Radiosurgery for Cerebral Arteriovenous Malformation (AVM) : Current Treatment Strategy and Radiosurgical Technique for Large Cerebral AVM

Arteriovenous malformations (AVMs) are congenital anomalies of the cerebrovascular system. AVM harbors 2.2% annual hemorrhage risk in unruptured cases and 4.5% annual hemorrhage risk of previously ruptured cases. Stereotactic radiosurgery (SRS) have been shown excellent treatment outcomes for patients with small- to moderated sized AVM which can be achieved in 80–90% complete obliteration rate with a 2–3 years latency period. The most important factors are associated with obliteration after SRS is the radiation dose to the AVM. In our institutional clinical practice, now 22 Gy (50% isodose line) dose of radiation has been used for treatment of cerebral AVM in single-session radiosurgery. However, dose-volume relationship can be unfavorable for large AVMs when treated in a single-session radiosurgery, resulting high complication rates for effective dose. Thus, various strategies should be considered to treat large AVM. The role of pre-SRS embolization is permanent volume reduction of the nidus and treat high-risk lesion such as AVM-related aneurysm and high-flow arteriovenous shunt. Various staging technique of radiosurgery including volume-staged radiosurgery, hypofractionated radiotherapy and dose-staged radiosurgery are possible option for large AVM. The incidence of post-radiosurgery complication is varied, the incidence rate of radiological post-radiosurgical complication has been reported 30–40% and symptomatic complication rate was reported from 8.1% to 11.8%. In the future, novel therapy which incorporate endovascular treatment using liquid embolic material and new radiosurgical technique such as gene or cytokine-targeted radio-sensitization should be needed.

Short-term Effect of Gamma Knife Radiosurgery for a Choroidal Tumor

Purpose@#To evaluate the effectiveness and safety of treating choroidal melanoma and cancer that has metastasized to the choroid with gamma knife radiosurgery (GKR). @*Methods@#We performed a retrospective chart review that included 10 eyes of eight patients with a diagnosis of choroidal tumors who underwent GKR between January 2016 and February 2019 and who had at least one month follow-up visit. @*Results@#The mean patient age was 57.9 ± 14.6 years (range, 32-83 years). The choroidal tumor group included six choroidal metastases and four choroidal melanomas. The mean follow-up period after GKR was 7.0 ± 4.3 months (range, 2-13 months). The mean cumulative marginal dose was 25.36 ± 7.35 Gy (range, 16-45 Gy). Pre- and postoperative magnetic resonance imaging revealed a reduction in tumor volume in eight of the 10 eyes and five of them presented with improved visual symptoms. One patient showed increased tumor volume; however, a new choroidal lesion was not observed. Another patient showed no reduction in tumor size; however, the pain had worsened, and the eye was enucleated. The mean maximum tumor diameter decreased from 1.60 ± 0.37 cm before to 1.22 ± 0.47 cm after GKR (p = 0.004), and the mean minimum diameter decreased from 0.62 ± 0.27 cm before to 0.38 ± 0.35 cm after GKR (p = 0.031). No radiation-induced optic neuropathy, retinopathy, or cataracts was observed in any of the cases during the follow-up period. @*Conclusions@#GKR was shown to be safe for choroidal lesions identified in orbital magnetic resonance imaging with a reduction in the size of choroidal tumors and eyeball preservation expected with this treatment approach.

Short-term Effect of Gamma Knife Radiosurgery for a Choroidal Tumor

Purpose@#To evaluate the effectiveness and safety of treating choroidal melanoma and cancer that has metastasized to the choroid with gamma knife radiosurgery (GKR). @*Methods@#We performed a retrospective chart review that included 10 eyes of eight patients with a diagnosis of choroidal tumors who underwent GKR between January 2016 and February 2019 and who had at least one month follow-up visit. @*Results@#The mean patient age was 57.9 ± 14.6 years (range, 32-83 years). The choroidal tumor group included six choroidal metastases and four choroidal melanomas. The mean follow-up period after GKR was 7.0 ± 4.3 months (range, 2-13 months). The mean cumulative marginal dose was 25.36 ± 7.35 Gy (range, 16-45 Gy). Pre- and postoperative magnetic resonance imaging revealed a reduction in tumor volume in eight of the 10 eyes and five of them presented with improved visual symptoms. One patient showed increased tumor volume; however, a new choroidal lesion was not observed. Another patient showed no reduction in tumor size; however, the pain had worsened, and the eye was enucleated. The mean maximum tumor diameter decreased from 1.60 ± 0.37 cm before to 1.22 ± 0.47 cm after GKR (p = 0.004), and the mean minimum diameter decreased from 0.62 ± 0.27 cm before to 0.38 ± 0.35 cm after GKR (p = 0.031). No radiation-induced optic neuropathy, retinopathy, or cataracts was observed in any of the cases during the follow-up period. @*Conclusions@#GKR was shown to be safe for choroidal lesions identified in orbital magnetic resonance imaging with a reduction in the size of choroidal tumors and eyeball preservation expected with this treatment approach.

Cyberknife Dosimetric Planning Using a Dose-Limiting Shell Method for Brain Metastases

OBJECTIVE: We investigated the effect of optimization in dose-limiting shell method on the dosimetric quality of CyberKnife (CK) plans in treating brain metastases (BMs). METHODS: We selected 19 BMs previously treated using CK between 2014 and 2015. The original CK plans (CKoriginal) had been produced using 1 to 3 dose-limiting shells : one at the prescription isodose level (PIDL) for dose conformity and the others at lowisodose levels (10–30% of prescription dose) for dose spillage. In each case, a modified CK plan (CKmodified) was generated using 5 dose-limiting shells : one at the PIDL, another at intermediate isodose level (50% of prescription dose) for steeper dose fall-off, and the others at low-isodose levels, with an optimized shell-dilation size based on our experience. A Gamma Knife (GK) plan was also produced using the original contour set. Thus, three data sets of dosimetric parameters were generated and compared. RESULTS: There were no differences in the conformity indices among the CKoriginal, CKmodified, and GK plans (mean 1.22, 1.18, and 1.24, respectively; p=0.079) and tumor coverage (mean 99.5%, 99.5%, and 99.4%, respectively; p=0.177), whereas the CKmodified plans produced significantly smaller normal tissue volumes receiving 50% of prescription dose than those produced by the CKoriginal plans (p < 0.001), with no statistical differences in those volumes compared with GK plans (p=0.345). CONCLUSION: These results indicate that significantly steeper dose fall-off is able to be achieved in the CK system by optimizing the shell function while maintaining high conformity of dose to tumor.

Gamma Knife Radiosurgery for Metastatic Brain Tumors with Exophytic Hemorrhage

OBJECTIVE: Metastatic brain tumors (MBTs) often present with intracerebral hemorrhage. Although Gamma Knife surgery (GKS) is a valid treatment option for hemorrhagic MBTs, its efficacy is unclear. To achieve oncologic control and reduce radiation toxicity, we used a radiosurgical targeting technique that confines the tumor core within the hematoma when performing GKS in patients with such tumors. We reviewed our experience in this endeavor, focusing on local tumor control and treatment-associated morbidities. METHODS: From 2007 to 2014, 13 patients with hemorrhagic MBTs were treated via GKS using our targeting technique. The median marginal dose prescribed was 23 Gy (range, 20–25). GKS was performed approximately 2 weeks after tumor bleeding to allow the patient’s condition to stabilize. RESULTS: The primary sites of the MBTs included the liver (n=7), lung (n=2), kidney (n=1), and stomach (n=1); in two cases, the primary tumor was a melanoma. The mean tumor volume was 4.00 cm³ (range, 0.74–11.0). The mean overall survival duration after GKS was 12.5 months (range, 3–29), and three patients are still alive at the time of the review. The local tumor control rate was 92% (tumor disappearance 23%, tumor regression 46%, and stable disease 23%). There was one (8%) instance of local recurrence, which occurred 11 months after GKS in the solid portion of the tumor. No GKS-related complications were observed. CONCLUSION: Our experience shows that GKS performed in conjunction with our targeting technique safely and effectively treats hemorrhagic MBTs. The success of this technique may reflect the presence of scattered metastatic tumor cells in the hematoma that do not proliferate owing to the inadequate microenvironment of the hematoma. We suggest that GKS can be a useful treatment option for patients with hemorrhagic MBTs that are not amenable to surgery.

Cyberknife Dosimetric Planning Using a Dose-Limiting Shell Method for Brain Metastases

OBJECTIVE: We investigated the effect of optimization in dose-limiting shell method on the dosimetric quality of CyberKnife (CK) plans in treating brain metastases (BMs).METHODS: We selected 19 BMs previously treated using CK between 2014 and 2015. The original CK plans (CKoriginal) had been produced using 1 to 3 dose-limiting shells : one at the prescription isodose level (PIDL) for dose conformity and the others at lowisodose levels (10–30% of prescription dose) for dose spillage. In each case, a modified CK plan (CKmodified) was generated using 5 dose-limiting shells : one at the PIDL, another at intermediate isodose level (50% of prescription dose) for steeper dose fall-off, and the others at low-isodose levels, with an optimized shell-dilation size based on our experience. A Gamma Knife (GK) plan was also produced using the original contour set. Thus, three data sets of dosimetric parameters were generated and compared.RESULTS: There were no differences in the conformity indices among the CKoriginal, CKmodified, and GK plans (mean 1.22, 1.18, and 1.24, respectively; p=0.079) and tumor coverage (mean 99.5%, 99.5%, and 99.4%, respectively; p=0.177), whereas the CKmodified plans produced significantly smaller normal tissue volumes receiving 50% of prescription dose than those produced by the CKoriginal plans (p < 0.001), with no statistical differences in those volumes compared with GK plans (p=0.345).CONCLUSION: These results indicate that significantly steeper dose fall-off is able to be achieved in the CK system by optimizing the shell function while maintaining high conformity of dose to tumor.

Gamma Knife Radiosurgery for Metastatic Brain Tumors with Exophytic Hemorrhage

OBJECTIVE: Metastatic brain tumors (MBTs) often present with intracerebral hemorrhage. Although Gamma Knife surgery (GKS) is a valid treatment option for hemorrhagic MBTs, its efficacy is unclear. To achieve oncologic control and reduce radiation toxicity, we used a radiosurgical targeting technique that confines the tumor core within the hematoma when performing GKS in patients with such tumors. We reviewed our experience in this endeavor, focusing on local tumor control and treatment-associated morbidities.METHODS: From 2007 to 2014, 13 patients with hemorrhagic MBTs were treated via GKS using our targeting technique. The median marginal dose prescribed was 23 Gy (range, 20–25). GKS was performed approximately 2 weeks after tumor bleeding to allow the patient’s condition to stabilize.RESULTS: The primary sites of the MBTs included the liver (n=7), lung (n=2), kidney (n=1), and stomach (n=1); in two cases, the primary tumor was a melanoma. The mean tumor volume was 4.00 cm³ (range, 0.74–11.0). The mean overall survival duration after GKS was 12.5 months (range, 3–29), and three patients are still alive at the time of the review. The local tumor control rate was 92% (tumor disappearance 23%, tumor regression 46%, and stable disease 23%). There was one (8%) instance of local recurrence, which occurred 11 months after GKS in the solid portion of the tumor. No GKS-related complications were observed.CONCLUSION: Our experience shows that GKS performed in conjunction with our targeting technique safely and effectively treats hemorrhagic MBTs. The success of this technique may reflect the presence of scattered metastatic tumor cells in the hematoma that do not proliferate owing to the inadequate microenvironment of the hematoma. We suggest that GKS can be a useful treatment option for patients with hemorrhagic MBTs that are not amenable to surgery.

Clinical Outcomes of Gamma Knife Radiosurgery for Metastatic Brain Tumors from Gynecologic Cancer : Prognostic Factors in Local Treatment Failure and Survival

OBJECTIVE: Brain metastases in gynecologic cancer (ovarian, endometrial, and cervical cancer) patients are rare, and the efficacy of Gamma Knife Radiosurgery (GKRS) to treat these had not been evaluated. We assessed the efficacy of GKRS and prognostic factors for tumor control and survival in brain metastasis from gynecologic cancers. METHODS: This retrospective study was approved by the institutional review board. From May 1995 to October 2012, 26 women (mean age 51.3 years, range 27-70 years) with metastatic brain tumors from gynecologic cancer were treated with GKRS. We reviewed their outcomes, radiological responses, and clinical status. RESULTS: In total 24 patients (59 lesions) were available for follow-up imaging. The median follow-up time was 9 months. The mean treated tumor volume at the time of GKRS was 8185 mm³ (range 10-19500 mm³), and the median dose delivered to the tumor margin was 25 Gy (range, 10-30 Gy). A local tumor control rate was 89.8% (53 of 59 tumors). The median overall survival was 9.5 months after GKRS (range, 1-102 months). Age-associated multivariate analysis indicated that the Karnofsky performance status (KPS), the recursive partitioning analysis (RPA) classification, and the number of treated lesions were significant prognostic factors for overall survival (HR=0.162, p=0.008, HR=0.107, p=0.038, and HR=2.897, p=0.045, respectively). CONCLUSION: GKRS is safe and effective for the management of brain metastasis from gynecologic cancers. The clinical status of the patient is important in determining the overall survival time.

Characteristics and Treatments of Large Cystic Brain Metastasis: Radiosurgery and Stereotactic Aspiration

Brain metastasis represents one of the most common causes of intracranial tumors in adults, and the incidence of brain metastasis continues to rise due to the increasing survival of cancer patients. Yet, the development of cystic brain metastasis remains a relatively rare occurrence. In this review, we describe the characteristics of cystic brain metastasis and evaluate the combined use of stereotactic aspiration and radiosurgery in treating large cystic brain metastasis. The results of several studies show that stereotactic radiosurgery produces comparable local tumor control and survival rates as other surgery protocols. When the size of the tumor interferes with radiosurgery, stereotactic aspiration of the metastasis should be considered to reduce the target volume as well as decreasing the chance of radiation induced necrosis and providing symptomatic relief from mass effect. The combined use of stereotactic aspiration and radiosurgery has strong implications in improving patient outcomes.

Upfront Stereotactic Radiosurgery for Pineal Parenchymal Tumors in Adults

OBJECTIVE: Pineal parenchymal tumors (PPTs) in adults are rare, and knowledge regarding their optimal management and treatment outcome is limited. Herein, we present the clinical results of our series of PPTs other than pineoblastomas managed by stereotactic radiosurgery (SRS) at upfront setting. METHODS: Between 1997 and 2014, nine consecutive adult patients with the diagnosis of PPTs, either pineocytoma or pineal parenchymal tumor of intermediate differentiation, were treated with SRS. There were 6 men and 3 women. The median age was 39 years (range, 31-53 years). All of the patients presented with symptoms of hydrocephalus. Endoscopic third ventriculostomy and biopsy was done for initial management. After histologic diagnosis, patients were treated with Gamma Knife with the mean dose of 13.3 Gy (n=3) or fractionated Cyberknife with 32 Gy (n=6). RESULTS: After a mean follow-up of 78.6 months (range, 14-223 months), all patients were alive and all of their tumors were locally controlled except for one instance of cerebrospinal fluid seeding metastasis. On magnetic resonance images, tumor size decreased in all patients, resulting in complete response in 3 patients and partial response in 6. One patient had experienced temporary memory impairment after SRS, which improved spontaneously. CONCLUSION: SRS is effective and safe for PPTs in adults and can be considered as a useful alternative to surgical resection at upfront setting.

Growing Organized Hematomas Following Gamma Knife Radiosurgery for Cerebral Arteriovenous Malformation : Five Cases of Surgical Excision

Organized hematoma is a rare complication that can develop following gamma knife radiosurgery (GKS) for cerebral arteriovenous malformation (AVM). Here, we describe 5 patients with growing organized hematomas that developed from completely obliterated AVMs several years after GKS. The patients were 15, 16, 30, 36, and 38 years old at the time of GKS, respectively, and 3 patients were female. Four AVMs were located in the lobe of the brain, and the remaining AVM were in the thalamus. Between 2-12 years after GKS, patients developed progressive symptoms such intractable headache or hemiparesis and enhancing mass lesions were identified. Follow-up visits revealed the slow expansion of the hematomas and surrounding edema. Steroids were ineffective, and thus surgery was performed. Histology revealed organized hematomas with a capsule, but there was no evidence of residual AVMs or vascular malformation. After surgery, the neurological symptoms of all patients improved and the surrounding edema resolved. However, the hematoma continued to expand and intraventricular hemorrhage developed in 1 patient whose hematoma was only partially removed. GKS for cerebral AVM can be complicated by growing, organized hematomas that develop after complete obliteration. Growing hematomas should be surgically evacuated if they are symptomatic. Radical resection of the hematoma capsule is also strongly recommended.

Peritumoral Brain Edema after Stereotactic Radiosurgery for Asymptomatic Intracranial Meningiomas: Risks and Pattern of Evolution

OBJECTIVE: To investigate the risks and pattern of evolution of peritumoral brain edema (PTE) after stereotactic radiosurgery (SRS) for asymptomatic intracranial meningiomas. METHODS: A retrospective study was conducted on 320 patients (median age 56 years, range 24-87 years) who underwent primary Gamma Knife radiosurgery for asymptomatic meningiomas between 1998 and 2012. The median tumor volume was 2.7 cc (range 0.2-10.5 cc) and the median follow-up was 48 months (range 24-168 months). Volumetric data sets for tumors and PTE on serial MRIs were analyzed. The edema index (EI) was defined as the ratio of the volume of PTE including tumor to the tumor volume, and the relative edema indices (rEIs) were calculated from serial EIs normalized against the baseline EI. Risk factors for PTE were analyzed using logistic regression. RESULTS: Newly developed or increased PTE was noted in 49 patients (15.3%), among whom it was symptomatic in 28 patients (8.8%). Tumor volume larger than 4.2 cc (p4.2 cc), of hemispheric location, or with pre-treatment PTE. PTE usually develops within months, reaches its maximum degree until a year, and resolves within 2 years after SRS.

Effects of an Epithelial Growth Factor Receptor-Tyrosine Kinase Inhibitor Add-on in Stereotactic Radiosurgery for Brain Metastases Originating from Non-Small-Cell Lung Cancer

OBJECTIVE: This study was aimed at optimizing the treatment of non-small-cell lung cancer (NSCLC) patients who are candidates for stereotactic radiosurgery (SRS) for brain metastases and harbor activating epithelial growth factor receptor (EGFR) mutations. METHODS: We retrospectively reviewed the medical records from 2005 to 2010 of NSCLC patients with brain metastases harboring an activating EGFR mutation. Patients who received a combination therapy of SRS and EGFR-tyrosine kinase inhibitor (TKI) for brain metastases and those who received SRS without EGFR-TKI were compared. The primary endpoint was progression-free survival (PFS) of the brain metastases. RESULTS: Thirty-one patients were eligible for enrolment in this study (SRS with TKI, 18; SRS without TKI, 13). Twenty-two patients (71.0%) were women and the median overall age was 56.0 years. PFS of brain lesions was not significantly prolonged in SRS with TKI treatment group than in SRS without TKI group (17.0 months vs. 9.0 months, p=0.45). Local tumor control rate was 83.3% in the combination therapy group, and 61.5% in the SRS monotherapy group (p=0.23). There were no severe adverse events related with treatment in both groups. CONCLUSIONS: Therapeutic outcome of concurrent SRS and TKI treatment was not superior to SRS monotherapy, however, there was no additive adverse events related with combined treatment.

Clinical Outcome in Gamma Knife Radiosurgery for Metastatic Brain Tumors from the Primary Breast Cancer : Prognostic Factors in Local Treatment Failure and Survival

OBJECTIVE: Brain metastases in primary breast cancer patients are considerable sources of morbidity and mortality. Gamma knife radiosurgery (GKRS) has gained popularity as an up-front therapy in treating such metastases over traditional radiation therapy due to better neurocognitive function preservation. The aim of this study was to clarify the prognostic factors for local tumor control and survival in radiosurgery for brain metastases from primary breast cancer. METHODS: From March 2001 to May 2011, 124 women with metastatic brain lesions originating from a primary breast cancer underwent GKRS at a tertiary medical center in Seoul, Korea. All patients had radiosurgery as a primary treatment or salvage therapy. We retrospectively reviewed their clinical outcomes and radiological responses. The end point of this study was the date of patient's death or the last follow-up examination. RESULTS: In total, 106 patients (268 lesions) were available for follow-up imaging. The median follow-up time was 7.5 months. The mean treated tumor volume at the time of GKRS was 6273 mm3 (range, 4.5-27745 mm3) and the median dose delivered to the tumor margin was 22 Gy (range, 20-25 Gy). Local recurrence was assessed in 86 patients (216 lesions) and found to have occurred in 36 patients (83 lesions, 38.6%) with a median time of 6 months (range, 4-16 months). A treated tumor volume >5000 mm3 was significantly correlated with poor local tumor control through a multivariate analysis (hazard risk=7.091, p=0.01). Overall survival was 79.9%, 48.3%, and 15.3% at 6, 12, and 24 months, respectively. The median overall survival was 11 months after GKRS (range, 6 days-113 months). Multivariate analysis showed that the pre-GKRS Karnofsky performance status, leptomeningeal seeding prior to initial GKRS, and multiple metastatic lesions were significant prognostic factors for reduced overall survival (hazard risk=1.94, p=0.001, hazard risk=7.13, p<0.001, and hazard risk=1.46, p=0.046, respectively). CONCLUSION: GKRS has shown to be an effective and safe treatment modality for treating brain metastases of primary breast cancer. Most metastatic brain lesions initially respond to GKRS, though, many patients have further CNS progression in subsequent periods. Patients with poor Karnofsky performance status and multiple metastatic lesions are at risk of CNS progression and poor survival, and a more frequent and strict surveillance protocol is suggested in such high-risk groups.

Endovascular and Microsurgical Treatment of Superior Cerebellar Artery Aneurysms

OBJECTIVE: Superior cerebellar artery (SCA) aneurysms are regarded as being as difficult to treat surgically as posterior circulation aneurysms. We describe here a series of 33 of these aneurysms treated with microsurgery or embolization. METHODS: Between June 1997 and August 2007, 33 patients (9 men, 24 women; age, 29 to 76 years) with SCA aneurysms underwent microsurgical (n = 12) or endovascular (n = 21) treatment. Twenty two patients presented with subarachnoid hemorrhage. Thirty aneurysms were located in the junction between the SCA and the basilar artery (BA), two in the proximal SCA (S1) and one in the distal SCA (S2-3). RESULTS: Of the 29 SCA aneurysms, located in the junction between the SCA and BA, which were available on conventional angiography, 20 were lateral-superior, six lateral-horizontal, two lateral inferior, and one posterior type. Of the 12 patients treated microsurgically, eight had clinically excellent or good outcomes. Causes of poor outcomes included initial poor clinical status (n = 2), infarction due to parent artery compromise (n = 1), and artery of Heubner injury due to surgery for a coexisting anterior communicating artery aneurysm (n = 1). Of the 21 patients treated endovascularly, 17 had clinical good or excellent outcomes. Causes of clinically poor outcomes included initial poor clinical status (n = 2) and infarction due to thrombosis of exposed coil mesh (n = 1). One patient underwent embolization resulted in death due to vasospasm. Three patients required additional embolization for coil compaction. CONCLUSION: There was no morbidity related to perforator injury, regardless of the treatment modality. Embolization or microsurgery is an effective modality, with relatively low procedural morbidity and mortality rates.

Association of the Neuronal Cell Adhesion Molecule (NrCAM) Gene Variants with Personality Traits and Addictive Symptoms in Methamphetamine Use Disorder

OBJECTIVE: 1) To investigate the relationship between NrCAM polymorphisms and methamphetamine abuse in an ethnically homogenous Korean population. 2) To further support our findings by investigating the association among NrCAM gene variants, certain personality traits, and addictive symptoms of methamphetamine abusers. METHODS: Thirty-seven male methamphetamine abusers (age=43.3+/-7.8) and30 non-users (16 men, 14 women; age=59.8+/-10.4) were recruited. Ten single nucleotide polymorphisms (SNPs) in the NrCAM gene were assayed to compare genotype distributions between the 2 groups. Personality characteristics were measured using the Temperament and Character Inventory (TCI) and the NEO Personality Inventory, Revised (NEO PI-R). Addictive symptoms were assessed using the Diagnostic Interview for Genetic Studies (DIGS) and reviews of the subject's medical records. RESULTS: Among the 10 SNPs in the NrCAM gene, the frequency of the TA genotype at rs1990162 was significantly lower in methamphetamine abusers compared to non-users (p=0.042). In the 3 NrCAM gene SNPs (rs381318, rs2072546, and rs6954366), the distribution of genotypes and alleles were significantly associated with some traits in the TCI and NEO PI-R. Genotypes and alleles at 5 gene SNPs (rs2142325, rs381318, rs1269621, rs1269634, and rs1990162) were associated with certain addictive symptom dimensions in the patients. CONCLUSION: These findings support the idea that NrCAM is associated with genetic susceptibility of methamphetamine abuse and is also associated with certain personality characteristics that may increase disturbed addictive behavior.

Surgical Treatment of Unruptured Intracranial Middle Cerebral Artery Aneurysms: Angiographic and Clinical Outcomes in 143 Aneurysms

OBJECTIVE: The purpose of this study was to determine the outcomes of surgical clipping in patients with unruptured middle cerebral artery (MCA) aneurysms. METHODS: A retrospective single-center database of 125 consecutive patients with 143 small MCA aneurysms (< 10 mm) who underwent surgical clipping was reviewed from January 2007 to December 2010. Clinical outcomes were assessed based on surgery-related complications and follow-up (mean: 17 months) using the modified Rankin scale (mRS). Angiographic outcomes were evaluated by conventional angiography (N = 96) or computed tomography angiography (N = 29) at postoperative weeks 1 and 6. RESULTS: There were no cases of mortality. There were three surgery-related complications (intracranial hemorrhage, meningitis and wound infection, respectively). The hemorrhagic event caused transient neurological deficits. All patients showed good clinical outcomes during follow-up (mRS 0-1). There was angiographic evidence of complete occlusion in 137 aneurysms (95.8%), a small residual neck in three aneurysms (2.2%) and partial for three aneurysms. In the three cases with partial clipping, the decision was made preoperatively to leave the residual sac to maintain distal flow, and muscular wrapping was performed. CONCLUSION: Our study demonstrates that surgical clipping of unruptured small MCA aneurysms yields favorable clinical and angiographic outcomes. Aneurysmal clipping can be safely recommended for patients with small unruptured MCA aneurysms.

Technical Pitfalls in the Endovascular Treatment of Traumatic Pseudoaneurysm of the Internal Carotid Artery: Case Report / 대한뇌혈관외과학회지

A posttraumatic pseudoaneurysm of the internal carotid artery (ICA) is a rare cause of massive epistaxis, and this can be fatal. Treating a ruptured traumatic pseudoaneurysm of the cavernous ICA is challenging as the treated patient has the same risk profile as an untreated patient if the procedure results in only incomplete occlusion. For this reason, additional procedures need to be performed for these cases. The present report describes two cases of a traumatic ICA pseudoaneurysm that was only partially occluded by endovascular balloon placement because an external carotid-ophthalmic artery anastomosis was not detected. The patients were immediately and successfully treated by performing surgical clipping of the ICA.

Direct Carotid Cavernous Fistula of an Adult-Type Persistent Primitive Trigeminal Artery with Multiple Vascular Variations

We report a case of spontaneous right carotid-cavernous fistula (CCF) in a proximal segment of persistent primitive trigeminal artery (PPTA) and combined vascular anomalies such as left duplicated hypoplastic proximal posterior cerebral arteries and a variation of anterior choroidal artery supplying temporal and occipital lobe. A 45-year-old male presented with progressive right exophthalmos, diplopia, and ocular pain. With manual compression of the internal carotid artery, a cerebral angiography revealed a right CCF from a PPTA. Treatment involved the placement of detachable non-fibered and fibered coils, and use of a hyperglide balloon to protect against coil herniation into the internal carotid artery. A final angiograph revealed complete occlusion of PPTA resulted in no contrast filling of CCF.

Ischemic Complications Occurring in the Contralateral Hemisphere after Surgical Treatment of Adults with Moyamoya Disease

OBJECTIVE: Direct revascularization surgery is regarded as the most effective method of treatment of adults with moyamoya disease. These patients, however, have a higher risk of perioperative ischemic complications than do patients with atherosclerotic stroke, and are at risk for ischemic complications in the hemisphere contralateral to the one operated on. We investigated the incidence and risk factors for ischemic stroke in the contralateral hemisphere after surgical treatment of adults with moyamoya disease. METHODS: We retrospectively reviewed the medical records and results of neuroimaging studies on 79 hemispheres of 73 consecutive patients with adult moyamoya disease (mean+/-SD age, 37.96+/-11.27 years; range, 18-62 years) who underwent direct bypass surgery over 6 years. RESULTS: Ischemic complications occurred in 4 of 79 (5.1%) contralateral hemispheres, one with Suzuki stage 3 and three with Suzuki stage 4. Three patients showed posterior cerebral artery (PCA) involvement by moyamoya vessels. Advanced stage of moyamoya disease (Suzuki stages 4/5/6; p=0.001), PCA involvement (p=0.001) and postoperative hypotension (mean arterial blood pressure <80% of preoperative mean arterial blood pressure) on the first (p<0.0001) and second (p=0.003) days after surgery were significantly correlated with postoperative contralateral ischemic complications. CONCLUSION: In patients with advanced moyamoya disease and involvement of the PCA, intentional hypotension can result in ischemic stroke in the hemisphere contralateral to the one operated on. Careful control of perioperative blood pressure is crucial for good surgical results.