[Variation of Superficial Temporal Artery-Middle Cerebral Artery(STA-MCA)Bypass].

Superficial temporal artery-middle cerebral artery(STA-MCA)bypass surgery is a common operation in neurosurgery. There are several variations of this surgical method. We conducted a questionnaire survey on the details of surgical procedures in 171 neurosurgical institutes in Japan. Contrary to expectations, wide variations emerged in some surgical procedures, including the shape of skin and muscle incisions, the site of the temporary clip at the donor artery(STA), and the cutting method of the donor end. Western Japan institutions tended to vary more in terms of skin incision methods and donor cutting methods. It will likely be useful in the future to be aware of the numerous variations in surgical methods.

Novel method of intraoperative ocular movement monitoring using a piezoelectric device: experimental study of ocular motor nerve activating piezoelectric potentials (OMNAPP) and clinical application for skull base surgeries.

Intraoperative monitoring systems that utilize various evoked potentials for the detection and/or preservation of cranial nerves have become increasingly common due to recent technical and commercial developments, particularly during skull base surgeries. We established a novel system for the intraoperative monitoring of the extraocular motor nerves (eOMNs) using a piezoelectric device capable of detecting imperceptible vibrations induced by ocular movement, with sensors placed on the eyelids alone. We first evaluated the efficacy and reliability of this device for the intraoperative monitoring of eOMNs in two Beagle dogs. Based on the results, we then determined the appropriate stimulation parameters for use in human surgical cases involving removal of various skull base tumors. Animal experiments revealed that a 0.4 mA monopolar electrical stimulation was required to elicit significant responses and that these responses were not inferior to those obtained via the electrooculogram/electromyogram. Significant responses were also detected in preliminary clinical investigations in human patients, following both direct and indirect monopolar electrical stimulation of the oculomotor and abducens nerves, although obtaining responses from the trochlear nerve was difficult. Intraoperative monitoring using a piezoelectric device provides a simple and reliable method for detecting eOMNs, especially the oculomotor and abducens nerves. This monitoring system can be adapted to various surgeries for skull base tumor.

Leakage sign for acute subdural hematoma in clinical treatment.

BACKGROUND: Acute subdural hematoma (ASDH) is a serious traumatic disease, and predictive methods for hematoma growth are necessary to decide whether emergent operation is necessary. This study aimed to evaluate the incidence of "leakage" using computed tomography angiography (CTA) in patients with ASDH and to identify its prognostic value. METHODS: Sixty-seven patients with ASDH were examined using CTA (mean age 64.1 ± 20.6 years; 24 men) by analyzing two serial scans (CTA phase and delayed phase). We defined a positive leakage sign as a > 10% increase in Hounsfield units (HU) in the region of interest. Hematoma expansion was determined using plain CT after 24 h in patients who did not undergo emergent surgery. RESULTS: Of the 67 patients, conservative therapy was administered to 35 patients; of these patients, 9 showed hematoma expansion, and 8 of these 9 patients (88.9%) showed positive leakage signs. The sensitivity and specificity of leakage signs to hematoma expansion in the no-surgery group were 88.8% and 76.1%, respectively. All positive leakage signs were found within 4.5 h of injury; patients showing negative leakage signs showed a decreased tendency towards hematoma 24 h after injury. Patients presenting with positive leakage signs had poor outcomes. CONCLUSIONS: The results indicated that the leakage sign is a sensitive predictor of hematoma expansion and poor outcomes in ASDH. If the hematoma is small but leakage sign-positive, strict observation is necessary and aggressive surgery may improve outcomes.

Bilateral Internal Carotid Artery Aneurysms at the Subpetrosal Portion with Unilateral Lower Cranial Nerve Palsies: Review and Consideration of Surgical Strategy.

BACKGROUND: Symptomatic bilateral extracranial internal carotid artery (ICA) aneurysms at the subpetrosal portion are extremely rare, and their treatment strategy remains unknown. CLINICAL PRESENTATION: A 42-year-old man presented to our hospital with a 2-month history of sudden onset of hoarseness, dysarthria, and dysphagia. Magnetic resonance imaging, magnetic resonance angiography, and computed tomography angiography revealed extracranial bilateral ICA aneurysms at the subpetrosal portion. The left-sided aneurysm compressed the left-sided lower cranial nerves (IX, X, XI, and XII), whereas the right-sided aneurysm was asymptomatic. We prioritized the treatment of the right-sided aneurysm to prevent bilateral lower cranial nerve deficits. This strategy was used because aneurysm treatment is not guaranteed to cure the left-sided cranial nerve palsies that lasted for 2 months. The right-sided ICA aneurysm was treated with ICA ligation and high-flow extracranial-intracranial bypass using the radial artery as bypass graft. Stent-assisted coil embolization was performed to the left-sided ICA aneurysm after 17 days. The patient showed no right-sided symptoms, and his left-sided symptoms remarkably improved 1 year after surgery. CONCLUSION: Our unique surgical strategy of prioritizing the aneurysm on the "asymptomatic" side may be one of the best treatment approaches in an extremely rare bilateral aneurysm case.

Leakage Sign for Primary Intracerebral Hemorrhage: A Novel Predictor of Hematoma Growth.

BACKGROUND AND PURPOSE: Recent studies of intracerebral hemorrhage treatments have highlighted the need to identify reliable predictors of hematoma expansion. Several studies have suggested that the spot sign on computed tomographic angiography (CTA) is a sensitive radiological predictor of hematoma expansion in the acute phase. However, the spot sign has low sensitivity for hematoma expansion. In this study, we evaluated the usefulness of a novel predictive method, called the leakage sign. METHODS: We performed CTA for 80 consecutive patients presenting with spontaneous intracerebral hemorrhage. Two scans were completed: CTA phase and delayed phase (5 minutes after the CTA phase). By comparing the CTA phase images, we set a region of interest with a 10-mm diameter and calculated the Hounsfield units. We defined a positive leakage sign as a >10% increase in Hounsfield units in the region of interest. Additionally, hematoma expansion was determined on plain computed tomography at 24 hours in patients who did not undergo emergent surgery. RESULTS: Positive spot signs and leakage signs were present in 18 (22%) patients and 35 (43%) patients, respectively. The leakage sign had higher sensitivity (93.3%) and specificity (88.9%) for hematoma expansion than the spot sign. The leakage sign, but not the spot sign, was significantly related with poor outcomes (severely disabled, vegetative state, and death) in all of the patients (P=0.03) and in patients with a hemorrhage in the putamen (P=0.0016). CONCLUSIONS: The results indicate that the leakage sign is a useful and sensitive method to predict hematoma expansion.

Endovascular Treatments for Aneurysms Involving a Major Branch.

Remarkable advances have been made in the endovascular treatment of intracranial cerebral aneurysms. These advances include various adjunctive techniques, increased indications for endovascular treatment, and improved treatment results. Furthermore, the number of cerebral aneurysm treatments using flow diverters (FDs) is expected to increase. However, the reported long-term rate of branch artery occlusion after FD treatment has been reported is 15.8%. Moreover, the complete aneurysm obliteration rate is low if normal branches arise from an aneurysm neck or dome. Flow diverter placement for ophthalmic artery, posterior communicating artery, and anterior choroidal artery aneurysms is often difficult because these normal branches often arise from the aneurysm neck or dome. Therefore, in many cases, coil embolization, which can occlude the aneurysm while preserving branch vessels, should be selected. Although not yet established, various adjunctive techniques and other endovascular treatments that can be performed safely have been reported. Treatment must be planned after understanding the advantages and disadvantages of each treatment method.

Clinical and radiographic characteristics of patients with non-functioning pituitary adenomas categorized according to their serum prolactin concentration: novel predictors of postoperative transient diabetes insipidus following surgery.

PURPOSE: Non-functioning pituitary adenomas (NFPAs) are often associated with hyperprolactinemia, which is known as the "stalk effect". However, the relationships between hyperprolactinemia and the radiographic characteristics of the tumor that affects the pituitary stalk have not been well characterized. We aimed to identify the differences in the clinical and radiographic characteristics of patients with NFPA, with and without hyperprolactinemia. METHODS: We enrolled 107 patients with NFPA and allocated them to hyperprolactinemia and non-hyperprolactinemia groups using two different cut-off values: (1) the upper limit of the normal reference range, adjusted for sex and menopausal status, and (2) the upper quartile across the cohort, and compared their clinical and radiographic characteristics. These analyses were conducted to clarify the relationship between the "stalk effect" and the postoperative change in antidiuretic hormone secretion. RESULTS: The specific radiographic characteristics of the patients included the presence of a cystic or hemorrhagic tumor and the presence of pituitary stalk deviation, which were more frequent in the patients with hyperprolactinemia. Interestingly, the incidence of postoperative transient diabetes insipidus was statistically significantly higher in the hyperprolactinemia group (≥40 ng/mL) and in the group with radiologic evidence of stalk deviation, which were shown to be independent risk factors on multivariate analysis. CONCLUSION: The presence of a "stalk effect" was associated with a higher risk of postoperative transient diabetes insipidus, reflecting perioperative pituitary stalk dysfunction following NFPA surgery, especially in patients with serum prolactin concentrations ≥40 ng/mL and radiologic evidence of stalk deviation.

Leakage sign is a reliable predictor of hematoma expansion in acute epidural hematoma.

BACKGROUND: Hematoma expansion in small/medium-sized acute epidural hematoma (AEDH) cases upon emergency admission is critical. Predicting hematoma expansion can lead to early surgical interventions, improving outcomes and eliminating the need to check for expansion via computed tomography (CT). This study aimed to identify the most reliable predictors of AEDH expansion. METHODS: We retrospectively collected data from patients with pure AEDH not requiring surgical treatment upon emergency admission from 2012-2022. We assessed clinical and laboratory data, time from injury to the first CT, and time to follow-up CT. Factors predictive of hematoma expansion on the second follow-up CT, including the leakage sign (LS), were analyzed. RESULTS: A total of 23 patients with pure AEDH without surgery at admission were included, and LS was positive in 18. Thirteen patients showed hematoma expansion. The hematoma expansion group showed a significantly higher rate of positive LS and lower mean platelet count than the group without hematoma expansion. LS's predictive value for AEDH expansion showed 100% sensitivity and 50% specificity. All patients with negative LS and normal platelet counts showed no hematoma expansion. Analyzing the time from injury to the first CT suggested that LS (+) within 120 min strongly predicted hematoma expansion. Reconstructed three-dimensional images of the leakage point on the skull revealed multiple mottled bleeding points on the dural surface. CONCLUSION: LS can predict hematoma expansion in patients with pure AEDH for whom emergency surgery is unnecessary at admission. The time from injury and platelet counts must also be considered.

Bold-S Signs on Computed Tomography Angiography Are Sensitive Markers for Diagnosing Subcortical Hemorrhage Due to Dural Arteriovenous Fistulae on Emergent Admission.

An optimal treatment strategy for subcortical hematomas caused by dural arteriovenous fistulae (dAVF) is important because of the high rebleeding rate. However, it is very difficult to diagnose that on admission. Therefore, an early sensitive predictive marker for subcortical hemorrhage caused by dAVF is necessary, especially during the first contact on admission. S-shaped dilated vessels around the hematoma (bold-S sign) on computed tomography angiography (CTA) performed during admission could be one such marker. Herein, we evaluated the characteristics of these vessels. Among 273 patients with intracerebral hemorrhage between April 2012 and March 2020, 67 patients with subcortical hematomas who underwent CTA on admission without arteriovenous malformations were included. The patients in the dAVF group (n = 7) showed fewer disturbances in consciousness, milder neurological deficits, and more frequent seizures than patients without dAVF (without dAVF group, n = 60). All patients in the dAVF group had dilated S-shaped vessels (2.59 ± 0.27 mm) around the hematomas, and only 20% of the patients in the without dAVF group had these vessels (1.69 ± 0.22 mm). The ratio of the ipsilateral S-shaped/contralateral largest vessels was 1.80 ± 0.29 in the dAVF group and 1.07 ± 0.16 in the group without dAVF. We called the dilated S-shaped vessels the "bold-S sign," with a cutoff ratio of 1.5. Bold-S sign findings are novel and help in diagnosing subcortical hematomas caused by dAVF on admission.

Visual Outcomes and Surgical Approach Selection Focusing on Active Optic Canal Decompression and Maximum Safe Resection for Suprasellar Meningiomas.

The goal of treating patients with suprasellar meningioma is improving or preserving visual function while achieving long-term tumor control. We retrospectively examined patient and tumor characteristics and surgical and visual outcomes in 30 patients with a suprasellar meningioma who underwent resection via an endoscopic endonasal (15 patients), sub-frontal (8 patients), or anterior interhemispheric (7 patients) approach. Approach selection was based on the presence of optic canal invasion, vascular encasement, and tumor extension. Optic canal decompression and exploration were performed as key surgical procedures. Simpson grade 1 to 3 resection was achieved in 80% of cases. Among the 26 patients with pre-existing visual dysfunction, vision at discharge improved in 18 patients (69.2%), remained unchanged in six (23.1%), and deteriorated in two (7.7%). Further gradual visual recovery and/or maintenance of useful vision were also observed during follow-up. We propose an algorithm for selecting the appropriate surgical approach to a suprasellar meningioma based on preoperative radiologic tumor characteristics. The algorithm focuses on effective optic canal decompression and maximum safe resection, possibly contributing to favorable visual outcomes.

Neurosurgical Treatment of Patients with Posterior Fossa Acute Subdural Hematoma Right after Cardiac Surgery.

As posterior fossa acute subdural hematoma (ASDH) right after cardiac surgery is extremely rare, the clinical course and optimal treatment strategy remain undetermined. We performed a retrospective analysis of patients with posterior fossa ASDH right after cardiac surgery requiring neurosurgical treatment at our institution over a 7-year period and, in this study, discussed the neurosurgical strategy and clinical course. Collected data included clinical history, laboratory results, time course, symptoms, neurosurgical treatment, outcome at discharge, and imaging studies. All six patients were women who had no history of head trauma and had received antithrombotic therapy during the perioperative period of cardiac surgery. All patients showed lower platelets count and were diagnosed with ASDH within 3 days (longest time 64 h) right after cardiac surgery. After discontinuation of anticoagulation therapy and administration of reversal agents, they underwent emergency hematoma evacuation craniotomy (n = 5) or burr hole drainage surgery (n = 1), which were performed in the prone (n = 4) or lateral (n = 2) positions. Four of these patients showed favorable outcomes, and two showed poor outcomes. One of the poor-outcome patients received three antithrombotic therapies, and another developed rapidly progressive ASDH. Posterior fossa ASDH associated with antithrombotic therapy right after cardiac surgery is frequently found in women, and emergent neurosurgical treatment with anticoagulation discontinuation and reversal agent administration can be performed safely. Burr hole drainage surgery might be acceptable in nonsevere cases. By contrast, we must pay attention to cases receiving both anticoagulant and antiplatelet drugs and rapid progression cases.

Relationship between Transient Cortical Blindness and Contrast Medium Leakage That Occurs after Endovascular Treatment of Posterior Circulation Aneurysms.

Objective: The mechanism of transient cortical blindness after endovascular treatment-a rare phenomenon-has not been elucidated; however, it is assumed to be related to contrast medium leakage (CML). We investigated the relationship between postoperative CML and cortical blindness in patients who underwent endovascular treatment for vascular lesions of posterior circulation. Methods: This retrospective cohort study included 28 patients who underwent endovascular treatment for posterior circulation aneurysms at our hospital between January 2014 and December 2018. Cerebral CT was performed immediately after endovascular treatment and 24 h later. CT images were retrospectively evaluated with special interest in the presence and distribution of leakage of the contrast medium (CM). Patients were classified into the following three groups based on CT findings: Group A, no CML (11 patients); Group B, unilateral CML (5 patients); and Group C, bilateral CML (9 patients). Results: The posterior circulation aneurysms were located in the basilar artery in 13 (52.0%) cases, in the posterior cerebral artery in 1 (4.0%) case, and in the vertebral artery in 11 (44.0%) cases. There was no difference regarding the adjunctive technique used for endovascular treatment between the groups. Patients in Group C used a significantly larger amount of CM than those in the other two groups. A longer operation time was associated with a larger amount of CM used during treatment. VerifyNow assay revealed that the P2Y12 reaction unit was significantly lower in Groups B and C. Cortical blindness was transiently observed in 2 of 9 patients (22.2%) in Group C, both of which showed CML surrounding the bilateral parieto-occipital sulcus. Conclusion: Both patients with cortical blindness showed bilateral CML, both of which showed CML surrounding the bilateral parieto-occipital sulcus. The CM-induced blood-brain barrier disruption may be the cause of cortical blindness.

Factors Associated with Rapidly Deteriorating Myelopathy in Patients with Spinal Arteriovenous Shunts.

Spinal arteriovenous (AV) shunts are rare conditions that sometimes present with myelopathy symptoms. The progression of the symptoms is usually gradual; however, some cases show rapid deterioration. We retrospectively investigated the factors that induced the rapid deterioration of myelopathy symptoms in patients with spinal AV shunts. We treated 33 patients with myelopathy with spinal AV shunts at our institutions, eight of whom experienced rapid deterioration (within 24 hours: 24.2%). Of these, three were related to the body movement or particular postures associated with playing golf, 30 minutes of Japanese straight sitting, and massage care. One patient showed deterioration after embolization for a tracheal aneurysm. The remaining four patients received steroid pulse therapy (high-dose steroid infusion) shortly before the rapid deterioration. These symptoms stopped progressing after cessation of steroid use. While positional or physical factors contributing to myelopathy deterioration might exist, we could not identify specific factors in this study. Nevertheless, rapid deterioration was frequently observed after high-dose steroid use. We must take care not to administer high-dose steroids for myelopathy caused by spinal AV shunt disease.

The eagle jugular syndrome as the cause of delayed intracranial hemorrhage after microvascular decompression for hemifacial spasm: A case report.

BACKGROUND: Eagle syndrome is a rare disorder whereby an elongated styloid process (ESP) causes not only some otolaryngological symptoms, but also cerebrovascular events caused by compression of the carotid artery. In recent years a syndrome, denominated as Eagle jugular syndrome, involving internal jugular vein (IJV) compression caused by an ESP has been proposed as a variation of Eagle syndrome. Clinical impact of the Eagle jugular syndrome on neurosurgical procedures has not been reported yet. CASE DESCRIPTION: We present a case of a 68-year-old woman who underwent microvascular decompression for hemifacial spasm of the left side and developed delayed intracranial hemorrhage on postoperative day 3. We also demonstrate that this patient developed ipsilateral IJV stenosis between an ESP and the muscle bundle of the rectus capitis lateralis with antero-flexion neck position, which would induce venous congestion in addition to surgical disruption of emissary vein. CONCLUSION: This case is the first report demonstrating the association of an ESP with postoperative delayed intracranial hemorrhage. Our report elucidates the importance of the awareness among neurosurgeons of considering the ESP as an important bony anomaly, especially when planning for posterior fossa surgery.

Efficacy of a Novel Prophylactic Barbiturate Therapy for Severe Traumatic Brain Injuries: Step-down Infusion of a Barbiturate with Normothermia.

This study aimed to examine the beneficial effects of a novel prophylactic barbiturate therapy, step-down infusion of barbiturates, using thiamylal with normothermia (NOR+sdB), on the poor outcome in the patients with severe traumatic brain injuries (sTBI), in comparison with mild hypothermia (MD-HYPO). From January 2000 to March 2019, 4133 patients with TBI were admitted to our hospital. The inclusion criteria were: a Glasgow coma scale (GCS) score of ≤8 on admission, age between 20 and 80 years, intracranial hematoma requiring surgical evacuation of the hematoma with craniotomy and/or external decompression, and patients who underwent management of body temperature and assessed their outcome at 6-12 months. Finally, 43 patients were included in the MD-HYPO (n = 29) and NOR+sdB (n = 14) groups. sdB was initiated intraoperatively or immediately after the surgical treatment. There were no significant differences in patient characteristics, including age, sex, past medical history, GCS on admission, type of intracranial hematoma, and length of hospitalization between the two groups. Although NOR+sdB could not improve the patient's poor outcome either at discharge from the intensive care unit (ICU) or at 6-12 months after admission, the treatment inhibited composite death at discharge from the ICU. The mean value of the maximum intracranial pressure (ICP) in the NOR+sdB group was <20 mmHg throughout the first 120 h. NOR+sdB prevented composite death in the ICU in patients with sTBI, and we may obtain novel insights into the beneficial role of prophylactic barbiturate therapy from suppression of the elevated ICP during the first 120 h.

A novel step-down infusion method of barbiturate therapy: Its safety and effectiveness for intracranial pressure control.

Intracranial pressure (ICP) has to be maintained quite constant, because increased ICP caused by cerebrovascular disease and head trauma is fatal. Although controlling ICP is clinically critical, only few therapeutic methods are currently available. Barbiturates, a group of sedative-hypnotic drugs, are recognized as secondary treatment for controlling ICP. We proposed a novel "step-down infusion" method, administrating barbiturate (thiamylal) after different time point from the start of treatment under normothermia, at doses of 3.0 (0-24 h), 2.0 (24-48 h), 1.5 (48-72 h), and 1.0 mg/kg/h (72-96 h), and evaluated its safety and effectiveness in clinical. In 22 patients with severe traumatic brain injury or severe cerebrovascular disease (Glasgow coma scale ≤8), thiamylal concentrations and ICP were monitored. The step-down infusion method under normothermia maintained stable thiamylal concentrations (<26.1 µg/ml) without any abnormal accumulation/elevation, and could successfully keep ICP <20 mmHg (targeted management value: ICP <20 mmHg) in all patients. Moreover the mean value of cerebral perfusion pressure (CPP) was also maintained over 65 mmHg during all time course (targeted management value: CPP >65 mmHg), and no threatening changes in serum potassium or any hemodynamic instability were observed. Our novel "step-down infusion" method under normothermia enabled to maintain stable, safe thiamylal concentrations to ensure both ICP reduction and CPP maintenance without any serious side effects, may provide a novel and clinically effective treatment option for patients with increased ICP.

Venous Anatomy of the Cavernous Sinus and Relevant Veins.

The cavernous sinus (CS) is a dural sinus located on each side of the pituitary fossa. Neoplastic and vascular lesions, such as arteriovenous fistulas, frequently involve the CS. This sinus plays a role as a crossroad receiving venous blood flow from the facial, orbital, meningeal, and neural venous tributaries. The relationship between these surrounding relevant veins and the CS, as well as the CS itself, varies anatomically. For safe and effective surgical and endovascular treatment of lesions involving the CS, knowledge of the anatomy and variations of the CS and the relevant surrounding veins is highly important. In this section, the anatomy and variations of the CS and the relevant surrounding veins are outlined.

Follow-up non-contrast MRA after treatment of intracranial aneurysms using microcoils with prominent metallic artifact: a comparative study of TOF-MRA and Silent MRA.

PURPOSE: Some of the detachable microcoils are associated with the prominent metallic artifact. We have applied Silent MRA to reduce the artifact. In this study, we present a retrospective study in which Silent MRA is used for cases showing prominent metallic artifact on conventional TOF-MRA due to a detachable bare platinum microcoil (Barricade coil). MATERIALS AND METHODS: Fifteen patients, who had undergone endosaccular embolization using Barricade coil and other detachable microcoils up to 3 days previously, were scanned with TOF-MRA and silent MRA at the same time. The treatment DSA and follow-up MRA images were graded by two experienced neuroradiologists, focusing on the visibility of residual aneurysm and parent arterial lumen. RESULTS: DSA images showed residual aneurysm (RA) in four, residual neck (RN) in six, and complete occlusion (CO) in five patients. TOF-MRA images showed RN in five, CO in four, mild defect (MD) in one, severe defect (SD) in three, and complete defect in two. In contrast, on Silent MRA, the grades were RA in two, RN in five, CO in five, and MD in three. CONCLUSION: Barricade coils are associated with prominent metallic artifact on TOF-MRA. Silent MRA is useful for follow-up MRA after embolization using Barricade coils. The metallic artifacts were compared between TOF-MRA and Silent MRA in patients treated by using Barricade coils. Barricade coils are associated with more metallic artifact on TOF-MRA than Silent MRA. Silent MRA is useful for follow-up MRA after embolization using Barricade coils.