Border Zone Maybe Correlated with Radiation Necrosis After Radiosurgery in Metastatic Brain Tumor.

BACKGROUND: Radiation necrosis (RN) after stereotactic radiosurgery (SRS) in brain metastases has been extensively evaluated, and RN is correlated with various risk factors. However, no study comprehensively analyzed the correlation between RN and the border zones of the brain that are vulnerable to ischemia. We hypothesized that patients with tumors in the border zone are at high risk of RN. Hence, the current study aimed to assess the correlation between border zone lesions and RN, with consideration of other predetermined factors. METHODS: This retrospective study included 117 patients with 290 lesions who underwent Gamma Knife SRS. Radiological and clinical analyses were performed to identify factors possibly correlated with RN. Notably, the lesion location was classified into 2 groups (border zone and nonborder zone) based on the blood supply. RESULTS: In total, 22 (18.8%) patients with 22 (7.5%) lesions developed RN. Univariate analysis revealed a significant correlation between RN and external border zone lesions, second course of SRS administered at the same site of the previous SRS, prescribed dose, and tumor volume. Multivariate analysis showed that border zone lesions, second course of SRS at the same site of the previous SRS, and tumor volume were significantly correlated with RN. CONCLUSIONS: Patients with tumors in the border zone are at high risk of RN. The potential risks of RN can be attributed hypothetically to hypoperfusion. Hence, the association between RN and border zone lesions seems reasonable.

Venous ectasia preceding intra-tumoral hemorrhage in a case of gliosarcoma with transverse sinus involvement.

Although intratumoral hemorrhage is common in patients with malignant brain tumors, reports on its clinical course are scarce. This report presents a rare case of a patient with intratumoral hemorrhage with gliosarcoma invading the venus sinus. This invasion and a small draining vein were observed at diagnosis. Magnetic resonance imaging performed 1 week later showed new-onset venous ectasia, which caused intratumoral hemorrhage. This case provides insight into the mechanisms underlying intratumoral hemorrhage and highlights the emergence of new intratumoral vasculature as a potential warning sign for hemorrhage.

Novel Animal Model of Spontaneous Cerebral Petechial Hemorrhage Using Focused Ultrasound in Rats.

Background and Objectives: Petechial cerebral hemorrhages can be caused by various factors, such as traumas, cerebral infarctions, and aging, and is related to the disruption of the blood-brain barrier or the cellular damage of blood vessels. However, there is no animal model that recapitulates cerebral petechial hemorrhages. Materials and Methods: Here, we implemented a petechial hemorrhage using a novel technology, i.e., microbubble-assisted focused ultrasound (MB + FUS). Results: This method increases the permeability of the blood-brain barrier by directly applying mechanical force to the vascular endothelial cells through cavitation of the microbubbles. Microbubble-enhanced cavitation has the advantage of controlling the degree and location of petechial hemorrhages. Conclusions: We thus generated a preclinical rat model using noninvasive focal MB + FUS. This method is histologically similar to actual petechial hemorrhages of the brain and allows the achievement of a physiologically resembling petechial hemorrhage. In the future, this method shall be considered as a useful animal model for studying the pathophysiology and treatment of petechial cerebral hemorrhages.

Effect of Cadherin-11 Expression on the Prognosis of a Newly Diagnosed Primary Glioblastoma.

BACKGROUND: Cadherin-11, a cell-to-cell adhesion molecule, is associated with higher tumor grade and decreased patient survival. The purpose of this study was to investigate the clinical significance of cadherin-11 expression in the progression and prognosis of a newly diagnosed primary glioblastoma (GBL). METHODS: Between 2007 and 2016, 52 out of 178 patients diagnosed with a GBL and satisfied the following criteria: 1) a new primary GBL, 2) gross-total resection, 3) immunohistochemically-available tissue, and 4) standardized adjuvant treatment. RESULTS: In terms of staining intensity, the low-intensity cadherin-11 group showed longer progression-free survival (PFS) than the high-intensity cadherin-11 group (median PFS, 12.0 months [95% CI, 11.1-12.9] vs. median PFS, 6.0 months [95% CI, 3.7-8.3]; p<0.001). The low-intensity cadherin-11 group revealed longer overall survival (OS) than the high-intensity cadherin-11 group (median OS, 20.0 months [95% CI, 11.8-16.6] vs. median OS, 15.0 months [95% CI, 11.8-18.2]; p=0.003). The staining intensity of cadherin-11 was a statistically significant factor in PFS and OS in terms of univariate and multivariate analyses (univariate analysis: p<0.001 and p=0.005; multivariate analysis: p<0.001 and p=0.005). CONCLUSION: Our clinical study demonstrates high cadherin-11 expression may be associated with poor PFS and OS for a newly diagnosed primary GBL.

Clinical significance of vitamin D in idiopathic normal pressure hydrocephalus.

BACKGROUND: Although recent studies show vitamin D deficiency is associated with cognitive decline, urinary incontinence, and gait instability, there has been no study on the effect of vitamin D on idiopathic normal pressure hydrocephalus (iNPH) characterized by the classic symptom triad of cognitive decline, urinary incontinence, and gait instability. We investigated the clinical significance of vitamin D in patients with iNPH. METHODS: Between 2017 and 2020, 44 patients who underwent ventriculoperitoneal shunt surgery were divided into low (< 15 ng/mL) and high (≥ 15 ng/mL) vitamin D groups according to the concentration of 25(OH)D, an effective indicator of vitamin D status. They were respectively evaluated according to clinical and radiological findings. RESULTS: The low vitamin D group (n = 24) showed lower preoperative cognition compared to the high vitamin D group (n = 20) in terms of Korean-Mini Mental Status Examination (K-MMSE) and iNPH grading scale (iNPHGS) (K-MMSE: 20.5 ± 5.4 versus 24.0 ± 4.5, p = 0.041; iNPHGS cognitive score: 2 ± 0.9 versus 1 ± 0.6, p = 0.025). And the low vitamin D group showed pre- and postoperatively more severe urinary incontinence (preoperative iNPHGS urinary score: 1 ± 1.0 versus 0 ± 0.9, p = 0.012; postoperative iNPHGS urinary score:1 ± 1.0 versus 0 ± 0.9, p = 0.014). The score of narrow high-convexity sulci for the low vitamin D group was lower (low vitamin D group: 1 ± 0.7 versus high vitamin D group: 2 ± 0.4, p = 0.031). CONCLUSION: Lower concentration of vitamin D in iNPH may be related to lower preoperative cognition, pre- and postoperative urinary incontinence, and brain morphological change.

Spindle cell oncocytoma of the sella turcica with anaplastic features and rapid progression in short-term follow-up: a case report with proposal of distinctive radiologic features.

We present a rare case of spindle cell oncocytoma (SCO) of the sella turcica with malignant histologic features and rapid progression. A 42-year-old woman experienced bilateral blurred vision and was preoperatively misdiagnosed as having a pituitary macroadenoma on magnetic resonance imaging. After surgery, SCO was diagnosed by the histopathologic features of interlacing fascicles of spindle tumor cells with finely granular, eosinophilic cytoplasm. Focal anaplastic changes and necrosis were present. Immunohistochemically, the tumor cells were positive for vimentin, epithelial membrane antigen, S-100, galectin-3, and thyroid transcription factor 1. Four months later, the tumor had progressed, and second surgery with adjuvant radiotherapy was performed; the patients remains under observation. In this report, we proposed distinctive radiologic features for differential diagnosis between SCO and other pituitary tumors.

Chronic Hyperglycemia before Spinal Cord Injury Increases Inflammatory Reaction and Astrogliosis after Injury: Human and Rat Studies.

Traumatic spinal cord injury (SCI) can cause permanent disabilities that seriously reduce quality of life. We evaluated the effects of chronic hyperglycemia before SCI on inflammatory markers and functional recovery after SCI in human patients and a rat model. In the human study, multivariate logistical regression analysis revealed that hemoglobin A1c (HbA1c) values, reflecting average plasma glucose concentration over a 3 month period, at admission were a significant risk factor for poor functional recovery. Moreover, patients with chronic hyperglycemia (HbA1c ≥ 6.5%) had high concentrations of inflammatory biomarkers (interleukin [IL]-6 and IL-8) of cerebrospinal fluid after SCI. Consistent with patient findings, chronic hyperglycemia before SCI in rats was associated with increased inflammatory responses and oxygen-free radicals in the spinal cord and blood, thus resulting in poor functional recovery and histological outcomes. Tight glucose control before SCI decreased the harmful effects of hyperglycemia after SCI in both human and rat studies. Our findings suggest that chronic hyperglycemia before SCI may be a significant prognostic factor with a negative impact on functional and histological outcomes, highlighting the importance of tight glucose control before SCI.

Gamma Knife Radiosurgery Using Co-Registration with PET-CT and MRI for Recurrent Nasopharyngeal Carcinoma with Previous Radiotherapy : A Single Center 14-Year Experience.

OBJECTIVE: We retrospectively evaluated the efficacy of Gamma Knife radiosurgery (GKS) for recurrent nasopharyngeal carcinoma (NPC) in patients who previously underwent radiotherapy, and analyzed the treatment outcomes over 14 years. METHODS: Ten patients with recurrent NPC who had previously received radiotherapy underwent stereotactic radiosurgery using a Gamma Knife® (Elekta Inc, Atlanta, GA, USA) between 2005 and 2018. The median target volume was 8.2 cm3 (range, 1.7-17.8), and the median radiation dose to the target was 18 Gy (range, 12-30). The median follow-up period was 18 months (range, 6-76 months). Overall and local failure-free survival rates were determined using the Kaplan-Meier method. RESULTS: The NPCs recurred at the primary cancer site in seven patients (70%), as distant brain metastasis in two (20%), and as an extension into brain in one (10%). The recurrent tumors in seven of the 10 patients (70%) were found on the routine follow-up imaging studies. Two patients presented with headache and one with facial pain. Local failure after GKS occurred in five patients (50%) : two of whom died eight and 6 months after GKS, respectively. No adverse radiation effects were noted after GKS. The 1- and 3-year overall survival rates after GKS were 90% and 77%, respectively. The local failure-free survival rates at 6 months, 1 year, and 3 years after GKS were 80%, 48%, and 32%, respectively. The median interval from GKS to local failure was 8 months (range, 6-12). Univariate analysis revealed that using co-registration with positron emission tomography-computed tomography (PET-CT) and magnetic resonance imaging (MRI) was associated with a lower local failure rate of recurrent NPC (p=0.027). CONCLUSION: GKS is an acceptable salvage treatment option for patients with recurrent NPC who previously received radiation therapy. PET-CT and MRI co-registration for dose planning can help achieve local control of recurrent NPC.

Stereotactic Radiosurgery for Dural Arteriovenous Fistulas Involving the Transverse-Sigmoid Sinus : A Single Center Experience and Review of the Literatures.

OBJECTIVE: We retrospectively assessed the efficacy of stereotactic radiosurgery (SRS) for dural arteriovenous fistulas (DAVFs) involving the transverse-sigmoid sinus and analyzed the angiographic and clinical results with our 8-year experience. METHODS: Nine patients with intracranial DAVFs involving the transverse-sigmoid sinus underwent SRS using a Gamma Knife® (Elekta Inc., Atlanta, GA, USA) between 2009 and 2016. Five patients underwent SRS for residual DAVFs after embolization and four patients were treated with SRS alone. The median target volume was 1.9 cm3 (range, 0.8-14.2) and the median radiation dose of the target was 17 Gy (range, 16-20). The median follow-up period was 37 months (range, 7-81). RESULTS: Pulsating tinnitus (33%) was the most common symptom. DAVFs were completely obliterated in four patients (44%) and subtotally obliterated in five (56%). Six patients (67%) showed complete recovery of symptoms or signs, and three (33%) showed incomplete recovery. One patient experienced a recurrent seizure. Adverse radiation effects after SRS occurred in one patient (11%). The total obliteration rates after SRS were 16.7%, 37.5%, and 68.7% at 1, 2, and 3 years, respectively. The median interval from SRS to total obliteration of the fistula was 31 months (range, 12-38). The rates at which the symptoms started to improve were 40% at 1 month and 80% at 2 months after SRS. Symptoms started to improve at a median of 5 weeks after SRS (range, 3-21). CONCLUSION: SRS with or without embolization is a safe and effective treatment to relieve symptoms and obliterate DAVFs on the transverse-sigmoid sinus.

Do Serum Vascular Endothelial Growth Factor and Endostatin Reflect Radiological Radiation-Induced Changes After Stereotactic Radiosurgery for Cerebral Arteriovenous Malformations?

OBJECTIVE: The aim of this study was to analyze serum levels of vascular endothelial growth factor (VEGF) and endostatin in patients with cerebral treated by stereotactic radiosurgery (SRS), and to assess their association with radiological radiation-induced changes (RICs). METHODS: To measure serum biomarkers, peripheral venous blood was collected before SRS and 1 week, 1 month, 3 months, and 6 months after SRS. To evaluate RICs, clinical and neuroimaging follow-up were performed concurrently every 6 months after SRS. RESULTS: Twenty-seven patients were enrolled (11 in the group with RIC, 16 in the group without RIC). Serum VEGF and endostatin levels were positively correlated (P = 0.036, r = 0.405). In the group with RIC, the median serum VEGF 6 months after SRS (58.98 pg/mL) was significantly higher than that of the group without RIC (15.17 pg/mL) (P = 0.001). Multivariate analysis revealed that higher VEGF 6 months after SRS (P = 0.001, hazard ratio, 1.032; 95% confidence interval, 1.012-1.052) and lower endostatin 1 month after SRS (P = 0.007, hazard ratio, 0.964; 95% confidence interval, 0.935-0.993) were significantly associated with RICs. CONCLUSIONS: Our results show that serum levels of VEGF 6 months after SRS were higher in the group with RIC. Serum levels of VEGF 6 months and endostatin 1 month after SRS were associated with the radiological RICs. Thus, serial measurements of serum VEGF and endostatin after SRS might help predict RICs in patients with arteriovenous malformation treated by SRS.

Brain Metastasis from Nasopharyngeal Carcinoma Treated with Stereotactic Radiosurgery.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a common malignant tumor of the head and neck, and is associated with high recurrence and low survival rates; however, distant brain metastasis from NPC is rare. CASE DESCRIPTION: The authors report 3 cases of brain metastasis from NPC treated with stereotactic radiosurgery (SRS). A 49-year-old woman presented was diagnosed with brain metastasis from NPC, which occurred 53 months after the initial diagnosis of NPC. Brain magnetic resonance imaging (MRI) revealed a well-enhanced large tumor on the frontal lobe, which was treated with SRS. Six months later, brain MRI revealed progression of the tumor. A 44-year-old man had undergone craniotomy and removal of a cerebellar tumor pathologically confirmed as metastasis from NPC. The recurrent brain metastasis was diagnosed via routine MRI follow-up examination 23 months after surgery. Brain MRI revealed a heterogeneously enhanced cerebellar large tumor, which was treated using hypofractionated SRS. Three months later, brain MRI revealed a significant decrease in the tumor size. A 60-year-old man was diagnosed with distant brain metastasis from NPC via routine positron emission tomography follow-up examination 14 months after the initial diagnosis of NPC. Brain MRI confirmed a homogeneously enhanced tumor on the cavernous sinus, which was treated with SRS. Three months later, brain MRI revealed virtual disappearance of the tumor. All 3 patients had undergone concurrent chemoradiotherapy after the initial diagnosis of NPC and underwent salvage SRS for brain metastasis from NPC. CONCLUSIONS: Despite the poor prognosis, salvage SRS was performed for these rare brain metastases from NPC.

Safe Margin beyond Dens Tips to Ventral Dura in Anterior Odontoid Screw Fixation : Analysis of Three-Dimensional Computed Tomography Scan of Odontoid Process.

OBJECTIVE: Anterior odontoid screw fixation is a safe and effective method for the treatment of odontoid fractures. The surgical technique is recommended for perforation of the apical cortex of the dens by the lag screw. However, overpenetration of the apical cortex may lead to potentially serious complications such as damages of adjacent vascular and neural structures. The purpose of this study was to assess the role of three-dimensional computed tomography (CT) scan to evaluate the safe margin beyond dens tip to ventral dura for anterior odontoid screw fixation. METHODS: We retrospectively analyzed the three-dimensional CT scans of the cervical spines in 55 consecutive patients at our trauma center. The patients included 38 males and 17 females aged between 22 and 73 years (mean age±standard deviation, 45.8±14.2 years). Using sagittal images of 3-dimensional CT scan, the safe margins beyond dens tip to ventral dura as well as the appropriate screw length were measured. RESULTS: The mean width of the apical dens tip was 9.6±1.1 mm. The mean lengths from the screw entry point to the apical dens tip and posterior end of dens tip were 39.2±2.6 mm and 36.6±2.4 mm. The safe margin beyond apical dens tip to ventral dura was 7.7±1.7 mm. However, the safe margin beyond the posterior end of dens tip to ventral dura was decreased to 2.1±3.2 mm, which was statistically significant (p<0.01). There were no significant differences of safe margins beyond dens tip to ventral dura with patient gender and age. CONCLUSION: Extension by several millimeters beyond the dens tip is safe, if the trajectory of anterior odontoid screw is targeted at the apical dens tip. However, if the trajectory of the screw is targeted to the posterior end of dens tip, extension beyond dens tip may lead to damage immediately adjacent to the vental dura mater.

Expression of Aquaporin 1 and 4 in the Choroid Plexus and Brain Parenchyma of Kaolin-Induced Hydrocephalic Rats.

OBJECTIVE: Aquaporin (AQP) is a recently discovered protein that regulates water homeostasis. The present study examines changes in AQP 1 and 4 in kaolin induced experimental hydrocephalic rats to elucidate the pathophysiology of water homeostasis in the disease. METHODS: Hydrocephalus was induced by percutaneous intracisternal injection of kaolin. The brain parenchyma and choroid plexus were obtained at 3, 7, 14 and 30 days after injection. Protein expressions of AQP 1 and 4 were measured by western blot, immunohistochemistry (IHC) and immunofluorescence (IF) stains. RESULTS: In the choroid plexus of the kaolin-induced hydrocephalus group, AQP 1 expression identified by western blot exhibited sharp decrease in the early stage (55% by the 3rd day and 22% by the 7th day), but indicated a 2.2-fold increase in the later stage (30th day) in comparison with control groups. In the parenchyma, a quantitative measurement of AQP 4 expression revealed variable results on the 3rd and 7th days, but indicated expression 2.1 times higher than the control in the later stage (30th day). In addition, the IHC and IF findings supported the patterns of expression of AQP 1 in the choroid plexus and AQP 4 in the parenchyma. CONCLUSION: Expression of AQP 1 decreased sharply in the choroid plexus of acute hydrocephalus rats and increased at later stages. Expression of AQP 4 in the brain parenchyma was variable in the early stage in the hydrocephalus group, but was higher than in the control in the later stage. These findings suggest a compensating role of AQPs in water physiology in hydrocephalus.

Chemical Vapor Deposition Growth of Large Single-Crystal Mono-, Bi-, Tri-Layer Hexagonal Boron Nitride and Their Interlayer Stacking.

Two-dimensional hexagonal boron nitride (h-BN) is a wide bandgap material which has promising mechanical and optical properties. Here we report the realization of an initial nucleation density of h-BN <1 per mm2 using low-pressure chemical vapor deposition (CVD) on polycrystalline copper. This enabled wafer-scale CVD growth of single-crystal monolayer h-BN with a lateral size up to ∼300 µm, bilayer h-BN with a lateral size up to ∼60 µm, and trilayer h-BN with a lateral size up to ∼35 µm. Based on the large single-crystal monolayer h-BN domain, the sizes of the as-grown bi- and trilayer h-BN grains are 2 orders of magnitude larger than typical h-BN multilayer domains. In addition, we achieved coalesced h-BN films with an average grain size ∼100 µm. Various flake morphologies and their interlayer stacking configurations of bi- and trilayer h-BN domains were studied. Raman signatures of mono- and multilayer h-BN were investigated side by side in the same film. It was found that the Raman peak intensity can be used as a marker for the number of layers.

Traumatic Brain Injury in Children under Age 24 Months: Analysis of Demographic Data, Risk Factors, and Outcomes of Post-traumatic Seizure.

OBJECTIVE: Traumatic brain injury (TBI) in children under age 24 months has characteristic features because the brain at this age is rapidly growing and sutures are opened. Moreover, children this age are completely dependent on their parents. We analyzed the demographic data and risk factors for outcomes in TBI patients in this age group to elucidate their clinical characteristics. METHODS: We retrospectively reviewed the medical records and radiological films of children under 24 months who were admitted to Kyungpook National University Hospital from January 2004 to December 2013 for TBI. Specifically, we analyzed age, cause of injury, initial Glasgow coma scale (GCS) score, radiological diagnosis, seizure, hydrocephalus, subdural hygroma, and Glasgow outcome scale (GOS) score, and we divided outcomes into good (GOS 4-5) or poor (GOS 1-3). We identified the risk factors for post-traumatic seizure (PTS) and outcomes using univariate and multivariate analyses. RESULTS: The total number of patients was 60, 39 males and 21 females. Most common age group was between 0 to 5 months, and the median age was 6 months. Falls were the most common cause of injury (n=29, 48.3%); among them, 15 were falls from household furniture such as beds and chairs. Ten patients (16.7%) developed PTS, nine in one week; thirty-seven patients (61.7%) had skull fractures. Forty-eight patients had initial GCS scores of 13-15, 8 had scores of 12-8, and 4 had scored 3-7. The diagnoses were as follows: 26 acute subdural hematomas, 8 acute epidural hematomas, 7 focal contusional hemorrhages, 13 subdural hygromas, and 4 traumatic intracerebral hematomas larger than 2 cm in diameter. Among them, two patients underwent craniotomy for hematoma removal. Four patients were victims of child abuse, and all of them had PTS. Fifty-five patients improved to good-to-moderate disability. Child abuse, acute subdural hematoma, and subdural hygroma were risk factors for PTS in univariate analyses. Multivariate analysis found that the salient risk factor for a poor outcome was initial GCS on admission. CONCLUSION: The most common cause of traumatic head injury in individuals aged less than 24 months was falls, especially from household furniture. Child abuse, moderate to severe TBI, acute subdural hematoma, and subdural hygroma were risk factors for PTS. Most of the patients recovered with good outcomes, and the risk factor for a poor outcome was initial mental status.

Stereotactic Radiosurgery for Dural Carotid Cavernous Sinus Fistulas.

OBJECTIVE: We reviewed our 7-year experience to assess the efficacy of stereotactic radiosurgery (SRS) for dural carotid cavernous fistulas (DCCFs). We analyzed the clinical outcome, complications, and angiographic results. METHODS: We performed a retrospective analysis of 18 consecutive patients with DCCFs treated by SRS alone using Gamma Knife between 2009 and 2015. Median target volume was 2.6 cm3 (range, 0.6-11.6 cm3), and median radiation dose to the target was 17 Gy (range, 14-19 Gy). Median follow-up period was 30 months (range, 6-65 months). RESULTS: Fifteen patients (83%) achieved total obliteration of the DCCF, and a subtotal obliteration of the DCCF was achieved in 3 patients (17%). Total obliteration rates after SRS were 53% at 1 year and 90% at 2 years. Twelve patients (67%) showed complete recovery from symptoms or signs, and 6 patients (33%) showed incomplete recovery. Improvement rates of neurologic function after SRS were 56% at 1 month, 72% at 3 months, and 94% at 6 months. None of the patients experienced radiation-related complications. A univariate analysis revealed that absence of hypertension (P = 0.025), seizure (P = 0.025), and cortical venous drainage (P = 0.013) were significantly associated with symptoms improvement. CONCLUSIONS: SRS for DCCFs offered a high obliteration rate with low risk of radiation-induced complications. In patients with benign DCCFs that are not amenable to embolization or microsurgery, SRS is a safe and effective treatment for complete obliteration of the arteriovenous shunt and for improving quality of life.

Stereotactic radiosurgery for intracranial dural arteriovenous fistulas: its clinical and angiographic perspectives.

BACKGROUND: To assess the efficacy of stereotactic radiosurgery (SRS) for intracranial dural arteriovenous fistulas (DAVFs), the authors retrospectively reviewed our 7-year experience. We evaluated the obliteration rate, improvement in clinical symptoms, and complications. METHODS: Thirty patients with DAVF underwent SRS using a Gamma Knife between 2009 and 2015. Twenty-three patients were treated with SRS alone, and seven patients underwent SRS for residual or recurrent DAVFs after embolization or surgery. Chemosis, diplopia, and pulsating tinnitus were the most common symptoms. Median target volume was 2.9 cm3 (range, 0.8-13.6 cm3), and median radiation dose to the target was 17 Gy (range, 12-20 Gy). Median follow-up period was 33 months (range, 6-82 months). RESULTS: At the last neuroimaging follow-up, DAVFs were totally obliterated in 23 patients (77%) and subtotally in 7 (23%). At the last clinical follow-up, 21 patients (70%) showed complete recovery, and 9 (30%) showed incomplete recovery in symptoms or signs. None experienced worsening symptoms or signs. Asymptomatic perilesional edema after SRS occurred in one patient (3%). Total obliteration rates after SRS were 43% at 1 year, 79% at 2 years, and 95% at 5 years. Improvement rates of neurological function after SRS were 12% at 1 month, 52% at 2 months, 72% at 3 months, and 96% at 6 months. A multivariate analysis revealed that Borden type 1 (p = 0.019, hazard ratio, 3.254, 95% confidence interval, 1.216-8.707) was significantly associated with symptom improvement. CONCLUSIONS: SRS for intracranial DAVFs provided a high obliteration rate and a relatively low risk of radiation-induced complications. In selected benign cases without cortical venous drainage, SRS is a safe and effective treatment for symptom relief and fistula obliteration, even though the time course of improvement is longer than those of embolization and surgery.

Chronic Subdural Hematoma Preceded by High-Impact Trauma: Does the Intensity of Trauma Influence the Pathogenesis of Traumatic Chronic Subdural Hematoma?

AIM: The purpose of this study was to investigate whether the intensity of trauma influences the pathogenesis of traumatic chronic subdural hematoma (CSDH). MATERIAL AND METHODS: Thirty-one patients treated surgically for traumatic CSDH were divided into high-impact and lowimpact groups according to the intensity of trauma. They were respectively evaluated with respect to clinical and radiological findings at presentation, and the subdural concentrations of interleukin-6 (IL-6), interleukin-8 (IL-8), vascular endothelial growth factor (VEGF), basic fibroblast growth factor, and beta-trace protein (ΒTP) [a highly specific protein in the cerebrospinal fluid (CSF)] related to the pathogenesis of CSDH. If ΒTP (subdural fluid/serum) was > 2, an admixture of CSF to the subdural fluid was indicated. RESULTS: The ΒTP (subdural fluid/serum) was > 2 in all patients with a traumatic CSDH. The mean concentration of subdural ΒTP in the high-impact group was higher than in the low-impact group (6.1 mg/L versus 3.9 mg/L), and the difference was statistically significant (p=0.02). In addition, mean concentrations of IL-6, IL-8 and VEGF were higher in the high-impact group, as compared to the low-impact group, though the differences did not reach statistical significance. CONCLUSION: Trauma may be related to CSF leakage into the subdural space in CSDH, and the intensity of trauma may influence the amount of CSF leakage. Although there is no direct correlation between the amount of CSF leakage and other subdural molecules, the intensity of trauma may be associated with larger concentrations of molecules in traumatic CSDH.