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Objective The incidence of aneurysms coexisting with arteriovenous malformations (AVMs) ranges between 2.7% and 16.7%. The anatomical relationship between AVM and aneurysm is critical in deciding the best management. Methods Between October 1994 and August 2017, gamma knife surgery (GKS) was performed in six patients with AVMs and associated aneurysms. The patients consisted of four men and two women with a mean age of 37.8 years (range, 18−57 years). The mean follow-up was 34.2 months (range, 13−84 months). The mean maximal dose was 35.9 Gy and the mean margin dose to AVM was 18 Gy. Coil embolization was performed in one of the aneurysms prior to GKS. In our study, GKS was performed in six AVM-associated aneurysms. Of the six aneurysms, four were intranidal and two were pedicular. The mean volume of AVMs was 3.6 cm3 (range, 1.6−6.5 cm3). Results The locations of aneurysms are as follows: four on posterior cerebral artery (PCA), one on posterior inferior cerebellar artery (PICA), and one on middle cerebral artery (MCA). Sublocation sites were MCA M3 above, PCA P3 above, and PICA distal. There were no GKS-related complications. Complete obliteration of AVM and aneurysm was documented in all four patients with intranidal aneurysm-associated AVMs. Both the aneurysm and AVM were completely obliterated in the two patients with proximal pedicular aneurysms. Conclusion GKS is a possible treatment for AVM with associated intranidal or pedicular aneurysms located above P3 or M3, etc., in which there is less turbulent flow and jet flow.

Abstract Stacked split-ring resonators (SSRR) arrays exhibiting polarization-sensitive dichroic responses in both visible and near-infrared wavelengths are realized over a centimeter-scale large area. The SSRR arrays are derived from pagoda-like nanorods fabricated from the self-assembly of a lamellae-forming polystyrene-b-poly (methyl methacrylate) copolymer (PS-b-PMMA) confined in cylindrical pores of anodized aluminum oxide (AAO) template. Along the nanorod direction, PS and PMMA nanodomains were alternately stacked with the same distance. Silver crescents and semi-hemispherical covers, which are essential for SSRR with the polarization sensitivity, were obliquely deposited on the single side of the nanorod after removing the AAO template and reactive-ion etching treatment. These sophisticated nanoscale architectures made by bottom-up fabrication can be applied to structural color, optical anti-counterfeiting, and commercial optical components in a large area.

Objective: Cystic tumors are not suitable for gamma knife radiosurgery (GKS) owing to the risks associated with acute radiation effect; moreover, fixation of the Leksell stereotactic frame may cause several complications. GKS that was performed after stereotactic cyst aspiration on the same day is fewer complications from stereotactic frame fixation and allows for GKS by decreasing the cystic tumor size in large cystic tumors. Methods: From March 2012 to July 2014, 4 patients was performed GKS after stereotactic cyst aspiration in the Simultaneous Day. A Leksell stereotactic frame was applied and MRI was used to guide cyst aspiration. The cystic fluid was aspirated and if needed an Ommaya reservoir was implanted. MRI was repeated for GKS and treatment was delivered using the Leksell Gamma Knife Perfexion on the same day. Results: 3 patients were metastatic tumors and one patient was craniopharyngioma. 3patients were implanted Ommaya reservoir. Mean tumor volume before aspiration was 22.3cc and Mean tumor volume after aspiration was 9.7cc. Mean marginal dose was 12.25 Gy(10-15 Gy). All patients improved clinical symptoms associated with mass effect immediately after aspiration. Solid portion of tumor was decreased in 3 patients. No patient suffered from procedure related complications. Conculsion: GKS after stereotactic cyst aspiration on the same day can be considered a safe and effective treatment option in patients with cystic tumors [ABSTRACT FROM AUTHOR]

Objective: Cystic tumors are not suitable for gamma knife radiosurgery (GKS) owing to the risks associated with acute radiation effect; moreover, fixation of the Leksell stereotactic frame may cause several complications. GKS that was performed after stereotactic cyst aspiration on the same day is fewer complications from stereotactic frame fixation and allows for GKS by decreasing the cystic tumor size in large cystic tumors. Methods: From March 2012 to July 2014, 4 patients was performed GKS after stereotactic cyst aspiration in the Simultaneous Day. A Leksell stereotactic frame was applied and MRI was used to guide cyst aspiration. The cystic fluid was aspirated and i f needed an Ommaya reservoir was implanted. MRI was repeated for GKS and treatment was delivered using the Leksell Gamma Knife Perfexion on the same day. Results: 3 patients were metastatic tumors and one patient was craniopharyngioma. 3patients were implanted Ommaya reservoir. Mean tumor volume before aspiration was 22.3cc and Mean tumor volume after aspiration was 9.7cc. Mean marginal dose was 12.25 Gy(10-15 Gy). All patients improved clinical symptoms associated with mass effect immediately after aspiration. Solid portion of tumor was decreased in 3 patients. No patient suffered from procedure related complications. Conculsion: GKS after stereotactic cyst aspiration on the same day can be considered a safe and effective treatment option in patients with cystic tumors [ABSTRACT FROM AUTHOR]

Objective: The goals of radiosurgery include preservation of neurological function and prevention of tumor growth. We document the results of gamma-knife radio-surgery for vestibular schwannoma. Methods: 215 patients underwent stereotactic radiosurgery for an vestibular schwannoma from October, 1994 to December, 2013. 162 of these patients were followed up for radiological and clinical evaluation. As pregamma-knife modality, surgical resection were done in 30 patients, and V-P shunt in 2 patients. Initial symptoms were headache (n=56), dizziness (n=39), tinnitus (n=42). While normal facial function(House-Brackmann grade 1) was present in 120 patients (74%), other patients showed grade 2 function in 19, grade 3 function in 16,and grade 4 function in 5. The Gardner/Robertson scale was used to code hearing function. Male to female ratio was 1:3. Mean tumor volume was 7.0 cm3. Mean dose delivered to the tumor margin was 14.3 Gy, and mean maximal dose was 27 Gy. Results: Mean follow-up duration of 62 months. 87 showed decrease(53.3%) in size, 56 patients(34.6 %)stationary, 3(1.2%) initial decrease follow up increase, 5 (3%) initial increase follow up decrease,and 148 patients(91.3%) were well controlled. Two patients experienced transient facial neuropathy, one transient trigeminal neuropathy and two transient hearing deterioration. After gamma-kniferadiosurgery, ventriculoperitoneal shunt was done in 7 patients. In 16 intracanalicular tumors, 7 showed decrease(43.8 %) in size, 9 patients(56.3 %)stationary. 14 vestibular schwannomas with cyst, 8 showed decrease(57.1 %) in size, 2 patients stationary, 4(28.5 %) increased. Conclusions:Gamma-knife radiosurgery can be used to treat postoperative residual tumors as well as in patients with concomitant medical problems in patients with preserved hearing function. Gammaknife radiosurgery is safe and effective method to treat small, medium sized(less than 3cm in extracanalicular diameter), intracanalicular vestibular schwannoma, associated with low rate of cranial neuropathy. In vestibular schwannomas with cyst, GammaKnife radiosurgery is effective except allmost cystic tumor. [ABSTRACT FROM AUTHOR]

Abstract: Objective: Tremor resulting from damage to midbrain structures is poorly understood and often difficult to treat. The authors report a case of AVM of the brainstem with resultant Rubral tremor which was successfully treated using a stimulating electrode placed in the contralateral ventralis intermedius nucleus (VIM) of the thalamus. Clinical Presentation: A 60-year-old man presented with hemorrhagic lesion of the upper brainstem diagnosed. He received GammaKnife Surgery for AVM, but 5 years later, midbrain tremor was developed. The patient subsequently developed an incapacitating right -extremity tremor refractory to medical treatment. Intervention: The patient underwent implantation of a deep brain stimulator in the VIM with symptomatic and functional improvement. Conclusion: Deep brain stimulation is an effective and safe intervention for tremor of unusual etiology. Electrode placement should be based on an understanding of the structure-function relationships underlying the various and distinct types of tremor. [ABSTRACT FROM AUTHOR]

Objective: The effectiveness of GammaKnife radiosurgery as primary treatment for small to medium sized brain tumors, AVM has been reported. But, the treatment of the multiple brain tumors and AVM, several times surgery is needed and we assessed the Gamma Knife Radiosurgery for multiple brain lesions . Methods: Between October, 1994 and December 2014, 12 patients with multiple brain lesions were treated with Gamma Knife radiosurgery (GKS). 2 patients (16.7 %) had AVM, 2 patients (16.7 %) had germinomas, 6 patients (50..0%) had multiple meningiomas, 1 patients (8.4 %) had meningiomas and pituiatry adenoma, 1 patient (8.4 %) had meningioma and schwannoma. The mean radiosurgical tumor volume was 5.6 ml (range 0.5-36 ml). The mean dose delivered to the lesion center was 25.2 Gy (range 20-45) and to the margin was 14.1 Gy (10-22.5 Gy). Results: All patients underwent serial MRI scanning with a mean duration of imaging follow-up 45 months (range 5-110). Among the 2 AVM patients, two lesions were treated with GammaKnife Surgery. In 1 patient the AVM was disappeared, 1 patient showed partial obliteration and retreated with Gamma Knife Surgery after 84 months. Pre Gamma Knife surgery, 2 germinoma patients (44%) underwent biopsies. And they received treated with GammaKnife surgery and booster radiotherapy. Imaging in 2 patients (32.3 %) demonstrated complete response during mean 56.5 months (range 55-58 months). Among the multiple meningioma patients, all 6 patients the tumor were stationary. Of 1 patient with meningioma and pituiatry tumor, initial she treated meningioma with GammaKnife surgery, but 4 years later, pituitary tumor was developed and retreated with GammaKnife surgery, which showed partial response through follow-up MRI image. In 1 pituiatry tumor and low cranial nerve schwannoma patient, partial response after GammaKnife surgery. Conclusion: Gamma-Knife radiosurgery is safe and effective treatment of multiple brain tumors and AVMs. Especially in cases of multiple AVM or meningioma, pituiatry tumor, schwannomas, silmultaneously treatment showed better results than the surgery. GK provides one time treated an advantage for all multiple brain tumors or AVMs. [ABSTRACT FROM AUTHOR]

Objectives: We assessed motor cortex stimulation for treatment of poststroke pain. Four patients with poststroke pain were studied. In three arm pain patients, we placed electrode grid in the epidural space to determine the best stimulation point for pain relief. In one leg pain patient, the 16-electrode array was implanted in the subdural interhemispheric fissure to treat lowerextremity pain guiding navigator system. In two patients with pain extending from the extremity to the trunk or hip, dual devices were implanted to drive two electrodes. Methods: All patients were male, mean age was 60.6 years(44-78 years). Disease entity was consisted with 1 hemorrhage, 3 infarction patients. Symtom sites was 3 arm pain patients, 1 leg pain patient. Results: All four patients experienced pain reduction (two each with excellent, and fair relief) from motor cortex stimulation. Testing performed with a subdural multiple-electrode grid was helpful in locating the best stimulation point for poststroke leg pain relief. Conclusion: Motor cortex stimulation may be effective for treating intractable poststroke pain. [ABSTRACT FROM AUTHOR]

Objectives: DBS is effective for movement disorder, pain, psychiatric disorders, etc. Sometimes, in Dystonia patient and parkinsonian-dystonia patient developed DBS lead fracture. Methods: We operated over 500 DBS and SCS, MCS operations during last 15 years. Among 6 patients developed DBS lead fractures. Disease entity consisted with 5 parkinsonism patients, 1 dystonia patient. 1) Among 1 parkinsonian 43-year-male patient devloped Rt DBS lead extension line fracture after 4 DBS operation. IPG showed battery was gone. We changed into new IPG and extension line. 2) 56-year-male patient operated STN DBS surgery in other hospital. 2 year later, Rt DBS impetance was bad, we checked radiography of skull and lead extension line fracture was suspected. In operation view, we checked lead extension line fracture and changed into new one. 3) 61-year-female patient operated Gpi- DBS surgery in other hospital. 3 years later, IPG connecting extension line fracture was developed and changed into new extension line. Results: 4) 65-year-male patient operated STN- DBS surgery in other hospital. 3 years later, IPG connecting extension line fracture was developed and changed into new extension line 5) 27-year-male dystonia patient operated Gpi- DBS surgery. 5years later, DBS lead connecting proximal extension line fracture was developed and changed into new extension line 6) 58- year-male Parkinsonism patient operated STN- DBS surgery. 5 years later, DBS lead connecting proximal extension line fracture was developed and changed into new extension line. DBS lead fracture site is 4 IPG connecting extension line, 2 DBS lead connecting proximal extension line. Conclusion: DBS is safe and effective treatment for intractable movement disorder patients. If patient's symptom is aggravated after DBS surgery and should check radiography of skull and, chest but rarely developed lead fracture in dystonia or parkinsonism patients. [ABSTRACT FROM AUTHOR]