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A thorough observation of the root exit zone (REZ) and secure transposition of the offending arteries is crucial for a successful microvascular decompression (MVD) for hemifacial spasm (HFS). Decompression procedures are not always feasible in a narrow operative field through a retrosigmoid approach. In such instances, extending the craniectomy laterally is useful in accomplishing the procedure safely. This study aims to introduce the benefits of a skull base approach in MVD for HFS.The skull base approach was performed in twenty-eight patients among 335 consecutive MVDs for HFS. The site of the neurovascular compression (NVC), the size of the flocculus, and the location of the sigmoid sinus are measured factors in the imaging studies. The indication for a skull base approach is evaluated and verified retrospectively in comparison with the conventional retrosigmoid approach. Operative outcomes and long-term results were analyzed retrospectively.The extended retrosigmoid approach was used for 27 patients and the retrolabyrinthine presigmoid approach was used in one patient. The measurement value including the site of NVC, the size of the flocculus, and the location of the sigmoid sinus represents well the indication of the skull base approach, which is significantly different from the conventional retrosigmoid approach. The skull base approach is useful for patients with medially located NVC, a large flocculus, or repeat MVD cases. The long-term result demonstrated favorable outcomes in patients with the skull base approach applied.Preoperative evaluation for lateral expansion of the craniectomy contributes to a safe and secure MVD.

Meningiomas have vascular supply from the tumor attachment on the dura mater. Gamma Knife radiosurgery (GKS) is known to have a vascular obliterating effect. This study aims to determine the benefits of high-dose irradiation to the tumor attachment compared to conventional dose planning in the long-term control of tumor growth with GKS.Two different dose plannings were retrospectively compared in 75 patients with meningioma treated with GKS as a primary treatment. Forty-three patients were irradiated over 20 Gy to the tumor attachment. The remaining 32 patients were treated with conventional-dose planning. Tumor growth control, reduction of enhancement on the gadolinium-enhanced magnetic resonance imaging (MRI), and neurological status were retrospectively assessed.The maximum dose on the tumor attachment was significantly higher in the high-dose group (23 Gy) than in the conventional group (16 Gy). The tumor margin was irradiated with the median of the 50% isodose line in both groups. The prescription doses resulted in 14 Gy and 12 Gy, respectively. The tumor control rate achieved 91% in both groups during the median follow-up period of 54 months. A decrease of enhancement on follow-up MRI was noted in one patient in each group. Kaplan-Meier analysis revealed no statistical difference in the progression-free survival between the two groups. The number of patients with improved neurological status showed no statistical difference.No obvious benefit of high-dose irradiation to the tumor attachment and margin was found in tumor control and neurological status in the long term.

The common trunk anomaly of the anterior and posterior inferior cerebellar artery (APC) is a variant artery that causes a hemifacial spasm (HFS). The anatomical characteristics include a large diameter of the trunk and the existence of the bifurcation near the facial nerve root entry zone (REZ). Despite APC being encountered at a constant rate in microvascular decompression (MVD), the anatomical and technical issues of transposing APC have not been entirely focused on yet.We reviewed our 68 cases with APC involvement. Patient background, radiological findings, and operative video recordings were reviewed retrospectively. The location of the bifurcation of APC and the distribution of perforators were investigated. Surgical outcomes were assessed in the long term.APC involvement was diagnosed preoperatively in all cases by careful observation with MRI. Three-dimensional images determined the anatomical characteristics of APC and depicted the relationship with the facial nerve. All patients had a bifurcation close to the root entry zone that was required to transpose, including the common trunk and the distal branches, to achieve sufficient decompression. While adequate transposition from the REZ was accomplished in most cases, it was difficult to complete transposition due to short perforators in 6 patients (8.8%), resulting in interposition. Fifty-three patients (77.9%) became spasm free immediately after surgery, 66 patients (97.1%) were after 6 months, and all patients (100%) became spasm free within a year. Spasm-free status was maintained during the follow-up period (4.7 years) in all patients except one in whom facial spasm recurred 2 years after the initial surgery.Transposing the common trunk with the bifurcation and distal branches contributes to obtaining favorable surgical outcomes in APC-related HFS.

Our aim was to determine the surface free energy (SFE) of semi-solid dosage forms (SSDFs) by establishing a reproducible method for measuring the contact angle of liquids to SSDFs. Four SSDFs were used: petrolatum, an oil/water (O/W) and a water/oil (W/O) cream, and an alcohol-based gel. The SSDFs were evenly spread on a glass slide, and the change in contact angle over time was measured by dropping water, glycerol, diiodomethane and n-hexadecane as the test liquids. Depending on the combination of test liquid and SSDF, the contact angle was either constant or decreased in an exponential manner. Contact angles may have decreased in an exponential manner because the reaction between the test liquid and the SSDF altered the interfacial tension between the two phases and changed the surface tension of the test liquid and the SFE of the SSDF. The contact angle of the test liquid to the SSDF could be determined reproducibly using the initial contact angle immediately after dropping the liquid on the SSDF as the contact angle before reaction. Using the obtained contact angles and the Owens-Wendt-Rabel-Kaelble equation, we calculated the SFE and its component for the SSDFs tested and found that the results reflect the physicochemical properties of SSDFs. Furthermore, the work of adhesion (WA) of the SSDF to Yucatan micropig skin was calculated using the SFE for the SSDFs. Interestingly, the WA values for all SSDFs tested were comparable.

To investigate the causes of failure and recurrence after microvascular decompression (MVD) for trigeminal neuralgia (TGN) and to analyze the results of redo surgery. Sixty-three cases of redo surgery were retrospectively reviewed. Reasons for re-exploration were categorized into 4 groups based on the operative findings. Patient characteristics, outcomes of re-exploration, and operative complications were analyzed by Kaplan–Meier and logistic regression analyses. Reasons for redo surgery were divided into arterial compression in 13 patients (21%), venous compression in 11 patients (17%), prosthesis-related in 25 patients (40%), and adhesion or negative exploration in 14 patients (22%). Immediate pain relief was obtained in 59 patients (94%) postoperatively with newly developed facial numbness in 17 patients (27%). Of these, 48 patients (76%) maintained pain-free 1 year postoperatively. Overall recurrence was noted in 17 patients (27%) during the median 49-month follow-up period. Most recurrences occurred within 1 year after redo surgery, but the prosthesis-related patients showed a continuous recurrence up to 4 years. Patients having vascular compression showed significantly better pain control than those without vascular contact in Kaplan–Meier analyses (p = 0.0421). No prognostic factor for pain-free 1 year after redo surgery was found. Redo surgery is effective for patients with remaining vascular compression rather than those without vascular contact. Teflon contact onto the nerve root should be avoided because it is a potential risk for recurrence and causes poor prognosis after redo surgery.

Trigeminal neuralgia (TGN) caused by the vertebrobasilar artery (VBA) is uncommon. The abducens nerve root is frequently dislocated by a tortuous VBA near the trigeminal nerve root. This unusual location of the root is not well known. This study aimed to investigate the location of the stretched abducens nerve root. The objective is 26 patients with VBA-related TGN who underwent microvascular decompression (MVD). We retrospectively investigated the course of the abducens nerve root with magnetic resonance imaging (MRI) with three-dimensional (3D) imaging and surgical findings. The displacement of the abducens nerve root on the affected side was compared to the contralateral side. The abducens nerve root was distorted by a tortuous VBA (46.2%) or the anterior inferior cerebellar artery (53.8%). The average length of the cisternal segment was stretched to 23.4 mm versus 12.4 mm on the contralateral side. The peak point of the elevated abducens nerve root was mostly located rostro-medial (65.4%) or caudo-medial (34.6%) to the neurovascular compression site of the trigeminal nerve with a mean distance of 9.1 mm. Contact with the trigeminal nerve root was observed in 7 patients (26.9%). Three-dimensional imaging was consistent with the surgical findings and useful in predicting the location of the abducens nerve root. No abducens nerve palsy was noted in our series. The abducens nerve root is located near the trigeminal nerve root in VBA-related TGN. Preoperative understanding of the unusual course of the abducens nerve root contributes to avoiding accidental nerve injury during MVD.

Neurosarcoidosis (NS) affects various sites of the central nervous system, including the cranial nerve, meninges, brain parenchyma, hypothalamus, and pituitary gland. NS rarely causes intracerebral vasculitis and subsequent strokes, or cerebral infarction and hemorrhage, which are associated with high mortality. Herein, we report a 71-year-old woman's case of stroke associated with NS, which showed aggressive cerebral vasculitis with brain herniation; it was resolved with corticosteroid therapy after accurate histopathological diagnosis. This case highlights the necessity of expecting NS to sometimes follow an aggressive course, presenting with vasculitis. Most patients with NS satisfactorily respond to corticosteroids, but this is not always the case. In cases of unfamiliar ischemic or hemorrhagic lesions, the possibility of NS must be considered.

Background One possibly problematic feature of lumboperitoneal shunt (LPS) placement involves inaccuracy in handling the shunt valve compared with ventriculoperitoneal shunt. Flushing the valve to ascertain shunt patency and adjusting the valve pressure in LPS are often more difficult than with ventriculoperitoneal shunt, particularly when the valve is routinely located in abdominal fat. To overcome this inaccuracy, we applied a simple alteration to the usual LPS procedure. We changed the valve location from the abdominal fat to a lumbar posterior site where the paravertebral spinal muscle, in contrast to the nonsupportive abdominal fat, offers a good anchoring point for valve implantation. Methods We retrospectively reviewed 51 consecutive patients undergoing LPS placement for normal pressure hydrocephalus. We divided the patients into 2 groups, anterior or lateral and posterior, and analyzed these 2 groups, focusing on technical features and outcomes. Results In the anterior or lateral group, 1 patient showed an inverted valve position, and errors occurred when adjusting the valve pressure in 3 patients. There were no wound complications, such as skin erosion. Two patients experienced periumbilical discomfort. In the posterior group, no patients showed an inverted valve position or errors associated with adjustment of the pressure. There were no wound complications, such as skin erosion, or reports of discomfort. Conclusions In this series, our modification increased the accuracy of handling the valve without increasing discomfort.

Background Contact of the main stem of the petrosal vein (PV) to the nerve root is a rare cause of trigeminal neuralgia (TGN). The implication of the PV in relation with neurovascular contact (NVC) is not fully understood. Objective To assess the operative procedures in microvascular decompression (MVD) in patients with PV involvement in the long-term. Methods We retrospectively reviewed 34 cases (7.0%) in 485 consecutive MVDs for TGN, whose PV main stem had contact with the trigeminal nerve root (PV-NVC). PV-NVCs were divided into 2 groups: concomitant arterial contact or no concomitant arterial contact. Surgical techniques, outcomes, complications, and recurrence were assessed. Results The anatomical relationship of the PV with the trigeminal nerve root was consistent with preoperative 3-dimensional imaging in all patients. Pain relief was obtained in most patients immediately after surgery (97.1%) by separating the PV from the nerve root. Postoperative facial numbness was noted in 9 patients (26.5%). Symptomatic venous infarctions occurred in 2 patients (5.9%). Recurrence of facial pain occurred in 3 patients (8.8%) with a median 48 mo follow-up period. Re-exploration surgery revealed adhesion being the cause of recurrence. The statistical analyses showed no difference in the surgical outcomes of the 2 groups. Conclusion Separating the PV from the nerve root contributes to pain relief in patients with PV conflict regardless of concomitant arteries. Preserving venous flow is crucial to avoid postoperative venous insufficiency.

Separation of the vertebrobasilar artery (VBA) from the trigeminal nerve root in microvascular decompression (MVD) is technically challenging. This study aimed to review the clinical features of VBA involvement in trigeminal neuralgia and evaluate surgical decompression techniques in the long term. We retrospectively reviewed the surgical outcomes of 26 patients (4.4%) with VBA involvement in 585 consecutive MVDs for TGN using a Teflon roll for repositioning the VBA. The final operative status of the nerve decompression was categorized into two groups: the separation group and the contact group. Separation of the VBA from the nerve root was completed in 13 patients in the separation group, and slight vascular contact remained in the remaining 13 patients of the contact group. The clinical features of VBA-related TGN were investigated and the operative results were analyzed. Multiple arteries are involved in neurovascular compression (NVC) in most cases. The anterior inferior cerebellar artery was the most common concomitant artery (69%). The site of the NVC varies from the root entry zone to the distal portion of the root. All patients were pain-free immediately after surgery and maintained medication-free status during the follow-up period, except for one patient (3.8%) who had recurrent facial pain 8 years after surgery. Postoperative facial numbness was observed in six patients (23%). Of these, one patient showed improvement within 3 months and the other five patients had persistent facial numbness (19.2%). Other neurological deficits include one dry eye, one diplopia due to trochlear nerve palsy, two decreased hearing (

The most preferred treatment for organized chronic subdural hematoma (OSDH) remains controversial. Although a large craniotomy has been reported to be necessary and effective for the treatment of an OSDH, a craniotomy is associated with postoperative hemorrhagic complications and recurrence. Although middle meningeal artery (MMA) embolization has been reported to be effective for a refractory chronic subdural hematoma (CSDH), its efficacy for an OSDH remains unclear. We report two cases of OSDH treated with MMA embolization followed by hematoma removal via a small craniotomy under local anesthesia with good progress. Case 1: A 71-year-old man underwent a single burr hole irrigation for a CSDH, which failed due to a solid hematoma. He underwent a small craniotomy under local anesthesia after an MMA embolization. During the craniotomy, a small hemorrhage from the hematoma and its outer membrane was observed. Postoperatively, the symptoms disappeared immediately, and the hematoma did not recur. Case 2: A 77-year-old man underwent a burr hole irrigation, but the hematoma was not evacuated because of an OSDH, and he remained in motor aphasia. After an MMA embolization, a craniotomy was performed under local anesthesia. Intraoperative hemorrhage was minimal, and after the craniotomy, his neurological symptoms improved without any recurrence. MMA embolization and hematoma removal with a small craniotomy could be a treatment option for an OSDH.

Highlights • There is little information regarding severe intraventricular hemorrhage casting associated with moyamoya disease. • Performing only external ventricular drainage in such a case is preferred way, however, there are no scientific date supporting this rule. • This is the description of aspiration of severe intraventricular hemorrhage in moyamoya disease patients in acute phase. • Our two cases suggested that early endoscopic aspiration of severe intraventricular hemorrhage may prevent poor outcomes., Introduction When severe intraventricular hemorrhage (IVH) casting in moyamoya disease (MMD) is mentioned, experts advocate not to evacuate the IVH in acute phase. However, the devastating outcomes derived from this empirical rule have not been addressed. Herein, we report two MMD cases undergoing obliteration of ruptured aneurysm and early complete aspiration of severe IVH casting, and showed good outcomes. Presentation of cases Case 1: A 55-year-old woman was admitted to our hospital. Her initial Glasgow Coma Scale (GCS) was 4 and a computerized tomography (CT) scan showed severe IVH. Cerebral angiography (CAG) revealed MMD and an aneurysm. Direct surgery was performed for the ruptured aneurysm, followed by endoscopic complete aspiration of residual IVH. The modified Rankin Scale (mRS) was 1 at discharge. Case 2: A 44-year-old woman was admitted to our hospital. Her initial GCS was 4 and the CT scan showed a severe IVH. CAG revealed MMD and an aneurysm. Transcatheter arterial embolization was carried out for the aneurysm, followed by endoscopic complete aspiration of the residual IVH. The mRS was 2 at discharge. Discussion Performing only external ventricular drainage in acute phase for such IVH casting is generally preferred way, however, there are no scientific date supporting this empirical rule. Early surgical removal of severe IVH casting is an approach for severe IVH casting in MMD. Conclusion Early aspiration of severe IVH casting is an option for managing MMD with critical intracranial pressure, and it has the potential to prevent poor outcomes in MMD patients with severe IVH.

Purpose: In the very elderly, complications such as postoperative pneumonia or delirium, which are directly associated with longer hospitalization, are more frequent. In order to overcome these drawbacks, we switched from general anesthesia to rachianesthesia for the lumboperitoneal shunt (LPS) procedure in idiopathic normal pressure hydrocephalus (iNPH) patients. This is because iNPH suffers particularly elderly patients, and neuraxial anesthesia techniques such as rachianesthesia reportedly decrease postoperative complications in patients of very advanced age as compared with general anesthesia. Methods: We retrospectively analyzed 45 patients who underwent LPS in our institution, and divided them into two groups based on the anesthetic approach; 1) general anesthesia, 2) rachianesthesia. We analyzed these two groups with regard to postoperative delirium score and the hospital stay.Results: In the general anesthesia group, two patients had respiratory complications after the surgery. The mean postoperative delirium score using the intensive care delirium screening checklist (ICDSC) was 1.3 (1.4) and the length of hospital stay was 13.9 (4.7) days. In the rachianesthesia group, no patients had respiratory complications. The postoperative mean ICDSC was 1.3 (1.4), and the length of hospital stay was 10.8 (2.1) days. The statistical analysis showed the rachianesthesia group to have significantly shorter hospital stays.Conclusions: LPS under rachianesthesia is an alternative to performing this procedure under general anesthesia in elderly patients.

Background: Saccular aneurysm in the distal segment of the middle cerebral artery (DMCA) occurs very rarely and often represents with a rupture. We report a successful surgical case of a DMCA aneurysm rupture with large cerebral and subarachnoid hemorrhage. Case Description: A 44-year-old female presented a sudden onset headache and coma (the Glasgow Coma Scale was 3). Head computed tomography (CT) revealed a subarachnoid hemorrhage around the right Sylvian fissure and large intracranial hematoma in the right parietal lobe. The CT angiography showed a saccular aneurysm in the peripheral cortical segment of the right angular branch of the right DMCA. We decided to perform a right craniotomy to evacuate hematoma and interrupt the aneurysm. Just after the dural incision, the aneurysm ruptured again. We applied a temporary clip on the artery proximal to the aneurysm before excising it. Conclusion: Aneurysm in DMCA can be treated safely with surgical excision and risk of sudden recurrent hemorrhage needs to be anticipated.

Background To assess efficacy and safety of a newly developed decompression technique in microvascular decompression for hemifacial spasm (HFS) with vertebral artery (VA) involvement. Methods A rigid Teflon (Bard® PTFE Felt Pledget, USA) with the ends placed between the lower pons and the flocculus creates a free space over the root exit zone (REZ) of the facial nerve (bridge technique). The bridge technique and the conventional sling technique for VA-related neurovascular compression were compared retrospectively in 60 patients. Elapsed time for decompression, number of Teflon pieces used during the procedure, and incidences of intraoperative manipulation to the lower cranial nerves were investigated. Postoperative outcomes and complications were retrospectively compared in both techniques. Results The time from recognition of the REZ to completion of the decompression maneuvers was significantly shorter, and fewer Teflon pieces were required in the bridge technique than in the sling technique. Lower cranial nerve manipulations were performed less in the bridge technique. Although statistical analyses revealed no significant differences in surgical outcomes except spasm-free at postoperative 1 month, the bridge technique is confirmed to provide spasm-free outcomes in the long-term without notable complications. Conclusions The bridge technique is a safe and effective decompression method for VA-involved HFS.

Anterior cerebral artery dissection (ACAD), especially simultaneously presenting with subarachnoid hemorrhage (SAH) and cerebral infarction (CI), is rare. Only a few cases of severe SAH due to ACAD have been reported. Herein, we present an unusual case of severe SAH with simultaneous CI caused by ACAD. A 56-year-old male was brought to our hospital for severe disturbance of consciousness. Head computed tomography (CT) disclosed SAH with intracerebral hematoma. We suspected ruptured anterior communicating artery saccular aneurysm on CT angiography. Emergency craniotomy was performed to avoid cerebral herniation which confirmed the ruptured ACAD of right A2. The dissecting site was treated by wrapping with a Goretex sheet. ACAD of A2 may present with a severe hemorrhagic event.

Background We describe a unique anastomosis procedure involving successful middle meningeal artery (MMA) to cortical middle cerebral artery (MCA) bypass, as well as superficial temporal artery (STA) to cortical MCA bypass. Case Description A 46-year-old woman with hemorrhagic Moyamoya disease underwent an anastomosis procedure with the MMA and STA serving as donor arteries. We performed a small craniotomy at the areas closest to the donor STA, MMA, and recipient cortical MCA, and completed STA-MCA and MMA-MCA direct bypass procedures. Conclusions This is a rare case of successful MMA-to-MCA revascularization to prevent rebleeding in a patient with Moyamoya disease. The MMA can be used as a donor artery for extracranial-intracranial anastomosis procedures in clinical practice settings.

In this study, we propose a new technique for evaluating wetting and adhesion of lotions to skin using surface tension measurements, contact angle measurements and calculations based on the Owens-Wendt-Rabel-Kaelble (OWRK) method. Three prescription lotions (Napageln® Lotion 3%, Sumilu® Lotion 3% and Felbinac Lotion 3% ｢Rakool｣） and two over-the-counter lotions (Feitas® Lotion and Salomethyl® FB Lotion α) were used. Based on the dispersive and polar components of the surface free energy of Yucatan micro pig (YMP) skin, isograms of contact angle (wetting envelope) and adhesion work of the YMP skin surface were constructed. Plotting the surface tension and its polar component of lotions on this isogram revealed that it is possible to predict the wettability and adhesion of lotions to YMP skin. Such diagrams can be easily constructed even using the surface free energy of other types of skin, such as that of humans and hairless mice. This evaluation method may be applicable to other external use medicines.

Watertight dural closure is a crucial step in preventing postoperative cerebrospinal fluid (CSF) leak and subsequent infection in posterior fossa surgery. The aim of this study is to assess an alternative use of collagen matrix double grafting in microvascular decompression (MVD). Dural closure using double collagen matrix grafts was retrospectively compared with autologous fascial grafting in 120 patients who underwent MVD. Double collagen matrix grafting technique, a combination use of inlay and onlay grafting (DuraGen®, Integra Lifesciences, Plainsboro, NJ, USA, $700–800 for an MVD craniotomy size), was applied in 60 patients (the collagen matrix group). In the remaining 60 patients, an autologous fascial graft was sutured in a watertight fashion to the dural defect (the fascia group). Postoperative wound complications, such as CSF leak and infection, were retrospectively compared between the two groups. CSF leaks were observed in 3 patients (5.0%) in the fascia group and in 2 patients (3.3%) in the collagen matrix group. All cases of CSF leakage presented with pseudomeningoceles except one patient who developed an incisional CSF leak. A repair surgery for CSF leak was required in this one patient in the fascia group. Subcutaneous abscesses were noted in 2 patients (3.3%) in the fascia group. There was no patient who developed a subcutaneous abscess in the collagen matrix group. One patient in each group developed aseptic meningitis. Statistical analyses revealed that the collagen matrix group showed non-inferior outcomes to the fascia group in CSF leaks and infectious complications. Double grafting technique with a combination of inlay and onlay collagen sheets is a safe and secure alternative for watertight dural closure despite a cost limitation.

Malaria remains one of the most important infectious diseases in the world. In 2017 alone, approximately 219 million people were infected with malaria, and 435,000 people died of this disease. Plasmodium falciparum, which causes falciparum malaria, is becoming resistant to artemisinin (ART) in Southeast Asia; therefore, new antimalarial drugs are urgently needed. Some excellent antimalarial drugs, such as quinine and ART, were originally obtained from plants. Hence, we analyzed the antimalarial effects of marine natural products to find new antimalarial agents. We used a malaria growth inhibition assay to determine the antimalarial ability and half-maximal inhibitory concentration (IC50) values of the marine organism-derived compounds. Three compounds (kapakahine A, kapakahine B, and kulolide-1) showed antimalarial effects, and one (kapakahine F) showed selective antimalarial effects on the Dd2 clone. Although the IC50 values obtained for these compounds were greater than that of ART, their potency against P. falciparum is sufficient to warrant further investigation of these compounds as possible drug leads.

We introduce a structural deterioration determination system that automatically measures the deflection of concrete utility poles from a 3D model created by using 3D point cloud data. As pole deflection is an accurate precursor of cracking, our automated deflection assessment system improves the efficiency of utility pole inspection, by replacing the conventional visual inspections needed to identify cracking. We show that the time and effort of inspection can be reduced by about 52% compared with conventional visual inspection work.

The trigeminocerebellar artery (TCA) is an infrequent anatomic anomaly of the branches originating from the basilar artery. It is clinically identifiable by the presence of the ipsilateral superior cerebellar artery and the anterior inferior cerebellar artery, and its course from the basilar artery to the cerebellar hemisphere. Because of its anatomic proximity to the trigeminal nerve root, the TCA often causes trigeminal neuralgia (TGN). Unlike other common arteries, repositioning the TCA is not always feasible when it penetrates the trigeminal nerve root (the intraneural type of TCA). In addition, the rich perforators originating from the TCA may limit its movability. The nerve decompression technique in such a rare condition has not yet been fully assessed. In this video, we present the nerve-splitting method for the intraneural type of TCA, in which sufficient isolation of the sensory root is achieved. The motor root of the trigeminal nerve originates from the brainstem slightly rostral of the root entry zone of the sensory root. Dissecting the motor root from its exit to the porous trigeminus allows mobilization of the root together with penetrating TCA away from the sensory root. The movability of the TCA increases by dissecting its perforators to the nerve root and brain stem. Sufficient separation of the sensory root contributes to ensuring the surgical result of nerve decompression and reducing the risk of recurrence due to adhesion. No complications of motor root retraction, such as masseter weakness and malocclusion, were noted in our experience. All data identifying the patients were anonymized. All procedures performed in this study were in accordance with the ethical standards of our institutional and national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. This study also obtained approval from the ethics committee of our institution. Written informed consent was obtained from all individual participants, as well as their first-degree relatives, included in this study.

Background Craniocervical junction arteriovenous fistula (CCJAVF) has a variety of forms, including dural and perimedullary arteriovenous fistulas. Owing to this anatomic variety, the terminologies for classifying CCJAVF, most of which aim to describe angiographic structures, have yet to be firmly established, and the current taxonomic classifications do not facilitate surgical strategies. Herein we focused on the existence of intradural feeder vessels, allowing the identification of 2 types of CCJAVF. This retrospective study aimed to assess the usefulness of our diagnostic classification for CCJAVF surgery. Methods We divided CCJAVF into 2 types: CCJAVF with an intradural feeder vessel and CCJAVF without an intradural feeder vessel. For the former type, we set the surgical goal of interrupting the intradural feeder and the draining veins behind the posterior spinal nerve. For the latter type, the surgical goal was to interrupt the draining veins behind the posterior spinal nerve. We retrospectively analyzed the outcomes of our surgical cases. Results Of 12 patients with CCJAVF, 8 underwent direct surgery. No patients showed exacerbation of neurological symptoms after surgery. One patient needed a second operation for residual shunt, and another patient developed an asymptomatic angiographic recurrence in the epidural space detected on follow-up imaging. The overall outcomes of surgical cases were good with an average modified Rankin Scale score of 1.0. Conclusions Our results indicate that our diagnostic classification for CCJAVF has the potential to simplify CCJAVF treatment without compromising patient outcomes.

We experimentally and theoretically investigate the effect of an air hole between cores in a multi-core fiber (MCF) on the suppression of crosstalk (XT). We clarify that XT decreases in proportion to the air hole diameter and that XT of about 20 dB in an MCF can be suppressed by employing just one air hole between cores. We confirm that the calculated XT suppression value is in good agreement with the measured value. We also clarify numerically that the minimum distance between cores satisfies the required XT without reducing the effective area by using an air hole. Next, we consider the influence of air holes on macro-bending loss and cutoff wavelength. We confirm that none are related to the arrangement of the air holes. Moreover, we discuss the relationship between the effective area and the core multiplicity factor (CMF) against several core arrangements. As a result, we show that the CMF in MCF with air holes can increase by 1 or more compared with that without air holes.

Background Catheter-based endovascular thrombectomy has gained popularity for use in patients with acute large-vessel occlusion; however, various complications have been reported. Herein, we present a unique, serious procedure-related complication. Case Description A 91-year-old woman with acute middle cerebral artery (MCA) occlusion underwent endovascular thrombectomy with a stent retriever, but the device could not be retrieved from the horizontal segment of MCA during the procedure. Subsequently, she underwent emergency craniotomy. The lodged stent was extracted with microforceps using a counter-stretch of the vessels, so as not to avulse the perforating arteries. The stent device was retrieved uneventfully through a sheath introducer that was inserted through the femoral artery. Postprocedural indocyanine green video angiography showed complete recanalization of the MCA and internal cerebral artery. Conclusions This is a rare case in which successful open surgery was performed to retrieve a snagged stent retriever, with successful recanalization of the large cerebral artery occlusion.

Background The neurological conditions of brainstem cerebral cavernous malformation (BCM) patients are usually ascertained using Karnofsky Performance Status (KPS) or the modified Rankin scale (mRS). However, these scales do not reflect slight changes in brainstem function, because neither KPS nor mRS includes brainstem symptoms such as worsening of swallowing or diplopia. The main problem when managing the BCM patients is that we can neither systematically record neurological changes nor conduct clinical outcome investigations of BCM due to the lack of an adequately detailed assessment system. Purpose We investigated the usefulness of the Kurtzke expanded disability status scale (EDSS), which is already in widespread clinical use for multiple sclerosis because it provides certainty in evaluating brainstem symptoms. Methods We retrospectively analyzed neurological transitions in surgical BCM cases using the modified Rankin scale (mRS), Karnofsky performance status (KPS), and EDSS. We compared each neurological score transition, and determined which scale allows the most accurate recording of neurological changes in patients. Results We proposed lesion removal for patients who showed both neurological deterioration and lesion enlargement caused by re-bleeding, and the surgery was accepted by 10 patients. EDSS allowed us to assess patient status more accurately than KPS or mRS particularly during the perioperative period. In the statistical analysis, only EDSS differed significantly during the period between the initial proposal of surgery and the immediate preoperative period. Conclusion Our results suggest EDSS to be superior for managing BCM patients, as compared to KPS and mRS. Thus, EDSS may serve as an alternative scale for assessing BCM patients.

We experimentally investigate the cutoff wavelength shortening effect that occurs when the cladding diameter is reduced. The influence of coating thickness, and thus, cladding diameter, on the transmission loss is also discussed. We derive an empirical model of cutoff wavelength and transmission loss as a function of the cladding diameter and coating thickness. The empirical model reveals that a further reduction in the cladding diameter of step index type bending-loss insensitive fiber (BIF) is possible. The validity of the proposed BIF design is confirmed using a 70-μm cladding diameter BIF and jumper cords. This BIF enables us to construct optical fiber networks with higher reliability.

Objective In direct aneurysm surgery, tentative clipping is frequently applied to facilitate aneurysm dissection. However, no systemic review on the pros and cons of tentative clipping has been conducted. This study aimed to investigate the efficacy and concerns of tentative clipping. Methods A total of 867 direct clippings in 737 patients were performed to treat intracranial aneurysms between 1994 and 2015. We retrospectively investigated the frequency, purpose, location, and adequacy of tentative clipping. Results Tentative clipping was performed in 149 of the 867 aneurysms that were clipped (17.2%). The purpose of tentative clipping was to dissect an aneurysm in 141 (94.6%), separate the vessels from the surface of a sac in 5 (3.4%), and prevent slipping of the final clip in 3 (2.0%) cases. Further dissection revealed that tentative clipping completely excluded the blood flow into the aneurysm in 126 (84.6%) of the 149 cases and incompletely shut it out in 23 (15.4%) cases. Five (21.7%) of the 23 patients with incomplete clipping had intraoperative aneurysm ruptures subsequently. Conclusions Tentative clipping facilitates dissection of the aneurysm sac from the surrounding structure but can occasionally lead to intraoperative rupture. Before applying tentative clips, surgeons should prepare for temporary clipping or additional tentative clipping in case of a rupture.

Background Kawasaki disease (KD) is an acute systemic vasculitis that primarily affects the coronary artery, but it does not commonly affect the carotid artery. Cerebral infarction (CI) with internal carotid artery stenosis (ICS) in patients with KD has not been reported until now. We report a patient with CI as a remote-phase complication of KD. Case Presentation A 32-year-old man presented with impaired consciousness. Magnetic resonance imaging and digital subtraction angiography confirmed CI and ICS. He successfully underwent carotid endarterectomy. The resected plaque had pathologic findings of KD, which suggested that the internal carotid artery suffered from chronic inflammation. Conclusion KD in childhood may cause symptomatic ICS as a sequela of a remote phase.

Background The trigeminocerebellar artery (TCA) is a variant branch of the basilar artery supplying the trigeminal nerve root and cerebellar hemisphere, which may contribute to trigeminal neuralgia (TGN). Despite its unique anatomic description, information regarding the preoperative diagnosis and surgical management of TCA is lacking. Objective To evaluate our preoperative diagnosis of TCA using 3-dimensional (3D) images and surgical management of TGN cases with TCA involvement. Methods We reviewed our 15 patients with TCA involvement (3.3%) among 460 consecutive patients undergoing microvascular decompression for TGN. In this study, all patients were examined using 3D images using GammaPlan (Elekta, Stockholm, Sweden). TCAs were divided into 2 groups based on surgical findings: encircling type and intraneural type. Biographical data, radiological findings, and operative video recordings were reviewed retrospectively. Surgical outcomes and follow-up were assessed and compared between the 2 groups. Results TCA involvement was confirmed preoperatively in 14 of the 15 patients using 3D images. All patients were operated with our unique transposition technique and became pain free immediately after the surgery. Pain-free status was maintained during the follow-up period (3.5 ± 2.6 yr) in all patients but one in whom pain recurred 4 yr after the initial surgery. Re-exploration revealed an adhesion between the Teflon felt and the nerve root. Conclusion Although TCA involvement is rare, an accurate preoperative diagnosis is essential because the decompression technique may differ from those used for other common cases. Scrutinizing anatomically rare variation with 3D images is recommended for predicting TCA involvement.

OBJECTIVEOne of the technical problems encountered in performing lumboperitoneal shunt (LPS) surgery involves operative positioning of the patient. To insert the spinal catheter into the subarachnoid lumbar space, LPS is usually performed with the patient in the lateral decubitus position. However, laparotomy around the periumbilical region, especially in obese patients in the lateral decubitus position, can be quite difficult. Thus, the authors added a simple modification to the laparotomy for LPS, altering the laparotomy site to the lateral side of the patient’s trunk. The aim of this study was to analyze this method in terms of technical features and outcomes.METHODSTwo LPS procedures were compared: routine periumbilical anterior abdominal laparotomy and our modified method using lateral abdominal laparotomy. The first 11 consecutive cases underwent routine anterior abdominal laparotomy with position changes or tilting of the operative bed, whereas the next 17 consecutive cases underwent lateral abdominal laparotomy not requiring position changes.RESULTSIn the anterior abdominal laparotomy group, the mean operative time was 72.36 ± 24.63 minutes. One patient had a spinal tube tear that required revision of the LPS 2 years postoperatively. In the lateral abdominal laparotomy group, the mean operative time was 38.82 ± 13.87 minutes. One patient experienced a postoperative headache and exhibited a thin, chronic subdural hematoma on imaging studies, which disappeared after adjustment of the valve pressure.CONCLUSIONSIn the current series, the operative duration was shorter in the lateral abdominal group compared with the anterior abdominal group, with no differences in complication rates. Lateral abdominal laparotomy simplifies LPS.

To clarify the requirements as regards the geometry of multicore fiber, we examined its minimum cladding thickness and maximum cladding diameter experimentally. We studied the relationship between cladding thickness and transmission loss for an eccentric core structure and revealed that the cladding thickness is mainly limited by confinement loss. We also confirmed that the dynamic fatigue corrosion of the optical fiber exhibits no clear dependence on coating thickness or cladding diameter. We discussed the relationship between the effective core area and the core multiplicity factor by considering several arrangements. We showed that optimizing the relationship between core arrangement and effective core area can maximize the core multiplicity factor.

Background: Some patients come to the hospital presenting with ischemic neurological deficits due to postsubarachnoid hemorrhage (SAH) cerebral vasospasm. In such a situation, neurosurgeons tend to avoid direct clipping, since mechanical irritation to the vessels could worsen the vasospasm and exacerbate ischemic symptoms. The optimal timing of direct clipping in patients with evidence of vasospasm is undetermined. Herein, we present the case of a patient who underwent direct clipping in the presence of severe symptomatic and post-SAH angiographic vasospasm. During surgery, we coated the severely spastic artery with nicardipine. Case Description: A 49-year-old woman was admitted to our hospital with the diagnosis of ruptured intracranial aneurysm and severe vasospasm. On the admission day, we performed direct clipping together with direct application of nicardipine to the spastic artery. Postoperative immediate cerebral angiography showed complete disappearance of the vasospasm. Conclusion: Direct clipping should not be contraindicated during the vasospasm period in patients with a ruptured aneurysm, and direct application of nicardipine on the spastic artery would completely relieve vasospasm.

In some patients with spontaneous subarachnoid hemorrhage(SAH), initial imaging investigations may not be able to detect a bleeding source;repeat imaging may be necessary to reveal these lesions. We reviewed a consecutive series of 45 patients with SAH and negative initial digital subtraction angiograms(DSA)during a 15-year period. The aims were to document the frequency and reason for the negative initial investigations, to determine the appropriate modality and timing of repeat examinations, and to investigate the identified bleeding sources. Twenty-eight(62%)patients underwent repeat DSA, 35(78%)underwent magnetic resonance imaging(MRI), and 33(73%)underwent computed tomography angiography(CTA). Nine lesions(5 small aneurysms, 2 craniocervical junction arteriovenous fistulas, 1 arteriovenous malformation, and 1 internal carotid artery dissection)were identified on subsequent DSA after 2-3 weeks. Most aneurysms were identified on an atypical vascular tree. CTA or MRI alone were unable to disclose the culprit lesions. In retrospect, human errors including oversight were the major reasons for the negative initial investigation results. It is, however, difficult to search for a tiny vascular lesion that might be anywhere in the cranium. Repeat DSA is still the gold standard for the inspection of hidden bleeding sources in patients with SAH of unknown origin.

This paper reviews recent progress on research of space division multiplexing (SDM) technology in Japan. Three multi-vendor SDM transmission trials, which have been conducted based on the four national projects since 2010, are summarized.

Background Intraosseous hemangioma is a rare bone tumor, accounting for 0.7%–1.0% of all bone tumors. It can occur at any age, but only 9% of cases are younger than 10 years old. Although this tumor is usually slow-growing and clinically silent, we experienced 2 pediatric patients undergoing surgery for skull hemangioma who presented with uncommon clinical manifestations. Case Decription Case 1 was a 9-year-old boy who presented with sudden onset of headache and was referred to our hospital. Radiologic images revealed an osteolytic oval lesion in the right parietal bone and acute subdural hemorrhage in the right cerebral hemisphere. The right parietal lesion was removed surgically. The lesion was found to have grown into the dura and to be adherent to the pia matter. The removed lesion was histologically confirmed to be a hemangioma. Case 2 was an 8-year-old girl who was referred to our hospital with an elastic mass that had been slowly enlarging for 7 years. Radiologic images revealed an osteolytic oval lesion in the right parietal bone. Surgical removal was thus planned. The lesion was found to be attached to the dura, and we removed the lesion with the surrounding bone and attached dura. Histologic examination confirmed the lesion to be a hemangioma. Conclusions Although skull hemangiomas show clinical heterogeneity, surgical removal is usually diagnostic and leads to good patient outcomes. On occasion, however, this tumor causes secondary changes in the dura, such that dural incision and dural plasty should be planned in advance of lesion removal.