Endoscopic debulking canalization for optic pathway glioma with obstructive hydrocephalus.

Optic pathway gliomas (OPGs) are benign tumors that can stop growing or even shrink. In recent years, surgical resection has not been considered the first-line treatment because of its high risk of complications. Chemotherapy is the mainstay of treatment for growing OPGs. Surgical treatment for OPGs with obstructive hydrocephalus is required. Ventriculoperitoneal shunting is effective for all types of hydrocephalus. However, long-term management is required, especially in pediatric cases, and there is a risk of shunt-related complications over a long lifespan. Debulking surgery for OPGs allows us to avoid shunt placement by creating a waterway and releasing the hydrocephalus. To reduce the surgical risk and invasiveness, we used an endoscopic canalization technique with a small-diameter cylinder. In this article, we present a case of endoscopic canalization of an obstructive hydrocephalus caused by OPGs in a 14-year-old female to illustrate our surgical technique.(Trial registration Registry name and number: Efficacy and safety of the neuro-endoscopic treatment for brain tumors (2019-0254)).

Increased cerebrospinal fluid S100B protein levels in patients with trigeminal neuralgia and hemifacial spasm.

BACKGROUND: The pathophysiology of neurovascular compression syndrome has not been fully elucidated, and cerebrospinal fluid levels of nerve tissue-related markers involved in this disorder have not yet been reported. METHODS: We measured cerebrospinal fluid levels of S100B protein, neuron-specific enolase, and myelin basic protein in 21 patients with trigeminal neuralgia, 9 patients with hemifacial spasms, and 10 patients with non-ruptured intracranial aneurysms (control). Cerebrospinal fluid levels of these markers were determined using commercially available assay kits. RESULTS: Both trigeminal neuralgia and hemifacial spasm groups showed significantly increased cerebrospinal fluid levels of S100B compared with the control group (1120 [IQR 391-1420], 766 [IQR 583-1500], and 255 [IQR 190-285] pg/mL, respectively; p = 0.001). There were no statistically significant differences in cerebrospinal fluid levels of neuron-specific enolase or myelin basic protein among the groups. CONCLUSION: Cerebrospinal fluid S100B levels were significantly higher in patients with trigeminal neuralgia and hemifacial spasm than in controls, which suggests the involvement of S100B in the underlying pathophysiology of neurovascular compression syndrome.

Endoscopic resection of cystic pontine tumour: three case reports and a proposal for minimally invasive dual-endoscopic surgery.

OBJECTIVE AND IMPORTANCE: We describe a new endoscopic technique, the dual-endoscopic method, in which two independent endoscopic systems are simultaneously used in the subtemporal space and intraparenchymal field for patients with pontine cystic tumours. Tumours were successfully removed through a sheath placed in the brainstem via the subtemporal keyhole approach, with safety ensured by the second subtemporal endoscope. CLINICAL PRESENTATION: A purely endoscopic subtemporal approach was performed in three cases of pontine cystic tumour, including two low-grade gliomas and a recurrent chordoma. The gliomas showed nodules. Recurrent chordoma consisted of a mucinous component. TECHNIQUE: Using a keyhole subtemporal approach and a 4.0-mm rigid endoscope with a high-definition camera, a transparent puncture needle containing a 2.7-mm rigid endoscope was inserted into the cyst. The tumour was removed using suction, biopsy forceps, and scissors simultaneously placed with the 2.7-mm endoscope in a transparent sheath. CONCLUSION: Since the 4.0-mm endoscope placed in the subtemporal space monitored all procedures of the 2.7-mm endoscope, tumour removal was performed safely without damaging the pons, cranial nerves, or vessels. We safely and successfully removed a cystic pontine tumour using a dual-endoscopic method. This new method ensures the safety of deep-seated endoscopic procedures via a minimally invasive transcranial approach.

Case report: Endoscopic endonasal transposterior clinoid approach for resection of posterior clinoid process meningioma: technical notes and literature review.

Background: Posterior clinoid process (PCP) meningioma is an exceedingly rare entity. It remains the most challenging skull base lesion for neurosurgeons due to its treacherous location that insinuates amongst critical neurovascular structures. This article will describe the technical notes using the endoscopic endonasal approach that provide the earliest devascularization and detachment of the tumor PCP meningioma. Methods: We are introducing the surgical implementation of an endoscopic endonasal approach to removing PCP meningioma. Furthermore, we perform a literature review of posterior clinoid process meningioma that undergoes surgical intervention, then summarize the benefits and limitations of each approach. Results: We present a case of right PCP meningioma that was removed using an endoscopic endonasal approach through the transposterior clinoid corridor in a 52-year-old-woman. We describe the technical notes in performing this approach to have the earliest devascularization and detachment of the tumor by performing posterior clinoidectomy. Safe tumor removal is performed with a wide and clear view of the surrounding neurovascular structure. Based on our database search, we found nine articles reported on the surgical management of PCP meningiomas, with a total number of 15 cases. All of the reported cases performed the tumor removal using the transcranial approach. Conclusion: The endoscopic endonasal transposterior clinoid approach circumvents all disadvantages faced by the traditional transcranial approach, providing the earliest approach to devascularized and detaching the tumor from its attachment at PCP. This approach demonstrates safety and efficacy, making it an acceptable alternative for PCP meningioma resections.

Safety and efficacy of the endoscopic transsphenoidal transclival approach performed using direct cortical stimulation for pontine cavernous malformations.

OBJECTIVE: Surgical treatment of brainstem cavernous malformations (CMs) is challenging. Surgery using the endoscopic transsphenoidal transclival approach (eTSTCA) is reported as a useful alternative for ventral brainstem CMs. However, CMs located in the ventral midline of the brainstem are rare, and only a small number of case reports on these CMs treated with the eTSTCA exist. The efficacy and safety of the eTSTCA have not yet been fully examined. METHODS: A retrospective analysis was performed for 5 consecutive patients who underwent surgery via the eTSTCA for treating ventral pontine CMs. RESULTS: The average maximum CM diameter was 26.0 mm (18-38 mm). All patients underwent MR-diffusion tensor imaging, which confirmed that the corticospinal tract (CST) deviated posteriorly or laterally to the CM. Direct brainstem cortical stimulation was performed to localize the CST before making the cortical incision. After the excision of the CM, the cavity was filled with artificial CSF to make an aqueous surgical field (wet-field technique) for observing the tumor cavity and confirming complete hemostasis and resection. Total removal was achieved in all patients. The preoperative modified Rankin Scale score was 3 in 3 patients and 4 in 2 patients, whereas it was 1 in 2 patients and 0 in 3 patients 3 months after surgery. Postoperative CSF leakage was observed in 1 patient, and transient abducens nerve palsy was observed in 1 patient. No other intra- or postoperative complications were observed. CONCLUSIONS: MR-diffusion tensor imaging and direct brainstem cortical stimulation were useful to ascertain the proximity of the CST to the CM. The endoscope provides a clear view even underwater, and it was safe and effective to observe the entire CM cavity and confirm complete hemostasis without additional retraction of the brainstem parenchyma, including the CST. The eTSTCA provides a direct access point to the lesion and may be a safer alternative treatment for patients whose CST deviates laterally or posteriorly to the CM.

A Case of Papillary Craniopharyngioma Mimicking Rathke's Cleft Cyst.

Craniopharyngioma (CP) and Rathke's cleft cyst (RCC) are both suprasellar lesions. They are sometimes difficult to distinguish due to their similar findings. We report a case of papillary craniopharyngioma (pCP) with the clinical findings suggesting RCC. A 42-year-old female with intellectual disability presented to our hospital with severe visual dysfunction. Preoperative images revealed a suprasellar cystic lesion without calcification. We performed transsphenoidal surgery. Since the cyst had condensed-milk-like content suggesting RCC, we performed cyst fenestration and wash without removal of the cyst wall. Thereafter, we found fish-egg-like structures on the cyst wall. The histopathological analysis revealed that they had papillary structures surrounded by hyperplastic squamous epithelium with parakeratosis. Immunostaining for BRAF V600E was positive, leading to the diagnosis of pCP. After the surgery, her visual function improved and follow-up Magnetic resonance imaging at 18 months postoperatively showed no apparent recurrence. The presence of condensed-milk-like content suggests a likelihood of RCC indicating that aggressive resection may not be necessary. In contrast, the existence of fish-egg-like structures suggests pCP and requires careful follow-up.

Pediatric-type high-grade gliomas with PDGFRA amplification in adult patients with Li-Fraumeni syndrome: clinical and molecular characterization of three cases.

Li-Fraumeni syndrome (LFS) is an autosomal dominant tumor predisposition syndrome caused by heterozygous germline mutations or deletions in the TP53 tumor suppressor gene. Central nervous system tumors, such as choroid plexus tumors, medulloblastomas, and diffuse gliomas, are frequently found in patients with LFS. Although molecular profiles of diffuse gliomas that develop in pediatric patients with LFS have been elucidated, those in adults are limited. Recently, diffuse gliomas have been divided into pediatric- and adult-type gliomas, based on their distinct molecular profiles. In the present study, we investigated the molecular profiles of high-grade gliomas in three adults with LFS. These tumors revealed characteristic histopathological findings of high-grade glioma or glioblastoma and harbored wild-type IDH1/2 according to whole exome sequencing (WES). However, these tumors did not exhibit the key molecular alterations of glioblastoma, IDH-wildtype such as TERT promoter mutation, EGFR amplification, or chromosome 7 gain and 10 loss. Although WES revealed no other characteristic gene mutations or copy number alterations in high-grade gliomas, such as those in histone H3 genes, PDGFRA amplification was found in all three cases together with uniparental disomy of chromosome 17p, where the TP53 gene is located. DNA methylation analyses revealed that all tumors exhibited DNA methylation profiles similar to those of pediatric-type high-grade glioma H3-wildtype and IDH-wildtype (pHGG H3-/IDH-wt), RTK1 subtype. These data suggest that high-grade gliomas developed in adult patients with LFS may be involved in pHGG H3-/IDH-wt. PDGFRA and homozygous alterations in TP53 may play pivotal roles in the development of this type of glioma in adult patients with LFS.

Usefulness of three-dimensional computed tomography to quantify the subarachnoid hemorrhage volume: prediction of symptomatic vasospasm.

We quantified the subarachnoid hemorrhage (SAH) volume in 64 patients on three-dimensional computed tomography (3D-CT) scans and studied the correlation between the SAH volume and the occurrence of symptomatic vasospasm (SVS). We studied 64 patients with SAH onset (day 0) and on days 1, 4, 7, and 14. We compared the hematoma volume by 3D-CT with 2D-CT on day 0 and examined the correlation between the hematoma volume and the occurrence of SVS. The hematoma volume, including the volume of normal structures, was automatically calculated (V1). The volume of normal structures manifesting identical CT numbers was previously calculated in patients without intracranial lesions (V2). The total hematoma volume was defined as V1 minus mean value of V2 (= 12 ml). The mean hematoma volume by 3D-CT was 48 ± 12 ml and by 2D-CT was 31 ± 45 ml (mean ± SD, n = 64). The hematoma volume was significantly larger by 3D-CT than by 2D-CT (p < 0.05). At all time points, the hematoma volumes were significantly larger in patients with than without SVS. We developed a new method for the quantitative determination of the SAH volume by 3D-CT. This method may allow us to quantify the volume of SAH in clinical studies of cerebral vasospasm.

Eyelid myokymia caused by a trigeminal schwannoma as determined by the trigeminal-evoked blink reflex.

A 57-year-old man had trigeminal schwannoma in Meckel's cave with eyelid myokymia only. The evaluation of the trigeminal-evoked blink reflex was useful for confirming eyelid myokymia and contributed to surgical decision-making. In patients with persistent eyelid myokymia, neurophysiological and imaging evaluations may be useful for determining the underlying pathophysiology.

Surgical reconstruction for spheno-orbital meningioma extending into the sphenoid sinus with hyperostosis.

Spheno-orbital meningiomas (SOMs) are complex tumors that grow and extend into nearby structures. SOM tumor growth is often associated with hyperostosis caused by tumor cell infiltration and bone alteration. We describe the case of a 64-year-old man with SOM that extended into the sphenoid sinus without a direct connection between the intracranial and extracranial lesions. This report emphasizes the importance of identifying the growth patterns of SOMs and assessing the paranasal sinuses adjacent to the hyperostotic orbit walls from preoperative images.

Local Control Failure After Five-Fraction Stereotactic Radiosurgery Alone for Symptomatic Brain Metastasis From Squamous Cell Lung Carcinoma Despite 43 Gy to Gross Tumor Margin With Internal Steep Dose Increase and Tumor Shrinkage During Irradiation.

Five-fraction (fr) stereotactic radiosurgery (SRS) is increasingly being applied to large brain metastases (BMs) >2-3 cm in diameter, for which 30-35 Gy is the commonly prescribed dose. Since 2018, to further enhance both safety and efficacy, we have limited the five-fr SRS to approximately ≤3 cm BMs and adopted our own modified dose prescription and distribution: 43 and 31 Gy cover the boundaries of the gross tumor volume (GTV) and 2 mm outside the GTV, respectively, along with a steep dose increase inside the GTV boundary, that is, an intentionally very inhomogeneous GTV dose. Herein, we describe a case of symptomatic BM treated with five-fr SRS using the above policy, which resulted in a maximum tumor response with nearly complete remission (nCR) followed by gradual tumor regrowth despite obvious tumor shrinkage during irradiation. A 71-year-old man who had previously undergone surgery for squamous cell carcinoma (SCC) of the lungs presented with right-sided hemiparesis attributed to the para-falcine BM (27 mm in maximum diameter, 5.38 cm3). The BM was treated with five-fr SRS, with 99.2% of the GTV covered with 43 Gy and 59% isodose. Neurological symptoms improved during SRS, and obvious tumor shrinkage and mitigation of perilesional edema were observed upon completion of SRS. No subsequent anti-cancer pharmacotherapy was administered due to idiopathic pulmonary fibrosis (IPF). Despite a maximum response with nCR at four months, the tiny residual enhancing lesion gradually enlarged from 7.7 months to 22.7 months without neurological worsening. Although a consistent T1/T2 mismatch suggested the dominance of brain radionecrosis, 11C-methionine positron emission tomography showed increased uptake in the enhancing lesion. Pathological examination after total lesionectomy at 24.6 months revealed viable tumor tissue. Post-SRS administration of nintedanib for IPF may have provided some anti-tumor efficacy for lung SCC and may mitigate the adverse effects of SRS. The present case suggests that even ≥43 Gy with ≤60% isodose to the GTV boundary and ≥31-35 Gy to the 2 mm outside the GTV are insufficient to achieve long-term local tumor control by five-fr SRS alone in some large BM from lung SCC.

Hemifacial spasm caused by multiple vascular attachments due to remote compression effects of a dermoid cyst in the cerebellar hemisphere: illustrative case.

BACKGROUND: Dermoid cysts located laterally in the posterior fossa are rare. The authors report the case of a dermoid cyst in the cerebellar hemisphere presenting with hemifacial spasm (HFS) caused by multiple vascular attachments due to remote compression effects. OBSERVATIONS: A 48-year-old man presented with left HFS. Computed tomography showed a mass lesion in the left cerebellar hemisphere with calcification and erosion of skull bone. Magnetic resonance imaging showed no contrast enhancement of the lesion and a dural defect. The lesion compressed the brainstem and cerebellopontine cistern, but no vascular attachments to the facial nerve were seen. Tumor removal and microvascular decompression were performed. The lesion was composed of soft tissue containing oil-like liquid and hairs, and the border of the cerebellar arachnoid was clear. There were multiple vascular attachments to the root exit zone, facial nerve, and brainstem. After displacing these arteries, the intraoperative abnormal muscle response disappeared. Histopathological findings showed stratified squamous epithelium, keratin flakes, calcifications, and hairs. The HFS disappeared completely and has remained absent for 27 months. LESSONS: The dermoid cyst originating from occipital bone compressed the cerebellar hemisphere, displacing multiple vessels and leading to HFS. Tumor removal and the removal of all vascular factors can completely resolve HFS.

Subcutaneous transplantation of human embryonic stem cells-derived pituitary organoids.

Introduction: The pituitary gland, regulating various hormones, is central in the endocrine system. As spontaneous recovery from hypopituitarism is rare, and exogenous-hormone substitution is clumsy, pituitary replacement via regenerative medicine, using pluripotent stem cells, is desirable. We have developed a differentiation method that in mice yields pituitary organoids (POs) derived from human embryonic stem cells (hESC). Efficacy of these POs, transplanted subcutaneously into hypopituitary mice, in reversing hypopituitarism was studied. Methods: hESC-derived POs were transplanted into inguinal subcutaneous white adipose tissue (ISWAT) and beneath dorsal skin, a relatively avascular region (AR), of hypophysectomized severe combined immunodeficient (SCID) mice. Pituitary function was evaluated thereafter for ¾ 6mo, assaying basal plasma ACTH and ACTH response to corticotropin-releasing hormone (CRH) stimulation. Histopathologic examination of organoids 150d after transplantation assessed engraftment. Some mice received an inhibitor of vascular endothelial growth factor (VEGF) to permit assessment of how angiogenesis contributed to subcutaneous engraftment. Results: During follow-up, both basal and CRH-stimulated plasma ACTH levels were significantly higher in the ISWAT group (p < 0.001 - 0.05 and 0.001 - 0.005, respectively) than in a sham-operated group. ACTH secretion also was higher in the ISWAT group than in the AR group. Histopathologic study found ACTH-producing human pituitary-cell clusters in both groups of allografts, which had acquired a microvasculature. POs qPCR showed expression of angiogenetic factors. Plasma ACTH levels decreased with VEGF-inhibitor administration. Conclusions: Subcutaneous transplantation of hESC-derived POs into hypopituitary SCID mice efficaciously renders recipients ACTH-sufficient.

Efficacy and safety of bevacizumab, irinotecan, and temozolomide combination for relapsed or refractory pediatric central nervous system embryonal tumor: a single-institution study.

OBJECTIVE: This study aimed to evaluate the efficacy and safety of combination therapy with bevacizumab (Bev), irinotecan (CPT-11), and temozolomide (TMZ) in children with central nervous system (CNS) embryonal tumor relapse. METHODS: The authors retrospectively examined 13 consecutive pediatric patients with relapsed or refractory CNS embryonal tumors who received combination therapy comprising Bev, CPT-11, and TMZ. Specifically, 9 patients had medulloblastoma, 3 had atypical teratoid/rhabdoid tumor (AT/RT), and 1 had CNS embryonal tumor with rhabdoid features. Of the 9 medulloblastoma cases, 2 were categorized in the Sonic hedgehog subgroup and 6 in molecular subgroup 3 for medulloblastoma. RESULTS: The complete and partial objective response rates were 66.6% in patients with medulloblastoma and 75.0% in patients with AT/RT or CNS embryonal tumors with rhabdoid features. Furthermore, the 12- and 24-month progression-free survival rates were 69.2% and 51.9% for all patients with recurrent or refractory CNS embryonal tumors, respectively. In contrast, the 12- and 24-month overall survival rates were 67.1% and 58.7%, respectively, for all patients with relapsed or refractory CNS embryonal tumors. The authors observed grade 3 neutropenia, thrombocytopenia, proteinuria, hypertension, diarrhea, and constipation in 23.1%, 7.7%, 23.1%, 7.7%, 7.7%, and 7.7% of patients, respectively. Furthermore, grade 4 neutropenia was observed in 7.1% of patients. Nonhematological adverse effects, such as nausea and constipation, were mild and controlled with standard antiemetics. CONCLUSIONS: This study demonstrated favorable survival outcomes in patients with relapsed or refractory pediatric CNS embryonal tumors and thus helped to investigate the efficacy of combination therapy comprising Bev, CPT-11, and TMZ. Moreover, combination chemotherapy had high objective response rates, and all adverse events were tolerable. To date, data supporting the efficacy and safety of this regimen in the relapsed or refractory AT/RT population are limited. These findings suggest the potential efficacy and safety of combination chemotherapy in patients with relapsed or refractory pediatric CNS embryonal tumors.

Skull base reconstruction using various types of galeal flaps.

BACKGROUND: Failure of skull base reconstruction is a life-threatening issue. This study describes surgical techniques utilising various types of galeal flaps and reports on outcome of these procedures for skull base reconstruction. METHOD: Clinical records of 136 patients (75 men, 61 women; mean age, 50.0 years) who required skull base reconstruction with galeal flaps were reviewed retrospectively. Patients had undergone skull base surgeries with simultaneous reconstruction for benign tumours in 77 patients, malignant tumours in 53, and other lesions in 6. We repaired dural defects using a fascial patch, and covered the skull base defects using various types of galeal flap according to the size and location of the skull base defects. Routine spinal drainage was not used in any patients. FINDINGS: Reconstruction was performed as planned in all patients. We utilised a galea frontalis flap in 17 patients, temporoparietal galeal flap in 95, temporoparietal galeal flap with calvarial bone in 9, and bipedicled temporoparietal galeal flap in 15. Postoperative complications included scalp wound necrosis in 8 patients (5.9%), transient leakage of cerebrospinal fluid in 3 (2.2%), and intracranial infection in 2 (1.5%). Necrosis of the galeal flaps was not encountered. CONCLUSIONS: Galea is a well-vascularised tissue with homogenous thickness. Since the galeal layer covers the entire head area, various types of galeal flap can be elevated to cover any size and location of skull base defect.

[Removal of bamboo fragments transorbitally penetrated into the cerebellum and temporal lobe 30 years after the injury].

A 37-year-old male presented with transorbitally penetrating bamboo fragments, which resulted in multiple brain abscesses during 30 years. Neurological examination revealed left blindness, oculomotor palsy, trigeminal nerve (V1) anesthesia, and cerebellar ataxia. Computed tomography demonstrated foreign bodies and two ring enhanced lesions in the cerebellum. Magnetic resonance imaging demonstrated a hypointense mass penetrating through the cavernous sinus into the posterior fossa, and another mass into the temporal lobe. Cerebral angiography showed that the sylvian vein drained to the pterygoid plexus. Two weeks after the drainage of two cerebellar abscesses using an endoscope, bamboo fragments were removed using a zygomatic anterior petrosal approach. Occlusion of the draining vein to the pterygoid plexus might cause temporal venous infarction. Using indocyanine green intraoperative angiography, we confirmed the collateral venous flow of the sylvian vein after temporary occlusion of the draining vein to the pterygoid plexus. Postoperative course was uneventful. Foreign bodies must be removed even after 30 years to prevent repetitive brain abscesses.

Aluminous hydrous magnesium silicate as a lower-mantle hydrogen reservoir: a role as an agent for material transport.

The potential for storage of a large quantity of water/hydrogen in the lower mantle has important implications for the dynamics and evolution of the Earth. A dense hydrous magnesium silicate called phase D is a potential candidate for such a hydrogen reservoir. Its MgO-SiO2-H2O form has been believed to be stable at lower-mantle pressures but only in low-temperature regimes such as subducting slabs because of decomposition below mantle geotherm. Meanwhile, the presence of Al was reported to be a key to enhancing the thermal stability of phase D; however, the detailed Al-incorporation effect on its stability remains unclear. Here we report on Al-bearing phase D (Al-phase D) synthesized from a bridgmanite composition, with Al content expected in bridgmanite formed from a representative mantle composition, under over-saturation of water. We find that the incorporation of Al, despite smaller amounts, into phase D increases its hydrogen content and moreover extends its stability field not only to higher temperatures but also presumably to higher pressures. This leads to that Al-phase D can be one of the most potential reservoirs for a large quantity of hydrogen in the lower mantle. Further, Al-phase D formed by reaction between bridgmanite and water could play an important role in material transport in the lower mantle.

Long-term control of clival chordoma with initial aggressive surgical resection and gamma knife radiosurgery for recurrence.

PURPOSE: Chordomas are locally destructive tumors with high rates of recurrence, and therapeutic strategies remain controversial. This study analyzed long-term outcomes for clival chordomas after initial aggressive surgical resection and gamma knife radiosurgery for recurrence and investigated clinical factors predicting recurrence. METHODS: Clinical records were reviewed for 19 consecutive patients (11 men, 8 women; mean age, 43.1 years) with clival chordoma who underwent initial surgical resection using skull base approaches (mean follow-up after surgical resection, 87.2 months). All tumors were aggressively removed, along with the surrounding bone. Four patients were treated with radiotherapy after surgical resection.Recurrent lesions were treated with gamma knife radio surgery or reoperation. Factors predicting tumor recurrence were analyzed, including age, tumor extension, extent of resection and MIB-1 labeling index. Patient status was evaluated using the Karnofsky performance scale (KPS). RESULTS: Tumor resection was total, subtotal and partial in 14, 4 and 1 patients, respectively. Tumors recurred in 11 patients. Overall, 2- and 5-year progression-free survival rates were 77.9% and 47.9%, respectively. The MIB-1 labeling index was independently associated with recurrence.The optimum cutoff point for the MIB-1 labeling index was 3.44%. All recurrent tumors were totally resected or controlled by gamma knife (mean follow-up after recurrence, 71.2 months). All patients survived and were active (mean KPS at final follow-up, 89.5%). CONCLUSION: Long-term control of clival chordomas was achieved. Recurrent tumors were controlled with gamma knife radiosurgery, since lesions were localized and small after initial aggressive resection. The MIB-1 labeling index can provide important information for predicting tumor recurrence.

Factors predicting growth of vestibular schwannoma in neurofibromatosis type 2.

We retrospectively reviewed characteristics of patients with neurofibromatosis type 2 to identify factors predicting further growth of bilateral vestibular schwannomas. Subjects comprised 27 neurofibromatosis type 2 patients with 54 vestibular schwannomas, followed for 24-204 months (mean, 86 months). This study investigated factors predictive of vestibular schwannoma growth in neurofibromatosis type 2. Features distinguishing actively growing from quiescent VS were determined for untreated course (28 vestibular schwannomas) and posttreatment course (including either resection or radiosurgery; 33 vestibular schwannomas). A general estimation equation was used to identify factors affecting tumor growth. During the untreated course, 19 vestibular schwannomas showed growth and 9 vestibular schwannomas were stable. No factors predictive of growth were shown. During the posttreatment course (23 surgical resections, ten radiosurgeries), ten treatments were followed by growth and 23 were followed by stability, with growth showing an association with onset at an early age (p = 0.007). Multivariate analysis identified no factors predictive of growth. After treatment, close follow-up is warranted for patients with onset at an early age.

Measurement of optic nerve blood flow during dissection of parasellar tumors.

The authors describe direct measurement of optic nerve blood flow (ONBF) and examine the application of such monitoring to detecting optic nerve ischemia during parasellar tumor surgery. Prospective evaluation was performed for 26 patients requiring surgery for parasellar tumors. Ophthalmologic examination was performed pre- and postoperatively. ONBF was measured using laser Doppler flowmetry before tumor dissection (initial ONBF) and after tumor removal (final ONBF). The waveform was analyzed using a data acquisition system. Initial ONBF could be measured in 16 patients (22 nerves; 8.9 +/- 0.9 ml/100 g/min). Final ONBF could be determined in all 26 patients (42 nerves; 10.8 +/- 0.7 ml/100 g/min). In the 22 nerves with initial measurements, final ONBF (11.3 +/- 0.6 ml/100 g/min) was significantly increased (p < 0.01). In six patients whose optic canal was unroofed, ONBF did not change immediately; nonetheless, an increase was prominent in the final phase (p < 0.05). In another six patients, a small vessel adjacent to the optic nerve was temporarily occluded. ONBF was demonstrably reduced in three patients and recovered quickly after reperfusion. Intraoperative ONBF measurement may be useful as real-time monitoring for prediction and prevention of intraoperative optic nerve ischemia.