Acute Hemorrhagic Leukoencephalitis with Concurrent Retinal Vasculitis in an Elderly Japanese Patient: A Case Report.

A 68-year-old Japanese man developed a fever, headache, hiccups, and altered consciousness. Brain magnetic resonance imaging (MRI) revealed a hemorrhagic lesion in the right temporal lobe and multiple high-intensity white matter lesions. A brain biopsy showed pathological findings consistent with acute disseminated encephalomyelitis (ADEM), suggesting a diagnosis of acute hemorrhagic leukoencephalitis (AHLE), an aggressive ADEM variant. The patient also developed myodesopsia and was diagnosed with retinal vasculitis, likely due to a hyperimmune state caused by AHLE. Corticosteroids enabled full recovery. Although AHLE is uncommon in elderly individuals, clinicians should be aware of its occurrence in this patient subgroup and recognize potential retinal manifestations associated with AHLE.

Allogeneic Stem Cell Therapy for Acute Ischemic Stroke: The Phase 2/3 TREASURE Randomized Clinical Trial.

Importance: Cell therapy is a promising treatment approach for stroke and other diseases. However, it is unknown whether MultiStem (HLCM051), a bone marrow-derived, allogeneic, multipotent adult progenitor cell product, has the potential to treat ischemic stroke. Objective: To assess the efficacy and safety of MultiStem when administered within 18 to 36 hours of ischemic stroke onset. Design, Setting, and Participants: The Treatment Evaluation of Acute Stroke Using Regenerative Cells (TREASURE) multicenter, double-blind, parallel-group, placebo-controlled phase 2/3 randomized clinical trial was conducted at 44 academic and clinical centers in Japan between November 15, 2017, and March 29, 2022. Inclusion criteria were age 20 years or older, presence of acute ischemic stroke (National Institutes of Health Stroke Scale [NIHSS] score of 8-20 at baseline), confirmed acute infarction involving the cerebral cortex and measuring more than 2 cm on the major axis (determined with diffusion-weighted magnetic resonance imaging), and a modified Rankin Scale (mRS) score of 0 or 1 before stroke onset. Data analysis was performed between May 9 and August 15, 2022. Exposure: Patients were randomly assigned to either intravenous MultiStem in 1 single unit of 1.2 billion cells or intravenous placebo within 18 to 36 hours of ischemic stroke onset. Main Outcomes and Measures: The primary end points were safety and excellent outcome at day 90, measured as a composite of a modified Rankin Scale (mRS) score of 1 or less, a NIHSS score of 1 or less, and a Barthel index score of 95 or greater. The secondary end points were excellent outcome at day 365, mRS score distribution at days 90 and 365, and mRS score of 0 to 1 and 0 to 2 at day 90. Statistical analysis of efficacy was performed using the Cochran-Mantel-Haenszel test. Results: This study included 206 patients (104 received MultiStem and 102 received placebo). Their mean age was 76.5 (range, 35-95) years, and more than half of patients were men (112 [54.4%]). There were no between-group differences in primary and secondary end points. The proportion of excellent outcomes at day 90 did not differ significantly between the MultiStem and placebo groups (12 [11.5%] vs 10 [9.8%], P = .90; adjusted risk difference, 0.5% [95% CI, -7.3% to 8.3%]). The frequency of adverse events was similar between treatment groups. Conclusions and Relevance: In this randomized clinical trial, intravenous administration of allogeneic cell therapy within 18 to 36 hours of ischemic stroke onset was safe but did not improve short-term outcomes. Further research is needed to determine whether MultiStem therapy for ischemic stroke has a beneficial effect in patients who meet specific criteria, as indicated by the exploratory analyses in this study. Trial Registration: ClinicalTrials.gov Identifier: NCT02961504.

Successful treatment with urgent revascularization and parent artery occlusion for a ruptured intratumoral aneurysm following prior meningioma surgery: illustrative case.

BACKGROUND: An intratumoral aneurysm encased within the associated intracranial tumor is rare, and hemorrhage caused by its rupture is even more rare. While urgent and adequate surgical treatment is important, the treatment can be difficult given the limited understanding of this rare condition. OBSERVATIONS: A 69-year-old man who had undergone meningioma surgery 30 years prior presented with a disturbance in consciousness. Magnetic resonance imaging revealed massive intracerebral and subarachnoid hemorrhage. A round, partially calcified mass, which was diagnosed as recurrent meningioma, was also observed. Subsequent cerebral angiography revealed that the source of the hemorrhage was an intratumoral aneurysm in the dorsal internal carotid artery (ICA) encased within the recurrent meningioma. Urgent surgical ICA trapping and high-flow graft bypass were conducted. The postoperative course was uneventful, and he was referred to another hospital for rehabilitation. LESSONS: This is the first case report of a ruptured intratumoral aneurysm being treated with urgent combined revascularization and parent artery trapping surgery. This surgical approach may be a feasible treatment option for such a challenging condition. Additionally, this case highlights the importance of diligent long-term follow-up after skull-base surgery, as minor intraoperative vascular wall injury may trigger the development and rupture of an intracerebral aneurysm.

[Dural Arteriovenous Fistulae in the Tentorium Manifesting as Dementia].

BACKGROUND: Tentorial dural arteriovenous fistula(dAVF)is a relatively rare disease which accounts for about 4.8% of all types of dAVF reported in Japan. Approximately 12.5% of intracranial dAVFs manifest with dementia-like symptoms. However, a tentorial dAVF typically presents more aggressively and rarely manifests as dementia. Here, we report the case of a patient with a tentorial dAVF manifesting as dementia, who was successfully treated with surgical interruption of the draining vein using indocyanine green video angiography(ICG-VA). CASE PRESENTATION: A case of a 69-year-old man with a history of colon cancer, hypertension, and previous stroke presenting with cognitive impairment. CT showed multiple intracranial hemorrhages in the left parietal and occipital lobes, and MRI demonstrated flow void in the left cerebellopontine angle. DSA revealed left tentorial dAVF with venous reflux. We performed surgical interruption of the draining vein. The patient's mental status immediately returned to baseline. Serial MRIs showed decreasing edema in the left occipital lobe and thalamus. CONCLUSIONS: Cognitive impairment is an uncommon but curable symptom of tentorial dAVF. Surgical interruption of the draining vein using ICG-VA is a relatively simple and safe procedure to perform in such a case.

Superficial Temporal Artery-Superior Cerebellar Artery Bypass with Anterior Petrosectomy.

BACKGROUND: Superficial temporal artery (STA) to superior cerebellar artery (SCA) bypass is associated with a relatively high risk of surgical complications, such as hematoma and/or edema caused by temporal lobe retraction. Therefore, the right side is typically used to avoid retraction of the left temporal lobe. In this report, we present a case of left STA-SCA bypass with anterior petrosectomy to avoid retraction of dominant-side temporal lobe and describe the surgical technique in detail. CASE DESCRIPTION: A 69-year-old man presented with gradual worsening of dysarthria and gait disturbance. Magnetic resonance imaging showed no signs of acute infarction, but digital subtraction angiography showed severe stenosis of basilar artery and faint flow in the distal basilar artery. On 3-dimensional computed tomography angiography, posterior communicating arteries were not visualized; we could identify the left SCA, but not the right SCA. Despite dual antiplatelet therapy, a small fresh brainstem infarct was detected 10 days after admission. To avert fatal brainstem infarction and further enlargement of the infarct, we performed left STA-SCA bypass with anterior petrosectomy to avoid retraction of the dominant-side temporal lobe. Postoperative imaging revealed no new lesions, such as infarction or temporal lobe contusional hematoma, and confirmed the patency of the bypass. Postoperative single-photon emission computed tomography demonstrated improved cerebral blood flow in the posterior circulation. The patient was transferred to another hospital for rehabilitation. CONCLUSIONS: This method helps minimize the risk of injury to the temporal lobe, especially that of the dominant side.

A significant correlation between delayed cure after microvascular decompression and positive response to preoperative anticonvulsant therapy in patients with hemifacial spasm.

Although microvascular decompression (MVD) is a reliable treatment for hemifacial spasm (HFS), the postoperative course is varied. We retrospectively analyzed the resolution pattern of the spasm and specified predictors for delayed cure after MVD. This study included 114 consecutive patients with typical HFS. All of them were followed up for at least 1 year after operation. Patients were divided into three groups depending on the postoperative course: immediate cure, delayed cure, and failure. To identify the predictive factors for delayed cure after MVD, logistic regression analyses were applied using candidate clinical factors, such as duration of symptom, the tendency of the spasm, preoperative medical treatment, and offending vessels. Among the 114 patients, 107 patients were cured. For those cured, 65 patients were classified as immediate cure and 42 patients were classified as delayed cure. Cumulative spasm-free rates after 1 week, 1 month, and 3 months after MVD were 70, 88, and 97 %, respectively. No predictive factors between the cured and failure groups were observed. According to multivariate analysis, preoperative anticonvulsant therapy was found to be the sole significant predictive factor for delayed cure after MVD (p = 0.025). A significant correlation between delayed cure and preoperative anticonvulsant therapy was found in our study, which suggests that hyperexcitation of the facial nucleus plays an important role in pathogenesis of delayed cure. Therefore, if a patient demonstrating a positive response to preoperative anticonvulsant therapy showed a persistent spasm after MVD, reoperation should be delayed for at least 3 months after the initial operation.

[Metronidazole-Induced Encephalopathy during Brain Abscess Treatment:Two Case Reports].

Metronidazole is a widely used antibiotic against anaerobic bacteria and protozoa. We report two cases of metronidazole-induced encephalopathy(MIE)during treatment of a brain abscess with metronidazole. The patients developed mental disturbance, and brain MRI showed reversible signals on DWI, FLAIR, and T2. Case 1: A 48-year-old woman was admitted to our hospital with a cerebellar abscess. We initiated treatment with oral metronidazole. After taking the medication, she developed mental disturbance, and her brain MRI showed a hyperintensity within the corpus callosum. We suspected metronidazole toxicity and discontinued metronidazole treatment. The symptoms resolved rapidly within a week, and the hyperintensity on the MRI disappeared. Case 2: A 22-year-old man was admitted to our hospital with a brain abscess. We initiated treatment with oral metronidazole. On day 38, he developed mental disturbance, and his MRI showed hyperintensities within the bilateral dentate nuclei and corpus callosum. These symptoms were consistent with MIE. After cessation of metronidazole, his symptoms and abnormal MRI signals completely disappeared.

Case Report: Trigeminal Neuralgia Caused by a Minute Meningioma with Hyperostosed Suprameatal Tubercle.

Cerebellopontine angle tumors might occasionally provoke trigeminal neuralgia but are usually large enough to be diagnosed radiographically. We present a case of trigeminal neuralgia caused by a very small meningioma covering the suprameatal tubercle that displayed hyperostosis at the entrance of Meckel's cave and was not obvious on routine magnetic resonance (MR) images. A 72-year-old woman with intractable trigeminal neuralgia in the left V3 territory was referred to our institution. Preoperative imaging studies revealed that the left trigeminal nerve was medially distorted at the entrance of Meckel's cave by a laterally seated bone bulge covered by a minute enhanced lesion. Trigeminal nerve decompression surgery was performed via a retrosigmoid intradural suprameatal approach. We found a small meningioma that had compressed and flattened the trigeminal nerve root at the entrance of Meckel's cave, which was grossly and totally removed by suprameatal tubercle resection. There was no vascular compression of the trigeminal nerve root. The trigeminal neuralgia ceased completely after the operation. Accurate preoperative determination of the causative pathologies is essential to achieve adequate surgical results after microvascular decompression for neurovascular compression syndrome. Because conventional MR sequences are inadequate for the precise interpretation of complex neurovascular anatomy in the cerebellopontine angle and such small tumors can be overlooked on routine MR studies, high-resolution thin-slice MR examinations and careful radiological interpretations are required for correct diagnosis and treatment.

Histologically confirmed case of cerebral vasculitis associated with Crohn's disease--a case report.

BACKGROUND: Extraintestinal manifestations in Crohn's disease (CD) are frequent and well recognized. However, neurological involvement secondary to CD is rare, and there have been few histologically confirmed cases of cerebral vasculitis secondary to CD. CASE PRESENTATION: A 58-year-old left-handed man with a history of refractory CD who had fever of over 38 °C, progression of CD symptoms, and Gerstmann's syndrome consulted our hospital. Laboratory data showed elevation of C-reactive protein (CRP) and hypoproteinemia. T2-weighted magnetic resonance imaging (MRI) revealed a right parietal high-intensity lesion. Catheter angiography showed segmental multiple narrowing and occlusion in the distal part of the middle cerebral artery and anterior cerebral artery. Angiography also revealed multiple venous occlusions in the affected parietal area. To confirm the diagnosis, the patient underwent open biopsy, and histological examination revealed cerebral vasculitis. The patient was then started on high-dose prednisolone (60 mg/day) in addition to his previous therapy, which included mesalazine, adalimumab, and azathioprine. CRP elevation, hypoproteinemia, and gastrointestinal symptoms immediately improved after starting this treatment. Neurological status improved simultaneously with CD symptom improvement, and follow-up brain MRI revealed a reduction in the size of the right parietal lobe lesion. He returned to normal status and was discharged from our hospital 5 weeks after admission. CONCLUSION: This is an important case of histologically confirmed cerebral vasculitis associated with CD. The clinical course of our case clearly illustrates the relevance of the occurrence of cerebral vasculitis and the exacerbation of CD.

Reappraisal of Microsurgical Revascularization for Anterior Circulation Ischemia in Patients with Progressive Stroke.

BACKGROUND: Intravenous thrombolysis using tissue plasminogen activator and endovascular treatment for acute ischemic stroke is becoming an established standard therapy. However, there is no consensus in the treatment of patients who are suffering from progressive neurologic symptoms in the later stages. The purpose of this study was to evaluate the safety and efficacy of microsurgical revascularization in such patients with progressive stroke. METHODS: We retrospectively reviewed the clinical and radiological records of 14 consecutive patients with progressive stroke who underwent emergency open surgery for anterior circulation occlusion within 7 days after onset. Surgical candidates were carefully selected on the basis of symptom severity, diffusion-weighted imaging, and perfusion study. Superficial temporal artery to middle cerebral artery bypass was applied for atherosclerotic occlusion, and microsurgical embolectomy was applied for embolic occlusion. RESULTS: Superficial temporal artery to middle cerebral artery bypass was performed in 12 patients, microsurgical embolectomy in 1, and the combination of these modalities in 1. As a result, complete revascularization was achieved in all patients. The National Institutes of Health Stroke Scale scores significantly improved after surgery (at third postoperative day, P < 0.05; at 14th postoperative day, P < 0.01). A favorable outcome (modified Rankin Scale 0-2) was achieved in 12 of the 14 (85.7%) patients. Minor intracerebral hemorrhage occurred in 1 patient and hyperperfusion syndrome occurred in 1 patients; however, the patients subsequently recovered without additional treatment. CONCLUSIONS: Microsurgical revascularization is a feasible treatment option for patients with progressive stroke due to anterior circulation major vessel occlusion.

[Risk Factors for Adverse Events after Implantation of BCNU Wafers in High-grade Gliomas].

BACKGROUND: In Japan, patients with malignant glioma have been treated with BCNU wafers (Gliadel®) since January 2013. Several adverse events(AEs)associated with implantation of BCNU wafers, including cerebral edema or cyst formation, are recognized. Here, we report a retrospective review of the experience with implantation of BCNU wafers in our institutions and our findings regarding the risk factors for the AEs. METHODS: We reviewed the records of patients with malignant glioma who were implanted with BCNU wafers between April 2013 and September 2014. Their AEs were examined clinically and radiologically and evaluated according to Common Terminology Criteria for Adverse Events (CTCAE) grading. For investigating the association between risk factors and incidence of AEs, histological diagnosis, extent of resection, and period of BCNU wafers implantation surgery were selected as possible risk factors. RESULTS: Twenty-one patients were included in this investigation. There were no associations among incidence of AEs and histological diagnosis or extent of tumor resection. However, regarding the period of BCNU wafers implantation, additional resection for newly diagnosed tumors and resection for recurrent tumors tended to increase the rate and severity of AEs, especially cerebral edema, compared to primary resection. CONCLUSION: In cases of BCNU wafers implantation, the incidence and degree of AEs might increase if additional resection for newly diagnosed tumors or resection for recurrent tumors is performed. Our investigation revealed that AEs associated with implantation of BCNU wafers tend to occur in the repeated glioma surgery.

[Rapid spontaneous resolution of acute epidural hematoma in an infant:a case report].

Resolution of acute epidural hematoma (AEDH) usually takes several weeks. The authors present an infantile case of AEDH that rapidly decreased within a day and review the literature. A 7-month-old boy fell from a height of approximately one meter and sustained a head injury. On presentation, a skull fracture in the right temporoparietal region was found and a small AEDH was observed on computed tomography (CT) 1 hr after the injury. He was transferred to our institute because of growing AEDH, shown by CT images taken 3 hr after the injury. We decided to treat him conservatively as he did not exhibit any neurological deficits on admission. CT images 24hr after the injury showed significant reduction of the AEDH. There was also an increase in the subcutaneous hematoma. Follow-up CT images did not show enlargement of the AEDH. The patient was discharged with no neurological deficits 3 days after admission. Rapid resolution of the AEDH might have been due to transmigration of the hematoma into the epicranial layer through the fracture gap.

Prognostic factors for survival in patients with high-grade meningioma and recurrence-risk stratification for application of radiotherapy.

BACKGROUND: Radiotherapy for high-grade meningioma (HGM) is one of the essential treatment options for disease control. However, appropriate irradiation timing remains under debate. The object of this study is to discern which prognostic factors impact recurrence in HGM patients and to propose a risk-stratification system for the application of postoperative radiotherapy. METHODS: We retrospectively reviewed 55 adult patients who were diagnosed with Grade II and III intracranial meningioma. Cox regression models were applied to the analysis for impact on early recurrence in HGM patients without postoperative radiotherapy. RESULTS: Grade III malignancy (P = 0.0073) and transformed histology (P = 0.047) proved to be significantly poor prognostic factors of early recurrence by multivariate analysis. The other candidates for recurrence factors were Simpson Grade 3-5 resection, preoperative Karnofsky Performance status < = 70%, and MIB-1 labeling index > = 15%. According to these prognostic factors, postoperative HGM patients could be stratified into three recurrence-risk groups. The prognoses were significantly different between each group, as the 3-year actual recurrence-free rates were 90% in low-risk group, 31% in intermediate-risk group, and 15% in high-risk group. CONCLUSION: We propose recurrence-risk stratification for postoperative HGM patients using clinically available factors. Our results suggest that the prognosis for patients with high-risk HGMs is dismal, whereas HGM patients belonging to the low-risk group could have favorable prognoses. This stratification provides us with the criteria necessary to determine whether to apply adjuvant radiotherapy to postoperative HGM patients, and to also help identify potentially curable HGMs without adjuvant radiotherapy.

[Reversible cerebral vasoconstriction syndrome associated with stroke: three case reports].

Reversible cerebral vasoconstriction syndrome(RCVS)is characterized by severe headache and diffuse segmental constriction of cerebral arteries that resolves spontaneously within a few months. Although manifestations of stroke are not included in diagnostic criteria of RCVS, it is known that some cases may be associated with stroke, including intracerebral hemorrhage, subarachnoid hemorrhage, or cerebral infarction. We present three cases of RCVS associated with various types of stroke, and then review the literature. Case 1:A 49-year-old woman presented with a headache followed by left hemiparesis and dysarthria. One month before the onset, she was transfused for severe anemia caused by uterus myoma. CT images revealed intracerebral hemorrhages in the right putamen and right occipital lobe. Angiography revealed multiple segmental constrictions of the cerebral arteries. One month after the onset, these vasoconstrictions improved spontaneously. Case 2:A postpartum 38-year-old woman who had a history of migraine presented with thunderclap headache. Imaging revealed a focal subarachnoid hemorrhage in the right postcentral sulcus and segmental vasoconstriction of the right middle cerebral artery. One week after the onset, this vasoconstriction improved spontaneously. Case 3:A 32-year-old woman who had a history of migraine presented with headache followed by left homonymous hemianopsia. Imaging revealed a cerebral infarction of the right occipital lobe and multiple constrictions of the right posterior cerebral artery. These vasoconstrictions gradually improved spontaneously.

Combined petrosal approach for resection of petroclival meningioma.

The authors demonstrate a step-by-step surgical technique of the combined petrosal approach for resection of petroclival meningioma. The basic concept of this approach is the combination of the anterior- and posterior-petrosal approaches uniting the infra- and supratentorial surgical fields, thereby providing wide surgical exposure. Our techniques are featured by 1) mastoidectomy preceding craniotomy for minimal bone loss; 2) removal of the tentorium over the tumor for achieving devascularization and wide exposure; 3) water-tight dural closure by using autologous fascia graft, non-penetrating titanium clips, and multi-layered technique for avoiding postoperative cerebrospinal fluid leakage. The video can be found here: http://youtu.be/zMlNE8kMcHA .

Giant skull base atypical meningioma presenting with rapidly progressive impaired consciousness caused by severe venous congestion: case report.

A 43-year-old female presented with a giant skull base atypical meningioma manifesting as rapid progression of impaired consciousness. The meningioma was located in the ethmoid sinus, sphenoid sinus, nasal cavity, and left middle temporal fossa, and the intracranial portion of the tumor involved the left temporal region with massive surrounding brain edema in the left temporal lobe and basal ganglia. She underwent emergent fronto-temporo-parietal decompressive craniectomy, and the intracranial portion of the tumor was resected to control intracranial pressure. She recovered consciousness and neurological function dramatically, and subsequently underwent radical tumor resection via combined extended transbasal and left lateral transzygomatic infratemporal fossa approaches one month after the initial surgery. The extensive brain edema completely disappeared after tumor resection, and the patient fully recovered without neurological deficits except anosmia and small visual field defect. Rapid neurological deterioration and disturbance of consciousness caused by extensive peritumoral brain swelling are unusual in meningioma. In this case, the extemporaneous decompressive craniectomy was highly useful in the management of increased intracranial pressure.

Anterior interhemispheric approach for tuberculum sellae meningioma.

BACKGROUND: The tuberculum sellae meningioma (TSM) arises from the tuberculum sellae, chiasmatic sulcus, and limbus sphenoidale. OBJECTIVE: To retrospectively analyze patients with TSM who underwent surgery via an anterior interhemispheric approach, with special attention to visual outcomes. METHODS: Nine consecutive patients between April 2004 and December 2009 were examined. Visual impairment score (VIS) was used to analyze the visual status of the patients. A VIS is the sum of the scores in specific tables for visual acuity and visual field defects. Visual status was sequentially evaluated in the preoperative period and within 2 weeks of the operation. Any change in the VIS was considered an improvement or deterioration of visual function. All tumors were removed via an anterior interhemispheric approach. Following the wide dissection of the interhemispheric fissure, the tumor was first detached from its origin and debulked with the ultrasonic aspirator starting at the midline. The debulking continued until the arachnoid plane separating the nerve and tumor was visualized. RESULTS: Gross total resection (Simpson I + II) was achieved in all 9 patients. The average VIS was 56.1 in the preoperative period and 26.3 in the postoperative period. Among 9 patients, 8 patients had an improvement of the VIS after surgery. VIS was unchanged in 1 patient, and no patients experienced visual deterioration. Other nonvisual complications, such as rhinoliquorrhea, venous infarction, and permanent anosmia, occurred in 3 patients. CONCLUSION: Despite the small number of patients, a high resection rate and favorable visual outcome support the suitability of this approach for resection of TSM.

Primary closure of a cerebrospinal fluid fistula by nonpenetrating titanium clips in endoscopic endonasal transsphenoidal surgery: technical note.

Postoperative cerebrospinal fluid (CSF) leakage is one of the most common and aggravating complications in transsphenoidal surgery. Although primary closure of the fistula would be the most desirable solution for an intraoperatively encountered CSF leak, it is difficult to achieve in such a deep and narrow operative field. In this article, the authors report endonasal endoscopic applications of no-penetrating titanium clips to repair a CSF fistula following tumor removal. The AnastoClip Vessel Closure System (VCS; LeMaitre Vascular, Boston, MA) was used for closure of a CSF fistula in endonasal transsphenoidal surgery. In all four patients, CSF leakage was successfully obliterated primarily with two to five clips. There was no postoperative CSF rhinorrhea or complications related to the use of the VCS. Metal artifact by the clips on postoperative images was tolerable. Primary closure of the fistula using the VCS was an effective strategy to prevent postoperative CSF leakage in transsphenoidal surgery. Future application can be expanded to reconstruction of the skull base dura via endonasal skull base approaches.

Dural opening/removal for combined petrosal approach: technical note.

Detailed descriptions of stepwise dural opening/removal for combined petrosal approach are presented. Following maximum bone work, the first dural incision was made along the undersurface of the temporal lobe parallel to the superior petrosal sinus. Posterior extension of the dural incision was made in a curved fashion, keeping away from the transverse-sigmoid junction and taking care to preserve the vein of Labbé. A second incision was made perpendicular to the first incision. After sectioning the superior petrosal sinus around the porus trigeminus, the incision was extended toward the posterior fossa dura in the middle fossa region. The tentorium was incised toward the incisura at a point just posterior to the entrance of the trochlear nerve. A third incision was made longitudinally between the superior petrosal sinus and the jugular bulb. A final incision was initiated perpendicular to the third incision in the presigmoid region and extended parallel to the superior petrosal sinus connecting the second incision. The dural complex consisting of the temporal lobe dura, the posterior fossa dura, and the freed tentorium could then be removed. In addition to extensive bone resection, our strategic cranial base dural opening/removal can yield true advantages for the combined petrosal approach.