The Effect of Epidermal Growth Factor Receptor Mutation on Intracranial Progression-Free Survival of Non-Small Cell Lung Cancer Patients with Brain Metastasis Underwent Gamma Knife Radiosurgery

Background@#The aim of this study was to survey prognostic factors, particularly those focusing on epidermal growth factor receptor (EGFR) mutations, of patients with non-small cell lung cancer (NSCLC) after Gamma Knife Radiosurgery (GKRS) for metastatic brain tumors. @*Methods@#We retrospectively reviewed the medical records of 98 patients with NSCLC who underwent GKRS for brain metastases from August 2010 to July 2017. The primary endpoint was progression-free survival (PFS) of the intracranial disease. We analyzed variables such as age, sex, Karnofsky Performance Status, recursive partitioning analysis (RPA) class, smoking status, primary cancer pathology, EGFR mutations, and time to brain metastases as prognostic factors. @*Results@#The median overall survival (OS) of the patients was 16 months [95% confidence interval (CI), 13-21 months]. Median systemic PFS and intracranial PFS were 9 months (95% CI, 8-11 months) and 11 months (95% CI, 7-14 months), respectively. Kaplan-Meier survival analysis revealed that the patients with EGFR mutations had longer intracranial PFS than those without EGFR mutation (median intracranial PFS: 19 vs. 10 months with p=0.01) while they had no benefits in OS and systemic PFS. Furthermore, the patients harboring adenocarcinoma had longer OS ( p<0.01) and intracranial PFS ( p<0.01) and the patients with lower RPA class had longer OS ( p=0.02) and intracranial PFS ( p=0.03). @*Conclusion@#EGFR mutations, primary cancer pathology, and RPA class may be proposed as prognostic factors for intracranial PFS in NSCLC patients after GKRS for brain metastasis in this study.

Anterior Spinal Artery Syndrome Occurring after One Level Segmental Artery Ligation during Spinal Surgery / 대한신경손상학회지

In treating the ventral pathology of spine, ligating the segmental vessels is sometimes necessary. This may cause spinal cord ischemia, and concerns of neurologic injury have been presented. However, spinal cord ischemic injury after sacrificing segmental vessels during spine surgery is very rare. Reports of this have been scarce in the literature and most of these complications occur after multi-level segmental vessel ligation. Here we report a case of a patient with postoperative anterior spinal artery syndrome, which occurred after ligating one level segmental vessels during spinal surgery for a T8 vertebral pathologic fracture. Despite its rarity, the risk of spinal cord ischemic injury after segmental vessel ligation is certainly present. Surgeons must keep in mind such risk, and surgery should be planned under a careful risk-benefit consideration.

Disappearance of a Distal Shunt Catheter: A Case Report of an Unusual Cause of Shunt Malfunction / 대한신경손상학회지

Shunt malfunction is a common complication in patients who undergo ventriculoperitoneal shunt (VPS) placement for the treatment of hydrocephalus. A plethora of reports regarding shunt malfunctions due to distal catheter migration have been demonstrated in the literature. However, to our knowledge, there have been no reports thus far of shunt malfunctions caused by the complete disappearance of a distal catheter. A 70-year-old man was admitted to our hospital for progressive gait disturbance beginning approximately 5 months ago. He received a VPS for posthemorrhagic hydrocephalus and was doing well over the course of 18 months of follow-up. Since no increase in the size of the ventricle was observed on brain computed tomography taken at the outpatient clinic, we tried to readjust the pressure setting of his programmable shunt valve to relieve his symptoms. Without any progression, we discovered later by chance that the distal shunt catheter was missing. Shunt revision surgery was performed. At the 2-year follow-up, a slight improvement in gait was observed. Although it is very rare, the distal catheter can disappear without any noticeable symptoms. If shunt malfunction is suspected, it is important to check whether the entire shunt system is structurally intact.

Recurrence of Small Cerebral Aneurysms (< 4 mm) Treated Endovascularly Using Target® Nano™ Coils

OBJECTIVE: In our series, endovascular coiling with Target® Nano™ coils (Stryker Neurovascular, Fremont, CA, USA) with diameters of 1 or 1.5 mm exhibited favorable technical feasibility in the treatment of small cerebral aneurysms (< 4 mm). However, little is known about the recurrence of small cerebral aneurysms treated using Target® Nano™ coils. We investigated recurrence following the treatment of small cerebral aneurysms using Target® Nano™ coils. MATERIALS AND METHODS: Between January 2012 and November 2013, 143 patients with 148 small cerebral aneurysms (< 4 mm) were included our study. A total of 135 cerebral aneurysms (91.2%) were unruptured; 45 cerebral aneurysms (30.4%) were treated by endovascular coiling using Target® Nano™ coils. Follow-up radiological images were obtained for 132 cerebral aneurysms (89.2%) over a range of 3 to 58 months (mean, 34.3 months; standard deviation, 14.2). RESULTS: In the group treated with Target® Nano™ coils, radiological outcomes revealed complete occlusion in 33 (73.3%), residual necks in eight (17.8%), and residual sacs in four (8.9%) cases. Follow-up radiological outcomes revealed complete occlusion in 35 (77.8%) and residual necks in four (8.9%) cases that exhibited stable coil masses. In the group that was not treated with Target® Nano™ coils, radiological outcomes revealed complete occlusion in 69 (67%), residual necks in 18 (17.5%), and residual sacs in 16 (15.5%) cases. Follow-up radiological outcomes revealed complete occlusion in 87 (84.5%) and residual necks (5.8%) in six cases that exhibited stable coil masses. No significant differences were observed in the radiological outcomes or follow-up radiological outcomes between the two groups. No recurrences or retreatments occurred in our series. CONCLUSION: Endovascular treatment using Target® Nano™ coils may be a robust treatment option for small cerebral aneurysms (< 4 mm).

Considerations in Treating Neonatal and Infantile Patients with a Retrocerebellar Arachnoid Cyst: in the Perspective of Different CSF Dynamics

Arachnoid cysts found under the age of 1 year are more likely to grow in size, relatively short term follow-up is required. Retrocerebellar location predicts a high risk of hydrocephalus, and the time window until irreversible neuronal damage is often narrow if the arachnoid cyst increases in size and becomes symptomatic. However, when and how to treat a neonatal or infantile patient with a retrocerebellar arachnoid cyst is still a controversial subject. We recently experienced 3 differently treated very young pediatric patients with retrocerebellar arachnoid cysts. One patient was treated two weeks after birth by a cystoperitoneal shunt. This patient showed normal development after the surgery. The other patient was treated by a ventriculoperitoneal shunt and subsequent cystoventriculostomy at the age of 4 months because of his mother's refusal on 14th day after birth. This one showed developmental delay despite of decreasing size of ventricles after the surgery. The last patient was treated with microscopic fenestration, which failed in its initial attempt. A revision operation by cyst excision succeeded and had no problem after the surgery. Therefore, we suggest that early surgical intervention for retrocerebellar arachnoid cyst can be considered. Although there are concerns of long term complications related to shunts, a cystoperitoneal shunt would be a feasible treatment if we consider the minor cerebrospinal fluid pathway which is the dominant cerebrospinal fluid dynamic at this age.

The Interference Phenomenon of Microcatheters in the Jailing Treatment for Internal Carotid Artery Side Wall Aneurysms with an Open Cell Stent System

OBJECTIVE: Excelsior XT-27 (Stryker Neurovascular, Fremont, CA, USA) or Rebar 27 (eV3 Covidien, Irvine, CA, USA) microcatheters have recently been used to overcome the limitations of the Renegade Hi-Flo microcatheter such as interference between two microcatheters (one for stent delivery and the other for cerebral aneurysm coiling) during the jailing technique. We evaluated differences and influential factors related to the interference phenomenon according to these two microcatheters group. MATERIALS AND METHODS: Between June 2011 and September 2013, the jailing technique was applied to 94 internal cerebral artery (ICA) aneurysms. The jailing technique with the Neuroform EZ stent system was performed using Renegade (n = 22), Rebar (n = 35), and XT-27 microcatheters (n = 37). In the Renegade Hi-Flo microcatheter group, the jailing technique was successful in 19/22 patients (86.4%) and interference between the two microcatheters occurred in 6/21 patients (28.6%). In the Rebar and XT-27 microcatheter group, the jailing technique was successful in 71/72 patients (98.6%) and interference between the two microcatheters occurred in 1/72 patients (1.4%). RESULTS: There was a significant difference in the interference between the two delivered microcatheters group (p-value < 0.000) and the carotid siphon angle (p-value: 0.004) in the univariate analysis. In the multiple logistic regression analysis, the Rebar and XT-27 microcatheter group (odds ratio [OD] [95% confidence interval (CI)]; 31.277 [3.138-311.729], p-value: 0.003) and the carotid siphon angle (OD [95%CI]; 0.959 [0.922-0.997], p-value: 0.035) were found to be influential factors in the interference phenomenon. CONCLUSION: The Rebar 27 and XT-27 microcatheters were more successful and exhibited less interference between the two microcatheters than the Renegade Hi-Flo microcatheter.

Intra-arterial Thrombolysis for Central Retinal Artery Occlusion after the Coil Embolization of Paraclinoid Aneurysm

The most common complication of coil embolization for cerebral aneurysms is thrombo-embolic stroke; in rare cases, these strokes, can present with central retinal artery occlusion. At our institution, a 53-year-old woman underwent stent-assisted coiling of the aneurysm. The patient's vision was improved immediately after intra-arterial thrombolysis and had further improved 8 months later. This report describes our experience of a rare case of central retinal artery occlusion after coil embolization that was successfully treated by intra-arterial thrombolysis.

Optimal Treatment Decision for Brain Metastases of Unknown Primary Origin: The Role and Timing of Radiosurgery

BACKGROUND: Up to 15% of all patients with brain metastases have no clearly detected primary site despite intensive evaluation, and this incidence has decreased with the use of improved imaging technology. Radiosurgery has been evaluated as one of the treatment modality for patients with limited brain metastases. In this study, we evaluated the effectiveness of radiosurgery for brain metastases from unknown primary tumors. METHODS: We retrospectively evaluated 540 patients who underwent gamma knife radiosurgery (GKRS) for brain metastases radiologically diagnosed between August 1992 and September 2007 in our institution. First, the brain metastases were grouped into metachronous, synchronous, and precocious presentations according to the timing of diagnosis of the brain metastases. Then, synchronous and precocious brain metastases were further grouped into 1) unknown primary; 2) delayed known primary; and 3) synchronous metastases according to the timing of diagnosis of the primary origin. We analyzed the survival time and time to new brain metastasis in each group. RESULTS: Of the 540 patients, 29 (5.4%) presented precocious or synchronous metastases (34 GKRS procedures for 174 lesions). The primary tumor was not found even after intensive and repeated systemic evaluation in 10 patients (unknown primary, 34.5%); found after 8 months in 3 patients (delayed known primary, 1.2%); and diagnosed at the same time as the brain metastases in 16 patients (synchronous metastasis, 55.2%). No statistically significant differences in survival time and time to new brain metastasis were found among the three groups. CONCLUSION: Identification of a primary tumor before GKRS did not affect the patient outcomes. If other possible differential diagnoses were completely excluded, early GKRS can be an effective treatment option for brain metastases from unknown primary tumor.

A Network Analysis of 15O-H2O PET Reveals Deep Brain Stimulation Effects on Brain Network of Parkinson's Disease

PURPOSE: As Parkinson's disease (PD) can be considered a network abnormality, the effects of deep brain stimulation (DBS) need to be investigated in the aspect of networks. This study aimed to examine how DBS of the bilateral subthalamic nucleus (STN) affects the motor networks of patients with idiopathic PD during motor performance and to show the feasibility of the network analysis using cross-sectional positron emission tomography (PET) images in DBS studies. MATERIALS AND METHODS: We obtained [15O]H2O PET images from ten patients with PD during a sequential finger-to-thumb opposition task and during the resting state, with DBS-On and DBS-Off at STN. To identify the alteration of motor networks in PD and their changes due to STN-DBS, we applied independent component analysis (ICA) to all the cross-sectional PET images. We analysed the strength of each component according to DBS effects, task effects and interaction effects. RESULTS: ICA blindly decomposed components of functionally associated distributed clusters, which were comparable to the results of univariate statistical parametric mapping. ICA further revealed that STN-DBS modifies usage-strengths of components corresponding to the basal ganglia-thalamo-cortical circuits in PD patients by increasing the hypoactive basal ganglia and by suppressing the hyperactive cortical motor areas, ventrolateral thalamus and cerebellum. CONCLUSION: Our results suggest that STN-DBS may affect not only the abnormal local activity, but also alter brain networks in patients with PD. This study also demonstrated the usefulness of ICA for cross-sectional PET data to reveal network modifications due to DBS, which was not observable using the subtraction method.

Transsylvian-Transinsular Approach for Deep-Seated Basal Ganglia Hemorrhage: An Experience at a Single Institution

OBJECTIVE: Treatment of spontaneous intracerebral hemorrhage (ICH) remains controversial. However, an extensive hemorrhage with a poor mental status is suitable for surgical evacuation. Our experience with the transsylvian-transinsular (TS-TI) microsurgical approach for deep-seated basal ganglia (BG) ICH was investigated. MATERIAL AND METHODS: A retrospective review was conducted on 86 patients with BG ICH who underwent an operation at the Department of Neurosurgery of our Hospital from September 2011 to October 2014. Thirteen patients underwent craniotomy and the TS-TI microsurgical approach for hematoma evacuation. Twenty-seven patients underwent conventional craniotomy with the trans-cortical transtemporal (TC-TT) approach, and 46 patients underwent a burrhole operation and hematoma drainage using a frameless stereotaxic device (ST). RESULTS: The average age distribution was similar. The preoperative Glasgow coma scale (GCS) was similar for the TC-TT and TS-TI groups. The pre-operative hematoma levels were higher in the TC-TT (109.4 +/- 48.6 mL) and TS-TI (96.0 +/- 39.0 mL) groups than in the ST group (46.5 +/- 23.5 mL). The hematoma removal rate was 77% in the TC-TT group, 88% in the TS-TI group, and 34% in the ST group. The mean maintenance period of a hematoma catheter was 3.6 days in the ST group. The clinical outcome showed correlation with the preoperative neurological symptoms. CONCLUSION: The TS-TI group was superior to the TC-TT group for evacuation of an intracerebral hematoma.

Reliability of Stereotactic Coordinates of 1.5-Tesla and 3-Tesla MRI in Radiosurgery and Functional Neurosurgery

OBJECTIVE: The aims of this study are to identify interpersonal differences in defining coordinates and to figure out the degree of distortion of the MRI and compare the accuracy between CT, 1.5-tesla (T) and 3.0T MRI. METHODS: We compared coordinates in the CT images defined by 2 neurosurgeons. We also calculated the errors of 1.5T MRI and those of 3.0T. We compared the errors of the 1.5T with those of the 3.0T. In addition, we compared the errors in each sequence and in each axis. RESULTS: The mean difference in the CT images between the two neurosurgeons was 0.48+/-0.22 mm. The mean errors of the 1.5T were 1.55+/-0.48 mm (T1), 0.75+/-0.38 (T2), and 1.07+/-0.57 (FLAIR) and those of the 3.0T were 2.35+/-0.53 (T1), 2.18+/-0.76 (T2), and 2.16+/-0.77 (FLAIR). The smallest mean errors out of all the axes were in the x axis : 0.28-0.34 (1.5T) and 0.31-0.52 (3.0T). The smallest errors out of all the MRI sequences were in the T2 : 0.29-0.58 (1.5T) and 0.31-1.85 (3.0T). CONCLUSION: There was no interpersonal difference in running the Gamma Plan(R) to define coordinates. The errors of the 3.0T were greater than those of the 1.5T, and these errors were not of an acceptable level. The x coordinate error was the smallest and the z coordinate error was the greatest regardless of the MRI sequence. The T2 sequence was the most accurate sequence.

Temozolomide Salvage Chemotherapy for Recurrent Anaplastic Oligodendroglioma and Oligo-Astrocytoma

OBJECTIVE: To evaluate the efficacy of temozolomide (TMZ) chemotherapy for recurrent anaplastic oligodendroglioma (AO) and anaplastic oligoastrocytoma (AOA). METHODS: A multi-center retrospective trial enrolled seventy-two patients with histologically proven AO/AOA who underwent TMZ chemotherapy for their recurrent tumors from 2006 to 2010. TMZ was administered orally (150 to 200 mg/m2/day) for 5 days per 28 days until unacceptable toxicity occurred or tumor progression was observed. RESULTS: TMZ chemotherapy cycles administered was median 5.3 (range, 1-41). The objective response rate was 24% including 8 cases (11%) of complete response and another 23 patients (32%) were remained as stable disease. Severe side effects (> or =grade 3) occurred only in 9 patients (13%). Progression-free survival (PFS) of all patients was a median 8.0 months (95% confidence interval, 6.0-10.0). The time to recurrence of a year or after was a favorable prognostic factor for PFS (p<0.05). Overall survival (OS) was apparently differed by the patient's histology, as AOA patients survived a median OS of 18.0 months while AO patients did not reach median OS at median follow-up of 11.5 months (range 2.7-65 months). Good performance status of Eastern Cooperative Oncology Group 0 and 1 showed prolonged OS (p<0.01). CONCLUSION: For recurrent AO/AOA after surgery followed by radiation therapy, TMZ could be recommended as a salvage therapy at the estimated efficacy equal to procarbazine, lomustine, and vincristine (PCV) chemotherapy at first relapse. For patients previously treated with PCV, TMZ is a favorable therapeutic option as 2nd line salvage chemotherapy with an acceptable toxicity rate.

Factors Related to Outcomes of Subthalamic Deep Brain Stimulation in Parkinson's Disease

OBJECTIVE: Subthalamic nucleus (STN) deep brain stimulation (DBS) is an effective treatment of choice for patients with advanced idiopathic Parkinson's disease (PD) who have motor complication with medication. The objectives of this study are to analyze long-term follow-up data of STN DBS cases and to identify the factors related to outcomes. METHODS: Fifty-two PD patients who underwent STN DBS were followed-up for more than 3 years. The Unified Parkinsons Disease Rating Scale (UPDRS) and other clinical profiles were assessed preoperatively and during follow-up. A linear regression model was used to analyze whether factors predict the results of STN DBS. We divided the study individuals into subgroups according to several factors and compared subgroups. RESULTS: Preoperative activity of daily living (ADL) and the magnitude of preoperative levodopa response were shown to predict the improvement in UPDRS part II without medication, and preoperative ADL and levodopa equivalent dose (LED) were shown to predict the improvement in UPDRS part II with medication. In UPDRS part III with medication, the magnitude of preoperative levodopa response was a predicting factor. CONCLUSION: The intensity of preoperative levodopa response was a strong factor for motor outcome. And preoperative ADL and LED were strong factors for ADL improvement. More vigorous studies should be conducted to elucidate how levodopa-induced motor complications are ameliorated after STN DBS.