Excessive Heat Generation by Power-Driven Craniotomy Tools: A Possible Cause of Autologous Bone Flap Resorption Observed in an Ex Vivo Simulation.

BACKGROUND: Bone flap resorption is an issue after autologous cranioplasty. Critical temperatures above 50°C generated by power-driven craniotomy tools may lead to thermal osteonecrosis, a possible factor in resorption. This ex vivo study examined whether the tools produced excessive heat resulting in bone flap resorption. METHODS: Using swine scapulae maintained at body temperature, burr holes, straight and curved cuts, and wire-pass holes were made with power-driven craniotomy tools. Drilling was at the conventional feed rate (FR) plus irrigation (FR-I+), at a high FR plus irrigation (hFR-I+), and at high FR without irrigation (hFR-I-). The temperature in each trial was recorded by an infrared thermographic camera. RESULTS: With FR-I+, the maximum temperature at the burr holes, the cuts, and the wire-pass holes was 69.0°C, 56.7°C, and 46.2°C, respectively. With hFR-I+, these temperatures were 53.1°C, 52.1°C, and 46.0°C, with hFR-I- they were 56.0°C, 66.5°C, and 50.0°C; hFR-I- burr hole- and cutting procedures resulted in the highest incidence of bone temperatures above 50°C followed by FR-I+, and hFR-I+. At the site of wire-pass holes, only hFR-I- drilling produced this temperature. CONCLUSIONS: Except during prolonged procedures in thick bones, most drilling with irrigation did not reach the critical temperature. Drilling without irrigation risked generating the critical temperature. Knowing those characteristics may be a help to perform craniotomy with less thermal bone damage.

Combination of neuroendoscopic hematoma evacuation and endovascular coil embolization for a ruptured anterior choroidal artery aneurysm in patients with moyamoya disease: illustrative cases.

BACKGROUND: The treatment strategy for hemorrhagic moyamoya disease (MMD) due to a ruptured aneurysm at the distal portion of the anterior choroidal artery remains controversial. The authors successfully treated the ruptured aneurysm with neuroendoscopic hematoma evacuation, followed by endovascular coil embolization. OBSERVATIONS: The authors encountered two patients with massive hemorrhagic MMD whose MMD had already been diagnosed and who had a periventricular anastomosis due to a ruptured aneurysm of the distal portion of the anterior choroidal artery involving the periventricular anastomosis. In both cases, neuroendoscopic hematoma evacuation was performed for hemorrhagic MMD in the acute phase, followed by endovascular coil embolization of the ruptured aneurysm in the chronic phase. In both endovascular treatments, the patient's condition was stabilized by hematoma evacuation, allowing a detailed preoperative evaluation of the anatomical findings of the vessel and functional findings of intraoperative neurophysiological monitoring using continuous monitoring of motor evoked potentials to preserve motor function. LESSONS: Combination therapy can be useful for hemorrhagic MMD in patients with diagnosed MMD with a periventricular anastomosis. Additionally, a preoperative understanding of the vascular construction and intraoperative neurophysiological monitoring will aid in the successful coil embolization of aneurysms at the distal portion of the anterior choroidal artery with hemorrhagic MMD.

Angiographic evaluation of the distance from the top of the jugular bulb to the inferior petrosal sinus-internal jugular vein junction: simple classification and identification method for the orifice of the non-visualized inferior petrosal sinus during neuroendovascular surgery.

BACKGROUND: The inferior petrosal sinus (IPS) is the transvenous access route for neurointerventional surgery that is occasionally undetectable on digital subtraction angiography (DSA) because of blockage by a clot or collapse. This study was aimed at analyzing the distance from the jugular bulb (JB) to the IPS-internal jugular vein (IJV) junction and proposing a new anatomical classification system for the IPS-IJV junction to identify the non-visualized IPS orifice. METHODS: DSA of 708 IPSs of 375 consecutive patients were retrospectively investigated to calculate the distance from the top of the JB to the IPS-IJV junction, and a simple classification system based on this distance was proposed. RESULTS: The median distance from the top of the JB to the IPS-IJV junction was 20.8 ± 14.7 mm. Based on the lower (10.9 mm) and upper (31.1 mm) quartiles, IPS-IJV junction variants were: type I, 0-10 mm (22.3%); type II, 11-30 mm (45.8%); type III, > 31 mm (23.9%); and type IV, no connection to the IJV (8.0%). Bilateral distances showed a positive interrelationship, with a correlation coefficient of 0.86. The bilateral symmetry type (visualized IPSs bilaterally) according to our classification occurred in 267 of 300 (89.0%) patients. CONCLUSIONS: In this study, the IPS-IJV junction was located far from the JB (types II and III), with a higher probability (69.6%). This distance and the four-type classification demonstrated high degrees of homology with the contralateral side. These results would be useful for identifying the non-visualized IPS orifice.

Multiple trauma complicated by traumatic vertebral artery injury without cervical vertebral injury: A case report.

Background: Blunt traumatic vertebral artery injury is commonly associated with head and cervical spinal trauma. However, those associated with chest or upper extremity injuries without cervical spine-related trauma are rare. Case presentation: A 94-year-old woman was injured in a motor vehicle crash. She was diagnosed with traumatic subarachnoid hemorrhage, bilateral subdural hematomas, right vertebral artery injury, and right clavicle fracture. No cervical spine injuries were observed. It was possible that the fracture fragment of the right clavicle may have directly injured the right vertebral artery. Coil embolization was performed for the vertebral artery injury. The patient had a good postoperative course and was transferred to the hospital for rehabilitation on day 65. Conclusion: Regarding the high-risk injury mechanism, blunt traumatic vertebral artery injuries in the V1-2 segment may occur in cases with clavicle fractures.

Frontotemporal Craniotomy for Clipping of Unruptured Aneurysm Using a Diamond-Coated Thread Wire Saw and Reconstruction Using Calcium Phosphate Cement without Metal Fixation.

Metal fixation systems for cranial bone flaps cut by a drill are convenient devices for cranioplasty, but cause several complications. We use modified craniotomy using a fine diamond-coated threadwire saw (diamond T-saw) to reduce the bone defect, and osteoplasty calcium phosphate cement without metal fixation. We report our outcomes and tips of this method. A total of 78 consecutive patients underwent elective frontotemporal craniotomy for clipping of unruptured intracranial aneurysms between 2015 and 2019. The follow-up periods ranged from 13 to 66 months. The bone fixation state was evaluated by bone computed tomography (CT) and three-dimensional CT (3D-CT). The diamond T-saw could minimize the bone defect. Only one wound infection occurred within 1 week postoperatively, and no late infection. No pain, palpable/cosmetically noticeable displacement of the bone flap, fluid accumulations, or other complications were observed. The condition of bone fixation and the cosmetic efficacy were thoroughly satisfactory for all patients, and bone CT and 3D-CT demonstrated that good bone fusion. No complication typical of metal fixation occurred. Our method is technically easy and safety, and achieved good mid-term bone flap fixation in the mid-term course, so has potential for bone fixation without the use of metal plates.

RAB35 is required for murine hippocampal development and functions by regulating neuronal cell distribution.

RAB35 is a multifunctional small GTPase that regulates endocytic recycling, cytoskeletal rearrangement, and cytokinesis. However, its physiological functions in mammalian development remain unclear. Here, we generated Rab35-knockout mice and found that RAB35 is essential for early embryogenesis. Interestingly, brain-specific Rab35-knockout mice displayed severe defects in hippocampal lamination owing to impaired distribution of pyramidal neurons, although defects in cerebral cortex formation were not evident. In addition, Rab35-knockout mice exhibited defects in spatial memory and anxiety-related behaviors. Quantitative proteomics indicated that the loss of RAB35 significantly affected the levels of other RAB proteins associated with endocytic trafficking, as well as some neural cell adhesion molecules, such as contactin-2. Collectively, our findings revealed that RAB35 is required for precise neuronal distribution in the developing hippocampus by regulating the expression of cell adhesion molecules, thereby influencing spatial memory.

Scratching and Stretching the Shrunken Cranial Dura for Primary Closure.

BACKGROUND: At craniotomy, the dura shrinks due to the drying effect of illumination and air exposure, rendering its primary closure difficult. When the opening is narrow, it can be patched with autologous grafts. However, tissue harvesting and meticulous suturing take time. As the cost-effectiveness of using dural substitutes is poor, we developed a new technique that involves dural scratching for the primary closure of dural openings. METHODS: We applied our technique because in 53 adults who underwent supratentorial craniotomy we encountered difficulties with the primary closure of a dural opening 5 mm or less in width. With a scalpel, we placed several fine scratches parallel to the edge of the opening on the surface of the dura, taking care not to perforate the deep layer. This relieved dural tension and the tissue was stretched enough to permit closing with sutures. RESULTS: Our technique achieved primary dural closure in 46 of 53 patients (87%) who primarily had undergone narrow supratentorial craniotomies. The other 7 additionally required small autologous grafts to patch narrow residual openings at the intersection of the durotomy. There were no procedure-related complications such as cerebrospinal fluid leakage and persistent headache due to tension of the closed dura. CONCLUSIONS: Dural scratching is simple, safe, requires no special instrumentation, facilitates primary closure of the shrunken dura by stretching, and reduces the need for patch grafting.

Coexistence of anterior cranial fossa dural arteriovenous fistula and arteriovenous malformation with the same drainage system: illustrative case.

BACKGROUND: The authors report a rare case of coexistence of dural arteriovenous fistula (DAVF) and arteriovenous malformation (AVM), with a common trunk drainer from both DAVF and AVM in the left anterior cranial fossa (ACF) with simple DAVF in the right ACF. OBSERVATIONS: A 63-year-old female presented with seizure. Cerebral angiography showed bilateral DAVFs in the ACF and AVM in the left frontal lobe. A dilated frontal vein acted as a simple drainer of the right DAVF. In contrast, a dilated vein with large varix was the common drainer of both the left DAVF and the AVM. During surgery, indocyanine green videoangiography was performed with direct observation. In the left ACF, the drainer occlusion of the DAVF resulted in partial shrinkage of the varix and decreased distal blood flow. Additional main feeder occlusion of the AVM could decrease the blood flow further, but not completely because of the residual pial supplies for the AVM. Finally, the nidus of the AVM with varix was removed by en bloc resection. LESSONS: Neurosurgeons should be aware of the coexistence of DAVF and AVM with a common trunk drainer. Only simple occlusion of the drainer from DAVF is not sufficient, so removal of the AVM is essential.

Endoscope-integrated indocyanine green video angiography and the detection of the fragile periventricular collaterals associated with moyamoya disease: illustrative cases.

BACKGROUND: Hemorrhagic moyamoya disease (MMD) and the fragile periventricular collaterals are known to have a causal relationship. Digital subtraction angiography and magnetic resonance angiography have shown the presence of fragile periventricular moyamoya vessels. However, dynamic fragile periventricular moyamoya vessels have never been observed under direct vision. OBSERVATIONS: The authors treated two patients with hemorrhagic MMD: a 42-year-old man with intraventricular hemorrhage and a 47-year-old woman with intracerebral hemorrhage. Endoscope-integrated indocyanine green video angiography (EICG angiography) could visualize the dynamic fragile periventricular collaterals. In particular, EICG angiography enabled visualization of invisible moyamoya vessels buried in the subependyma and characterization of the blood flow in the moyamoya vessels located inside the lateral ventricles and hematoma cavity. LESSONS: EICG angiography can confirm the fragile periventricular collaterals associated with MMD by direct visualization. The high spatial resolution and real-time imaging can help to avoid accidental hemorrhage in and after evacuation of hemorrhage in patients with MMD.

Relationship between subarachnoid hemorrhage and nonocclusive mesenteric ischemia as a fatal complication: patient series.

BACKGROUND: Nonocclusive mesenteric ischemia (NOMI) causes intestinal necrosis due to irreversible ischemia of the intestinal tract. The authors evaluated the incidence of NOMI in patients with subarachnoid hemorrhage (SAH) due to ruptured aneurysms, and they present the clinical characteristics and describe the outcomes to emphasize the importance of recognizing NOMI. OBSERVATIONS: Overall, 7 of 276 consecutive patients with SAH developed NOMI. Their average age was 71 years, and 5 patients were men. Hunt and Kosnik grades were as follows: grade II, 2 patients; grade III, 3 patients; grade IV, 1 patient; and grade V, 1 patient. Fisher grades were as follows: grade 1, 1 patient; grade 2, 1 patient; and grade 3, 5 patients. Three patients were treated with endovascular coiling, 3 with microsurgical clipping, and 1 with conservative management. Five patients had abdominal symptoms prior to the confirmed diagnosis of NOMI. Four patients fell into shock. Two patients required emergent laparotomy followed by second-look surgery. Four patients could be managed conservatively. The overall mortality of patients with NOMI complication was 29% (2 of 7 cases). LESSONS: NOMI had a high mortality rate. Neurosurgeons should recognize that NOMI can occur as a fatal complication after SAH.

Using a Carpenter's Square to Localize Narrow or Multilayered Chronic Subdural Hematomas Diagnosed on Computed Tomography.

BACKGROUND: Chronic subdural hematomas (CSDHs) with narrow or multilayered hematomas must be accurately localized for burr hole drainage. We present a simple alternative localization method using conventional computed tomography (CT) scans acquired for the initial diagnosis and a commercially available carpenter's square (CS). METHODS: Using our novel method, we localized 77 narrow or multilayered CSDHs. A single burr hole site on the thickest portion of narrow hematomas or on the site allowing access to both the isolated superficial layer and the deep layer of multilayered hematomas was identified on axial CT images; the image was parallel to the orbitomeatal line (OML). On the target CT slice, the level from the OML and from the surface of the forehead to the intended burr hole (sagittal distance) was measured. The OML and the level of the CT target slice were marked using the CS. Then, the CS was placed at the marked target level; the 2 edges of the CS were situated on the frontal and temporal scalp and parallel to the OML and the sagittal line. The sagittal distance was then marked. RESULTS: All burr holes reached the CSDHs. The mean deviation of the burr holes was 4.7 mm inferior and 1.4 mm anterior to the intended site. In 65 instances (84.4%), a deviation within 10 mm was observed in both the superoinferior and the anteroposterior directions. CONCLUSIONS: Our simple and inexpensive method can localize narrow or multilayered CSDHs with acceptable accuracy and increases the efficiency of routine clinical work.

Strategic neuronavigation-guided emergent endoscopic evacuation of the hematoma caused by ruptured brain arteriovenous malformation: Technical note and retrospective case series.

The treatment strategy for ruptured brain arteriovenous malformations (bAVMs) in the acute phase is still controversial. We describe five consecutive cases of successful emergent endoscopic evacuation (EEE) of intracerebral hematoma (ICH) caused by ruptured bAVMs with the electromagnetic (EM)-neuronavigation system to avoid damage to the bAVMs intended to save valuable time in the emergent phase. A single-institution retrospective analysis was performed in patients with ruptured bAVMs treated by the EM-navigated EEE as part of the strategic multimodality therapy. EM-navigated EEE was performed as follows: 1) obtaining three-dimensional computed tomography to identify the location of the nidus, large draining vein, feeding artery, and hematoma; 2) using a supine position without rigid head fixation for both supra- and infratentorial hematoma; 3) planning the entry point and trajectory of the endoscope as far as possible from the location of the nidus using the EM-navigation system; 4) designing a linear skin incision line suitable for the endoscopic surgery as well as possible decompressive craniectomy; and 5) performing EM-navigated endoscopic partial evacuation of ICH. EM-navigated EEE of ICH was successfully performed for all 5 patients, resulting in partial removal of the ICH without rebleeding from bAVMs. The mean surgical time was 37 min. Subsequent strategic endovascular embolization and curative resection of bAVMs could be performed for all patients, achieving Glasgow Coma Scale score of 15. EM-navigated EEE of partial ICH may be valuable in the emergent phase of ruptured bAVMs with massive life-threatening ICH to reduce the intracranial pressure and to obtain better prognosis.

Life-threatening traumatic epistaxis due to massive bleeding into the maxillary sinus.

A 77-year-old woman with no medical history fell, and her face was strongly impacted on the ground. On arrival at our hospital, her initial vital signs were stable. She underwent an endoscopy to stop the bleeding. However, identification of the origin of the bleeding failed, and her injury resulted in hemorrhagic shock during the procedure. Head to face contrast computed tomography showed extravasation of contrast media into the maxillary sinus. Transcatheter arterial embolization was performed for the ruptured infraorbital artery branching from the maxillary artery. She recovered from the "shock" state after transcatheter arterial embolization and was admitted to the intensive care unit. There were no complications associated with transcatheter arterial embolization during hospitalization. For this case, early recognition of an active hemorrhage was challenging because the hemorrhage was pooled in the sinuses. Although epistaxis is sometimes fatal, transcatheter arterial embolization can be the first choice for the treatment of life-threatening epistaxis, owing to its safety and effectiveness.

Spatial and temporal diversity of DCLK1 isoforms in developing mouse brain.

Doublecortin-like kinase 1 (DCLK1) is a Doublecortin family kinase involved in a range of brain development processes including cell migration, axon/dendrite growth, and synapse development. The Dclk1 gene potentially generates multiple splicing isoforms, but the detailed expression patterns in the brain as well as in vivo functions of each isoform are still incompletely understood. Here we assessed expression patterns of DCLK1 isoforms using multiple platforms including in silico, in situ, and in vitro datasets in the developing mouse brain, and show quantitative evidence that among the four DCLK1 isoforms, DCLK1-L and DCL are mainly expressed in the embryonic cortex whereas DCLK1-L and CPG16 become dominant compared to DCL and CARP in the postnatal cortex. We also provide compelling evidence that DCLK1 isoforms are distributed in the partially distinct brain regions in the embryonic and the postnatal stages. We further show that overexpression of DCLK1-L, but not the other isoforms, in neural progenitors causes severe migration defects in the cortex, and that the migration defects are dependent on the kinase activity of DCLK1-L. Our data thus uncover partially segregated localization of DCLK1 isoforms in the developing mouse brain and suggest different roles for distinct DCLK1 isoforms in the brain development and function.

Cortical Neural Damage Associated with Cerebral Hyperperfusion after Reperfusion Therapy for Acute Ischemic Stroke: 123I-iomazenil Single-photon Emission Computed Tomography Findings.

We present an 88-year-old man with cerebral hyperperfusion (CH) after acute reperfusion therapy. He developed acute cerebral ischemia as a result of occluded middle cerebral artery that was subsequently recanalized with endovascular thrombectomy. I-123 N-isopropyl-p-iodoamphetamine single-photon emission computed tomography (SPECT) after reperfusion therapy showed increased cerebral blood flow (CBF) in brain areas that exhibited no abnormal findings on magnetic resonance imaging (MRI). Follow-up MRI did not demonstrate structural brain damage associated with CH. However, later I-123 iomazenil SPECT imaging showed a reduction in benzodiazepine receptor binding potential (BRBP) in these areas, a finding that correlates with cortical neural damage. CH is being increasingly observed after endovascular treatment for acute stroke. However, little is known about CH when not associated with cerebral hemorrhage or infarction. The role of CH after reperfusion therapy in causing brain damage remains unclear. BRBP on I-123 iomazenil SPECT images is useful to evaluate brain neural density: a reduction in cortical BRBP indicates cortical neural damage or loss. Our findings suggest that post-reperfusion hyperperfusion induces cortical neural damage even in the absence of associated brain infarction or hemorrhage on MRI. Early postoperative SPECT is recommended to detect CH after acute reperfusion therapy. CH should be considered when the recovery from stroke is unexpectedly poor for a patient.

A Case of Synchronous Occurrence of Intracranial Germinoma and Systemic Sarcoidosis.

Although the synchronous occurrence of testicular seminoma and systemic sarcoidosis has been reported, that of intracranial germinoma and systemic sarcoidosis is unknown. A 26-year-old man presented with symptoms of panhypopituitarism and consciousness disturbance. Imaging demonstrated a large nodule in the upper right lung field and swelling of multiple bilateral pulmonary and mediastinal lymph nodes in addition to the bifocal pineal and suprasellar tumors with obstructive hydrocephalus. The pathological diagnosis of the intracranial bifocal tumors was pure germinoma, whereas that of the mediastinal lymph nodes was epithelioid granuloma. Three courses of chemotherapy using carboplatin and etoposide were administered, followed by whole ventricle irradiation. The intracranial tumors completely disappeared, but the lung nodule and mediastinal lymph nodes progressed. Whole-body fluorine-18-fluorodeoxyglucose positron emission tomography demonstrated accumulation in the mediastinal lymphadenopathy, lung masses, and multiple lymph nodes of the whole body. Transbronchial lung biopsy revealed epithelioid granuloma with multinucleated giant cells. In conjunction with the high blood concentration of angiotensin-converting enzyme and soluble interleukin-2 receptor, these findings established a diagnosis of sarcoidosis. This is the first report of synchronous occurrence of intracranial germinoma and sarcoidosis. Such coexistence is extremely rare, but we should mind that sarcoidosis can occur with intracranial germinoma.

Adeno-Associated Virus-Mediated Single-Cell Labeling of Mitral Cells in the Mouse Olfactory Bulb: Insights into the Developmental Dynamics of Dendrite Remodeling.

Neurons typically remodel axons/dendrites for functional refinement of neural circuits in the developing brain. Mitral cells in the mammalian olfactory system remodel their dendritic arbors in the perinatal development, but the underlying molecular and cellular mechanisms remain elusive in part due to a lack of convenient methods to label mitral cells with single-cell resolution. Here we report a novel method for single-cell labeling of mouse mitral cells using adeno-associated virus (AAV)-mediated gene delivery. We first demonstrated that AAV injection into the olfactory ventricle of embryonic day 14.5 (E14.5) mice preferentially labels mitral cells in the olfactory bulb (OB). Birthdate labeling indicated that AAV can transduce mitral cells independently of their birthdates. Furthermore, in combination with the Cre-mediated gene expression system, AAV injection allows visualization of mitral cells at single-cell resolution. Using this AAV-mediated single-cell labeling method, we investigated dendrite development of mitral cells and found that ~50% of mitral cells exhibited mature apical dendrites with a single thick and tufted branch before birth, suggesting that a certain population of mitral cells completes dendrite remodeling during embryonic stages. We also found an atypical subtype of mitral cells that have multiple dendritic shafts innervating the same glomeruli. Our data thus demonstrate that the AAV-mediated labeling method that we reported here provides an efficient way to visualize mitral cells with single-cell resolution and could be utilized to study dynamic aspects as well as functions of mitral cells in the olfactory circuits.

Intravascular treatment for ruptured facial artery aneurysm via percutaneous cardiopulmonary support device: A case report.

Even in cases of cardiac arrest caused by hemorrhagic shock, when reliable control of the bleeding source is possible, ECPR may be an effective treatment option if anticoagulant therapy is well-managed and is withdrawn early.

[Cerebral Amyloid Angiopathy-related Inflammation Demonstrating Early Venous Filling on Digital Subtraction Angiography:A Case Report].

Cerebral amyloid angiopathy-related inflammation(CAA-RI)is a rare condition thought to be caused by an inflammatory response to amyloid beta(Aß)protein in the walls of the small arteries and capillaries of the cerebral cortex. A 73-year-old female presented with left hemiparesis and dysarthria. Fluid-attenuated inversion recovery(FLAIR)imaging disclosed progressive enlargement of infiltrative white matter abnormalities in the right temporo-occipito-parietal lobes. Interestingly, digital subtraction angiography(DSA)demonstrated early venous filling. Pathological examination of the biopsy specimen demonstrated lymphocytes infiltration surrounding the blood vessels and in the thickened walls with amyloid-beta deposition. The diagnosis given was CAA-RI. The patient was successfully treated with high dose corticosteroids and clinical improvement was associated with shrinkage of the high intensity lesion on FLAIR imaging. Early venous filling resolved on the follow-up DSA. Most patients with CAA-RI can be treated with corticosteroids. However, the clinical condition will worsen without appropriate treatment. Early diagnosis is the key. If an expanding disease of the white matter appears in an elderly patient, we should exclude other cerebrovascular diseases by DSA, followed by biopsy without delay. The present case demonstrated that early venous filling on DSA may appear until inflammation is resolved by the treatment of CAA-RI.