[Benefits and Pitfalls of Re-Operation for Recurrent Meningioma].

Malignant forms of meningioma, such as atypical and anaplastic meningiomas, commonly relapse. Recently, there have been many reports elucidating the molecular biological mechanisms underlying meningioma recurrence. Tumors with loss of CDKN(cyclin dependent kinase)2A and 2B or lack of the tri-methylation of lysine 27 on histone H3 protein have a particularly high recurrence rate. In general, primary treatment for recurrent meningiomas comprises stereotactic radiosurgery(SRS)or stereotactic radiotherapy(SRT). However, re-operation is recommended for SRS-, SRT-refractory tumors. One of the benefits of reoperation is that it allows tumor control while decompressing the normal tissue, and changing the tumor microenvironment. Another is that it facilitates the acquisition of pathological and molecular genetic information, which can enable clinicians to recommend precision medicine. However, during reoperation, it is often difficult to detach the tumor from the surrounding brain tissue and cranial nerves because of severe adhesion. In cases of malignant meningiomas with multiple relapses, it is important to share the purpose and goal of the surgery with the patients and their families. In other words, which is being prioritized more, a high resection rate or functional outcomes? Furthermore, salvage surgery should also be a consideration.

Selective surgical mamillo-thalamic tract disconnection in hypothalamic hamartoma results in complete disappearance of gelastic seizures.

Hypothalamic hamartoma is a less common condition characterized by the several types of epileptic seizures including the gelastic type. It is reported that gelastic seizures are resistant to medical treatment with anticonvulsants, while stereotactic thermocoagulation or Gamma Knife radiosurgery are effective for seizure control. Here, we report an individual case where direct surgical resection disconnecting hypothalamic hamartoma from mammillothalamic tract resulted in complete disappearance of gelastic seizures without deterioration of cognitive function. A 6-year-old boy developed gelastic seizures at the age of 2 and suffered from precocious puberty. Anticonvulsants including carbamazepine and zonisamide failed to control seizures. The patient underwent direct division of the mammillothalmic tract by removal of hypothalamic hamartoma partially via anterior interhemispheric approach. It was observed that gelastic seizures disappeared completely after the surgical treatment without any endocrine and cognitive dysfunction for a follow-up period of 14 years. The mammillothalamic tract which connects anterior nucleus of thalamus and mammillary bodies plays a key role in gelastic seizures related to hypothalamic hamartoma. In this case, we disconnected the hamartoma specifically from the mammillary bodies and not from the rest of hypothalamus. Effectively, it enabled permanent control of seizures. This result shows that fibers connecting other hypothalamic structures and the dorsomedial nucleus of thalamus are not involved in gelastic seizure propagation from the hypothalamic hamartoma. When surgical treatment of hypothalamic hamartomas is performed it has high morbidity associated with hypothalamic disorders. Therefore, disconnection between hypothalamic hamartoma and mammillary bodies presents a possibility of reducing hypothalamic damage. Surgical disconnection between hamartoma and mammillothalamic tract carries minimal hypothalamic injury risk and our results suggest that it has the potential of seizure control for intractable gelastic seizures with less complications.

Mucosal thickening of the maxillary sinus is frequently associated with diffuse glioma patients and correlates with poor survival prognosis of GBM patients: comparative analysis to meningioma patients.

Glioma patients were frequently associated with mucosal thickening of the maxillary sinus (MTMS), which reflects mucosal inflammation. We suspected that MTMS is associated with impaired mucosal immune response and correlated with dysfunction in the anti-tumor immune response in diffuse glioma patients. Therefore, the aim of this study was to determine whether the occurrence of diffuse glioma is correlated with MTMS compared to meningioma and control groups. Furthermore, we investigated whether MTMS is associated with overall survival (OS) in glioblastoma (GBM) patients. This study included 343 patients with newly diagnosed diffuse gliomas and 218 patients with meningioma treated at our institution between 2015 and 2018. As control, 201 patients with headache who did not have an intracranial organic lesion were included. Using three-axis MR images, we evaluated the incidence of MTMS in all patients. Additionally, we investigated the relationship between MTMS and OS. The incidence of MTMS in patients with diffuse glioma was significantly higher than that in the meningioma (p < .0001) and control groups (p < .0001). In 128 patients with GBM, MTMS status correlated significantly with OS (p = .0064). We revealed that the incidence of MTMS is significantly associated with patients with diffuse glioma. This suggests that MTMS is indirectly involved in the occurrence of diffuse gliomas. Furthermore, the presence of MTMS correlated significantly with shorter OS in GBM patients, indicating that MTMS is involved in suppression of anti-tumor immune response. Preoperative recognition of MTMS might be useful for improving the clinical management of GBM patients.

Maximum Nidus Depth as a Risk Factor of Surgical Morbidity in Eloquent Brain Arteriovenous Malformations.

BACKGROUND: Eloquent location of a brain arteriovenous malformation (BAVM) is known to increase the surgical risk. Surgical removal of such BAVMs is challenging. Useful indicators for the safe removal of eloquent BAVMs are needed. The aim of this study was to determine the surgical risk factors for these challenging entities. METHODS: The authors retrospectively reviewed 29 motor and/or sensory BAVM patients who underwent surgeries. The risk factors for surgical morbidity were analyzed. As a new risk factor, maximum nidus depth, was evaluated. RESULTS: Complete obliteration was achieved in 28 patients (96.6%). Postoperative transient and permanent neurological deteriorations were seen in nine patients (31.0%) and five patients (17.2%), respectively. In univariate analysis, maximum nidus depth (p = 0.0204) and asymptomatic onset (p = 0.0229) were significantly correlated with the total morbidity. In multivariate analysis, only maximum nidus depth was significantly correlated with total morbidity (p = 0.0357; odds ratio, 2.78598; 95% confidence interval, 0.8866-8.7535). The cut-off value for the maximum nidus depth was 36 mm for total morbidity (area under the curve [AUC], 0.7428) and 41 mm for permanent morbidity (AUC, 0.8833). The cutoff value of the maximum nidus size was 30 mm for total morbidity (AUC, 0.5785) and 30 mm for permanent morbidity (AUC, 0.7625). AUC was higher for the maximum nidus depth than it was for the maximum nidus size. CONCLUSIONS: Maximum nidus depth was significantly associated with surgical morbidity of eloquent BAVMs. The maximum nidus depth is a novel and a simpler indicator of the risk of surgical morbidity.

PiTMaP: A New Analytical Platform for High-Throughput Direct Metabolome Analysis by Probe Electrospray Ionization/Tandem Mass Spectrometry Using an R Software-Based Data Pipeline.

A new analytical platform called PiTMaP was developed for high-throughput direct metabolome analysis by probe electrospray ionization/tandem mass spectrometry (PESI/MS/MS) using an R software-based data pipeline. PESI/MS/MS was used as the data acquisition technique, applying a scheduled-selected reaction monitoring method to expand the targeted metabolites. Seventy-two metabolites mainly related to the central energy metabolism were selected; data acquisition time was optimized using mouse liver and brain samples, indicating that the 2.4 min data acquisition method had a higher repeatability than the 1.2 and 4.8 min methods. A data pipeline was constructed using the R software, and it was proven that it can (i) automatically generate box-and-whisker plots for all metabolites, (ii) perform multivariate analyses such as principal component analysis (PCA) and projection to latent structures-discriminant analysis (PLS-DA), (iii) generate score and loading plots of PCA and PLS-DA, (iv) calculate variable importance of projection (VIP) values, (v) determine a statistical family by VIP value criterion, (vi) perform tests of significance with the false discovery rate (FDR) correction method, and (vii) draw box-and-whisker plots only for significantly changed metabolites. These tasks could be completed within ca. 1 min. Finally, PiTMaP was applied to two cases: (1) an acetaminophen-induced acute liver injury model and control mice and (2) human meningioma samples with different grades (G1-G3), demonstrating the feasibility of PiTMaP. PiTMaP was found to perform data acquisition without tedious sample preparation and a posthoc data analysis within ca. 1 min. Thus, it would be a universal platform to perform rapid metabolic profiling of biological samples.

Do Direct Bypasses Really Resolve Capillary Vessels in Moyamoya Disease? Delayed Hemorrhage Potentially Relevant to Direct Bypasses: A Pathological Investigation.

OBJECTIVE: Moyamoya disease is a chronic but progressive obliterative cerebrovascular disease of bilateral internal carotid arteries (ICAs) causing hemorrhagic or ischemic cerebral strokes. Surgical revascularization has the potential for resolving the capillary vessels, but the effect on the occlusive ICA and the moyamoya vessels after a direct bypass remains unclear. PATIENT: A 2-year-old girl with a history of repeated transient ischemic attacks and direct bypasses but demonstrating improvement and associated anomaly is reported. A year and a half later, after a bilateral revascularization, an intracerebral capsulized hematoma growth was identified, and it was removed surgically. Neovascularization including many microvessels similar to capillary telangiectasia were identified by pathological investigation despite the reduction of moyamoya vessels on the repeated angiograms after the revascularization surgeries. In the present case, proliferation of capillary vessels was clearly confirmed by direct bypasses. CONCLUSION: There is no doubt that direct bypasses prevent further ischemic stroke by improving cerebral blood flow. However, they may result in failure in reducing the load of moyamoya vessels, albeit decreasing the potential risk of hemorrhagic strokes.

Multimodal Interventional Treatment and Outcomes for Unruptured Arteriovenous Malformations.

BACKGROUND: This study aimed to evaluate the selection and outcomes of multimodal interventional treatment for unruptured brain arteriovenous malformations (uAVMs) in ARUBA-eligible patients in a single institution. METHODS: We retrospectively reviewed the data of 94 patients with uAVMs treated between 2002 and 2014. They were divided into an intervention group and a conservative group. The primary outcome was defined as the composite of death or symptomatic stroke. Functional outcome was assessed using the modified Rankin Scale (mRS). RESULTS: The intervention and conservative groups included 75 and 19 patients, respectively, with mean follow-up periods of 59.2 ± 41.6 and 72.8 ± 39.2 months (P = 0.20), among whom the primary outcome occurred in 9 (12.3%) and 3 (17.6%) patients, respectively (P = 0.91). The proportion of patients with an mRS score ≥ 2 at last follow-up was not significantly different between the two groups (6.9% vs. 11.7%). In the intervention group, the incidence of death or stroke was lower and functional outcomes were better among patients with grade I/II AVMs than among patients with grade III AVMs. CONCLUSION: For patients with uAVMs, interventional treatment is not inferior to medical treatment alone, and careful selection should be made for patients with grade III AVMs.

Long-term outcomes following thrombectomy for acute ischemic stroke in patients with a left ventricular assist device: a case series and literature review.

BACKGROUND: Left ventricular assist devices (LVADs) were developed for the treatment of patients with severe heart failure (HF) as a bridge to heart transplantation (HT). Although long-term LVAD support results in substantial improvements, their long-term use often leads to severe acute ischemic stroke (AIS). Serious neurological events make it difficult to continue LVAD support, and these patients are excluded as candidates for HT. AIS remains a challenging problem in patients receiving LVAD support. Recently, although thrombectomy has been established in selected patients who are independent, it has not been established in patients who are not completely independent, such as those with LVAD support. METHODS: We describe four AIS patients with severe HF who were implanted with an LVAD as a bridge to HT. Five mechanical thrombectomies were performed for AIS associated with an LVAD in four patients. A literature review is presented and compared to the present results. RESULTS: Good recanalization was achieved in all patients. In three cases, marked neurological improvement was observed, and modified Rankin Scale (mRS) scores were maintained without deterioration. The median total follow-up period was 592 days. In one patient, HT was successfully performed after thrombectomy. Currently, two of the patients without neurological deficits are awaiting HT. CONCLUSIONS: Embolism is a major problem encountered by patients under LVAD support while waiting for an HT. Thrombectomy for AIS associated with LVAD support is a useful and safe treatment modality. It is possible to maintain a reasonable mRS score in patients who are not completely independent.

Rosette-forming glioneuronal tumor of the fourth ventricle with neurocytoma component.

Rosette-forming glioneuronal tumor (RGNT) was first published in 2002 and was described as a benign and indolent tumor. It was also included in the 2007 World Health Organization (WHO) classification of tumors as a grade 1 tumor for its benign clinical behavior and the possibility of surgical cure. Pathologically, RGNT is a mixed neuronal-glial tumor which consists of two distinct histological components-one with uniform neurocytes forming rosettes and/or perivascular pseudorosettes and the other being astrocytic in nature resembling pilocytic astrocytoma (biphasic pattern). We present the clinical course and pathological findings of two distinctively different cases. The first one was a 4-year-old girl with head trauma and a tumor which was incidentally found by CT. Pathology revealed that the tumor contained neurocytoma components and areas of relatively high proliferative ability with the first report of the presence of midsized bright elliptic cells. The other case was a 19-year-old girl whose imaging studies showed hydrocephalus and a brain stem tumor. She underwent endoscopic third ventriculostomy and biopsy, followed by observation. An MRI taken 6 months later showed progression of the tumor and she subsequently had the tumor excised. We are considering the possibility for our RGNT cases to correspond to a higher WHO grade as they have shown rapid progression, contrary to the already established, and their character, origin, differential diagnosis, and treatment plans have been discussed.

Application of indocyanine green (ICG) fluorescence for endoscopic biopsy of intraventricular tumors.

BACKGROUND: Many reports have already indicated the benefit of pathological diagnosis of intra- and periventricular tumors with neuroendoscopic biopsy. However, it is also well known that studies can be occasionally inconclusive because of the small and/or inadequate samples for identification of abnormal tissues. The application of indocyanine green (ICG) fluorescence for endoscopical tumor biopsy under the intraventricular surroundings is a new area not previously reported. We attempted visual differentiation of intraventricular lesions from the surrounding structure using ICG fluorescence and considered the most appropriate region for biopsy. METHODS: Three cases (13­14 year-old boys) with secondary hydrocephalus caused by intra- and periventricular tumors were operated for endoscopic transventricular biopsy combined with endoscopic third ventriculostomy. Final pathological diagnoses were suprasellar malignant lymphoma and germ cell tumors in two patients, both associated with intraventricular dissemination. Enhanced tumor visualization with 12.5 mg of ICG administration was obtained using the D-light P light equipment and ICG telescope 5.8 mm/19 cm. RESULTS: It was possible to identify the tumor mass margins themselves and detect the differences of intratumoral ICG accumulation. The areas of tumor dissemination were identifiable by neuroendoscopy but unable to be visualized by ICG fluorescence. CONCLUSIONS: We were able to obtain an ICG fluorescence imaging inside the cerebral ventricles by new D-light P system comprised of a camera head telescope. ICG fluorescence with neuroendoscopy can provide useful information for choosing the point of biopsy of intra- and periventricular tumors. However, we need to assess if the ICG accumulation site is the most appropriate for biopsy.

A modified method to enhance the safety of endoscopic third ventriculostomy (ETV)--transendoscopic pulse-waved microvascular Doppler-assisted ETV, technical note.

INTRODUCTION: Endoscopic third ventriculostomy (ETV) is a simplified treatment relative to shunting for several types of hydrocephalus. The fatal complication of ETV is intraoperative hemorrhage due to arterial injury of the basilar artery, posterior cerebral arteries, and their perforators. MATERIAL AND METHODS: Here, we present a modified technique of ETV by using a transendoscopic pulse-waved microvascular Doppler probe and videoscope head to avoid vascular injury behind the tuber cinereum (TC). The microvascular Doppler probe can detect the basilar artery complex through the TC. CONCLUSION: Ventriculostomy with the probe head helps prevent vascular injury by informing the presence of invisible vessels under endoscopic view during perforation, and the method introduced here is certain to prove invaluable for enhancing the safety of ETV.

[Pediatric medulloblastoma presenting as cerebellar hemorrhage: a case report].

Medulloblastomas usually cause cerebellar ataxia and acute hydrocephalus owing to their increase in size. Cerebellar hemorrhage is an extremely rare initial clinical presentation of medulloblastoma. Herein, we report a case of medulloblastoma in an 8-year-old girl who presented with initial cerebellar intratumoral hemorrhage. The patient initially presented with mild headache;the differential diagnosis by using the initial computed tomography and magnetic resonance images was difficult, as bleeding from a cerebellar vascular malformation(cavernous angioma or arteriovenous malformation)was considered more likely. Hydrocephalus or typical findings indicative of medulloblastoma were not observed. We initially only observed the patient at another institution because the hematoma was relatively small(1.5×1×1cm). After follow-up imaging for pathological diagnosis, surgical removal was performed at our institute 49 days after the hemorrhage was observed. Complete tumor removal was achieved, and the histopathological diagnosis was medulloblastoma. The patient received whole brain and spinal irradiation(23.4Gy;posterior fossa local:50.4Gy)and chemotherapy(cyclophosphamide, 1,000mg/m2/day on day 1;vincristine, 1.5mg/m2/day on day 1;etoposide, 100mg/m2/day on days 1-3;cisplatin, 90mg/m2/day on day 2). No recurrences or neurological deficits were observed during a 2-year follow-up. This was a rare case of medulloblastoma presenting as cerebellar hemorrhage. Cerebellar medulloblastoma is among the common pediatric brain tumors;therefore, it should be diagnosed accurately and quickly.

Intraoperative pre- and post-craniofacial reconstruction intracranial pressure (ICP) monitoring in children with craniosynostosis.

INTRODUCTION: One of the goals of cranial vault expansion performed in patients with craniosynostosis (CS) is to reduce the harmful effects associated with elevated intracranial pressure (ICP). Until now, clear guidelines on when cranial vault expansion should take place have not been established except in unacceptable cosmetic deformities. MATERIALS AND METHODS: This paper illustrates the potential benefit of ICP monitoring in determining the time of surgery. The ICP of six patients (ranging from 7 months to 8 years) was measured before and after surgery. For the first time, we regulated end-tidal carbon dioxide, the position and movements, the level of sedation and the monitoring site of our patients under anesthesia to report accurate ICP readings. RESULTS: The mean pre- and postoperative ICPs were 14.7 and 4.2 mmHg, respectively. Pressure sensor was placed through a burr hole under general anesthesia and remained through all stages of recording. Though ICP monitoring has been reported before, the physiological fluctuations of ICP and patient's condition affected results. Under our ICP monitoring protocol, the six-patient study represents a suggestion to standardize ICP measurements under certain conditions in order to improve the reproducibility of ICP monitoring and therefore establish the need for optimal timing of cranial vault expansion in pediatrics. CONCLUSION: Although we cannot clearly define the indications and establish normal pediatric ICP values from the result of this study because of the small number of cases and some other limitations, this is a new approach to define ICP increase as a potential indication for surgery in CS.

Diagnostic and management difficulties in a case of multiple intracranial juvenile xanthogranuloma.

INTRODUCTION: Juvenile xanthogranuloma (JXG) preferentially occurs in childhood, and its characteristics have been thought to be benign and with slow growth. JXG is classified as an inflammatory disease, which forms multiple lesions in the patients' head, neck, and other organs and typically skin. JXG is rare, and few case reports have been published in the past, particularly with multiple intracranial lesions, which as in our case, is an extremely rare finding. CASE: Patient is a 4-year-old boy who presented with polydypsia and polyuria for 1 year. He had been followed up only under l-deamino-8-D-arginine vasopressin until he started vomiting and his level of consciousness deteriorated. Then, magnetic resonance imaging (MRI) revealed multiple intracranial lesions. He underwent biopsy via small craniotomy, and pathology was confirmed as juvenile xanthogranuloma. The patient received chemotherapy, in complete compliance with JLSG-02 protocol. FINDINGS: JXG is characteristic with homogenous enhancement with contrast matter and, most importantly, high intensity on diffusion-weighted image (DWI). The DWI was high when the degree of diffusion of water is restricted, as seen in inflammation and, additionally, the change of intensity after administration of steroid would reflect its anti-inflammatory nature. However, though the steroid therapy made high-intensity lesions decrease signal intensity, the size and the number of lesions did not change at all. As we expected, after we stopped steroid administration to the patient, his consciousness deteriorated and we found again the very-high-intensity lesions. We consider the intensity on DWI to reflect progression of the lesions.

Bilateral symptomatic large cavernous carotid artery aneurysms treated by extracranial-intracranial bypass with parent artery occlusion.

Bilateral large cavernous sinus internal carotid aneurysms (CCAs) occur very rarely. While the choice of treatment method is important, the timing of contralateral side treatment is equally important. We herein report the case of a 72-year-old woman who presented with progressive bilateral visual impairment and was treated by two-stage. First, the left CCAs had been treated, and the aneurysm was thrombosed, but her left visual acuity did not recover; the right CCA was becoming larger 2 years later, and her right visual acuity began worsening. The right CCAs was treated by almost same method. Her right visual acuity improved compared with the second preoperative findings. Our case findings suggest the importance of considering the appropriate timing to avoid symptom aggravation in patients with bilateral CCAs.

Enterprise Treatment for Recurrent Basilar Tip Aneurysm after PulseRider-assisted Coil Embolization: A Case Report.

PulseRider (Cerenovus, Irvine, CA, USA) is a relatively novel device used for the treatment of wide-neck aneurysms with a coil-assisted effect. However, treatment options for recurrent aneurysms after PulseRider-assisted coil embolization remain controversial. Here we report a case of recurrent basilar tip aneurysm (BTA) treated with Enterprise 2 after PulseRider-assisted coil embolization. A woman in her 70s underwent coil embolization for a subarachnoid hemorrhage with ruptured BTA 16 years ago. Recurrence was detected at 6-year follow-up, and an additional coil embolization was performed. Nevertheless, gradual recurrence still occurred, and PulseRider-assisted coil embolization was performed without any complications 9 years after the second treatment. However, recurrence was detected once more at 6-month follow-up. Thus, stent-assisted coil embolization using Enterprise 2 (Cerenovus) through PulseRider was selected for angular remodeling. Enterprise 2 was deployed between the right P2 segment of the posterior cerebral artery (PCA) and basilar artery (BA) after an effective coil embolization, which achieved effective angular remodeling between the right PCA and BA. The patient's postoperative course was uneventful, and no recanalization was detected after half a year. Although PulseRider is effective for wide-neck aneurysm treatment, recurrence remains a possibility. Additional treatment using Enterprise 2 is safe and effective with the expectation of angular remodeling.

Urgent Carotid Artery Stenting with Intracranial and Carotid Stent for Symptomatic Bilateral Consecutive Internal Carotid Artery Dissection: A Case Report.

Spontaneous internal carotid artery dissection (CAD) is a relatively rare disease, with patients, including those with bilateral CAD, often recovering after conservative therapy. However, patients with symptomatic and progressive disease require urgent carotid artery stenting (CAS). If CAD extends to the petrous portion of the internal carotid artery (ICA), it is difficult to treat with a carotid stent alone. This report describes a rare case of consecutive spontaneous bilateral CAD that required an intracranial stent with an interval of 4 years between the first and second CAS. A 58-year-old man with a history of dyslipidemia was admitted for transient ischemic attacks. He underwent CAS with carotid and intracranial stents on the third day for the left CAD due to exacerbation of symptoms under antithrombotic therapy and new stroke on magnetic resonance imaging (MRI). He recovered well. However, 4 years after the initial treatment, the patient was admitted again because of a sudden headache, photophobia, and transient weakness of the left lower limb. He was diagnosed with CAD on the contralateral side. He underwent CAS with carotid and intracranial stents due to progressive neurological deterioration under antithrombotic therapy. After treatment, he was clinically stable without any new infarctions on a follow-up MRI. He was discharged without neurological deficit. Our case of bilateral internal CAD treatment demonstrated that early revascularization with immediate stenting with carotid and intracranial stents in CAD contributes to the prevention of extensive neurological damage, thereby providing a favorable outcome in some cases.

Kissing Aneurysms of the Posterior Inferior Cerebellar Artery Treated by Anchor Coil Technique and Stenting from the Contralateral Side: A Case Report.

Kissing aneurysms refer to the condition in which two cerebral aneurysms with separate necks are in contact with each other. At present, there is scarce information on kissing aneurysms occurring near the vertebral artery (VA)-posterior inferior cerebellar artery (PICA). We report the first case of VA-PICA and nonbranched PICA kissing aneurysms, which were successfully treated with contralateral stenting after the anchor coil technique using two microcatheters. A 64-year-old woman was diagnosed with a left VA-PICA aneurysm (5.5 mm) and an adjacent small PICA aneurysm (2.5 mm) with the aneurysmal walls in close contact. For stenting, microcatheters were navigated to the PICA from the contralateral side, and framing coils for the anchor were placed into each aneurysm from the ipsilateral side. Next, a Neuroform Atlas stent was deployed from the PICA to the distal side of the VA, and coiling was completed using the jailing technique. The patient had a good postoperative course, and a left vertebral angiogram revealed complete occlusion of both aneurysms after 6 months. Adequate surgical planning and application of an appropriate stent-assisted coil embolization technique contributed to the success of the procedure in this rare case.

A Case of Cavernous Malformation of the Midbrain Removed via an Interhemispheric Transcallosal Subchoroidal Approach.

Cavernous malformations of the midbrain have a higher rate of hemorrhage and a poorer prognosis than vascular malformations of other brain areas. Surgical resection of these lesions is often necessary to avoid neurological deficits in affected patients. Herein, the literature surrounding cavernous malformations was examined, and the case of a 48-year-old man with left hemiparesis and diplopia caused by incomplete right oculomotor nerve palsy, who was diagnosed with a hemorrhage from a midbrain cavernous malformation, was discussed. The lesion expanded gradually on magnetic resonance imaging and was symptomatic; radical removal of the lesion before the onset of irreversible symptoms due to recurring bleeding was therefore considered to be beneficial for the patient. Surgical removal of the entire cavernous malformations of the midbrain was performed using an interhemispheric transcallosal subchoroidal approach, with excellent postoperative results and complete recovery from the oculomotor nerve palsy and left hemiparesis. This case shows that this approach is the most appropriate for surgical resections of lesions in the upper midbrain.