武藤 淳

Object The interpeduncular cistern, including the retrochiasmatic area, is one of the most challenging regions to approach surgically. Various conventional approaches to this region have been described; however, only the endoscopic endonasal approach via the dorsum sellae and the transpetrosal approach provide ideal exposure with a caudal-cranial view. The authors compared these 2 approaches to clarify their limitations and intrinsic advantages for access to the interpeduncular cistern Methods Four fresh cadaver heads were studied. An endoscopic endonasal approach via the dorsum sellae with pituitary transposition was performed to expose the interpeduncular cistern. A transpetrosal approach was performed bilaterally, combining a retrolabyrinthine presigmoid and a subtemporal transtentorium approach. Water balloons were used to simulate space-occupying lesions. “Water balloon tumors” (WBTs), inflated to 2 different volumes (0.5 and 1.0 ml), were placed in the interpeduncular cistern to compare visualization using the 2 approaches. The distances between cranial nerve (CN) III and the posterior communicating artery (PCoA) and between CN III and the edge of the tentorium were measured through a transpetrosal approach to determine the width of surgical corridors using 0- to 6-ml WBTs in the interpeduncular cistern (n = 8). Results Both approaches provided adequate exposure of the interpeduncular cistern. The endoscopic endonasal approach yielded a good visualization of both CN III and the PCoA when a WBT was in the interpeduncular cistern. Visualization of the contralateral anatomical structures was impaired in the transpetrosal approach. The surgical corridor to the interpeduncular cistern via the transpetrosal approach was narrow when the WBT volume was small, but its width increased as the WBT volume increased. There was a statistically significant increase in the maximum distance between CN III and the PCoA (p = 0.047) and between CN III and the tentorium (p = 0.029) when the WBT volume was 6 ml. Conclusions Both approaches are valid surgical options for retrochiasmatic lesions such as craniopharyngiomas. The endoscopic endonasal approach via the dorsum sellae provides a direct and wide exposure of the interpeduncular cistern with negligible neurovascular manipulation. The transpetrosal approach also allows direct access to the interpeduncular cistern without pituitary manipulation; however, the surgical corridor is narrow due to the surrounding neurovascular structures and affords poor contralateral visibility. Conversely, in the presence of large or giant tumors in the interpeduncular cistern, which widen the spaces between neurovascular structures, the transpetrosal approach becomes a superior route, whereas the endoscopic endonasal approach may provide limited freedom of movement in the lateral extension.

We present the case of a 50-year-old female with a 1-year history of right-side facial numbness, as well as an electric shock-like sensation on the right-side of the face and tongue. She was previously diagnosed with vertigo and trigeminal neuralgia. MRI was obtained showing a large right cerebellopontine angle mass. A retrosigmoid approach was performed and total removal was achieved after dissection of tumor from brainstem and cranial nerves IV, V, VI, VII and VIII. Pathology confirmed the diagnosis of a meningioma (WHO Grade I). The patient was discharged neurologically intact on the third postoperative day free of complications. The video can be found here: http://youtu.be/-tR0FtMiUDg.

OBJECTIVES/HYPOTHESIS: A pedicled nasoseptal flap is our preferred reconstructive technique after endoscopic endonasal skull base surgery. Its harvesting implies that the donor site (septal cartilage) is left bare. Secondary healing leads to crusting at the donor site that negatively affects the patient's quality of life and requires multiple outpatient debridements. A nasoseptal reverse rotation flap was designed to eliminate this problem; however, its outcomes have not been reported. STUDY DESIGN: Retrospective review. METHODS: We retrospectively reviewed the clinical charts of patients who underwent endoscopic endonasal skull base surgery at the Wexner Medical Center at The Ohio State University from November 2010 to September 2012, and in whom a reverse flap was used. We analyzed patients' demographics, pathology, and outcomes regarding the reverse flap. RESULTS: Forty-nine patients with various pathologies were included (11 meningiomas, seven craniopharyngiomas, five pituitary macroadenomas, five chondrosarcomas, five meningoencephaloceles, three chordomas, 11 malignant tumors, two other lesions). There were two patients lost to follow-up. Mean follow-up time was 11 weeks (range = 1-39 weeks). A follow-up examination 1 to 2 weeks after surgery revealed a complete re-epithelialization in 46 of 47 patients (97.87%). Adverse events included granuloma (n = 1), anterior dehiscence (n = 1), and excoriated mucosa (n = 1). Factors such as underlying disease, prior chemoradiotherapy, and postoperative chemoradiotherapy did not seem to affect the healing of the reverse flap. CONCLUSIONS: The reverse flap provides complete remucosalization of the denuded donor septum, decreasing septal crusting within the first 1 to 2 postoperative weeks, and adds minimal morbidity.

BACKGROUND: The anterior skull base is a deep and narrow area, which makes dural repair technically challenging. The goal of this study was to demonstrate the efficacy of a new instrument for anterior skull base dural repair. METHODS: Ten patients underwent surgery via the transbasal approach, combined with either a transfacial or a transnasal endoscopic resection. The dural repair was performed prior to tumor resection, and the new instrument was used to suture the fascia lata in an underlay fashion. The repaired dural defect was then covered with a pericranial flap. RESULTS: The follow-up period ranged from 2 to 18 months, with an average follow-up time of 8.7 months. During this period, none of the patients experienced cerebrospinal fluid leakage, meningitis, tension pneumocephalus, abscess formation, or flap necrosis. CONCLUSIONS: Our findings suggest that the use of this instrument combined with the technique of suturing the fascia lata in an underlay fashion and covering it with a pericranial flap, may be an effective alternative approach to anterior skull base reconstruction.

OBJECTIVE: There is agreement that symptomatic sacral meningeal cysts with a check-valve mechanism and/or large cysts representing space-occupying lesions should be treated surgically. This study investigated factors indicating a need for surgical intervention and surgical techniques for sacral meningeal cysts with a check-valve mechanism. METHODS: In ten patients presenting with sciatica and neurological deficits, myelography, computed tomography (CT) myelography, and magnetic resonance imaging (MR imaging) detected sacral meningeal cysts with a check-valve mechanism. One patient had two primary cysts. Ten cysts were type 2 and one cyst was type 1. Nine of the ten patients had not undergone previous surgery, while the remaining case involved recurrent cyst. For the seven patients with normal (i.e., not huge or recurrent) type 2 cysts and no previous surgery (eight cysts), suture after collapse of the cyst wall was performed. For the recurrent type 2 cyst, duraplasty and suture with collapse of the cyst wall were performed to eliminate the check-valve mechanism. For the remaining type 2 cyst, a primary root was sacrificed because of the huge size of the cyst. For the type 1 cyst, the neck of the cyst was ligated. RESULTS: In all cases, chief complaints disappeared immediately postoperatively and no deterioration of clinical symptoms has been seen after a mean follow-up of 27 months. CONCLUSIONS: The presence or absence of a check-valve mechanism is very important in determining the need for surgical intervention for sacral meningeal cysts.

Craniopharyngiomas are notorious for their ability to invade the hypothalamus and third ventricle. Although several transcranial approaches have been proposed for their treatment, the endonasal route provides direct access to the tumor with no need for cerebral retraction or manipulation of the optic apparatus. After the lesion is debulked, the unique angle of approach achieved with this technique enables the surgeon to perform an extra-capsular dissection and visualize the walls of the third ventricle, the foramina of Monro, and the anterior comissure. Moreover, the enhanced magnification and lighting afforded by the endoscope facilitate safe tumor removal, particularly in areas where there is loss of clear lesion delimitation and greater infiltration of the surrounding structures. Herein we present the case of a 68-year-old female patient with a 3-month history of visual deterioration accompanied by worsening headaches. Investigation with magnetic resonance imaging revealed a heterogeneous mass in the suprasellar region, extending into the third ventricle and displacing the pituitary gland and stalk inferiorly. Hormonal profile was within expected range for her age. An endonasal, fully endoscopic, transplanum transtuberculum approach was performed. Gross-total removal was achieved and pathology confirmed the diagnosis of craniopharyngioma. Postoperative recovery was marked by transient diabetes insipidus. Closure was achieved with a pedicled nasoseptal flap; despite exploration of the third ventricle, there was no cerebrospinal fluid leakage. Pituitary function was preserved. Visual function has fully recovered and the patient has been uneventfully followed since surgery. The video can be found here: http://youtu.be/it5mpofZl0Q.

Choroid plexus cysts are frequent benign intraventricular lesions that infrequently cause symptoms, usually in the form of obstructive hydrocephalus. These instances are even less common in the adult population. When warranted, treatment seeks to reestablish cerebrospinal fluid flow and does not necessarily require resection of the cyst itself. Hence, endoscopic exploration of the ventricles with subsequent cyst ablation is the current treatment of choice for these lesions. Herein we present the case of a 25-year-old female patient with a 3-week history of intermittent headaches. Investigation with computerized tomography (CT) of the head detected supratentorial hydrocephalus, with enlargement of the lateral and third ventricles. Magnetic resonance imaging revealed a homogeneous cystic lesion in the third ventricle. A right-sided, pre-coronal burr hole was carried out, followed by endoscopic exploration of the ventricular system. A third-ventriclostomy was performed. With the aid of the 30-degrees endoscope, a cyst arising from the choroid plexus was visualized along the posterior portion of the third ventricle, obstructing the aqueduct opening. The cyst was cauterized until significant reduction of its dimensions was achieved and the aqueduct opening was liberated. Postoperative recovery was without incident and resolution of the hydrocephalus was confirmed by CT imaging. The patient reports complete improvement of her headaches and has been uneventfully followed since surgery. The video can be found here: http://youtu.be/XBtj_SqY07Q. (http://thejns.org/doi/abs/10.3171/2013.V1.FOCUS12332)

Musashi1 (MSI1) is an RNA-binding protein that plays critical roles in nervous-system development and stem-cell self-renewal. Here, we examined its role in the progression of glioma. Short hairpin RNA (shRNA)-based MSI1-knock down (KD) in glioblastoma and medulloblastoma cells resulted in a significantly lower number of self renewing colony on day 30 (a 65% reduction), compared with non-silencing shRNA-treated control cells, indicative of an inhibitory effect of MSI1-KD on tumor cell growth and survival. Immunocytochemical staining of the MSI1-KD glioblastoma cells indicated that they ectopically expressed metaphase markers. In addition, a 2.2-fold increase in the number of MSI1-KD cells in the G2/M phase was observed. Thus, MSI1-KD caused the prolongation of mitosis and reduced the cell survival, although the expression of activated Caspase-3 was unaltered. We further showed that MSI1-KD glioblastoma cells xenografted into the brains of NOD/SCID mice formed tumors that were 96.6% smaller, as measured by a bioluminescence imaging system (BLI), than non-KD cells, and the host survival was longer (49.3±6.1 days vs. 33.6±3.6 days; P<0.01). These findings and other cell biological analyses suggested that the reduction of MSI1 in glioma cells prolonged the cell cycle by inducing the accumulation of Cyclin B1. Furthermore, MSI1-KD reduced the activities of the Notch and PI(3) kinase-Akt signaling pathways, through the up-regulation of Numb and PTEN, respectively. Exposure of glioma cells to chemical inhibitors of these pathways reduced the number of spheres and living cells, as did MSI1-KD. These results suggest that MSI1 increases the growth and/or survival of certain types of glioma cells by promoting the activation of both Notch and PI(3) kinase/Akt signaling.

A previously healthy 68-year-old woman presented with a rare case of subdural empyema which developed at the site of preceding acute subdural hematoma (SDH). She was first admitted for treatment of an acute SDH after a fall. Since she was neurologically intact and the SDH volume decreased with conservative management, she was discharged 9 days after admission for follow up as an outpatient. Three days after discharge, she unexpectedly returned with worsening headache and altered mental status. Brain computed tomography (CT) showed increased SDH volume. Her condition deteriorated rapidly after presentation, with further increase in SDH volume. Copious pus in addition to the SDH was evacuated by emergency drainage, establishing the diagnosis of subdural empyema. Streptococcus pneumoniae was identified from bacterial cultures. Despite improvement in postoperative CT findings, she fell into septic shock and died 3 days after the drainage. Autopsy revealed meningitis and lobar pneumonia, and the postmortem diagnosis was invasive pneumococcal disease. Infection of acute SDH resulting in subdural empyema by S. pneumoniae is extremely rare. However, invasive pneumococcal disease is not uncommon in the elderly and tends to cause intracranial bleeding. Considering the high mortality rate of invasive pneumococcal disease and the low vaccination rate among the elderly in Japan, neurosurgeons should ask about the pneumococcal vaccination status.<br>

Rhabdoid tumor (RT) of the central nervous system is an uncommon and aggressive neoplasm that usually affects pediatric patients. Currently, these tumors are classified as malignant RT or atypical teratoid/RT. Another entity of intraparenchymal brain tumor with a rhabdoid component is the extremely rare rhabdoid glioblastoma. A 23-year-old woman presented with a malignant RT in the right thalamus. The tumor was adjacent to the right lateral ventricle and was partially resected. Histological examination revealed prominent proliferation of rhabdoid cells, which is consistent with a diagnosis of malignant RT; the typical features of glioblastoma were not observed. The tumor cells stained positively for integrase interactor-1 and glial fibrillary acidic protein. Therefore, the tumor may have originated from glial components. Genetic analysis using comparative genomic hybridization showed a deoxyribonucleic acid copy-number gain on chromosome 7 but not on chromosome 22. The tumor did not respond to chemotherapy or radiotherapy, and the patient survived for only 4 months after surgery. The present case of malignant RTs shows certain similarities with those of rhabdoid glioblastoma. Further accumulation and analysis of data, including data from genetic analyses, may lead to the identification of a new type of malignant RT.

BACKGROUND: Literature on tumors originating from Meckel's cave (MC) and their surgical treatment are scarce. OBJECTIVE: We present 37 cases of tumors originating from MC, the largest single-institution series reported thus far, and discuss the ideal surgical methods for each tumor type in relation to the normal and pathological anatomy of MC. METHODS: We studied 37 cases of surgery for tumors in MC (26 schwannomas, 7 meningiomas, 2 epidermoids, 1 hemangiopericytoma, and 1 dermoid) performed at our institution between 1986 and 2008. We excluded cases of large tumors of unknown origin, especially meningiomas. Surgery for tumors in MC was performed via 2 approaches: anterolateral interdural access (Dolenc's) approach and posterior access via the anterior petrosal approach (APA). RESULTS: The Dolenc approach was useful for parasellar tumors, especially schwannomas, because it resulted in minimal damage to the temporal lobe and adjacent cranial nerves. The APA was useful for dumbbell-shaped tumors extending into the posterior fossa. Tumors of nonmeningeal origin (schwannomas, epidermoids, and dermoids) were safely resected, with no postoperative complications except facial hypesthesia. However, incidence of postsurgical paresthesia and abducens palsy were higher in meningioma and hemangiopericytoma, because of invasion into the Gasserian ganglion, the cavernous sinus (CS), or Dorello's canal. CONCLUSION: An understanding of meningeal structure around MC enhances the radicality of tumor resection and helps minimize damage to adjacent structures. However, meningiomas and hemangiopericytomas occurring in MC, which can infiltrate into the CS, should be treated by both surgery and radiosurgery to minimize postoperative complications.

A 61-year-old woman presented an intracranial epidermoid tumor manifesting as dizziness and right facial hypesthesia. Magnetic resonance (MR) imaging revealed a well-defined lobulated mass in the right cerebellopontine angle as nearly isointense to the cerebrospinal fluid (CSF) on both T(1)- and T(2)-weighted images but inhomogeneously hyperintense on fluid-attenuated inversion recovery images. MR imaging performed 1 year later revealed that the tumor had significantly enlarged, and now appeared hyperintense to the CSF on T(1)- and T(2)-weighted images. The lesion was confirmed at surgery to be an epidermoid tumor filled with xanthochromic fluid. Histological examination found no evidence of hemorrhage in the resected tumor, so the changes in the MR imaging signal intensity were attributed to changes in the protein concentration of the intratumoral fluid, accumulation of debris, or some other non-hemorrhagic process.

A 59-year-old female presented with a huge non-functioning pituitary adenoma which mainly extended from the intrasellar region to the epidural space of the anterior cranial base, manifesting as a 2-year history of disturbance of the visual field. Transsphenoidal surgery was performed to decompress the optic pathway as the first step of a two-staged operation. Postoperative magnetic resonance images unexpectedly showed spontaneous regression of the major portion of the epidural tumor which had not been manipulated during the first operation. The reason for the spontaneous regression remains unclear.

OBJECTIVE: Various operative procedures have been described for the treatment of pediatric moyamoya disease. However, the majority of invasive or radical procedures proposed have focused primarily on revascularization and few have discussed to maximizing preservation of the already growing neovascular network. METHODS: This present procedure describes the supratemporal artery is anastomosed to the inner layer of the dura mater and surrounded by the outer layer as a sandwich with a blunt procedure of dural layer separation. RESULTS: This technique efficiently established an anastomotic connection between the supratemporal artery and the cortical brain, and the dura mater postoperatively with maximally preserving the existing vascular network. CONCLUSION: IDAS, the modified surgical technique of EDAS, shall be benefit in preserving the already developed collateral circulation, and underlying structure over the brain cortex as much as possible, which is important particularly in pediatric moyamoya patients.