant for surgical exposure and treatment of aneurysms by clip placement.

A 52-year-old woman developed subarachnoid hemorrhage (SAH) caused by a ruptured right internal carotid artery (ICA) aneurysm. Because of the aneurysm configuration, the authors decided to delay surgery and instead undertook serial imaging studies of the aneurysm. The patient remained alert but developed acute bilateral deafness on Day 7. Audiological examination and auditory brainstem responses suggested that the hearing disturbance was cortical in origin. Three-dimensional computed tomography (CT) angiography showed severe vasospasm in the right middle cerebral artery (MCA) and moderate vasospasm in the left ICA and MCA. Three-tesla magnetic resonance (MR) imaging was performed 2 days after the onset of symptoms. Diffusion-weighted and T2-weighted MR images showed an acute infarction in the right insular cortex caused by vasospasm. Perfusion-weighted MR imaging, particularly mean transit time mapping, revealed hypoperfusion in both temporal lobes including the auditory cortex and right auditory radiation. The vasospasm was treated with induction of mild hypertension and hypervolemia. Follow-up MR images, 3D CT angiograms, and audiometry performed 2 weeks after the first examination showed recovery of vasospasm and resolution of perfusion abnormality and hearing disturbance. On Day 26, the aneurysm was successfully occluded with clips and the patient was discharged with no deficits. To the authors' knowledge, this is the first reported case of reversible cortical auditory dysfunction purely due to bilateral cerebral vasospasm detected using perfusion MR imaging after SAH.

The authors report three cases of progressive vasogenic brain edema surrounding a cerebral aneurysm after endovascular coil embolization. In all three cases embolization was incomplete due to the aneurysms' large sizes and wide necks. Follow-up magnetic resonance imaging revealed de novo vasogenic brain edema surrounding the aneurysms 3 to 6 months after the initial treatment. The edema progressed in parallel with regrowth of the aneurysms. All three aneurysms were deep in the brain parenchyma and showed intramural enhancement, suggesting hemorrhage or inflammation. Each patient underwent a second embolization for the aneurysm regrowth, which resulted in improvement of the edema. Based on the findings in these cases and review of the literature, it is suggested that incomplete occlusion of larger aneurysms that are deep within the brain may lead to a disorganized intraluminal thrombosis, aneurysm pulsing, and intramural hemorrhage or inflammation, all of which are associated with brain edema following aneurysm recanalization and regrowth. It should be kept in mind that incomplete embolization of larger aneurysms may cause such malignant change and that this complication may occur after endovascular treatment.

Object: Nonconvulsive status epilepticus (NCSE) is an underrecognized and poorly understood complication of aneurysmal subarachnoid hemorrhage (SAH). The authors evaluated the risk factors, electroencephalographic (EEG) characteristics, hospital course, and clinical outcomes associated with NCSE in a population with SAH treated at a single institution., Methods: The hospitalization and outcome data were reviewed in 11 patients who had received a diagnosis of NCSE and SAH. The study included individuals from a cohort of 389 consecutive patients with SAH who were treated between March 2003 and June 2005, and who were analyzed retrospectively. The patients' medical history, neurological grade, events of hospitalization, EEG morphological patterns, and disposition were analyzed. Advanced age, female sex, need for ventriculostomy, poor neurological grade (Hunt and Hess Grade III, IV, or V), thick cisternal blood clots, and structural lesions (intracerebral hemorrhage and stroke) were common in the population with NCSE. Patients with normal results on angiograms, good neurological grade (Hunt and Hess Grade I or II), and minimal SAH (Fisher Grade 1 or 2) were at lower risk. The most common ictal patterns were intermittent, and consisted of generalized periodic epileptiform discharges. Medical complications were also frequent, and the outcome of these patients was poor despite aggressive treatment regimens., Conclusions: Nonconvulsive status epilepticus is a devastating complication of SAH with a high rate of associated morbidity. Based on these findings it appears that the patients at highest risk for NCSE can be identified, and this should provide a basis for further studies designed to determine the clinical significance of various EEG patterns and to develop preventative strategies.

This 34-year-old man with a 10-year history of HIV infection presented with an acute onset of severe headache, fever, nausea, vomiting, and left-sided weakness. Computed tomography (CT) scanning demonstrated diffuse subarachnoid hemorrhage (SAH), and subsequent CT angiography revealed multiple large and giant intracranial aneurysms with diffuse vasculopathy. The patient's CD4-positive cell count was low, although he had been receiving combination antiretroviral therapy and his viral load was undetectable. The preponderance of the literature on HIV-infected patients with intracranial vascular involvement has concerned children in whom there is a high viral load. In such children, appropriate antiretroviral therapy may result in the complete resolution of these vascular abnormalities. In the present study, the authors report on the unique case of an HIV-infected adult patient who presented with SAH, diffuse intracranial vasculopathy, and multiple giant and fusiform aneurysms, despite having received adequate antiretroviral treatment and demonstrating an undetectable viral load. Intracranial vascular involvement in these patients may become increasingly common as the management of HIV infection continues to improve and afflicted patients survive for longer periods.

Partially thrombosed giant aneurysms that are located at the basilar artery (BA) bifurcation and are not amenable to clip application are among the most challenging lesions for neurosurgeons. They compress vital structures such as the brainstem and the thalamus, and the prognosis is extremely poor when they are left untreated. Although obliteration of the upper BA is a promising approach for these aneurysms, some lesions are refractory to this treatment, and effective additional strategies have not been clearly established. The authors report a case treated by placement of clips in the unilateral posterior cerebral artery (PCA) and posterior communicating artery as well as by superficial temporal artery-PCA bypass after unsuccessful upper BA obliteration. Complete thrombosis and dramatic shrinkage of the aneurysm were obtained.

The incidence of aneurysms coexisting with arteriovenous malformations (AVMs) ranges between 2.7 and 16.7%. The anatomical relationship between the AVM and the aneurysm is critical in deciding the best management. As a broad guide, this relationship can be classified as follows: 1) aneurysms unrelated to the AVM; or 2) aneurysms located on the feeding vessels to the nidus, which may be far away from the nidus or close to it or even within the nidus itself. Although radiosurgery has been widely accepted as a method of choice for AVM treatment, the role of radiosurgery for arterial aneurysms has not been adequately discussed.

Object: The authors conducted a study to determine the utility of the clinical profile and magnetic resonance (MR) angiography in evaluating patients with isolated third cranial nerve palsies or posterior communicating artery (PCoA) aneurysms., Methods: Three-dimensional time-of-flight MR angiography was performed in a consecutive series of patients with isolated acute third cranial nerve palsy not due to a ruptured aneurysm and in patients with unruptured PCoA aneurysms. A neuroradiologist, masked to the identities of the patients, interpreted reformatted maximum intensity projection (MIP) and source images of the PCoAs and aneurysms. The investigators assessed clinical features of oculomotor nerve dysfunction and focal head pain. Cases involving cranial third nerve palsy without aneurysms were classified as Group 1 (no case entailed catheter-based angiography), and cases involving PCoA aneurysms seen on MR angiography (42 cases confirmed by catheter-based angiography) were classified as Group 2. The mean age of the 73 patients in Group 1 was 60.1 years and that of the 45 patients in Group 2 was 59.1 years (p = 0.37). The pattern and severity of oculomotor (p = 0.61) and lid (p = 0.83) dysfunction and pain frequency (p = 0.2) were similar for the 73 patients with vasculopathy in Group 1 and the 15 symptomatic patients in Group 2. Abnormal pupils were observed in 38% of the patients in Group 1 and 80% of those in Group 2 (p = 0.016). In cases of complete external third nerve palsy, nine of 22 in Group 1 and none of four in Group 2 had normal pupil function. For all patients, source imaging showed 206 PCoAs (85%) and MIP imaging demonstrated 120 PCoAs (49%). Of 48 aneurysms (three bilateral), MIP imaging showed 44 (92%) and source imaging showed 47 (98%). Only a 2-mm aneurysm seen on catheter-based angiography was missed by MR angiography. Symptomatic aneurysms were equal or greater than 4 mm in size., Conclusions: Only the presence of complete external third nerve palsy and normal pupil function allowed ischemia to be clinically distinguished from a PCoA aneurysm in a patient with isolated third nerve palsy and no subarachnoid hemorrhage. When source image MR angiography demonstrates normal findings, catheter-based angiography need not be performed in these patients, even if pupil function is abnormal.

Object: Neurogenic stunned myocardium in aneurysmal subarachnoid hemorrhage (SAH) is associated with a wide spectrum of reversible left ventricular wall motion abnormalities and includes a subset of patients with a pattern of apical akinesia and concomitant sparing of basal segments called "tako-tsubo cardiomyopathy"., Methods: After obtaining institutional review board approval, the authors retrospectively identified among all patients admitted to the Mayo Clinic's Neurological Intensive Care Unit between January 1990 and January 2005 those with aneurysmal SAH who had met the echocardiographic criteria for tako-tsubo cardiomyopathy. Among 24 patients with SAH-induced reversible cardiac dysfunction, the authors identified eight with SAH-induced tako-tsubo cardiomyopathy. All eight patients were women with a mean age of 55.5 years (range 38.6-71.1). Seven patients presented with a poor-grade SAH, reflected by a Hunt and Hess grade of III or IV. Four patients underwent aneurysm clip application, and four underwent endovascular coil occlusion. The initial mean ejection fraction (EF) was 38% (range 25-55%), and the mean EF at recovery was 55% (range 40-68%). Cerebral vasospasm developed in six patients, but cerebral infarction developed in only three patients., Conclusions: The authors describe the largest cohort with aneurysmal SAH-induced tako-tsubo cardiomyopathy. In the SAH population, tako-tsubo cardiomyopathy predominates in postmenopausal women and is often associated with pulmonary edema, prolonged intubation, and cerebral vasospasm. Additional studies are warranted to understand the complex mechanism involved in tako-tsubo cardiomyopathy and its intriguing relationship to neurogenic stunned myocardium.