Neutrophil Enzyme Myeloperoxidase Modulates Neuronal Response in a Model of Subarachnoid Hemorrhage by Venous Injury.

Background and Purpose: Aneurysmal subarachnoid hemorrhage (SAH) is associated with the development of delayed cognitive deficits. Neutrophil infiltration into the central nervous system is linked to the development of these deficits after SAH. It is however unclear how neutrophil activity influences central nervous system function in SAH. The present project aims to elucidate which neutrophil factors mediate central nervous system injury and cognitive deficits after SAH. Methods: Using a murine model of SAH and mice deficient in neutrophil effector functions, we determined which neutrophil effector function is critical to the development of deficits after SAH. In vivo and in vitro techniques were used to investigate possible pathways of neutrophils effect after SAH. Results: Our results show that mice lacking functional MPO (myeloperoxidase), a neutrophil enzyme, lack both the meningeal neutrophil infiltration (wild type, sham 872 cells/meninges versus SAH 3047, P=0.023; myeloperoxidase knockout [MPOKO], sham 1677 versus SAH 1636, P=NS) and erase the cognitive deficits on Barnes maze associated with SAH (MPOKO sham versus SAH, P=NS). The reintroduction of biologically active MPO, and its substrate hydrogen peroxide (H2O2), to the cerebrospinal fluid of MPOKO mice at the time of hemorrhage restores the spatial memory deficit observed after SAH (time to goal box MPOKO sham versus MPOKO+MPO/H2O2, P=0.001). We find evidence of changes in neurons, astrocytes, and microglia with MPO/H2O2 suggesting the effect of MPO may have complex interactions with many cell types. Neurons exposed to MPO/H2O2 show decreased calcium activity at baseline and after stimulation with potassium chloride. Although astrocytes and microglia are affected, changes seen in astrocytes are most consistent with inflammatory changes that likely affect neurons. Conclusions: These results implicate MPO as a mediator of neuronal dysfunction in SAH through its effect on both neurons and glia. These results show that, in SAH, the activity of innate immune cells in the meninges modulates the activity and function of the underlying brain tissue.

Imaging patterns of venous-related brain injury in children.

Venous-related brain injury is a common form of cerebrovascular injury in children and encompasses a diverse group of cerebrovascular diagnoses. The purpose of this pictorial essay is to introduce the relevant anatomy, pathophysiology and various imaging patterns of venous-related cerebral injury in children. Unifying concepts to better understand the effects of venous hypertension in the developing brain will be emphasized. These unifying concepts will provide the imaging professional with a conceptual framework to better understand and confidently identify imaging patterns of venous-related cerebral injury.

The intracranial bridging veins: a comprehensive review of their history, anatomy, histology, pathology, and neurosurgical implications.

INTRODUCTION: The intracranial bridging veins are pathways crucial for venous drainage of the brain. They are not only involved in pathological conditions but also serve as important landmarks within neurological surgery. METHODS: The medical literature on bridging veins was reviewed in regard to their historical aspects, embryology, histology, anatomy, and surgery. CONCLUSION: Knowledge on the intracranial bridging veins and their dynamics has evolved over time and is of great significance to the neurosurgeon.

[Intracranial hemorrhage associated with injury of the critical diploic venous system in clipping for unruptured cerebral aneurysm: a case report].

A case of intracranial hemorrhage associated with injury of a critical diploic venous system in clipping for an unruptured cerebral aneurysm was reported. A 67-year-old female presented with a sense of floating. Magnetic resonance angiography (MRA) showed a C1-2 portion aneurysm of the left internal carotid artery 13 mm in size projecting supero-laterally. Three-dimensional CT angiography (3DCTA) volume rendering revealed a developed left fronto-anterior temporal diploic venous system draining the frontal cortical venous return. Because of the large and wide-necked aneurysm, we planned clipping surgery for the purpose of a complete cure. The operation was performed with left fronto-temporal craniotomy at the expense of the diploic venous system. Using techniques such as bipolar coagulation and suction decompression, neck clipping was accomplished via the distal trans-sylvian approach. After the operation, the patient was noticed to be delirious, and post-operative CT demonstrated intracranial hemorrhage in the left frontal lobe with severe brain edema. Motor aphasia was remarkable, but it was gradually relieved, and she left our hospital with no motor weakness. 3 months after the operation, her aphasia was faintly perceptible but she could live independently. We concluded that the injury of a diploic venous system could cause intracranial hemorrhage with intractable brain edema by critically interrupting the frontal venous return.

[Traumatic arteriovenous pial fistula masquerading as a carotid-cavernous fistula: an uncommon disorder with an unusual presentation]. / Fístula arteriovenosa pial traumática que simula una fístula carotidocavernosa: una enfermedad infrecuente con una presentación excepcional.

Traumatic intracranial pial arteriovenous fistulae are infrequent lesions. Their cardinal signs have been related to mass effect and hemorrhage, but their clinical manifestations due to venous retrograde flow into ophthalmic veins has never been described. This phenomenon is usually seen in dural arteriovenous fistula draining to the cavernous sinus or carotid-cavernous sinus fistula.A traumatic intracranial pial arteriovenous fistula arising from the supraclinoid internal carotid artery in a young patient was revealed by aggressive behavior and ophthalmologic manifestations. The endovascular management included the use of coils, stent, and ethylene-vinyl alcohol with transient balloon occlusion of the parent vessel.

Classification of Peritumoral Veins in Convexity and Parasagittal Meningiomas and Its Significance in Preventing Cerebral Venous Infarction.

OBJECTIVE: The medium (2-4 cm) convexity located closer to the sinus and parasagittal meningiomas (Sindou type I-Ⅲ) without obvious invasion of the superior sagittal sinus are considered simple to operate on. However, the tumors are often accompanied by the cortical bridging vein. Because of lack of collateral vein circulation in cortical areas, the damage of peritumoral veins will subsequently lead to venous infarction. To avoid the serious complications caused by intraoperative injury of peritumoral veins, it is necessary to define the classification of the progression of peritumoral veins and tumors to guide surgical safety. METHODS: The clinical information of 57 patients with convexity and parasagittal meningiomas was collected and retrospectively analyzed. All patients underwent preoperative magnetic resonance imaging and magnetic resonance venography scanning to observe the imaging characteristics of peritumoral veins and preoperative evaluation. The actual relationship between the tumor and peritumoral vein was observed intraoperatively. Postoperative computed tomography and magnetic resonance imaging were used to determine tumor resection and the presence of venous infarction. RESULTS: According to preoperative magnetic resonance venography and intraoperative findings, we divided the peritumoral veins into 3 types: type A (n = 33, 57.9%), the vein surrounds the tumor; type B (n = 15, 26.3%), the vein is located on the ventral side of the tumor; and type C (n = 9, 15.8%), the vein is located on the dorsal side of the tumor. Peritumoral vein injury occurred in 6 cases followed by serious complications. Treatments were as follows: 4 cases underwent decompression and 2 cases were treated conservatively. The prognosis Glasgow Outcome Scale (GOS) scores were as follows: 3 cases were score 5 for injury of posterior frontal vein or middle frontal vein, 2 cases were score 3 for injury of the central vein, 1 case was score 1 for death due to injury of the central vein. All cases were followed up for 6 months. CONCLUSIONS: Attention should be paid to the peritumoral vein of special meningiomas. Injured vein in the medial third of superior sagittal sinus carries a high rate of postoperative morbidity. Understanding the type of peritumoral veins preoperatively can be used as a guide in determining the corresponding protective strategy during surgery, which can significantly decrease postoperative disability and improve quality of life.

The petrosal vein mutilation affects the SOD activity, MDA levels and AQP4 level in cerebellum and brain stem in rabbit.

Cerebral edema after brain surgery remains a life-threatening complication in the clinic. For a better operating field view, superior petrosal vein (SPV) can be easily damaged during neurosurgery. SPV sacrifice may sometimes be inevitable in clinic. However, the safety of SPV sacrifice is still a controversial question. Whether petrosal vein injury has an effect on cerebral edema after brain surgery is still unknown. In this study, rabbits were divided into two groups. The rabbits in the surgery group underwent petrosal vein sacrifice. The control group was subjected to sham surgery. Cerebellum and brain stem tissues were collected at 4 h, 8 h, 12 h, 24 h, 48 h and 72 h post-surgery. The superoxidase dismutase (SOD) activity and expression of malondialdehyde (MDA) were tested in the collected samples. Quantitiative real time polymerase chain reaction and immunohistochemistry were used to detect the mRNA and protein levels, respectively, of aquaporin 4 (AQP4) in the tissue samples. Compared to the control sham group, the activity of SOD and MDA expression in cerebellum was decreased and increased, respectively, at 4 h, 8 h, 12 h and 24 h post-, surgery The SOD activity and expression of MDA in brain stem was decreased and increased, respectively, only in 4 h after surgery, compared with control group. The mRNA and protein levels of AQP4 were increased in cerebellum at 4 h, 8 h, 12 h and 24 h after surgery, but in the brain stem, the levels were increased only at 4 h after surgery compared with sham group. Our results thus show that SPV sacrifice influences oxidative stress and the expression of AQP4 in cerebellum and brain stem of rabbits; highlighting the importance of protecting the petrosal vein during neurosurgery.

Peduncular hallucinosis following microvascular decompression for trigeminal neuralgia without direct brainstem injury: case report.

We report a 68-year-old woman who experienced visual hallucinations diagnosed as peduncular hallucinosis (PH) following microvascular decompression for trigeminal neuralgia. Postoperative MRI showed only ischemic oedema of the left cerebellar hemisphere due to retraction. Our case first reveals that PH can be induced without direct brainstem injury, instead possibly by a cerebellar lesion.

Global/local head models to analyse cerebral blood vessel rupture leading to ASDH and SAH.

Blunt and rotational head impacts due to vehicular collisions, falls and contact sports cause relative motion between the brain and skull. This increases the normal and shear stresses in the (skull/brain) interface region consisting of cerebrospinal fluid (CSF) and subarachnoid space (SAS) trabeculae. The relative motion between the brain and skull can explain many types of traumatic brain injuries (TBI) including acute subdural hematomas (ASDH) and subarachnoid hemorrhage (SAH) which is caused by the rupture of bridging veins that transverse from the deep brain tissue to the superficial meningeal coverings. The complicated geometry of the SAS trabeculae makes it impossible to model all the details of the region. Investigators have compromised this layer with solid elements, which may lead to inaccurate results. In this paper, the failure of the cerebral blood vessels due to the head impacts have been investigated. This is accomplished through a global/local modelling approach. Two global models, namely a global solid model (GSM) of the skull/brain and a global fluid model (GFM) of the SAS/CSF, were constructed and were validated. The global models were subjected to two sets of impact loads (head injury criterion, HIC = 740 and 1044). The relative displacements between the brain and skull were determined from GSM. The CSF equivalent fluid pressure due to the impact loads were determined by the GFM. To locally study the mechanism of the injury, the relative displacement between the brain and skull along with the equivalent fluid pressure were implemented into a new local solid model (LSM). The strains of the cerebral blood vessels were determined from LSM. These values were compared with their relevant experimental ultimate strain values. The results showed an agreement with the experimental values indicating that the second impact (HIC = 1044) was strong enough to lead to severe injury. The global/local approach provides a reliable tool to study the cerebral blood vessel ruptures leading to ASDH and/or SAH.

Acute Posttraumatic Cerebral Venous Sinus Thrombosis-Induced Malignant Increased Intracranial Pressure Treated with Endovascular Dural Sinus Thrombectomy and Stenting.

BACKGROUND: Posttraumatic cerebral venous sinus thrombosis (CVST) is a major complication after head injury. Impaired venous outflow caused by CVST leads to increased intracranial pressure (IICP) refractory to medications and surgical decompression and often results in devastating consequences. Currently, there is no consensus on the treatment strategy. CASE DESCRIPTION: Here we report a case of posttraumatic CVST in a young male motorcyclist involved in a high-speed traffic accident. On admission, the patient immediately underwent decompressive hemicraniectomy. However, refractory malignant IICP developed within 24 hours after the operation. Computed tomography venography revealed compression of the right sigmoid sinus by the fractured temporal bone and extensive thrombosis toward the jugular bulb. Dural sinus thrombectomy and stenting were performed accordingly. After the procedure, IICP was alleviated immediately and the sedatives and medications were tapered off within days. The patient gradually recovered from deep comatose status and underwent cranioplasty 5 weeks later. Finally, the patient was discharged with only mild left wrist weakness. CONCLUSIONS: Acute cerebral sinus thrombosis caused by trauma may result in malignant IICP refractory to medications and surgical decompression. We have demonstrated that endovascular angioplasty and sinus stenting are effective in restoring venous outflow and reducing intracranial pressure. We have also demonstrated that appropriate and timely interventions are important to ensure quick and good recovery in patients with CVST.

Inflicted traumatic brain injury in infants and young children.

This article will discuss the subject of inflicted or abusive head injury in infants and young children. Inflicted neurotrauma is a very common injury and a frequent problem in attempting to distinguish between inflicted and accidental injury. Inflicted head injury occurs usually in the home in the presence of the individual who has inflicted the injury outside the view of unbiased witnesses. Distinguishing between inflicted and accidental injury may be dependent upon the pathological findings and consideration of the circumstances surrounding the injury. The most common finding in an inflicted head injury is the presence of subdural hemorrhage. Subdural hemorrhage may occur in a variety of distributions and appearances. The natural history of subdural bleeding and the anatomy of the "subdural" will be considered. The anatomy of the dura and its attachment to the skull and to the arachnoid determines how subdural bleeding evolves into the cleaved dural border cell layer and as well as how bridging veins are torn and anatomically where bleeding will occur. Different biomechanical mechanisms result in different distributions of subdural blood and these differences will be discussed.

Incidence, Pathophysiology, and Prevention Strategies for Cerebral Venous Complications after Neurologic Surgery: A Systematic Review of the Literature.

BACKGROUND: Complications arising from cerebral venous occlusion/sacrifice during neurosurgical procedures have received comparatively less attention in the neurosurgical literature. Consequently, cerebral venous complications are not given due recognition, even though most practicing neurosurgeons would agree that they are not uncommon. We present a review of complications arising from venous sacrifice/occlusion during neurosurgery and discuss strategies described in the literature to prevent such occurrences. METHODS: We conducted a systematic review of the literature to provide a synopsis of the current evidence regarding cerebral venous injury after a neurosurgical procedure. The objectives of this review were to assess the incidence of venous injuries after a neurosurgical procedure with their clinical outcome and to evaluate current strategies and technical advances for their prevention. Complications related to dural venous sinuses were not considered in this review. RESULTS: Twenty-six relevant articles were identified and reviewed. Complications from cerebral venous occlusion/sacrifice are being increasingly recognized, and venous preservation strategies are being promoted in the neurosurgical literature. Based on our review of literature, the incidence of venous injury can range from 2.6% to 30%. We discuss the pathophysiology after venous injury and factors affecting outcome after cerebral venous injury. An overview of surgical techniques described to prevent or manage venous injury during neurosurgical procedures is presented. CONCLUSIONS: The unpredictable response of the brain to venous injury causes catastrophic complications in a few patients. To avoid these complications, meticulous venous preservation should be a goal in all neurosurgical procedures. Increased recognition of cerebral venous complications over the last 2 decades has resulted in the increasing recognition among neurosurgeons that venous preservation is an essential tenet of neurosurgery.

Evaluation of Venous Drainage Patterns for Skull Base Meningioma Surgery.

The evaluation of venous drainage patterns prior to surgery for skull base meningioma is important owing to their deep location and the vulnerability of surrounding vascular structures. In recent years, the microsurgical skull base approach has matured as a surgical technique, making it an important option for reducing complications related to skull base meningioma surgery. In addition, knowledge of the venous anatomy can prevent venous drainage route disturbance and potentially life-threatening complications. Hence, this topic review aimed to provide an overview of normal venous anatomy as it relates to the microsurgical skull base approach, discuss known changes in venous drainage routes that are associated with the progression of skull base meningioma and the selection of an appropriate operative approach with the highest likelihood of preserving venous drainage structures.

Mechanics of acute subdural hematomas resulting from bridging vein rupture.

OBJECT: Based on data from primate experiments it is known that rotational acceleration in the sagittal plane and in a forward direction is most likely to produce acute subdural hematomas due to bridging vein rupture. For protection against these lesions, knowledge of rotational acceleration tolerance levels in humans is required. In the present study the authors analyze human tolerance levels for bridging vein rupture by performing head impact tests in cadavers. METHODS: Ten unembalmed cadavers were subjected to 18 occipital impacts producing head rotation in the sagittal plane with varying rotational acceleration magnitudes and pulse durations. Rotational acceleration was calculated from the linear acceleration histories recorded by three uniaxial accelerometers mounted on the side of the head. Bridging vein ruptures were detected by injecting contrast dye into the superior sagittal sinus under fluoroscopy and by autopsy procedures. Bridging vein ruptures were produced in six head impact tests: one test with a pulse duration of 5.2 msec and a peak rotational acceleration of 13,411 rad/second2; three tests with a pulse duration between 7 and 8 msec and a peak rotational acceleration of 12,558, 10,607, and 8567 rad/second2; and two tests with a pulse duration longer than 10 msec and a peak rotational acceleration as low as 5267 rad/second2. CONCLUSIONS: This is the only cadaveric study of bridging vein rupture focused on short pulse durations, which are usually associated with falls. The data suggest a tolerance level of approximately 10,000 rad/second2 for pulse durations shorter than 10 msec, which seems to decrease for longer pulse durations.

Representation of cerebral bridging veins in infants by postmortem computed tomography.

The postmortem diagnosis of shaken baby syndrome, a severe form of child abuse, may be difficult, especially when no other visible signs of significant trauma are obvious. An important finding in shaken baby syndrome is subdural haemorrhage, typically originating from ruptured cerebral bridging veins. Since these are difficult to detect at autopsy, we have developed a special postmortem computed tomographic (PMCT) method to demonstrate the intracranial vein system in infants. This method is minimally invasive and can be carried out conveniently and quickly on clinical computed tomography (CT) systems. Firstly, a precontrast CT is made of the infant's head, to document the original state. Secondly, contrast fluid is injected manually via fontanel puncture into the superior sagittal sinus, followed by a repeat CT scan. This allows the depiction of even very small vessels of the deep and superficial cerebral veins, especially the bridging veins, without damaging them. Ruptures appear as extravasation of contrast medium, which helps to locate them at autopsy and examine them histologically, whenever necessary.

The Analysis of the Petrosal Vein to Prevent Venous Complications During the Anterior Transpetrosal Approach in the Resection of Petroclival Meningioma.

BACKGROUND: The anterior transpetrosal approach (ATPA) has been used in the resection of petroclival meningioma (PCM) for more than 20 years. Although PCM sometimes involves the petrosal vein and its preservation has been an important issue, the precise risk of petrosal vein sacrifice and subsequent venous complications associated with the use of the ATPA in patients with PCM has not yet been elucidated. METHODS: We used computed tomographic (CT) digital subtraction venography (DSV) in the retrospective analysis of the petrosal vein and its tributaries in patients with PCM before and after surgery. We also examined the incidence of postoperative venous complications in each of the patients. RESULTS: The detection rate of the petrosal vein and some of its tributaries on CT-DSV in patients with PCM was significantly lower than that in controls. Preoperatively, CT-DSV detected the petrosal vein in 71.8% of patients with PCM. The detected petrosal veins were preserved after the operation in 64.3% of these patients. No venous complications involving petrosal vein were observed in any of the patients. Anastomosis between the petrosal vein and the basal vein via the pontotrigeminal vein was found to be significantly more developed in the patients with PCM compared with the controls. CONCLUSIONS: Our study demonstrated that the ATPA could be performed safely on patients with PCM from the viewpoint of venous preservation. Preoperative CT-DSV is important for assessing the petrosal vein and its tributaries to facilitate a safer operation.

Knife blade penetrating stab wound to the brain--case report--.

A 28-year-old man attempted to kill himself with a knife stab into the parietal area. Neuroimaging showed no vascular impairment except slow venous flow around the knife due to tamponading. After obtaining informed consent, the knife was removed through a craniotomy without new brain injury. Postoperative neurological findings showed no deficit. Follow-up angiography revealed no vascular impairment. No infection occurred. Brain stab wounds cause numerous complications, such as intracranial hemorrhage, injury of important vessels, and infections. Minimal blade movement during removal and precautions to prevent massive hemorrhage are essential.

[Visualization of bridging veins by means of postmortem computed tomography]. / Darstellung der Brückenvenen mit der postmortalen Computertomographie.

At autopsy, visualization of lesions of the bridging veins, a frequent source of subdural bleeding, is difficult due to their anatomical localization. On the other hand their demonstration is of great importance for the assignment to a chronologically defined trauma. For this reason a postmortem method using computed tomography was developed to visualize the intracranial venous system by means of X-ray contrast media. In subdural bleedings, in which the skull had not been opened up, ruptured vessels could be accurately localized with this method, so that targeted dissection was possible during the subsequent autopsy.

Multifocal Signal Loss at Bridging Veins on Susceptibility-Weighted Imaging in Abusive Head Trauma.

Identifying abusive head trauma (AHT) in infants is difficult because often there are no externally visible injuries and symptoms are nonspecific. The radiological finding that usually raises suspicion of AHT--especially when found with retinal hemorrhage and inappropriate history--is subdural hematoma (SDH). In addition to that, bridging vein thrombosis, assessed by imaging or autopsy, has been reported as a sign of the traumatic cause of SDH. Here we present two cases of AHT-associated SDH in infants, in which multifocal signal loss at bridging veins was present on susceptibility-weighted imaging without signs of venous infarction. As susceptibility-weighted imaging has been reported to be more sensitive for blood products than gradient-echo T2-weighted imaging, we propose that it might help to identify clot formation on injured bridging veins and therefore increase the sensitivity of imaging studies for a traumatic cause of SDH, helping to identify AHT that is considered to be caused by violent shaking.

Minimizing Collateral Brain Injury Using a Protective Layer of Fibrin Glue: Technical Note.

BACKGROUND: Neurosurgical procedures expose the brain surface to a constant risk of collateral injury. We describe a technique where the brain surface is covered with a protective layer of fibrin glue and discuss its advantages. METHODS: A thin layer of fibrin glue was applied on the brain surface after its exposure in 34 patients who underwent different craniotomies for tumoral and vascular lesions. Data of 35 more patients who underwent standard microsurgical technique were collected as a control group. Cortical and pial injuries were evaluated using an intraoperative visual scale. Eventual abnormal signals at the early postoperative T2-weighted fluid-attenuated inversion recovery (T2FLAIR) magnetic resonance imaging (MRI) sequences were evaluated in oncological patients. RESULTS: Total pial injury was noted in 63% of cases where fibrin glue was not used. In cases where fibrin glue was applied, a significantly lower percentage of 26% (P < 0.01) had pial injuries. Only 9% had injuries in areas covered with fibrin glue (P < 0.0001). Early postoperative T2FLAIR MRI confirmed the differences of altered signal around the surgical field in the two populations. CONCLUSION: We propose beside an appropriate and careful microsurgical technique the possible use of fibrin glue as alternative, safe, and helpful protection during complex microsurgical dissections. Its intrinsic features allow the neurosurgeon to minimize the cortical manipulation preventing minor collateral brain injury.