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Background Intracranial carotid artery aneurysm can be treated via microsurgical or endovascular techniques. The optimal planning is the result of the careful patient selection through clinical, anatomic, and angiographic analysis. Clinical Presentation We present a case of ruptured internal carotid artery (ICA) aneurysm that became a complex aneurysm after failure of multi-endovascular and surgery treatment. We describe complete trapping in awake craniotomy after failure of coiling, stenting, and bypassing. Conclusions ICA aneurysms could become complex aneurysms following multi-treatment failure. Endovascular approaches to treat ICA aneurysms include coiling, stenting, flow diverter stenting, and stenting-assisted coiling technique. The role of surgery remains relevant. To avoid severe neurologic deficits, recurrence, and the need of retreatment, a multidisciplinary discussion with experienced endovascular and vascular neurosurgeons is mandatory in such complex cases.

Background.Spinal schwannomas are common benign spinal tumors. Their treatment has significantly evolved over the years, and preserving neurological functions has become one of the main treatment goals together with tumor resection.Study Design and Aims.Retrospective review focused on clinical assessment, treatment techniques, and outcomes.Methods.A retrospective study on our surgical series was performed. Clinical and operative data were analyzed. In regard to neurophysiologic monitoring, patients were retrospectively divided into two groups comparing the outcomes before and after introduction of routine intraoperative neurophysiology tests.Results.From 1951 to 2010, 367 patients overall were treated. Diagnosis was obtained using angiography and/or myelography (pre-CT era), MRI, or CT scan. A posterior spinal approach was used for most patients; complex approaches were adopted for treatment of giant/dumbbell tumors. A trend of neurophysiology monitoring decreasing the rate of post-op neurological deficits was observed but was not statistically significant enough to draft evidence-based conclusions.Conclusions.Clinical and radiological assessment of spinal schwannomas has markedly changed over the course of 50 years. Diagnostic tools have improved, and detection of recurrence has become way more sensitive. Neurophysiologic monitoring has become a useful intraoperative tool to guide resection and prevent post-op neurological impairment.

Among traumatic brain injuries, acute subdural hematoma (aSDH) is considered one of the most devastating still retaining poor surgical outcomes in a considerable percentage of affected patients. However, according to results drawn from published samples of aSDH patients, overall mortality and functional recovery have been progressively ameliorating during the last decades.We present a retrospective analysis of 316 consecutive cases of post-traumatic aSDH operated on between 2003 and 2011 at our institution.Mortality was 67% (n = 212); a useful recovery was achieved in 16.4% cases (n = 52). Age65 years, a preoperative Glasgow coma scale (GCS) ≤ 8, specific pre-existing medical comorbidities (hypertension, heart diseases) were found to be strong indicators of unfavorable outcomes and death during hospitalization.Our results, compared with those of the inherent literature, led the authors to question both the "aggressiveness" of neurosurgical care indications in certain subpopulations of patients being known to fare worse or even die regardless of the treatment administered and the relevance of the results concerning mortality and functional recovery reported by third authors.

Endoscopic disc surgery (EDS) for lumbar spine disc herniation is a well-known but developing field, which is increasingly spreading in the last few years. Rate of recurrence/residual, complications, and outcomes, in comparison with standard microdiscectomy (MD), is still debated and need further data. We performed an extensive review based on the last 6 years of surgical series, systematic reviews, and meta-analyses reported in international, English-written literature. Articles regarding patients treated through endoscopic transforaminal or interlaminar approaches for microdiscectomy (MD) were included in the present review. Papers focused on endoscopic surgery for other spinal diseases were not included. From July 2009 to July 2015, we identified 51 surgical series, 5 systematic reviews, and one meta-analysis reported. In lumbar EDS, rate of complications, length of hospital staying, return to daily activities, and overall patients’ satisfaction seem comparable to standard MD. Rate of recurrence/residual seems higher in EDS, although data are nonhomogeneous among different series. Surgical indication and experience of the performing surgeon are crucial factors affecting the outcome. There is growing but still weak evidence that lumbar EDS is a valid and safe alternative to standard open microdiscectomy. Statistically reliable data obtained from randomized controlled trials (better if multicentric) are desirable to further confirm these results.

Background and Objective Since the 1960s, lasers have been used in neurosurgery for surgical removal of intracranial tumors. Because of its limited penetration (2 mm) through tissues and its wavelength, which is useful in water medium, the 2-µ thulium laser has been applied primarily in urology. Its features are attractive for application under microscope magnification during neurosurgical procedures. The aim of this study was to evaluate the usefulness of the 2-µ thulium laser during microsurgical removal of intracranial meningiomas. Materials and Methods Twenty patients with a diagnosis of intracranial meningiomas were treated with surgical intervention using a 2-µ thulium laser together with bipolar forceps, cavitron ultrasonic surgical aspirator (CUSA) and traditional microdissection instruments. Surgical removal was divided in four phases: (1) dissection from the external structures; (2) coagulation and debulking; (3) dissection from the deep structures; and (4) coagulation and removal of the basal implant. During all these steps, we evaluated the percentage of usage of the 2-µ thulium laser comparing them with bipolar forceps and ultrasonic aspirator and blunt dissection. Results Thulium laser was used mainly during phases 2 and 4 for 43% and 48.7% of the total removal, respectively. Although also useful during phases 1 and 3, it was only used for 2.2% and 31.3%, respectively: traditional dissection with scissors and forceps was preferred. Conclusions Thulium laser seems to be a useful aid in the surgery of intracranial meningiomas, especially to debulk, shrink, and coagulate the mass and the basal implant. Lasers Surg. Med. 45: 148–154, 2013. © 2013 Wiley Periodicals, Inc.

Background Single-level cervical radiculopathy may be treated conservatively with cervical tractions. Posterior cervical transfacet fusion with a facetal spacer is a viable option. The aim of the present study is to compare posterior cervical transfacet fusion with conservative physical treatment in single-level cervical radiculopathy. Methods A total of 80 patients were randomized in 2 groups, a surgical group in which patients were given posterior cervical transfacet fusion and a traction group in which patients were treated conservatively with mechanical cervical tractions. Visual analog scale for arm and neck, Neck Disability Index, and Short Form-36 (SF-36) questionnaires were administered preoperatively and after treatment up to 12 months. Results After treatment, visual analog scale arm scores were greater in traction group (4.7 vs. 1.5 the day after treatment) and at follow-up controls (traction group vs. surgical group: 5.3 vs. 0.6 at 1 month, 3.6 vs. 0.3 at 6 months, 1.8 vs. 0.2 at 12 months). Neck Disability Index scores were lower in the surgical group (surgical group vs. traction group: 4.4 vs. 20.3 at 1 month, 1.3 vs. 10.5 at 6 months). SF-36 scores were greater in the surgical group (surgical group vs. traction group: 96 vs. 70 at 1 month, 96.5 vs. 82.6 at 6 months). Neck disability index and SF-36 scores were superimposable between the groups at 12-month follow-up. No adjacent-segment arthrosis or late complications were reported at 1-year follow-up in the surgical group. Conclusions posterior cervical transfacet fusion is a safe and effective procedure to treat single-level cervical radiculopathy.

The authors evaluated the histological effects of the 2-μm thulium laser on meningioma tissue, comparing them to the results obtained using bipolar forceps and an ultrasonic aspirator.The authors analyzed nine samples of intracranial meningiomas. Four slices were obtained for every sample, and one incision was performed on each slice. Two incisions were made with a 2-μm thulium laser (one set to a 6 W and another set to a 12 W power level). One incision was made using a bipolar forceps and the other using an ultrasonic aspirator. Tissue was addressed and analyzed. Upon microscope analysis, three zones of laser action were identified: (A) a central crater; (B) a vaporized zone; and (C) a shrunken layer. These three layers were measured and compared.When addressed with the laser, all nine meningiomas presented a crater having an average depth of 1 mm. Three layers were clearly distinguished and measured: A (average depth: 0.8 mm at 6 W and 1.24 mm at 12 W); B (average depth: 0.32 mm at 6 W and 0.72 mm at 12 W); and C (average depth: 0.39 mm at 6 W and 0.44 mm at 12 W). On slices treated with bipolar forceps incisions, only zones B and C were identified. Ultrasonic aspirator incisions showed a deeper A zone (average depth: 2.93 mm), no B zone, and a tiny C zone (average depth: 0.16 mm).Thulium laser can be safely used for the surgical removal of intracranial meningiomas; beyond 2 mm under the surface of action, no tissue alterations were found. The lesions produced on meningiomas were characterized by vaporization and shrinking. When compared with bipolar forceps, the thulium laser offers cutting precision and vaporization of the tissue. When compared to the cavitron ultrasonic surgical aspirator (CUSA), the laser offers shrinking and coagulation of small vessels.

Introduction Intracranial cavernous hemangiomas are benign vascular malformations that can be divided into intra-axial and extra-axial types. Extra-axial cavernous angiomas (or hemangiomas) are rare lesions; intracranially, they arise in relation to the dura mater or at a spinal level mimicking meningiomas. They are very rarely reported in the posterior cranial fossa. Case Report The authors report a case of a cavernous angioma that occurred in the cerebellar falx of a 58-year-old man. The lesion was discovered during cranial computed tomography (CT) and magnetic resonance imaging (MRI) examinations. The patient underwent surgery with en-bloc removal of the tumor. No significant intraoperative bleeding or complications occurred during the postoperative course. Conclusion Intra-axial and extra-axial cavernous angiomas are histopathologically identical lesions, but by the radiological features, it is very difficult to distinguish the extra-axial cavernous angiomas from meningiomas, especially when dural tail sign and calcification are present.

The purpose of this study was to assess the feasibility of the use of the 2μ-thulium laser in harvesting nasal septal flaps.Nasal septal flaps are routinely performed in almost every trans-sphenoidal surgery. The preservation of the arterial vasculature is a mainstay of the procedure. However, the margins of the flap should be sufficiently healthy to regenerate faster, reducing the risk of possible complications.Eight patients underwent trans-sphenoidal surgery and removal of pituitary adenomas. Reparation of the defect was performed with the positioning of a rotational vascularized nasal-septal flap. The flaps were harvested with the aid of the 2μ-thulium laser. Every patient was then monitored for 6 months through seriated endoscopic endonasal controls.There were no complications related to the use of the laser, either intraoperatively, or postoperatively. The operative timing did not significantly differ from that of traditional techniques.The use of the 2μ-thulium laser for the harvesting of nasal septal vascularized flaps can be considered safe and feasible. The limited number of treated patients could be considered as the only restriction to the study. A larger study might have uncovered possible instrumentation-related complications, which were not observed in the present study.

Cavernous malformations are compact lesions composed of sinusoidal vascular channels that resemble dilated capillaries. They are found throughout the central nervous system with an estimated incidence in the general population of about 0.4%. Cavernous malformations occur as a sporadic form in which lesions tend to be solitary and as a familial form characterized by multiple lesions and a strong family history of seizures. The familial forms of this disease are inherited in an autosomal dominant mode. Genetic studies have identified three distinct loci associated with the familial forms of this disease—which have been termed cerebral cavernous malformations (CCM): CCM1 located on the long arm of chromosome 7 (7q21 to 7q22), CCM2 on the short arm of chromosome 7 (7p13-p15), and CCM3 on the long arm of chromosome 3 (3q25 to 3q27). In the CCM population, 40% of families link to CCM1, 20% to CCM2, and 40% to CCM3. Further analysis has demonstrated that mutations in the KRIT1 gene are responsible for CCM1. KRIT1 is a binding protein that interacts with Krev-1/rap1a, a member of the Ras family of GTPases with tumor-suppressing activity for the Ras oncogenes. These findings, along with the evidence from magnetic resonance imaging (MRI) studies that the de novo appearance of new lesions is relatively common, suggest that cavernous malformations should be reclassified as benign vascular tumors.

Although the human central nervous system used to be considered relatively resistant to the carcinogenic action of ionizing radiation, several lines of evidence now document a high incidence of secondary tumors in irradiated patients. The numerous reports of radiation-induced cerebral meningiomas generally distinguish those induced by high-dose radiation from those induced by low-dose radiation. We describe the case of patient who underwent subtotal resection of a chromophobe pituitary adenoma at the age of 18 years, who was successively treated by conventional fractionated radiotherapy with gamma rays emitted by a source of 60Co until a total dose of 41 Gy. Over the next 30 years the patient experienced all the known late effects of radiation, including panhypopituitarism, cranial-nerve deficits (II, III and VI), massive radiation necrosis involving the left cerebral hemisphere and causing right hemiparesis and aphasia and, ultimately, an atypical tentorial meningioma with early recurrence after total resection.

Chordoid meningioma is a rare variant of meningioma characterized by a more aggressive behavior. The present study documents the histological, radiological and clinical features of seven cases treated at the Policlinico Umberto I of Rome from 1999 to 2010. There were five males and two females. Most of the cases were located in the supratentorial space, especially the convexity. Surgical gross total resection was achieved in four cases. Of the remaining three cases, two relapsed and underwent further surgeries and adjuvant treatment. The MIB-1 index had a mean value of 7.5 (range 0.3-25.8). Tumors were composed of epithelioid cells or plump to spindle cells, forming cords, cribriforms or nests, in a mucoid matrix. All tumors showed diffuse positive immunoreactivity to vimentin and epithelial membrane antigen. Surgery is the first line of treatment for this kind of lesion. Gross total resection guaranteed a survival free from recurrences in our series. On the other hand, radiation therapy must be considered in patients submitted to a subtotal resection.

Extracranial-intracranial by-pass is a valid technique for the treatment of uncoilable and unclippable cerebral aneurysms combined with the treatment of the parent vessel. This technique is utilized in giant and fusiform aneurysms of the internal carotid artery of the prepetrous, petrous, intracavernous and paraclinoid segments. The rationality of this method is to exclude the aneurysm by trapping of the parent vessel and to revascularize the brain through a saphenous vein graft. We report our experience with 51 brain revascularizations performed between 1985 and 2001 at our Institution, 46 of these were done for the treatment of uncoilable and unclippable cerebral aneurysms. In the first period, preoperative balloon occlusion test was performed to assess the type of anastomosis, then we performed the test intraoperatively by EEG. The incidence of graft occlusion was 12.9%. Our experience in this series suggests that the indications for cerebral revascularization should be widened even to include patients with adequate collateral circulation, particularly those who have a long life expentancy.

Aneurysms in the pediatric population are a rare pathology with specific features which requires a deep knowledge of their pathogenesis for the best therapeutic choice; the authors report their experience with a patient presenting aneurysm of the middle cerebral artery (MCA) associated with proximal stenosis of the vessel. A six-year-old girl came to our observation after sudden onset of headache and left hemiparesis. Angio-MRI and angio-CT scan showed a right MCA dissecting aneurysms associated with proximal stenosis of the vessel. Patient started a therapy with low molecular weight heparin (LMWH), replaced, 15 days later, with acetyl-salicylic acid (ASA). Patient showed a rapid and almost complete neurological recovery, despite several radiological exams confirmed a complete occlusion of the right MCA. As many other authors noted, dissecting aneurysms in the pediatric population are probably due to a defect of the entire arterial wall. Combination of stenosis, turbulence and partial thrombosis of the aneurysm led to a complete occlusion of artery involved, leading to the formation of collateral circles. In our case, complete thrombosis was probably delayed with anticoagulant therapy and the progressive reinforcement of collateral circles lead to the patient's neurological recovery.

Background This study reports the anatomopathological classification of Tarlov cysts and the various treatment techniques described in the literature. Methods The authors present their patient series (19 cases) with a long follow-up (range 9 months to 25 years) treated by cyst remodeling around the root using titanium clips. Results The technique is effective in both avoiding cerebrospinal fluid leakage and resolving bladder dysfunction when urinary symptoms are incomplete and discontinuous. Conclusions The clipping technique for Tarlov cysts is easy, valid, safe, rapid, and effective.

Since the early 1980s, CO(2), neodymium-doped yttrium aluminum garnet (Nd:YAG), and other laser prototypes have been widely used in neurosurgery as an intraoperative aid along with the cavitron ultrasonic surgical aspirator (CUSA), bipolar forceps, and microdissection. However, the English literature contains almost no reports on the use of thulium lasers during neurosurgical procedures.We report our experience with a thulium laser during the surgical removal of a tentorial meningioma. The intraoperative technique utilized, as well as the clinical and radiological results of the procedure, are described.The thulium laser proved to be a useful tool during coagulation, shrinking, and resection of the basal implant of the tumor. Use of the laser made the surgical procedure faster and easier, and no intraoperative bleeding was noted. No side effects were observed.Our experience indicates that thulium lasers are a valid aid during resection of benign intracranial tumors under microscope magnification. Additional studies are required to define fully the role of these lasers in neurosurgical procedures.

Objective Despite new endovascular techniques and technological advances in microsurgery, the treatment of giant intracranial aneurysms is still a daunting neurosurgical task. Many of these aneurysms have a large, calcified neck, directly involve parent and collateral branches, and are partly thrombosed. In this retrospective review, we focused our analysis on the indications for high-flow, extracranial-intracranial (EC-IC) bypass surgery using a saphenous vein graft. Methods A series of 130 patients were treated between 1990 and 2004; 31 patients were managed endovascularly, and 99 patients were treated microsurgically (surgical clipping in 58 patients and high-flow EC-IC bypass followed by aneurysm trapping in 41 patients). We examined the patients' clinical records and pre- and postoperative case notes for cerebral angiographic examinations. Graft patency was verified with cerebral angiography, computed tomographic angiography, Doppler ultrasound, or graft palpation. Results The high-flow EC-IC bypass was used for all surgically treated prepetrous aneurysms (3 patients), intracavernous aneurysms (1 patient), intracavernous aneurysms with subarachnoid extension (23 patients), as well as for some supraclinoid aneurysms (12 of the 32 patients). It was also used for 1 of the 9 aneurysms located in the carotid bifurcation and 2 of 5 vertebrobasilar circulation aneurysms. Of the 58 patients managed by surgical clipping, 4 (6.9%) died, and 51 (94.4%) improved. Of the 41 patients managed with high-flow EC-IC bypass, 4 (9.8%) died and 34 (91.9%) improved. Graft patency at the follow-up examination was 92.7%. Conclusion The "gold standard" for the treatment of giant aneurysms remains surgical clipping. When direct surgical clipping or endovascular repair is contraindicated, the high-flow EC-IC bypass is a viable surgical option.

The authors present the surgical results obtained using the anterolateral approach to the craniocervical junction (CCJ) to resect a lesion with an extradural component located anterolateral to the foramen magnum and upper cervical spine.The anterolateral approach, which is a presternomastoid retrojugular route to the CCJ, was performed in 14 patients. The skin incision follows the anterior edge of the sternomastoid muscle. The vertebral artery (VA) was exposed at C-1. This approach was extended either down to the cervical spine or anteriorly to the jugular foramen, according to specific requirements. Two patients had previously undergone other surgical procedures. The follow-up period ranged from 4 months to 6.2 years. The tumor resection was complete in 11 cases and subtotal in two. In a case of vertebral coiling, a vein graft was interposed between the V1 and the V3 segments of the VA, and the bypass was still patent at the 2-year follow-up examination. In two cases involving a glomus tumor, there was a transitory postoperative seventh cranial nerve deficit.The aforementioned technique allows for sufficient access to lesions located anterolateral to the CCJ. It is indicated in cases in which lesions exhibit a significant extradural component, and it provides good control of the VA, the cervical portion of the internal carotid artery, sigmoid-jugular complex, and lower cranial nerves. This approach can easily be combined with a posterolateral approach and can be extended anteriorly toward the jugular foramen and inferiorly toward the lower cervical spine.

Background Klippel-Trenaunay-Weber syndrome is a rare mesodermal phakomatosis characterized by cutaneous hemangiomata, venous varicosities, and osseous–soft tissue hypertrophy of the affected limb. As the pathologic aspect of KTWS arises from the site in which malformations occur, the clinical picture varies widely from patients who complain for cosmetic reasons to patients with life-threatening lesions. Case Description We describe a very rare case in which KTWS was associated with a cervical intramedullary cavernous angioma surgically treated. Conclusion This report confirms the wide range of expression of vascular abnormalities in neurocutaneous developmental diseases and the need of a careful multisystemic evaluation of these patients.

Background Intracranial pial arteriovenous fistulas (pAVFs) are rare vascular lesions only recently considered distinct from arteriovenous malformations. Conservative management was associated with a high mortality rate. The abnormality of the lesion arises from its high-flow nature. The authors present a case of a cerebellar pAVF associated with aneurysms of the main feeding artery that was surgically treated. Case Description A 54-year-old woman was referred to us after an attack of severe headache and vomiting. Computerized tomography scan visualized a hematoma of the fourth ventricle. Digital subtraction angiography (DSA) revealed a cerebellar pAVF mainly fed by the right posteroinferior cerebellar artery (PICA) and with drainage into one of the superior cerebellar veins. The PICA presented a saccular aneurysm on its fourth segment and a fusiform dilatation on its third segment. The patient underwent surgical operation via a midline suboccipital craniotomy. The fusiform dilatation was wrapped and the saccular aneurysm was clipped. The most fistulous connections were closed. The draining vein at the level of torcular herophili was closed by application of a clip. Control DSA demonstrated exclusion of both the aneurysms and the fistula from the circulation. At 1-year follow-up, the patient was neurologically intact. Conclusions The association of a cerebellar pAVF and an aneurysm is rare. Surgical treatment of multiple-channel arteriovenous fistulas by closure of venous varix should guarantee the exclusion from the circulation and avoid recruitment of new arterial connections and recurrence. Attention must be paid to normal venous channels draining into the varix.

OBJECTIVE AND IMPORTANCE: Although the clinical and histological features of the pathological entity of spinal arachnoiditis ossificans (AO) have been established for some time, less attention has been paid to the treatment. We proposed a classification of spinal AO evaluating the possibilities and indications for surgical or conservative treatment. CLINICAL PRESENTATION: Type III has a lumbar localization, presents with less neurological involvement, and usually requires conservative treatment. In types I and II, which are usually thoracic, clinical worsening justifies surgical decompression or partial removal, whereas total removal is rarely achievable.achievable INTERVENTION: The literature was reviewed, and the reports on three patients were added to the published cases. On the basis of a reappraisal of the computed tomographic and magnetic resonance imaging documentation and the surgical descriptions the cases of AO were classified into three types: semicircular (Type I), circular (Type II), and englobing the caudal fibers (Type III). The indications for treatment were evaluated in terms of surgical possibilities and outcome. CONCLUSION: The classification proposed on the basis of radiological findings allows sufficient clinical differentiation of AO and evaluation of the possibilities for surgical treatment. The latter is conditioned by the type of arachnoiditis, degree of neurological involvement, and presence of any concomitant pathologicad findings.

Objective and importance Recent experimental and clinical evidence suggests that hemodynamic changes in the venous system can induce the formation of new arteriovenous malformations (AVMs). In a rat model, increased venous pressure induces the formation of soft tissue and dural AVMs. We report a clinical observation that may support these data. Clinical presentation A 4-year-old boy with a midline scalp AVM draining into the superior sagittal sinus had an associated intracranial/parenchymal AVM. The cerebral AVM increased venous pressure in the superior sagittal sinus as revealed by angiography. Intervention The scalp AVM was resected, and the intracranial AVM was treated by use of the gamma knife. Conclusion On the basis of reported experimental data and the morphological and hemodynamic characteristics in this patient's two lesions, we suggest that the scalp AVM might have been induced by hypertension in the superior sagittal sinus. This clinical observation supports the notion suggested by experimental studies that hemodynamic changes can induce the formation of associated AVMs.

✓ The authors describe the case of a patient with a symptomatic giant aneurysm of the posterior communicating artery (PCoA) associated with bilateral idiopathic occlusion of the internal carotid artery (ICA). The presence of severe tortuosity of the vertebral arteries (VAs), both at their origin from the subclavian artery and at the level of the third segment, impeded navigation of the catheter for embolization of the aneurysm with Guglielmi detachable coils (GDCs). A direct surgical approach was considered to be a high-risk procedure because of the bilateral occlusion of the ICAs and the size of the aneurysm. The following therapeutic strategy was therefore adopted: 1) balloon occlusion test of the left VA; 2) vertebro—vertebral bypass with saphenous vein graft to provide a pathway for subsequent embolization; 3) ICA—left middle cerebral artery bypass to ensure blood flow in the event that embolization resulted in closure of the PCoA; and 4) GDC embolization of the aneurysm via the posterior circulation graft to ensure complete exclusion of the lesion from the arterial circulation and preservation of the PCoA. At 3-month follow-up review the patient did not present with any neurological deficits; at 1-year control examination, magnetic resonance (MR) imaging and MR angiography both confirmed complete exclusion of the aneurysm and patency of the two bypasses.

Five patients operated on between 6 months and 7 years earlier for breast cancer were surgically treated for chronic subdural haematoma. This unusual association may be explained on the basis of known factors such as coagulative impairment subsequent to chemotherapy, a degree of cerebral atrophy or mild trauma. On the other hand, since four of the patients were taking antioestrogen therapy to control the disease, it is speculated that the oestrogenic properties of tamoxifen may have contributed to subdural bleeding.

In this article, the use of an awake craniotomy is reported to allow for formal neurological examination of a patient during trapping of a giant fusiform M2 aneurysm. This represents an elegant application of a technique more commonly used during the surgical treatment of intracranial tumors or during cortical resection for epilepsy than in the management of a complex neurovascular problem. It should be noted that such awake intraoperative testing can be challenging and will generally require an experienced surgeon and excellent coordination with the anesthesiology team. The authors should be commended for the smooth execution of this technique and the excellent result. At our center, the fact that this patient would have tolerated the occlusion would have been predicted by careful evaluation of the preoperative angiogram showing slow filling through the affected middle cerebral artery (MCA) segment and good leptomeningeal collateralization of the affected vascular territory. Intraoperative motor evoked potential's and somatosensory evoked potential's would have confirmed this, and an intraoperative arteriogram would have shown collateralization of the affected territory after temporary clipping of the involved segment. Despite this, we would likely have performed a low flow, superficial temporal artery-MCA, bypass in this case given the unpredictability of the collateral circulation to prevent an ischemic injury in delayed fashion and given the potential risk to language function, which cannot be properly monitored with electrophysiological testing in the asleep patient.[1,2] In our experience, such a bypass adds less than 1 hour to the procedure, carries minimal morbidity, allows the surgeon to rest better the night of surgery, and improves the safety of the occlusion for the patient.