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Unruptured intracranial aneurysms (UIAs) are a major public health issue. These lesions have become increasingly recognized in recent years with the advent of advanced cerebral imaging techniques. Epidemiological evidence from multiple sources suggests that most intracranial aneurysms do not rupture. Therefore, it is desirable to identify which UIAs are at greatest risk of rupture when considering which to repair. It is important to compare size-, site-, and group-specific natural history rates with size-, site-, and age-specific morbidity and mortality associated with UIA repair because increased natural history risk often is associated with increased risk of aneurysm repair. Patient age is crucial in decision making because of its major effect on operative morbidity and mortality; however, it does not substantially affect natural history. The effect of age is most notable in patients about 50 years of age and older for open surgery and about 70 years of age and older for endovascular procedures. In general, rupture risk is lowest for patients in asymptomatic group 1 (no history of subarachnoid hemorrhage) with UIAs less than 7 mm in diameter in the anterior circulation. Surgical morbidity and mortality are most favorable for asymptomatic patients younger than 50 years who have UIAs less than 24 mm in diameter in the anterior circulation and no history of ischemic cerebrovascular disease. Endovascular morbidity and mortality may be less age dependent, and this could favor endovascular procedures, particularly in patients aged 50 to 70 years. An important issue is determining immediate vs long-term risk regarding treatment effectiveness and durability. This issue emphasizes the importance of long-term follow-up in patients after surgical and endovascular procedures. [ABSTRACT FROM AUTHOR]

Aneurysmal subarachnoid hemorrhage (SAH) is often a neurologic catastrophe. Diagnosing SAH can be challenging, and treatment is complex, sophisticated, multidisciplinary, and rarely routine. This review emphasizes treatment in the intensive care unit, surgical and endovascular therapeutic options, and the current state of treatment of major complications such as cerebral vasospasm, acute hydrocephalus, and rebleeding. Outcome assessment in survivors of SAH and controversies in screening of family members are discussed. [ABSTRACT FROM AUTHOR]

After immediate intervention for cerebral infarction or transient ischemic attack (TIA), the primary goal is secondary prevention of future cerebral ischemia and prevention of complications related to the initial ischemic event. The goals of the diagnostic evaluation are to (1) determine potential contributing mechanisms (cardioembolic, large-vessel disease of the extracranial and intracranial vessels, small-vessel disease, coagulation defects, and cryptogenic), (2) identify contributing risk factors (hypertension, hyperlipidemia, tobacco use, diabetes), and (3) complete the evaluation in a cost-effective and safe manner. We provide a sequential approach to the diagnostic evaluation of cerebral infarction or TIA to optimize diagnostic yield of testing, minimize cost and potential harm to the patient, and provide information that will change management. This systematic approach focuses on 6 important questions: (1) Are the symptoms consistent with a cerebral infarction or TIA (versus nonischemic pathology)? (2) Where does the ischemic event localize? (3) What etiologies and mechanisms of cerebral infarction and TIA are possible? (4) What is the prevalence of each potential etiology? (5) What treatments are available for this etiology? (6) What tests and studies are useful to evaluate this etiology? [ABSTRACT FROM AUTHOR]

Background and Importance: Progressive episodic spells of altered levels of consciousness, often advancing to include paroxysmal autonomic instability, may be indicative of a diencephalic dysfunction underlying spontaneous intracranial hypotension (SIH). A rare, and often indolent, etiology may be spinal cerebrospinal fluid (CSF) leak-an elusive diagnosis, especially in cases of CSF-venous fistula (CVF) that are often missed on routine computed tomography (CT) myelography and magnetic resonance imaging (MRI)., Clinical Presentation: We report an unusual case of a 50-yr-old woman who presented with rapidly progressive cyclical, self-resolving episodes of altered mentation and decreased arousal later in the day. Scrutiny of serial brain MRIs led to a diagnosis of SIH, with severe downward diencephalic and brain stem displacement-resulting in cerebral aqueduct occlusion with obstructive hydrocephalus. Initial clinical improvement occurred with CSF diversion, but the patient quickly deteriorated-developing diencephalic spells, including extensor posturing and severely depressed levels of consciousness. Clinical improvement was seen with stopping CSF diversion and Trendelenburg-positioning. After intensive spinal imaging, dynamic CT myelography identified a left T10 nerve root diverticula and CSF-venous fistula. Surgical obliteration resulted in rapid, profound neurological improvement, and ultimately full neurological recovery by 1 yr., Conclusion: In our patient, worsening episodes of confusion, postural headaches, and autonomic instability developed due to SIH, which induced profound downward displacement and compression of the diencephalon and brain stem, and accompanied by subsequent obstructive hydrocephalus. Diagnostic persistence identified the CVF, which had caused the complex multifold pathophysiology and clinical presentation. If suspicion remains high for CVF, persistent spinal imaging, particularly with dynamic myelography, may be crucial., (© Congress of Neurological Surgeons 2021.)

Background and Objective: Epidural blood patch (EBP) is a safe and effective treatment for spontaneous intracranial hypotension (SIH), but clinical and procedural variables that predict EBP efficacy remain nebulous., Methods: This study is an institutional review board-approved retrospective case series with dichotomized EBP efficacy defined at 3 months. The study included 202 patients receiving 604 EBPs; iatrogenic cerebrospinal fluid leaks were excluded., Results: Of the EBPs, 473 (78%) were single-level, 349 (58%) lumbar, 75 (12%) bilevel, and 56 (9%) multilevel (≥3 levels). Higher volume (OR 1.64; p<0.0001), bilevel (3.17, 1.91-5.27; p<0.0001), and multilevel (117.3, 28.04-490.67; p<0.0001) EBP strategies predicted greater efficacy. Only volume (1.64, 1.47-1.87; p<0.0001) remained significant in multivariate analysis. Site-directed patches were more effective than non-targeted patches (8.35, 0.97-72.1; p=0.033). Lower thoracic plus lumbar was the most successful bilevel strategy, lasting for a median of 74 (3-187) days., Conclusions: In this large cohort of EBP in SIH, volume, number of spinal levels injected, and site-directed strategies significantly correlated with greater likelihood of first EBP efficacy. Volume and leak site coverage likely explain the increased efficacy with bilevel and multilevel patches. In patients with cryptogenic leak site, and either moderate disability, negative prognostic brain MRI findings for successful EBP, or failed previous lumbar EBP, a low thoracic plus lumbar bilevel EBP strategy is recommended. Multilevel EBP incorporating transforaminal administration and fibrin glue should be considered in patients refractory to bilevel EBP. An algorithmic approach to treating SIH is proposed., Competing Interests: Competing Interest: None declared., (© American Society of Regional Anesthesia & Pain Medicine 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Dr Albert L. Rhoton Jr became the focal point of neurosurgery's evolution in understanding the intricate and complex microanatomy of the human brain over the last 4 decades. His pioneering work on cadaveric specimens proved to be a pivotal endeavor in the pursuit to better understand the complex microsurgical anatomy of cranial surgery. This paper details his early career at the Mayo Clinic in Rochester, Minnesota. A comprehensive review and synthesis of data acquired from the institutional historical archives including the Annual Reports to the Executive Committee, the Reports to the Board of Directors, the MAYOVOX Newsletter, the illustration archives of the Mayo Clinic Division of Creative Media, staff biographies, curriculum vitae, personal interviews, as well as full-text journal articles, and book publications was performed. Dr Rhoton was engaged in a busy clinical practice as a young staff at the Mayo Clinic. Records show he focused on tackling complex intracranial pathologies along with numerous basic research and neuroanatomy projects that became a major part of his life's work and passion. He was a great teacher and friend to countless individuals and his work will continue to impact and improve the care provided to neurosurgery patients for generations to come.

Background: There are conflicting data between natural history studies suggesting a very low risk of rupture for small, unruptured intracranial aneurysms and retrospective studies that have identified a much higher frequency of small, ruptured aneurysms than expected., Objective: To use the prospective International Study of Unruptured Intracranial Aneurysms cohort to identify morphological characteristics predictive of unruptured intracranial aneurysm rupture., Methods: A case-control design was used to analyze morphological characteristics associated with aneurysm rupture in the International Study of Unruptured Intracranial Aneurysms database. Fifty-seven patients with ruptured aneurysms during follow-up were matched (by size and location) with 198 patients with unruptured intracranial aneurysms without rupture during follow-up. Twelve morphological metrics were measured from cerebral angiograms in a blinded fashion., Results: Perpendicular height (P = .008) and size ratio (ratio of maximum diameter to the parent vessel diameter; P = .01) were predictors of aneurysm rupture on univariate analysis. Aspect ratio, daughter sacs, multiple lobes, aneurysm angle, neck diameter, parent vessel diameter, and calculated aneurysm volume were not statistically significant predictors of rupture. On multivariate analysis, perpendicular height was the only significant predictor of rupture (Chi-square 7.1, P-value .008)., Conclusion: This study underscores the importance of other morphological factors, such as perpendicular height and size ratio, that may influence unruptured intracranial aneurysm rupture risk in addition to greatest diameter and anterior vs posterior location., Competing Interests: Dr Mocco serves as a consultant to Cerebrotech, Pulsar, TSP Inc, and Rebound Medical. Dr Mocco has investor interests in Blockade Medical and TSP Inc. The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article.

Object: The aim of this study was to determine age-related differences in short-term (1-year) outcomes in patients with unruptured intracranial aneurysms (UIAs)., Methods: Four thousand fifty-nine patients prospectively enrolled in the International Study of Unruptured Intracranial Aneurysms were categorized into 3 groups by age at enrollment: < 50, 50-65, and > 65 years old. Outcomes assessed at 1 year included aneurysm rupture rates, combined morbidity and mortality from aneurysm procedure or hemorrhage, and all-cause mortality. Periprocedural morbidity, in-hospital morbidity, and poor neurological outcome on discharge (Rankin scale score of 3 or greater) were assessed in surgically and endovascularly treated groups. Univariate and multivariate associations of each outcome with age were tested., Results: The risk of aneurysmal hemorrhage did not increase significantly with age. Procedural and in-hospital morbidity and mortality increased with age in patients treated with surgery, but remained relatively constant with increasing age with endovascular treatment. Poor neurological outcome from aneurysm- or procedure-related morbidity and mortality did not differ between management groups for patients 65 years old and younger, but was significantly higher in the surgical group for patients older than 65 years: 19.0% (95% confidence interval [CI] 13.9%-24.4%), compared with 8.0% (95% CI 2.3%-13.6%) in the endovascular group and 4.2% (95% CI 2.3%-6.2%) in the observation group. All-cause mortality increased steadily with increasing age, but differed between treatment groups only in patients < 50 years of age, with the surgical group showing a survival advantage at 1 year., Conclusions: Surgical treatment of UIAs appears to be safe, prevents 1-year hemorrhage, and may confer a survival benefit in patients < 50 years of age. However, surgery poses a significant risk of morbidity and death in patients > 65 years of age. Risk of endovascular treatment does not appear to increase with age. Risks and benefits of treatment in older patients should be carefully considered, and if treatment is deemed necessary for patients older than 65 years, endovascular treatment may be the best option.

Background: Ventral spinal epidural meningeal cysts are rare entities for which the pathogenesis is poorly understood., Objective: We present the clinical, radiographic, surgical, and pathologic findings of 4 patients with extensive ventral spinal epidural meningeal cysts and review the relevant literature. In addition, we discuss a suspected mechanism for pathogenesis., Methods: Four patients with anterior spinal epidural meningeal cysts are retrospectively reviewed., Results: Ventral spinal epidural meningeal cysts are often large, extending on average from C2 to L1 in our series. Patients typically present with a prolonged course of symptoms and signs, including segmental muscle weakness and atrophy, subtle myelopathy, mild to moderate spinal pain, and headache. Histopathologic analysis of the cyst wall demonstrates collagenous tissue consistent with dura but without arachnoid features. Dynamic computed tomographic myelography is the study of choice for localization of the primary dural defect. Patient symptoms and neurological deficits routinely improve after appropriate surgical intervention., Conclusion: Diverse signs and symptoms herald the presentation of ventral spinal meningoceles. Intraoperative, radiographic, and pathological findings are all suggestive of an intradural dissection as the etiology. Hence, they may be more appropriately named "ventral spinal intradural dissecting meningoceles." Definitive treatment involves identification and obliteration of the dural defect.

Background and Purpose: Chronic inflammation is postulated as an important phenomenon in intracranial aneurysm wall pathophysiology. This study was conducted to determine if aspirin use impacts the occurrence of intracranial aneurysm rupture., Methods: Subjects enrolled in the International Study of Unruptured Intracranial Aneurysms (ISUIA) were selected from the prospective untreated cohort (n=1691) in a nested case-control study. Cases were subjects who subsequently had a proven aneurysmal subarachnoid hemorrhage during a 5-year follow-up period. Four control subjects were matched to each case by site and size of aneurysm (58 cases, 213 control subjects). Frequency of aspirin use was determined at baseline interview. Aspirin frequency groups were analyzed for risk of aneurysmal hemorrhage. Bivariable and multivariable analyses were performed using conditional logistic regression., Results: A trend of a protective effect for risk of unruptured intracranial aneurysm rupture was observed. Patients who used aspirin 3× weekly to daily had an OR for hemorrhage of 0.40 (95% CI, 0.18-0.87); reference group, no use of aspirin), patients in the "< once a month" group had an OR of 0.80 (95% CI, 0.31-2.05), and patients in the "> once a month to 2×/week" group had an OR of 0.87 (95% CI, 0.27-2.81; P=0.025). In multivariable risk factor analyses, patients who used aspirin 3 times weekly to daily had a significantly lower odds of hemorrhage (adjusted OR, 0.27; 95% CI, 0.11-0.67; P=0.03) compared with those who never take aspirin., Conclusions: Frequent aspirin use may confer a protective effect for risk of intracranial aneurysm rupture. Future investigation in animal models and clinical studies is needed.

Background: Myelopathy from ectatic vertebral artery compression of the spinal cord at the cervicomedullary junction is a rare condition., Case Description: A 63-year-old female was originally diagnosed with occult hydrocephalus syndrome after presenting with symptoms of ataxia and urinary incontinence. Ventriculoperitoneal shunting induced an acute worsening of the patient's symptoms as she immediately developed a sensory myelopathy. An MR scan demonstrated multiple congenital abnormalities including cervicomedullary stenosis with anomalous vertebral artery compression of the dorsal spinal cord at the cervicomedullary junction. The patient was taken to surgery for a suboccipital craniectomy, C1-2 laminectomy, vertebral artery decompression, duraplasty, and shunt ligation. Intraoperative findings confirmed preoperative radiography with ectactic vertebral arteries deforming the dorsal aspect of the spinal cord. There were no procedural complications and at a 6-month follow-up appointment, the patient had experienced a marked improvement in her preoperative signs and symptoms., Conclusion: Myelopathy from ectatic vertebral artery compression at the cervicomedullary junction is a rare disorder amenable to operative neurovascular decompression.

Background: Embolization of spinal dural arteriovenous fistulae (SDVAFs) has emerged as an alternative to surgery. However, surgical disconnection is a simple and effective procedure., Objective: To review results and complications of surgical treatment of 154 consecutive SDAVFs., Methods: The records of 154 consecutive patients with SDAVFs were retrospectively reviewed., Results: There were 120 males and 34 females (male/female ratio 3.5:1, mean age 63.6 years). The SDAVFs were located at the thoracic level in 92 patients and at the lumbar and sacral spine levels in 45 and 15 patients, respectively. The most common presenting symptoms were motor dysfunction (65 patients), sensory loss (31 patients), and paresthesias without sensory loss (13 patients). The mean interval from symptom onset to definitive diagnosis was 24.7 months (median 12 months). Surgery resulted in complete exclusion of the fistula at first attempt in 146 patients (95%). There were no deaths or major neurological complications related to the surgery. Six percent of patients experienced subjective or objective worsening of preoperative symptoms and signs by the time of discharge that persisted at follow-up. Other surgical complications consisted of wound infection in 2 patients and deep venous thrombosis in 3. Eight patients were lost to follow-up; 141 patients (96.6%) experienced improvement (120 patients, 82.2%) or stability (21 patients, 14.4%) of motor function at last follow-up compared with their preoperative status. Other symptoms such as numbness, sphincter dysfunction, and dysesthesias/neuropathic pain improved in 51.5%, 45%, and 32.6%, respectively., Conclusion: Surgical obliteration of SDAVFs is safe and very effective. Prognosis of motor function is favorable after surgical treatment.

Background and Purpose: The purpose of this study was to determine and compare the rate of stroke, myocardial infarction, and death in patients undergoing early and late carotid endarterectomy (CEA) after a symptomatic event and in asymptomatic patients., Methods: We conducted a retrospective analysis of all CEAs performed in the Department of Neurosurgery between January 2004 and May 2009. Patients were divided into 3 groups: Group 1, asymptomatic patients; Group 2, symptomatic patients operated on >2 weeks after their transient ischemic attack or stroke; and Group 3, symptomatic patients operated on ≤2 weeks of their transient ischemic attack or stroke. Primary outcomes were any myocardial infarction, stroke, or death occurring within 30 days postoperatively. The secondary end point was transient ischemic attack within 30 days postoperatively., Results: Five hundred thirty-two CEAs were performed on 507 patients during the study period. Thirty-day follow-up was available for 500 patients with 525 CEAs. Groups 1, 2, and 3 consisted of 278, 105, and 142 CEAs, respectively. In total, 12 patients had primary outcomes. In Group 1, 5 patients had primary outcomes of stroke, myocardial infarction, or death (1.8%); in Group 2, 1 patient had primary outcomes (1.0%); and in Group 3, 6 patients had primary outcomes (4.2%). There was no significant difference in the rate of primary outcomes among the 3 groups (P=0.17) or when Groups 2 and 3 were compared (P=0.24)., Conclusions: Although the perioperative risk of transient ischemic attacks, stroke, death, and myocardial infarction is slightly higher in symptomatic patients operated on early, CEA can be done with an acceptable risk in properly selected symptomatic patients within 2 weeks of their transient ischemic attack or stroke.

A source of bleeding is often not evident during the evaluation of patients with superficial siderosis of the CNS despite extensive imaging. An intraspinal fluid-filled collection of variable dimensions is frequently observed on spine MR imaging in patients with idiopathic superficial siderosis. A similar finding has also been reported in patients with idiopathic intracranial hypotension. The authors report on a patient with superficial siderosis and a longitudinally extensive intraspinal fluid-filled collection secondary to a dural tear. The patient had a history of low-pressure headaches. His spine MR imaging and spine CT suggested the possibility of an underlying vascular malformation, but none was found on angiography. Repair of the dural tear resulted in resolution of the intraspinal fluid collection and CSF abnormalities. The significance of the association between superficial siderosis and idiopathic intracranial hypotension, and potential therapeutic and pathophysiological implications, are the subject of this report.

Objective: Although cardiovascular risk factors have been strongly linked to carotid intimal-media thickness, their association with plaque progression towards instability is poorly understood. We evaluated a large database of endarterectomy specimens removed from symptomatic and asymptomatic patients to determine the correlation between major cardiovascular risk factors and carotid plaque morphology., Methods: Incidence of thrombotic, vulnerable and stable plaques together with the degree of plaque inflammatory infiltration was evaluated in 457 carotid atherosclerotic lesions. Clinical records were reviewed in all cases for risk factors profile., Results: Thrombotic plaques were more frequently observed in patients affected by stroke (66.9%) as compared to TIA (36.1%) and asymptomatic patients (26.8%, p<0.001). Out of 457 carotid plaques removed during carotid endarterectomy, 181 (39.6%) were represented by thrombotic plaques, 72 (15.8%) by vulnerable plaques (thin cap fibroateroma) and 204 (44.6%) by stable plaques. At the multivariate analysis, a strong association was observed between hypertension, low HDL-cholesterol (HDL-C) and ratio of total to HDL-C >5 with vulnerable and thrombotic carotid plaques. Hypertension (p=0.001), hypercholesterolemia (p=0.05) and low HDL-C (p=0.001) significantly also correlated with the presence of high inflammatory infiltrate of the plaque. When multivariate analysis was restricted to asymptomatic patients, hypertension (p=0.009, OR 2.29), low HDL-cholesterol (p=0.01 OR 2.21) and the ratio of total to HDL-C >5 (p=0.03, OR 2.07) were confirmed to be the risk factors most significantly associated to unstable plaques. The relative risk to carry an unstable plaque for asymptomatic patients with high Framingham Risk Score as compared with those with low risk score was 2.06 (95% C.I., 1.26-3.36)., Conclusions: The present histopathological study identifies risk factors predictive of increased risk of carotid plaque rupture and thrombosis. Asymptomatic patients with high risk factors profile may constitute a specific target to reduce the likelihood of cerebrovascular accidents even in the presence of non-flow-limiting plaque., (Copyright 2009 Elsevier Ireland Ltd. All rights reserved.)

Object: Although nontraumatic spinal arteriovenous malformations and fistulas (AVMs and AVFs) restricted to the epidural space are rare, they can lead to significant neurological morbidity. Careful diagnostic imaging is essential to their detection and the delineation of the pathological anatomy. Aggressive endovascular and open operative treatment can provide arrest and reversal of neurological deficits., Methods: The authors report on 6 cases of extradural AVMs/AVFs causing progressive myelopathy. Clinical findings, diagnostic evaluation, treatment, and outcome are discussed. Special consideration is given to the anatomy of the lesions and the operative techniques used to treat them. A review of the literature concerning extradural vascular malformations is also presented., Results: All 6 cases of extradural AVMs had an extradural fistulous location with intradural medullary venous drainage. These cases illustrate progressive myelopathy through cord venous congestion (hypertension) that can be caused by an extradural nidus or fistula. In 4 cases, a large epidural lake was identified on angiography. At surgery, the epidural lake was obliterated and medullary drainage interrupted. All patients had stabilization of their neurological deficits and successful obliteration of the AVM/AVF was obtained., Conclusions: Extradural AVMs and AVFs are a poorly described entity with published clinical experience limited to sporadic case reports and small series. Although these lesions have a purely extradural location of arteriovenous shunting and early venous drainage, they can be responsible for acute and progressive neurological symptoms similar to those caused by their dural-based intradural counterparts. With careful imaging recognition of the pathological anatomy, surgical and endovascular techniques can be used for the treatment of extradural AVMs affording effective and durable obliteration with stabilization or reversal of neurological symptoms. Venous drainage directly correlates the pathologic mechanisms of presentation. Specific attention must be paid intraoperatively to the epidural lake common to both variants so that recurrence is avoided.

Background: Hydrophilic coatings on arterial introducer sheaths reduce the frequency of spasm during cardiac catheterization. Moreover, during treatment of cerebral artery aneurysms, hydrophilic coatings on microcatheters ease their maneuverability, and polymers within embolization coils enhance neointimal fibrosis at the aneurysm neck. Foreign-body giant cell reactions can result when a polymer is stripped from its source. CASES 1 AND 2: A 51-year-old man and a 66-year-old woman underwent coronary angiography via the radial artery, using hydrophilic-coated sheaths. They both developed tender lesions at the access site 2 weeks later. Microscopy of resected lesions showed pieces of hydrophilic coating and granulomatous inflammation, as has been reported by others. CASE 3: A 58-year-old woman underwent embolization of a ruptured distal right internal carotid artery aneurysm using polymer-containing coils. Nine months later, she began developing multiple right-sided cerebral ring-enhancing lesions. Biopsy revealed granulomas and microabscesses, in which polymer filaments were later identified. To our knowledge, this complication has not been described previously., Conclusions: Hydrophilic coating may dislodge and induce a prominent foreign-body granulomatous response or microabscesses. Although the culprit radial artery sheath is now rarely used, embolization coils containing polymers are commonly deployed in clinical practice and may be a source of recurrent inflammatory lesions.

Object: Spontaneous intracerebral hemorrhage is an uncommon but recognized initial presenting sign of both primary and metastatic brain tumors. The rate of tumor-related intracranial hemorrhage is variably reported from <1 to 14.6%. Hemorrhage in primary gliomas occurs in 3.7-7.2% of gliomas, mainly in glioblastoma muliforme and oligodendroglioma with low-grade astrocytomas accounting for <1%. Hemorrhage associated with pilocytic astrocytomas (PAs) is only sporadically reported. The authors report on a series of patients in whom PAs presenting as hemorrhages prompted them to examine the incidence of bleeding in these tumors., Methods: Cases involving a confirmed tissue diagnosis of PA from 1994-2005 were reviewed retrospectively. The authors included only patients with evidence of hemorrhage on computed tomography and/or magnetic resonance imaging seen prior to biopsy or resection and in the absence of trauma or other vascular pathological entities., Results: In 138 patients with histologically proven PAs, the mean age at diagnosis was 23 years. In 11 patients (8%; 5 male and 6 female) there was evidence of hemorrhage at presentation. There were no locations more susceptible to hemorrhage than any other, although no bleeding occurred within the cerebellum. All but 1 patient was treated with a gross-total resection., Conclusions: Hemorrhage in association with PAs likely results from the frequently observed abnormal vasculature in these tumors, occurs with a greater frequency than previously thought, and should be considered in the differential diagnosis of spontaneous intracerebral hemorrhage.

Craniopharyngiomas are low-grade epithelial neoplasms occurring almost exclusively in the sellar/suprasellar region. Histologic malignancy is extremely rare; the literature consists mostly of isolated case reports. Herein, we report 3 patients with craniopharyngiomas exhibiting histologic malignancy, 2 of which received radiation therapy before its appearance. Hematoxylin and eosin-stained slides and selected immunohistochemical stains were reviewed in all cases. Microvessel density analysis was performed in case 2. The patients included 2 men and 1 woman, age 14, 31, and 58 years at presentation, respectively. All patients expired 3 months to 9 years after first resection and 3 to 9 months after identification of histologic malignancy. The latter developed after multiple recurrences and radiation therapy in 2 cases, but seemed to arise de novo in 1 case resembling odontogenic ghost cell carcinoma and lacking any definite low-grade craniopharyngioma precursor. The malignant component of the other 2 cases resembled squamous cell carcinoma and low-grade myoepithelial carcinoma, respectively. The MIB-1 labeling index was markedly increased in the malignant component in comparison with the low-grade precursor. Malignant transformation in craniopharyngiomas, although rare, does exist. It assumes varied histologic appearances, usually after multiple recurrences and radiation therapy, and has a near uniformly fatal outcome. De novo malignancy in odontogenic tumors of the sella is even more unusual, but also has an ominous prognosis.

Unruptured intracranial aneurysms (UIAs) are a major public health issue. These lesions have become increasingly recognized in recent years with the advent of advanced cerebral imaging techniques. Epidemiological evidence from multiple sources suggests that most intracranial aneurysms do not rupture. Therefore, it is desirable to identify which UIAs are at greatest risk of rupture when considering which to repair. It is important to compare size-, site-, and group-specific natural history rates with size-, site-, and age-specific morbidity and mortality associated with UIA repair because increased natural history risk often is associated with increased risk of aneurysm repair. Patient age is crucial in decision making because of its major effect on operative morbidity and mortality; however, it does not substantially affect natural history. The effect of age is most notable in patients about 50 years of age and older for open surgery and about 70 years of age and older for endovascular procedures. In general, rupture risk is lowest for patients in asymptomatic group 1 (no history of subarachnoid hemorrhage) with UIAs less than 7 mm in diameter in the anterior circulation. Surgical morbidity and mortality are most favorable for asymptomatic patients younger than 50 years who have UIAs less than 24 mm in diameter in the anterior circulation and no history of ischemic cerebrovascular disease. Endovascular morbidity and mortality may be less age dependent, and this could favor endovascular procedures, particularly in patients aged 50 to 70 years. An important issue is determining immediate vs long-term risk regarding treatment effectiveness and durability. This issue emphasizes the importance of long-term follow-up in patients after surgical and endovascular procedures., (Reprinted with permission: Mayo Clin Proc. 2004;79(12):1572-1583 - © 2004 Mayo Foundation for Medical Education and Research.)

Objective: Spontaneous intracranial hypotension is typically caused by a spontaneous spinal cerebrospinal fluid (CSF) leak. The configuration of the related dural defects can be complex. We describe our experience with the surgical anatomy of these defects., Methods: Thirteen consecutive patients with spontaneous spinal CSF leaks who underwent surgical exploration at Mayo Clinic between 1994 and 2003 were studied. All patients' records, imaging studies, detailed intraoperative findings, and outcomes were reviewed., Results: There were four men and nine women with an average age of 40 years (range, 12-62 yr). Preoperative imaging studies revealed a single site of CSF leak in eight patients, two sites in three patients, and multiple sites in two patients. Intraoperatively, the exact site of leakage could not be found in four patients. Among the other nine patients, primary closure of a meningeal diverticulum was achieved in one patient. Significant regional attenuation of the dura prevented primary repair of the leak site in eight patients. Muscle, fibrin glue, and Gelfoam (Upjohn Co., Kalamazoo, MI) soaked in patient's own blood were commonly used to pack the epidural space in an attempt to seal the site of the leak. Ligation of two nonappendicular nerve roots allowed closure of the leak in one of these patients. Postoperatively, resolution of symptoms occurred in eight patients, significant improvement was noted in three patients, and only transient resolution in two. The mean duration of follow-up was 20.5 months., Conclusion: Surgery for closure of spontaneous spinal CSF leaks may not be straightforward. Even when extradural CSF leakage is discovered preoperatively by imaging studies, it may not always be possible to identify the exact site of the leakage intraoperatively. Furthermore, the anatomy of the dural defects may be complex and not amenable to primary closure. In such cases, the use of adjuvant techniques during surgical exploration may be effective.

Objective: Survival of cardiac arrest (CA) after aneurysmal subarachnoid hemorrhage (SAH) is poorly characterized. We analyzed the clinical course and outcome of patients who survived resuscitation for CA after aneurysmal SAH., Methods: Medical records of all patients with acute SAH treated at Mayo Clinic between 1990 and 1997 were reviewed. Three hundred five consecutive patients with angiographically proven aneurysmal SAH presenting within 7 days of ictus were analyzed. CA was defined as a pulseless state, documented by medical personnel, for which resuscitation was performed. Outcome was measured with the Glasgow Outcome Scale score at longest follow-up (mean, 16 mo)., Results: Data from 11 patients (3.6%) who had 14 episodes of CA were analyzed. Six patients had CA before reaching the hospital and were successfully resuscitated. Nine of 14 CA episodes occurred at hemorrhage or rehemorrhage. No patient with in-hospital CA failed to be resuscitated. Overall mortality in patients who had CA (46%) was higher than that of patients without CA (15%; P = 0.019). Outcome for all patients who had CA (mean Glasgow Outcome Scale score, 2.5) was worse than for patients without CA (mean Glasgow Outcome Scale score, 3.9; P = 0.005). However, half of the survivors of CA after SAH were living independently with limited deficit at longest follow-up., Conclusion: Most cases of CA occur at the time of initial or recurrent SAH. Resuscitation for in-hospital CA is likely to be successful. Although CA after aneurysmal SAH is associated with significantly higher mortality, the outcome of survivors of CA is not worse than that for other patients after aneurysmal SAH.

Objective: The new Accreditation Council for Graduate Medical Education (ACGME) requirements regarding resident work hours have been implemented since July 2003. Neurological surgery training programs have been especially affected because of the limited number of residency positions and the residents' long duty hours. The perceptions of program directors and residents may provide important insight into the evolution of new guidelines for improvement of resident training., Methods: We conducted a nationwide survey of 93 program directors and 617 residents to characterize their perceptions regarding the changes in their training programs related to compliance with the ACGME requirements. The survey was conducted from July through September 2003 using electronic mail., Results: The response rates were 45% and 23% among the program directors and residents, respectively. Most programs offered one (37%) or two (38%) resident training positions per year. Although 92% of programs had implemented the ACGME work hours requirements before or since July 2003, 8% had not yet implemented these guidelines. Sixty-eight percent of program directors indicated employment of ancillary health care professionals to fulfill the ACGME duty hours reform; 84% (95% confidence interval [CI], 64-94%) thought that this practice has not limited the residents' clinical experience. Eleven percent of respondents (18 of 164 respondents) who provided Level I trauma coverage were unable to maintain compliance with the ACGME guidelines. Ninety-three percent (95% CI, 89-96%) of all respondents thought that the work hour reform has had a negative impact on the continuity of patient care. Fifty-five percent (95% CI, 46-63%) of the residents and only 33% (95% CI, 20-50%) of the program directors thought that the ACGME requirements are likely to result in improved American Board of Neurological Surgery written test scores. Twenty-nine percent (95% CI, 22-37%) of the residents and 17% (95% CI, 8-32%) of the program directors thought that resident attendance at national conferences would increase. Similarly, although 46% (95% CI, 37-54%) of residents perceived that these work hour limitations would facilitate residents' research/publication-related activities, only 21% (95% CI, 11-37%) of program directors agreed. Forty-one percent (95% CI, 33-49%) of the residents and 74% (95% CI, 58-86%) of the program directors perceived that the chief residents operate on fewer complex cases since the institution of the ACGME duty hour guidelines. Seventy-five percent of residents think they are less familiar with their patients. Overall, 61% (95% CI, 53-69%) of the residents and 79% (95% CI, 63-89%) of the program directors noted that the ACGME guidelines have had a negative effect on their training programs., Conclusion: On the basis of their early experience, the majority of the residents and program directors think that the ACGME duty hour guidelines have had an adverse effect on continuity of patient care and resident training. The effects of these guidelines on neurosurgery programs should be carefully monitored, because more sophisticated solutions may be needed to address house staff fatigue. Strategies to enhance the educational content of the residents' work hours and to preserve continuity of patient care are necessary.

Object: Definitive data characterizing the safety and efficacy of carotid angioplasty with stent placement (CAS) for symptomatic, occlusive carotid artery (CA) disease require further refinements and standardization of techniques as well as large prospective studies on a par with the North American Symptomatic Carotid Endarterectomy Trial (NASCET). Despite the absence of such data, many surgeons have performed angioplasty and stent placement in patients with clinical or anatomical features known to add significant perioperative risk and capable of disqualifying the patients from participation in NASCET: There exists no cost analysis comparing high-risk endarterectomy with percutaneous angioplasty and stent insertion., Methods: Forty-five patients (29 men and 16 women) with high-risk, symptomatic CA stenosis have been treated with CAS at the authors' institution since 1996. Indications for this procedure included symptomatic recurrent stenosis following CA endarterectomy (CEA), active coronary disease, high CA bifurcation, and severe medical comorbidities. A longstanding CEA computer database was screened for control patients with similar risk factors; 391 patients (276 men and 115 women) were identified. Actual cost data, duration of hospital stay, and relevant clinical data from the time of treatment until hospital discharge were collected in each patient. The median total cost of CAS was dollar 10,628, whereas that for CEA was dollar 10,148 (p = 0.495)., Conclusions: In patients with high-risk, NASCET-ineligible CA stenosis there was no overall statistically significant cost difference between CEA and CAS. Given that there may not be a cost advantage for either procedure, procedural risk, efficacy, and durability should be key factors in determining the optimal treatment strategy.

Object: Previous studies have indicated an increased incidence of death in patients with subarachnoid hemorrhage (SAH) who are currently receiving anticoagulation therapy. The significance of previous aspirin use in patients with SAH is unknown. The authors analyzed the effects of prior aspirin use on clinical course and outcomes following aneurysmal SAH., Methods: The medical records of 305 patients with angiogram-confirmed aneurysmal SAH who consecutively presented to our institution between 1990 and 1997 within 7 days of ictus were analyzed. Twenty-nine (9.5%) of these patients had a history of regular aspirin use before onset of the SAH. The Glasgow Outcome Scale (GOS) was used to measure patient outcome at the longest available follow up. Aspirin users were older on average than nonusers (59 years of age compared with 53 years; p = 0.018). The mean admission Hunt and Hess grades of patients with and without aspirin use were similar (2 compared with 2.3; p = 0.51). Two trends, which did not reach statistical significance, were observed. 1) The rebleeding rate in aspirin users was 14.3%, compared with a 4.7% rebleeding rate in nonusers (p = 0.06). 2) Permanent disability from vasospasm was less common among aspirin users (23% compared with 50%; p = 0.069). Outcomes did not differ between aspirin users and nonusers (mean GOS Score 3.83 compared with GOS Score 3.86, respectively; p = 0.82)., Conclusions: Despite trends indicating increased rebleeding rates and a lower incidence of permanent disability due to delayed ischemic neurological deficits, there was no significant effect of previous aspirin use on overall outcome following aneurysmal SAH. Based on these preliminary data, the presence of an intracranial aneurysm is not a strict contraindication to aspirin use.

Context: Recent studies suggest that factors other than the degree of carotid stenosis are involved in ischemic stroke pathogenesis, especially modifications of plaque composition and related complications., Objective: To examine the role of carotid plaque rupture and thrombosis in ischemic stroke pathogenesis in patients undergoing carotid endarterectomy, excluding those with possible cardiac embolization or with severe stenosis of the circle of Willis., Design, Setting, and Patients: A total of 269 carotid plaques selected from an Interinstitutional Carotid Tissue Bank were studied by histology after surgical endarterectomy between January 1995 and December 2002. A total of 96 plaques were from patients with ipsilateral major stroke, 91 plaques from patients with transient ischemic attack (TIA), and 82 plaques from patients without symptoms., Main Outcome Measures: Differences in the frequency of thrombosis, cap rupture, cap erosion, inflammatory infiltrate, and major cardiovascular risk factors between study groups., Results: A thrombotically active carotid plaque associated with high inflammatory infiltrate was observed in 71 (74.0%) of 96 patients with ipsilateral major stroke (and in all 32 plaques from patients operated within 2 months of symptom onset) compared with 32 (35.2%) of 91 patients with TIA (P < .001) or 12 (14.6%) of 82 patients who were without symptoms (P < .001). In addition, a fresh thrombus was observed in 53.8% of patients with stroke operated 13 to 24 months after the cerebrovascular event. An acute thrombus was associated with cap rupture in 64 (90.1%) of 71 thrombosed plaques from patients with stroke and with cap erosion in the remaining 7 cases (9.9%). Ruptured plaques of patients affected by stroke were characterized by the presence of a more severe inflammatory infiltrate, constituted by monocytes, macrophages, and T lymphocyte cells compared with that observed in the TIA and asymptomatic groups (P = .001). There was no significant difference between groups in major cardiovascular risk factors., Conclusion: These results demonstrate a major role of carotid thrombosis and inflammation in ischemic stroke in patients affected by carotid atherosclerotic disease.

Objective: Hypovolemia after aneurysmal subarachnoid hemorrhage (SAH) may be mediated by natriuretic peptides and can further impair cerebral perfusion in dysautoregulated and vasospastic arterial territories. Dendroaspis natriuretic peptide (DNP), derived from the venom of Dendroaspis augusticeps, the Green Mamba snake, has recently been discovered in human plasma and atrial myocardium. There is no information regarding the presence or putative role of this peptide in patients with aneurysmal SAH., Methods: A sensitive and specific DNP radioimmunoassay was performed on venous blood samples obtained on post-SAH Days 1, 3, and 7 from 10 consecutive SAH patients (cases) and randomly from 9 healthy volunteers (controls). Clinical and laboratory data, including daily serum sodium concentration and fluid balance, were collected prospectively up to 7 days after the ictus., Results: Increase in plasma DNP levels occurred in five (63%) of eight patients who had DNP levels measured on Days 1 and 3 (mean increase, 29%). An increase in DNP level was significantly associated with development of a negative fluid balance (P = 0.003) and hyponatremia (P = 0.008). Three (75%) of the four patients who developed cerebral vasospasm during this study experienced an increase in DNP levels from Days 1 to 3., Conclusion: The present study is the first to find a significant association between elevated levels of DNP, a new member of the natriuretic peptide family, and the development of diuresis and natriuresis in patients with aneurysmal SAH. Our findings warrant further investigation by means of a large-scale, prospective, case-control study.

Introduction: Recent evidence suggests that magnesium may be neuroprotective in the setting of cerebral ischemia, and therapeutic magnesium infusion has been proposed for prophylaxis and treatment of delayed ischemic neurological deficit (DIND) resulting from vasospasm in patients with aneurysmal subarachnoid hemorrhage (SAH). We studied the association between serum magnesium levels, the development of DIND, and the outcomes of patients with SAH., Methods: We studied 128 consecutive patients with aneurysmal SAH treated at our institution between 1990 and 1997 who had a serum magnesium level measured at least once during the acute phase of their hospitalization. Delayed ischemic neurological deficit was defined as severe (major focal deficit or coma), moderate (incomplete focal deficit or decreased sensorium without coma), or none., Results: There was no significant difference in mean, minimum, or maximum serum magnesium levels between patients with and without DIND (1.93, 1.83, 2.02 versus 1.91, 1.84, 1.97 mg/dL, respectively). Similarly, no difference was found in mean serum magnesium levels among patients with severe (1.94 mg/dL), moderate (1.92 mg/dL), or no DIND (1.91 mg/dL). Analyses of serum magnesium levels before (0-4 days following SAH), during (4-14 days following SAH), and after (greater than 14 days following SAH) the period of highest risk for vasospasm revealed no association with the development or severity of DIND. Permanent deficit or death resulting from vasospasm and Glasgow Outcome Scale score at longest follow-up were similarly unaffected by serum magnesium levels overall or during any time interval. Forty (31.5%) patients were hypomagnesemic (less than 1.7 mg/dL) during hospitalization, but no difference in outcome (p = 0.185) or development of DIND (p = 0.785) was found when compared to patients with normal (1.7-2.1 mg/dL) or high (greater than 2.1 mg/dL) magnesium serum levels., Conclusion: We identified no relationship between serum magnesium levels and the development of DIND or outcome following aneurysmal SAH. Based on these data, magnesium supplementation to normal or high-normal physiological ranges seems unlikely to be beneficial for DIND resulting from vasospasm. However, no inference can be made regarding the value of therapeutic infusion of magnesium to supraphysiological levels.

The authors describe the case of a 38-year-old man with progressive headache and blurred vision related to a hemangiopericytoma located exclusively in the confluence of sinuses (CoS) and in the transverse sinuses bilaterally. They believe this is the first report in which a hemangiopericytoma of the dural sinuses has been described without any intradural component. Although the diagnosis was not suspected preoperatively, a gross-total resection of the tumor with restoration of sinus patency was achieved to relieve the symptoms. This diagnosis should be included in the preoperative differential diagnosis of a tumor of the CoS. Successful resection can be achieved in these cases.

Background: The management of unruptured intracranial aneurysms is controversial. Investigators from the International Study of Unruptured Intracranial Aneurysms aimed to assess the natural history of unruptured intracranial aneurysms and to measure the risk associated with their repair., Methods: Centres in the USA, Canada, and Europe enrolled patients for prospective assessment of unruptured aneurysms. Investigators recorded the natural history in patients who did not have surgery, and assessed morbidity and mortality associated with repair of unruptured aneurysms by either open surgery or endovascular procedures., Findings: 4060 patients were assessed-1692 did not have aneurysmal repair, 1917 had open surgery, and 451 had endovascular procedures. 5-year cumulative rupture rates for patients who did not have a history of subarachnoid haemorrhage with aneurysms located in internal carotid artery, anterior communicating or anterior cerebral artery, or middle cerebral artery were 0%, 2. 6%, 14 5%, and 40% for aneurysms less than 7 mm, 7-12 mm, 13-24 mm, and 25 mm or greater, respectively, compared with rates of 2 5%, 14 5%, 18 4%, and 50%, respectively, for the same size categories involving posterior circulation and posterior communicating artery aneurysms. These rates were often equalled or exceeded by the risks associated with surgical or endovascular repair of comparable lesions. Patients' age was a strong predictor of surgical outcome, and the size and location of an aneurysm predict both surgical and endovascular outcomes., Interpretation: Many factors are involved in management of patients with unruptured intracranial aneurysms. Site, size, and group specific risks of the natural history should be compared with site, size, and age-specific risks of repair for each patient.

Objective: Pulmonary complications challenge the medical management of patients who have sustained aneurysmal subarachnoid hemorrhage (SAH). We assessed the frequency and types of pulmonary complications after aneurysmal SAH and analyzed the impact of pulmonary complications on patient outcome., Methods: We reviewed the records of all patients with acute SAH treated at our institution between 1990 and 1997. Three hundred five consecutive patients with an aneurysmal hemorrhage source documented by angiography and treated within 7 days of ictus were analyzed. Outcomes at longest follow-up (mean, 16 mo) were measured by use of the Glasgow Outcome Scale., Results: Pulmonary complications were documented in 66 patients (22%). The pulmonary complications were nosocomial pneumonia in 26 patients (9%), congestive heart failure in 23 (8%), aspiration pneumonia in 17 (6%), neurogenic pulmonary edema in 5 (2%), pulmonary embolus in 2 (<1%), and other pulmonary disorders in 4 (1%); 11 patients had two pulmonary complications. The incidence of symptomatic vasospasm was greater in patients with pulmonary complications (63%) than in patients without pulmonary complications (31%) (P = 0.001), and this association was independent of age and clinical grade at admission (odds ratio, 3.68; P < 0.001). Overall clinical outcomes were worse in patients with pulmonary complications (mean Glasgow Outcome Scale score, 3.3) than in patients without pulmonary complications (mean Glasgow Outcome Scale score, 4.0; P = 0.0001), but pulmonary complications were not an independent predictor of worse outcome when adjusted for age and clinical grade at admission (odds ratio, 1.38; P = 0.315)., Conclusion: Patients who experience pulmonary complications after aneurysmal SAH have a higher incidence of symptomatic vasospasm than do patients without pulmonary complications. This most likely reflects both the failure to maintain aggressive hypervolemic and hyperdynamic therapy in patients with pulmonary compromise and the possible precipitation of congestive heart failure by hypervolemic therapy in patients with preexisting delayed ischemic neurological deficit. Although patients with pulmonary complications have worse overall clinical outcomes than do patients without pulmonary complications, this is attributable to older age and worse clinical grades at admission.

Object: Vascular bypass is performed in neurosurgery for a variety of pathological entities, including extracranial atherosclerotic disease, extra- and intracranial aneurysms, and tumors involving the carotid artery (CA) at the skull base or cervical regions. Creation of an interposition saphenous vein graft (SVG) is the typical method of choice when the superficial temporal artery is not an option., Methods: One hundred thirty consecutive patients treated with SVG between July 1988 and December 2002 at the Mayo Clinic were studied. A total of 130 procedures were performed in 130 patients. The indications were intracranial aneurysm in 51 patients (39%), CA occlusive disease in 36 (28%), extracranial CA aneurysm in 17 (13%), tumors involving the cervical CA in 11 (8%), vertebral artery occlusive disease in eight (6%), and other indications in six patients (5%). Among patients treated for intracranial aneurysms, 43 harbored giant aneurysms (> 25 mm in widest diameter) whereas the remaining eight patients harbored aneurysms that were large (15-25 mm in widest diameter). Among patients with CA occlusive disease, high-grade stenosis at the CA bifurcation was present in 29 and CA occlusion was demonstrated in seven., Conclusions: The use of SVG bypass remains a valuable component of the neurosurgical armamentarium for a variety of pathological entities. Despite a general trend toward decreased use because of improved endovascular technology, surgical facility with this procedure should be maintained.

Objective and Importance: Cyst formation within the brain parenchyma after endovascular coil occlusion of an intracranial aneurysm is a previously undescribed occurrence. We describe a 70-year-old woman who presented with a symptomatic pontine cyst 1 year after uncomplicated stenting and Guglielmi detachable coil occlusion of an unruptured basilar artery trunk aneurysm., Clinical Presentation: A 70-year-old woman presented with an episode of transient dysequilibrium and gait difficulty. Magnetic resonance imaging and cerebral angiography demonstrated a 15-mm distal basilar artery trunk aneurysm. Endovascular stenting and coil occlusion of the aneurysm were performed without technical complications. One year after the initial treatment, the patient developed progressive dysarthria, dysphagia, diplopia, and left hemiparesis. A large pontomesencephalic cyst adjacent to the coiled basilar aneurysm was identified on magnetic resonance imaging scans., Intervention: A subtemporal craniotomy and decompression of the pontomesencephalic cyst were performed. The patient's symptoms of brainstem dysfunction improved temporarily but recurred within 2 months, necessitating reoperation for cyst drainage and placement of a cyst-peritoneal shunt., Conclusion: Intra-axial cyst formation after stenting and endovascular occlusion of an intracranial aneurysm is an unusual occurrence and should be considered in the differential diagnosis of new neurological deficits after endovascular treatment. The pathophysiological mechanism of cyst formation in this case is not known.

Object: The authors studied patients with aneurysmal subarachnoid hemorrhage (SAH) to determine whether the incidence of symptomatic vasospasm or overall clinical outcomes differed between patients treated with craniotomy and clip application and those treated by endovascular coil occlusion., Methods: The authors reviewed 415 consecutive patients with aneurysmal SAH who had been treated with either craniotomy and clip application or endovascular coil occlusion at a single institution between 1990 and 2000. Three hundred thirty-nine patients underwent surgical clip application procedures, whereas 76 patients underwent endovascular coil occlusion. Symptomatic vasospasm occurred in 39% of patients treated with clip application, 30% of patients treated with endovascular coil occlusion, and 37% of patients overall. Compared with patients treated with clip application, patients treated with endovascular coil occlusion were more likely to suffer acute hydrocephalus (50 compared with 34%, p = 0.008) and were more likely to harbor aneurysms in the posterior circulation (53 compared with 20%, p < 0.001). Logistic regression models controlling for patient age, admission World Federation of Neurosurgical Societies (WFNS) grade, acute hydrocephalus, aneurysm location, and day of treatment revealed that, among patients with an admission WFNS grade of I to III, endovascular coil occlusion carried a lower risk of symptomatic vasospasm (odds ratio [OR] 0.34, 95% confidence interval [CI] 0.14-0.8) and death or permanent neurological deficit due to vasospasm (OR 0.28, 95% CI 0.08-1) compared with craniotomy and clip application. Similar models revealed no difference in the likelihood of a Glasgow Outcome Scale score of 3 or less at the longest follow-up review (median 6 months) between treatment groups (OR 0.58, 95% CI 0.28-1.21)., Conclusions: Patients with better clinical grades (WFNS Grades I-III) at hospital admission were less likely to suffer symptomatic vasospasm when treated by endovascular coil occlusion, compared with craniotomy and clip application. Nevertheless, there was no significant difference in overall outcome at the longest follow-up examination between the two treatment groups.

Object: Despite the widespread use of ventriculostomy in the treatment of acute hydrocephalus after aneurysmal subarachnoid hemorrhage (SAH), there is no consensus regarding the risk of rebleeding associated with ventriculostomy before aneurysm repair. This present study was conducted to assess the risk of rebleeding after preoperative ventriculostomy in patients with aneurysmal SAH., Methods: The authors reviewed the records of all patients with acute SAH who were treated at a single institution between 1990 and 1997. Thus, the records of 304 consecutive patients in whom an aneurysmal SAH source was documented on angiographic studies and who had presented to the authors' institution within 7 days of ictus were analyzed. Re-bleeding was confirmed by evidence of recurrent hemorrhage on computerized tomography scans in all cases. Forty-five patients underwent ventriculostomy for acute hydrocephalus after aneurysmal SAH at least 24 hours before aneurysm repair. Ventriculostomy was performed within 24 hours of SAH in 38 patients, within 24 to 48 hours in three patients, and more than 48 hours after SAH in four patients. The mean time interval between SAH and surgery in patients who did not undergo ventriculostomy was no different from the mean interval between ventriculostomy and surgery in patients who underwent preoperative ventriculostomy (3.6 compared with 3.8 days, p = 0.81). Fourteen (5.4%) of the 259 patients who did not undergo ventriculostomy suffered preoperative aneurysm rebleeding, whereas two (4.4%) of the 45 patients who underwent preoperative ventriculostomy had aneurysm rebleeding., Conclusions: No evidence was found that preoperative ventriculostomy performed after aneurysmal SAH is associated with an increased risk of aneurysm rebleeding when early aneurysm surgery is performed.

Object: The goal of this study was to determine the frequency of enlargement of unruptured intracranial aneurysms by using serial magnetic resonance (MR) angiography and to investigate whether aneurysm characteristics and demographic factors predict changes in aneurysm size., Methods: A retrospective review of MR angiograms obtained in 57 patients with 62 unruptured, untreated saccular aneurysms was performed. Fifty-five of the 57 patients had no history of subarachnoid hemorrhage. The means of three measurements of the maximum diameters of these lesions on MR source images defined the aneurysm size. The median follow-up period was 47 months (mean 50 months, range 17-90 months). No aneurysm ruptured during the follow-up period. Four patients (7%) harbored aneurysms that had increased in size. No aneurysms smaller than 9 mm in diameter grew larger, whereas four (44%) of the nine aneurysms with initial diameters of 9 mm or larger increased in size. Factors that predicted aneurysm growth included the size of the lesion (p < 0.001) and the presence of multiple lobes (p = 0.021). The location of the aneurysm did not predict an increased risk of enlargement., Conclusions: Patients with medium-sized or large aneurysms and patients harboring aneurysms with multiple lobes may be at increased risk for aneurysm growth and should be followed up with MR imaging if the aneurysm is left untreated.