Effectiveness of the 'hoisting method' for shunt placement.

PURPOSE: The abdominal procedure of ventriculoperitoneal or lumboperitoneal shunt is difficult because of a deep and narrow operative view, especially for obese patients. We have developed the 'Hoisting method,' which enables us to make abdominal procedures easy and safe. MATERIAL AND METHODS: We report our experience with five cases between April 2020 and March 2021. RESULTS: The placement of the shunt was easy and safe in all patients without any complications. CONCLUSION: The shunt method is very effective and easy without requiring additional devices.

[Surgical Technique for Lumbar Spinal Extraforaminal Schwannoma].

INTRODUCTION: Spinal neurinomas are frequently observed in the cauda equina, particularly within the dura mater. However, extraforaminal schwannomas(EFS), which are neither intradural nor dumbbell type, are relatively rare; hence, different surgical procedures have been employed. Here, we report 12 cases of lumbar EFS with total resection that were safely performed. METHODS AND SUBJECTS: This study was comprised of 12 patients with lumbar EFS(excluding those with neurofibromas)who were previously treated at our hospital. Using the Wiltse paraspinal approach, we inserted the microscope until it reached the tumor surface. After confirming the tumor surface, we inserted a scalpel to make an incision in a portion of the outer capsule. Then, we confirmed that the surfaces of the outer capsule and the tumor within the capsule could be dissected. Next, a thread was attached to the outer capsule and pulled upwards so that there was enough space to perform the required procedures within the capsule. Using a CUSA®, we removed the intracapsular tumor. After its removal, the outer capsule was treated carefully to ensure that the origin nerve was not damaged. RESULTS: In all cases, we successfully performed a total removal of the intracapsular tumor;in the mean postoperative observation period of 8 years, no recurrence was observed. Although temporary paralysis was observed in three patients, this improved over time. CONCLUSION: We report our experience with a surgical technique that ensured the safe removal of lumbar EFS. Satisfactory results were achieved, with no recurrences observed during the mean 8-year postoperative observation period.

Outcome of microvascular decompression for hemifacial spasm associated with the vertebral artery.

We retrospectively compared the outcome of microvascular decompression (MVD) for hemifacial spasm (HFS) associated with the vertebral artery (VA) with that of MVD for HFS unrelated to the VA. Between April 2008 and April 2015, 22 patients with VA-associated HFS underwent MVD at our institution. The median follow-up period was 28 months (range, 12-90 months). Results were classified as excellent in 19 patients (86 %), good in one (5 %), fair in one (5 %), and poor in one (5 %). Immediate complications developed in five patients (23 %), and one of these complications (5 %) was permanent. The surgical outcome of MVD for VA-associated HFS was similar to that of MVD for HFS unrelated to the VA; however, the incidence of complications was significantly more frequent in patients whose VA compressed the more proximal portion of the facial nerve root exit zone from the caudal side at the pontomedullary sulcus. We conclude that preoperative evaluation of VA compression patterns is important to predict the difficulty of the planned MVD procedure.

[A Rare Case of Cerebellar Hemangioblastoma Causing Taste Disorder].

Taste(gustation)is one of the five senses, and comprises the types: sweet, bitter, salty, sour, and umami. Taste disorders, such as dysgeusia and parageusia, are classified into 2 types: those with peripheral origin and those with central origin. The peripheral origin-type taste disorder is caused by zinc deficiency, mouth dryness, a side effect of radiotherapy or complication of systemic diseases such as, diabetes, hepatopathy, and nephropathy. The central origin-type taste disorder is reported to be caused due to demyelinating disease, pontine hemorrhage, pontine infarction, and thalamic infarction; it is very rarely caused by a brain tumor. We surgically treated a 69-year-old man with cerebellar hemangioblastoma who had developed taste disorder. The tumor compressed the solitary nucleus, which includes the taste tract in the central nervous system. On removal of the tumor, the taste disorder gradually improved.

Magnetic Resonance (MR) Imaging Assessment for Glossopharyngeal Neuralgia: Value of Three-Dimensional T2-Reversed MR Imaging (3D-T2R) in Conjunction with Other Modes of 3D MR Imaging.

BACKGROUND: To retrospectively examine the usefulness of gray-scale reversal imaging of T2-weighted images (3D-T2R) in conjunction with other modes of 3D MRI for preoperative assessments in patients with glossopharyngeal neuralgia (GPN) due to neurovascular compression. MATERIAL/METHODS: Imaging findings on 3D-T2R, constructive interference in steady state (CISS), and MRA were analyzed with reference to operative charts in 10 patients with GPN. RESULTS: Offending vessels were associated with the posterior inferior cerebellar artery (PICA) in 9 of 10 patients (90%). Eight of the 10 patients (80%) had offending vessels located at the supraolivary fossette. Of those eight patients, six (75%) had a shift of the ipsilateral vertebral artery to the affected side. Five (42%) and seven (48%) contact points were associated with the root entry/exit zone and the peripheral nerve system segment, respectively. In six of nine contact points (67%), 3D-T2R demonstrated the pathomorphological features at the contact points better than CISS. CONCLUSIONS: The offending vessels were mostly associated with posterior inferior cerebellar arteries, were frequently located at the supraolivary fossette, and had attachments at the root entry/exit zone and at the peripheral segment of the glossopharyngeal nerve, which was well demonstrated on 3D-T2R.

[Two Cases of Ruptured Cerebral Aneurysm Complicated with Delayed Coil Protrusion after Coil Embolization].

We report two cases of delayed coil protrusion after coil embolization for ruptured cerebral aneurysms. Case 1:An 82-year-old woman with a subarachnoid hemorrhage due to a ruptured small anterior communicating artery aneurysm underwent successful coil embolization. Eighteen days after the procedure, coil protrusion from the aneurysm into the right anterior cerebral artery was observed without any symptoms. Further coil protrusion did not develop after 28 days. Case 2:A 78-year-old woman with a subarachnoid hemorrhage due to a ruptured small left middle cerebral artery aneurysm underwent successful coil embolization. Twenty days after the procedure, coil protrusion from the aneurysm into the left middle cerebral artery was observed, with a transient ischemic attack. Further coil protrusion did not develop. Both patients recovered with antithrombotic treatment. Even though delayed coil protrusion after coil embolization is rare, it should be recognized as a long-term complication of coil embolization for cerebral aneurysms.

Arterial spin-labeling MR imaging of cerebral hemorrhages.

INTRODUCTION: The purpose of this study is to identify the characteristics of brain perfusion measured by arterial spin-labeling magnetic resonance imaging (ASL-MRI) in cerebral hemorrhages. METHODS: Brain blood flow values (CBF-ASL values) for cerebral and cerebellar hemispheres and segmented cerebral regions were measured by ASL-MRI in 19 putaminal hemorrhage patients and 20 thalamic hemorrhage patients in acute or subacute stages. We assessed the lateralities of CBF-ASL values and the relationships between CBF-ASL values and other imaging findings and clinical manifestations. RESULTS: Both the 19 putaminal hemorrhage patients and the 20 thalamic hemorrhage patients had significantly low CBF-ASL values of the contralateral cerebellum in subacute stage, suggesting that ASL-MRI might delineate crossed cerebellar diaschisis (CCD). Ipsilateral low CBF-ASL values were observed in frontal lobes and thalami with a putaminal hemorrhage and lentiform nuclei, temporal lobes, and parietal lobes with a thalamic hemorrhage, suggesting that ASL-MRI showed the ipsilateral cerebral diaschisis (ICD). In the putaminal hemorrhage patients, the hematoma volume negatively affected both the bilateral cerebellar and cerebral hemispheric CBF-ASL values. In the thalamic hemorrhage patients, a concomitant intraventricular hemorrhage caused low cerebral hemispheric CBF-ASL values. CONCLUSION: The use of ASL-MRI is sensitive to the perfusion abnormalities and could thus be helpful to estimate functional abnormalities in cerebral hemorrhage patients.

Outcome of microvascular decompression for trigeminal neuralgia treated with the stitched sling retraction technique.

The purpose of this retrospective study was to describe and evaluate the long-term outcome of microvascular decompression (MVD) with the stitched sling retraction technique for treating trigeminal neuralgia (TN). Between January 2007 and December 2012, 50 patients with idiopathic TN underwent MVD using the stitched sling retraction technique at our institution. The median follow-up period was 5.2 years (range, 1.8-6.8 years). Using Kaplan-Meier analysis, the rates of complete pain relief without medications were 88% at 1 year and 83% at 5 years. Recurrence was noted in two patients, and one patient was re-treated using a complementary procedure for pain relief. Although transient complications were observed in seven patients, no permanent neurological deficit was observed. We conclude that the stitched sling retraction technique is a safe and effective treatment for TN and maintains substantial pain relief and low recurrence rates over a long period of time.

Anatomy of the superior petrosal veins and their exposure and management during petrous apex meningioma surgery using the lateral suboccipital retrosigmoid approach.

During surgeries in the upper cerebellopontine angle (CPA), the superior petrosal veins (SPVs) often act as obstacles; and their sectioning sometimes causes serious complications. In this study, we introduced a classification system for the SPVs wherein their tributaries were classified into four groups on the basis of their courses and draining areas. We furthermore explained the detailed anatomy of the vein of the cerebellopontine fissure, which is the largest tributary. In surgeries of petrous apex meningioma, the knowledge of the displacement pattern of the vein is very helpful for avoiding major venous complications. Therefore, we elucidated its anatomical situation in relation to the original portion of the meningioma and the natural draining point of the vein into the superior petrosal sinus (SPS) in each patient. In addition, we described the methods and techniques used to expose and manage the vein of the cerebellopontine fissure during surgery using the lateral suboccipital retrosigmoid approach. Presenting two illustrative cases, we recommend that the initial exposure of the tumor should be performed through the infratentorial lateral supracerebellar route and that the suprafloccular cistern is the best area to find the vein of the cerebellopontine fissure. We emphasized the importance of the preservation of the vein of the cerebellopontine fissure and also proposed the order for exposure of SPV tributaries during upper CPA surgery using the retrosigmoid approach.

Posterior condylar canals and posterior condylar emissary veins-a microsurgical and CT anatomical study.

The posterior condylar canals (PCCs) and posterior condylar emissary veins (PCEVs) are potential anatomical landmarks for surgical approaches through the lateral foramen magnum. We conducted computed tomography (CT) and microsurgical investigation of how PCCs and PCEVs can aid in planning and performing these approaches. We analyzed the microanatomy of PCCs and PCEVs using cadaveric specimens, dry skulls, and CT images. The recognition frequency and geometry of PCCs and PCEVs and their relationships with surrounding structures were evaluated. PCCs were identified in 36 of 50 sides in dry bones and 82 of 100 sides by CT. PCCs had a 3.5-mm mean diameter and a 6.8-mm mean canal length. We classified their courses into four types according to intracranial openings: the sigmoid sinus (SS) type, the jugular bulb (JB) type, the occipital sinus type, and the anterior condylar emissary vein type. In most cases, PCEV originated near the boundary between the SS and JB. PCCs and PCEVs can be useful anatomical landmarks to differentiate the transcondylar fossa approach from the transcondylar approach, thus preventing unnecessary injury of the atlantooccipital joint. They can also be used as landmarks when the jugular foramen (JF) and hypoglossal canal (HGC) are being exposed. The area anterior to the brain stem and the medial part of HGC can be accessed by removal of the lateral foramen magnum medial to PCC. JF and the lateral part of HGC can be accessed by removal of the skull base lateral to PCC without damaging the lateral rim of the foramen magnum.

Obstructive hydrocephalus following aqueductal stenosis caused by supra- and infratentorial developmental venous anomaly: case report.

OBJECTIVE: We report a rare case of hydrocephalus following aqueductal stenosis caused by developmental venous anomaly (DVA). METHODS: Four years after the incidental discovery of asymptomatic DVA, the 10-year-old boy presented with symptoms of hydrocephalus. Enhanced computed tomographic scans and magnetic resonance images showed supra- and infratentorial DVAs with caput medusae appearances in the right basal ganglia and cerebellum. Three dilated collector veins in the right basal ganglia, floor of the third ventricle, and floor of the fourth ventricle gathered together to drain into the great vein of Galen. Three-dimensional fusion images showed that the serpentine dilated vein from the posterior fossa coursed in the aqueduct and caused the aqueductal stenosis, which was confirmed by operative endoscopy. RESULTS: Endoscopic third ventriculostomy was performed and the hydrocephalus was relieved. CONCLUSIONS: Although aqueductal stenosis caused by DVA is rare, it is important to be considered in the differential diagnosis of hydrocephalus. Three-dimensional reconstruction and fusion images are very useful.

3D Computer graphics simulation to obtain optimal surgical exposure during microvascular decompression of the glossopharyngeal nerve.

The affected artery in glossopharyngeal neuralgia (GPN) is most often the posterior inferior cerebellar artery (PICA) from the caudal side or the anterior inferior cerebellar artery (AICA) from the rostral side. This technical report describes two representative cases of GPN, one with PICA as the affected artery and the other with AICA, and demonstrates the optimal approach for each affected artery. We used 3D computer graphics (3D CG) simulation to consider the ideal transposition of the affected artery in any position and approach. Subsequently, we performed microvascular decompression (MVD) surgery based on this simulation. For PICA, we used the transcondylar fossa approach in the lateral recumbent position, very close to the prone position, with the patient's head tilted anteriorly for caudal transposition of PICA. In contrast, for AICA, we adopted a lateral suboccipital approach with opening of the lateral cerebellomedullary fissure, to visualize better the root entry zone of the glossopharyngeal nerve and to obtain a wide working space in the cerebellomedullary cistern, for rostral transposition of AICA. Both procedures were performed successfully. The best surgical approach for MVD in patients with GPN is contingent on the affected artery--PICA or AICA. 3D CG simulation provides tailored approach for MVD of the glossopharyngeal nerve, thereby ensuring optimal surgical exposure.

[Blood blister-like aneurysm on the posterior wall of the internal carotid artery causing subarachnoid hemorrhage: a case report].

We report a case of blood blister-like aneurysm(BBA)on the posterior wall of the internal carotid artery(ICA)causing subarachnoid hemorrhage(SAH). A 45-year-old man suffering from SAH(WFNS grade 5)was referred to our hospital. 3D-CT angiography showed a BBA on the posterior wall of the ICA. The aneurysm had been enlarged for a few days. Therefore we performed coil embolization. Four weeks after the operation, the aneurysm was found to have regrown. In the second operation the aneurysm was successfully treated by the ICA proximal occlusion with extracranial-intracranial bypass. Postoperative follow-up cerebral angiography detected no aneurysm. To our knowledge, BBA on the posterior wall of the ICA is rare. Radical surgery with bypass should be performed as soon as possible when the BBA is found to regrow. We discuss the clinical characteristics with a review of the literature.

Challenges in the Treatment of Severe Traumatic Brain Injury Based on Data in the Japan Neurotrauma Data Bank.

The Japan Neurotrauma Data Bank is a source of epidemiological data for patients with severe traumatic brain injury (TBI) and is sponsored by the Japan Society of Neurotraumatology. In this report, we examined the changes in the treatment of severe TBI in Japan based on data of the Japan Neurotrauma Data Bank. Controlling and decreasing intracranial pressure (ICP) are the primary objective of severe TBI treatment. Brain-oriented whole-body control or neurocritical care, including control of cerebral perfusion pressure, respiration, and infusion, are also increasingly considered important because cerebral tissues require oxygenation to improve the outcomes of patients with severe TBI. The introduction of neurocritical care in Japan was delayed compared with that in Western countries. However, the rate of ICP monitoring increased from 28.0% in 2009 to 36.7% in 2015 and is currently likely to be higher. Neurocritical care has also become more common, but the functional prognosis of patients has not significantly improved in Japan. Changes in the background of patients with severe TBI suggest the need for improvement of acute-phase treatment for elderly patients. Appropriate social rehabilitation from the subacute to chronic phases and introduction of cellular therapeutics are also needed for patients with TBI.

Association Between Cerebral Angiography and Asymmetrical Cortical and Deep/Medullary Vein Signs on T2 Star Magnetic Resonance Imaging in Patients with Hyperacute Horizontal Segment of the Middle Cerebral Artery Occlusion.

BACKGROUND: When treating acute ischemic stroke patients, evaluation of collateral flow to the ischemic area is essential. Blood-oxygen-level-dependent imaging, including T2 star (T2∗), can identify elevated deoxyhemoglobin levels, reflecting an increase in the oxygen extraction fraction. Prominent veins on T2∗ represent increased deoxyhemoglobin and cerebral blood volume. This study compared asymmetrical vein signs (AVSs) on T2∗ and digital subtraction angiography findings during mechanical thrombectomy (MT) in patients with hyperacute middle cerebral artery occlusion. METHODS: Clinical and imaging data of 41 patients with occlusion of the horizontal segment of the middle cerebral artery who underwent MT were collected. Patients were divided into 2 groups based on angiographic occlusion sites as: proximal and distal to the lenticulostriate artery (LSA). AVSs on T2∗ were divided into asymmetrical cortical vein sign (cortical AVS) and asymmetrical deep/medullary vein sign (deep/medullary AVS), and were compared with the findings of intraoperative digital subtraction angiography. RESULTS: Twenty-seven patients had AVSs. Cortical AVS was the only parameter with a significant association with poor angiographic collateral supply. In terms of occlusion site, deep/medullary AVS was the only parameter with a significant association with occlusion proximal to the LSA. CONCLUSIONS: In patients with occlusion of the horizontal segment of the middle cerebral artery, presence of the cortical AVS on T2∗ suggests a poor angiographic collateral supply, while presence of the deep/medullary AVS suggests impaired blood flow to the basal ganglia through LSAs. Both these signs contribute to poor outcomes in patients undergoing MT.

Surgical Treatment of Vertebral Compression Fracture in a Patient with Idiopathic Normal Pressure Hydrocephalus.

Idiopathic normal pressure hydrocephalus (iNPH) with gait disturbance can be effectively treated with a cerebrospinal fluid shunt. Furthermore, balloon kyphoplasty (BKP) is a successful minimally invasive treatment for osteoporotic vertebral compression fractures (VCFs). This case report presents the surgical management of an elderly patient with iNPH who presented after a VCF due to a fall. A 77-year-old woman who had been experiencing progressive gait disturbance for five years reported experiencing back pain one month after a fall. Imaging revealed a recent L1 VCF that did not compromise the spinal canal. Furthermore, the Mini-Mental State Examination results and the timed up-and-go test were 20 points and 17.96 seconds, respectively. Magnetic resonance imaging revealed ventriculomegaly with an Evans' index of 0.35. Her symptoms improved temporarily after a tap test, and she was diagnosed with probable iNPH. BKP was performed for VCFs, followed by the lumboperitoneal (LP) shunt placement for iNPH one month later. Following the operation, her symptoms improved without complications. After one month of performing BKP, an LP shunt would be placed to prevent shunt complications, such as infection and catheter-related neurological symptoms. Screening for iNPH in the elderly who present after VCFs due to a fall may identify iNPH patients who may benefit more from surgical treatments.

Fact-Finding Survey of Treatment of Traumatic Brain Injury in Japan: Standardization of Care and Collaboration Between Neurosurgery and Emergency Departments.

BACKGROUND: Standardization of seamless treatment from prehospital injury care to initial injury and specialized care through collaboration among departments have been promoted in Japan since 2000. This survey was conducted to examine the current status of the system for treatment of traumatic brain injury (TBI) in Japan. METHODS: In February 2022, questionnaires on the treatment system and TBI care were sent to 869 facilities that participated in a training program held by the Japan Neurosurgical Society. Responses were received from 480 facilities (55.2%). These responses were compared with those in a similar survey performed in 2008. RESULTS: Among the responding facilities, 39.4% had neurosurgeons in emergency departments. Initial care for TBI was the responsibility of the neurosurgery department in 42.3% of the facilities, the emergency department in 26.0%, and jointly between these departments in 29.6%; and neurocritical care was managed by the neurosurgery department in 81.9%, the emergency department in 5.2%, and jointly in 12.1%. For patients with acute-phase TBI, intracranial pressure monitoring was performed in 72.1%. Active normothermia was performed in 86.0%, and decompressive craniectomy in 99.4%, as required. There was compliance with guidelines for treatment and management of TBI in 93.3%. CONCLUSIONS: Comparison with the 2008 results suggested role-sharing between 2 departments in TBI treatment is increasing. TBI treatment compliance with the guidelines was high. In-hospital mortality of Japanese patients with TBI has decreased since 2000. This may be due to the progress with standardization of TBI treatment and collaboration among departments in compliance with guidelines.

Exposure of the wide interior of the fourth ventricle without splitting the vermis: importance of cutting procedures for the tela choroidea.

In recent years, new procedures for fourth ventricular surgeries have been developed with good results. In particular, the trans-cerebellomedullary fissure approach, which exposes the fourth ventricle without splitting the inferior vermis, has proven successful. For optimum results, specialized techniques should be employed in order to effectively open the roof of the fourth ventricle and obtain a wide exposure of its interior. These techniques include the following steps: (1) placement of an incision over the teania extending from the foramen of Magendie to the ventricular entrance of the lateral recess; (2) lateral extension of the incision to the roof of the lateral recess to facilitate its exposure; (3) implementation of the same procedure on the contralateral side. Upon completion of these steps, the bilateral cerebellar tonsils can be easily retracted superolaterally; this eventually exposes a wide interior of the ventricle. In order to ensure successful surgeries, explicit and accurate descriptions of technique are vital. In this article, we employ detailed illustrations to precisely demonstrate the operative procedures and techniques for fourth ventricular surgeries.

The C2 ganglion sectioning epidural approach to craniocervical junction chordoma: a technical case report.

In chordoma, complete surgical removal of the epidural tumor should be the first choice of treatment. Numerous surgical approaches to clival chordoma have been described: anterior approaches, lateral approaches, and posterolateral approaches. A multistaged operation with a combination of these approaches is generally performed. We used three approaches to remove a clival chordoma extending from the lower clivus anteriorly to the anterior perivertebral space and inferiorly to the C2 level. The epidural posterolateral approach through the vertebral artery (VA)-C2 interval space after resection of the C2 dorsal ganglion was the most effective. To our knowledge, the epidural posterolateral approach below VA, referred to as C2 ganglion sectioning epidural approach has not been reported as an independent approach in detail. We report a two-year-old girl with a lower clival chordoma which has been excised using C2 ganglion sectioning epidural approach.