Jaechan Park

Chronic subdural hematoma preceded by traumatic subdural hygroma.

Patients with traumatic subdural hygroma (SDG) are at an increased risk of developing chronic subdural hematoma (CSDH). However, the mechanism by which this occurs is still not fully understood. The purpose of this paper is to investigate the clinical characteristics and pathogenesis of CSDH, as well as the relationship between CSDH and SDG. We review the pertinent literature and retrospectively examine a series of cases in which CSDH had been preceded by SDG to understand the natural history and developmental mechanisms of these lesions. We discuss the cases of 24 patients in whom CSDH developed from traumatic SDG between 2001 and 2005. Headache was the most common symptom, and the mean Glasgow Coma Scale score was 14.1. Increases in SDG volume were observed in CT scans of 17 patients, and increased density and volume was observed in five patients. The mean interval between the two diseases was 57.6 days, and 13 patients developed new symptoms after the development of CSDH. The most common symptoms at that time were headache and hemiparesis. All patients underwent an operation, which resulted in good recovery in all but one case. The cycle of persistent SDG, rebleeding, coagulation and fibrinolysis contributes to the development of CSDH from SDG. It is important to understand the natural history of CSDH and carefully follow up patients with head injury, especially if it is associated with SDG, and the potential for the development of CSDH should be considered.

Switching Strategy for Mechanical Thrombectomy of Acute Large Vessel Occlusion in the Anterior Circulation

Background and Purpose— We introduce the concept of a switching strategy for mechanical thrombectomy with period-to-period analysis. In period 1, forced arterial suction thrombectomy with a Penumbra reperfusion catheter was performed, even in difficult cases; in period 2, forced arterial suction thrombectomy was initially performed, with switching to Solitaire in difficult cases. Methods— We analyzed 135 consecutive patients treated with mechanical thrombectomy with acute large vessel occlusion in the anterior circulation, 61 from period 1 and 74 from period 2. We defined difficult case for both periods as ≥3 failed attempts at recanalization. Results— Period 2 showed a trend for better angiographic outcome of Thrombolysis in Cerebral Infarction 2b-3 (73.8%, period 1 versus 85.1%, period 2; P=0.10). In interperiod subgroup analysis of difficult cases, switching significantly outperformed nonswitching in Thrombolysis in Cerebral Infarction 2b-3 recanalization (52.7% versus 82.9%; P=0.030). Differences in puncture-to-recanalization time, symptomatic intracranial hemorrhage incidence, and procedure-related complications were not statistically significant. Conclusions— A switching strategy using 2 mechanical thrombectomy techniques (forced arterial suction thrombectomy to Solitaire) may harbor better angiographic outcomes than a 1 technique only strategy (forced arterial suction thrombectomy).

The retrogasserian zone versus dorsal root entry zone: comparison of two targeting techniques of gamma knife radiosurgery for trigeminal neuralgia

BackgroundWe performed a comparative study of the retrogasserian zone (RGZ) with the dorsal root entry zone (DREZ) target to determine effective gamma knife radiosurgery (GKRS) technique in patients with medically refractory trigeminal neuralgia (TN).MethodsWe retrospectively reviewed the records of 39 patients with refractory TN undergoing GKRS between April 2005 and October 2008. Until October 2007, DREZ was used as the primary target point. Since November 2007, RGZ has been targeted, located anterior to DREZ. The pain outcome of patient, pain recurrence, and treatment-related complications were evaluated.FindingsUsing the Barrow Neurologic Index (BNI) pain score, 15 (93.8%) RGZ and 20 (87.0%) DREZ cases achieved treatment success (BNI pain score I–IIIb) (pu2009=u20090.631). Seven (43.8%) RGZ and four (17.4%) DREZ patients reported complete pain relief without medications (BNI pain score I). The time to a response after the GKRS was significantly shorter in the RGZ group (mean 4.1xa0weeks) than in the DREZ group (mean 6.4xa0weeks) (pu2009=u20090.044). The total complication rate (25.0%) in the RGZ group was similar to the DREZ group (26.1%); however, frequency of bothersome facial numbness and dry eye syndrome was lower in the RGZ group (0%, 0%) compared to the DREZ group (13.1%, 8.7%) (pu2009=u20090.255 and 0.503).ConclusionsThe RGZ targeting technique in the GKRS for TN had a better treatment success, with fewer bothersome complications compared to the DREZ target.

Gamma knife radiosurgery for multiple brain metastases from lung cancer

The aim of this study was to compare the effectiveness of gamma knife radiosurgery (GKS) for the treatment of multiple brain metastases from lung cancer with that of whole brain radiation therapy (WBRT). Patients with multiple (2-20) brain metastases were divided into two groups for initial brain tumor management: a GKS group (14 patients) and a WBRT group (19 patients). The patients were stratified by gender, age, initial Karnofsky performance status score, control of the primary site, known extracranial metastases, number of brain metastases, diameter of the maximal lesion, chemotherapy, and recursive partitioning analysis (RPA) Class. The 6-month and 1-year overall survival rates were 64.3% and 47.7%, respectively, in the GKS group, and 42.1% and 10.5%, respectively, in the WBRT group. The median survival time was 32 weeks in the GKS group and 24 weeks in the WBRT group. The overall survival time in the GKS group was significantly longer than in the WBRT group (p=0.04). The univariate analysis suggests that survival was increased in both patients with a controlled primary tumor site and in the GKS group (p=0.03, 0.04). The use of GKS in patients with multiple brain metastases significantly improved patient survival compared to the employment of WBRT. When we assessed the subgroups, systemic disease control and GKS were significant variables by univariate analysis.

Accuracy and Safety of Bedside External Ventricular Drain Placement at Two Different Cranial Sites : Kocher's Point versus Forehead.

OBJECTIVEnExternal ventricular drain (EVD) is commonly performed with a freehand technique using surface anatomical landmarks at two different cranial sites, Kochers point and the forehead. The aim of this study was to evaluate and compare the accuracy and safety of these percutaneous ventriculostomies.nnnMETHODSnA retrospectively review of medical records and head computed tomography scans were examined in 227 patients who underwent 250 freehand pass ventriculostomy catheter placements using two different methods at two institutions, between 2003 and 2009. Eighty-one patients underwent 101 ventriculostomies using Kochers point (group 1), whereas 146 patients underwent 149 forehead ventriculostomies (group 2).nnnRESULTSnIn group 1, the catheter tip was optimally placed in either the ipsilateral frontal horn or the third ventricle, through the foramen of Monro (grade 1) in 82 (81.1%) procedures, in the contralateral lateral ventricle (grade 2) in 4 (3.9%), and into eloquent structures or non-target cerebrospinal space (grade 3) in 15 (14.8%). Intracerebral hemorrhage (ICH) >1 mL developed in 5 (5.0%) procedures. Significantly higher incidences of optimal catheter placements were observed in group 2. ICH>1 mL developed in 11 (7.4%) procedures in group 2, showing no significant difference between groups. In addition, the mean interval from the EVD to ventriculoperitoneal shunt was shorter in group 2 than in group 1, and the incidence of EVD-related infection was decreased in group 2.nnnCONCLUSIONnAccurate and safe ventriculostomies were achieved using both cranial sites, Kochers point and the forehead. However, the forehead ventriculostomies provided more accurate ventricular punctures.

Thromboembolic Events after Coil Embolization of Cerebral Aneurysms : Prospective Study with Diffusion-Weighted Magnetic Resonance Imaging Follow-up

OBJECTIVEnIn order to assess the incidence of thromboembolic events and their clinical presentations, the present study prospectively examined routine brain magnetic resonance images (MRI) taken within 48 hours after a coil embolization of cerebral aneurysms.nnnMETHODSnFrom January 2006 to January 2008, 163 cases of coil embolization of cerebral aneurysm were performed along with routine brain MRI, including diffusion-weighted magnetic resonance (DW-MR) imaging, within 48 hours after the embolization of the aneurysm to detect the silent thromboembolic events regardless of any neurological changes. If any neurological changes were observed, an immediate brain MRI follow-up was performed. High-signal-intensity lesions in the DW-MR images were considered as acute thromboembolic events and the number and locations of the lesions were also recorded.nnnRESULTSnAmong the 163 coil embolization cases, 98 (60.1%) showed high-signal intensities in the DW-MR imaging follow-up, 66 cases (67.0%) involved the eloquent area and only 6 cases (6.0%) showed focal neurological symptoms correlated to the DW-MR findings. The incidence of DW-MR lesions was higher in older patients (>/=60 yrs) when compared to younger patients (<60 yrs) (p=0.002, odds ratio=1.043). The older patients also showed a higher incidence of abnormal DW-MR signals in aneurysm-unrelated lesions (p=0.0003, odds ratio=5.078).nnnCONCLUSIONnThe incidence of symptomatic thromboembolic attacks after coil embolization of the cerebral aneurysm was found to be lower than that reported in previous studies. While DW-MR imaging revealed a higher number of thromboembolic events, most of these were clinically silent and transient and showed favorable clinical outcomes. However, the incidence of DW-MR abnormalities was higher in older patients, along with unpredictable thromboembolic events on DW-MR images. Thus, in order to provide adequate and timely treatment and to minimize neurological sequelae, a routine DW-MR follow-up after coil embolization of cerebral aneurysms might be helpful, especially in older patients.

Risk of Shunt Dependent Hydrocephalus after Treatment of Ruptured Intracranial Aneurysms : Surgical Clipping versus Endovascular Coiling According to Fisher Grading System.

OBJECTIVEnThe amount of hemorrhage observed on a brain computed tomography scan, or a patients Fisher grade (FG), is a powerful risk factor for development of shunt dependent hydrocephlaus (SDHC). However, the influence of treatment modality (clipping versus coiling) on the rate of SDHC development has not been thoroughly investigated. Therefore, we compared the risk of SDHC in both treatment groups according to the amount of subarachnoid hemorrhage (SAH).nnnMETHODSnWe retrospectively reviewed 839 patients with aneurysmal SAH for a 5-year-period. Incidence of chronic SDHC was analyzed using each treatment modality according to the FG system. In addition, other well known risk factors for SDHC were also evaluated.nnnRESULTSnAccording to our data, Hunt-Hess grade, FG, acute hydrocephalus, and intraventricular hemorrhage were significant risk factors for development of chronic SDHC. Coiling group showed lower incidence of SDHC in FG 2 patients, and clipping groups revealed a significantly lower rate in FG 4 patients.nnnCONCLUSIONnBased on our data, treatment modality might have an influence on the incidence of SDHC. In FG 4 patients, the clipping group showed lower incidence of SDHC, and the coiling group showed lower incidence in FG 2 patients. We suggest that these findings could be a considerable factor when deciding on a treatment modality for aneurysmal SAH patients, particularly when the ruptured aneurysm can be occluded by either clipping or coiling.

Fibrinogen and D-dimer analysis of chronic subdural hematomas and computed tomography findings: a prospective study.

OBJECTIVEnWe investigated the relationship between fibrinolytic factors and computed tomography (CT) findings in patients with chronic subdural hematomas (CSDHs).nnnMETHODSnThirty-one patients with CSDHs were divided on the basis of CT findings into heterogeneous and homogeneous groups. A sample from the subdural hematoma was obtained at surgery to measure the concentrations of fibrinogen and D-dimer.nnnRESULTSnThe mean level of fibrinogen in the heterogeneous group, including the layering (n=4) and mixed (n=10) type, was 88.2±121.2 mg/dL, whereas in the homogeneous group, including high density (n=2), isodensity (n=9), and low density (n=6) types, it was <25 mg/dL. The concentration of fibrinogen was significantly higher in the heterogeneous group than in the homogeneous group (p=0.006). The mean level of D-dimer in the heterogeneous group was 35,407.9±16,325.5 μg/L, whereas for the homogeneous group it was 1476.4±2091.4 μg/L. The concentration of D-dimer was significantly higher in the heterogeneous group than in the homogeneous group (p<0.001).nnnCONCLUSIONSnThe layering and mixed types of CSDH exhibited higher concentrations of fibrinogen and D-dimer in subdural hematoma than the homogeneous types. These fibrinolytic factors appear to be associated with evolution in CSDHs with heterogeneous density.

Efficacy of Proximal Aspiration Thrombectomy for Using Balloon-Tipped Guide Catheter in Acute Intracranial Internal Carotid Artery Occlusion.

Objective Mechanical thrombectomy (MT) for acute intracranial internal carotid artery (ICA) occlusion is often complicated by difficult revascularization and non-involved territory embolization possibly related with larger clot-burden. This study aims to evaluate the efficacy of proximal aspiration thrombectomy (PAT) using a balloon-tipped guide catheter for clot-burden reduction in such cases with period-to-period analysis (period 1 : standard MT without PAT; period 2 : PAT first, then standard MT for the remaining occlusion). Methods Eighty-six patients who underwent MT for acute intracranial ICA occlusion were included in this analysis from the prospectively maintained stroke registry (33 patients in period 1 and 53 in period 2). In period 2, responder was defined as a case where some amount of clot was retrieved by PAT and the following angiography showed partial or full recanalization. Results Fifteen of fifty-three patients in period 2 (28.3%) were responders to PAT. There was a significantly higher incidence of atrial fibrillation in the responder subgroup. Period 2 showed a significantly shorter puncture-to-reperfusion time (94.5 minutes vs. 56.0 minutes; p=0.002), a significantly higher Thrombolysis in Cerebral Infarction of 2b-3 reperfusion (45.5% vs. 73.6%; p=0.009), but only a trend for better 3-month favorable outcome (mRS 0–2; 36.4% vs. 54.7%; p=0.097). There was no increase in the incidence of procedure-related complications or intracranial hemorrhage in period 2. Conclusion A strategy of PAT before standard MT may result in shorter puncture-to-reperfusion time and better angiographic outcome than a strategy of standard MT for acute intracranial ICA occlusion.

Inadvertent Self-Detachment of Solitaire AB Stent during the Mechanical Thrombectomy for Recanalization of Acute Ischemic Stroke: Lessons Learned from the Removal of Stent via Surgical Embolectomy.

We recently experienced self-detachment of the Solitaire stent during mechanical thrombectomy of acute ischemic stroke. Then, we tried to remove the detached stent and to recanalize the occlusion, but failed with endovascular means. The following diffusion weighted image MRI revealed no significant increase in infarction size, therefore, we performed surgical removal of the stent to rescue the patient and to elucidate the reason why the self-detachment occurred. Based upon the operative findings, the stent grabbed the main thrombi but inadvertently detached at a severely tortuous, acutely angled, and circumferentially calcified segment of the internal carotid artery. Postoperative angiography demonstrated complete recanalization of the internal carotid artery. The patients neurological deficits gradually improved, and the modified Rankin scale score was 2 at three months after surgery. In the retrospective case review, bone window images of the baseline computed tomography (CT) scan corresponded to the operative findings. According to this finding, we hypothesized that bone window images of a baseline CT scan can play a role in terms of anticipating difficult stent retrieval before the procedure.