While mechanical thrombectomy is known to be effective for distal medium vessel occlusion (DMVO) as well as large vessel occlusion, tortuous DMVO are predisposed to vessel injury during stent retriever thrombectomy. Furthermore, getting access to the thrombus may be difficult during suction thrombectomy using a dedicated suction catheter. Most studies describe DMVO treatment using stent retrievers and dedicated suction catheters, but there are limited studies reporting DMVO treated with suction thrombectomy using a microcatheter. Herein, we describe three cases of DMVO treated with suction thrombectomy that was performed using a microcatheter and subsequently showed good results. Therefore, suction thrombectomy using a microcatheter is a viable alternative treatment for tortuous DMVO.

Background: We aimed to evaluate long-term outcomes of gamma knife radiosurgery (GKS) for cerebral cavernous malformations (CCMs). Methods: Among the 233 CCM patients who underwent GKS, 79 adult patients (96 lesions) followed for over 10 years were included and analyzed retrospectively. Annual hemorrhage rate (AHR) was analyzed the entire cohort of 233 patients and the subset of 79 enrolled patients by dividing lesions into overall CCM lesions and brainstem lesions. AHR, neurologic outcome, adverse radiation effect (ARE), and changes of lesions in magnetic resonance imaging (MRI) were compared before and after GKS. Cox-regression analysis was performed to identify risk factors for hemorrhage following GKS. Results: Mean follow-up duration of 79 enrolled patients was 14 years (range, 10–23 years).The AHR of all CCMs for entire cohort at each time point was 17.8% (pre-GKS), 5.9% (≤ 2 years post-GKS), 1.8% (≤ 10 years post-GKS). The AHR of all CCM for 79 enrolled patients was 21.4% (pre-GKS), 3.8% (2 years post-GKS), 1.4% (10 years post-GKS), and 2.3% (> 10 years post-GKS). The AHR of brainstem cavernous malformation (CM) for entire cohort at each time point was 22.4% (pre-GKS), 10.1% (≤ 2 years post-GKS), 3.2% (≤ 10 years post-GKS). The AHR of brainstem CM for 79 enrolled patients was 27.2% (pre-GKS), 5.8% (2 years post-GKS), 3.4% (10 years post-GKS), and 3.5% (> 10 years post-GKS). Out of the 79 enrolled patients, 35 presented with focal neurologic deficits at the initial clinical visit. Among these patients, 74.3% showed recovery at the last follow-up. Symptomatic ARE occurred in five (6.4%) patients. No mortality occurred. Most lesions were decreased in size at the last follow-up MRI. Previous hemorrhage history (hazard ratio [HR], 8.38; 95% confidence interval [CI], 1.07–65.88; P = 0.043), and brainstem location (HR, 3.10; 95% CI, 1.26–7.64; P = 0.014) were significant risk factors for hemorrhage event. Conclusion GKS for CCM showed favorable long-term outcomes. GKS should be considered for CCM, especially when it has a previous hemorrhage history and brainstem location.

Background: Treatment for large (> 10 mL) arteriovenous malformations (AVMs) remains highly challenging. This study evaluated long-term effect of time-staged gamma knife radiosurgery (GKS) for large AVMs. Methods: For patients with large AVMs treated by time-staged GKS over 10 years, timestaged GKS was repeated every three years targeting the entire nidus if total obliteration was not achieved. Obliteration rate and post-GKS complications were assessed based on 10 mL volume interval of AVMs. Prognostic factors for these outcomes were evaluated using Cox regression analysis. Results: Ninety-six patients were analyzed. For AVMs in the 10–20 mL subgroup, a dose ≥ 13.5Gy yielded higher obliteration rate in the first GKS. In the 20–30 mL subgroup, a second GKS significantly boosted obliteration. AVMs > 30 mL did not achieve any obliteration with the first GKS. Among 35 (36.4%) cases lost to follow-up, 7 (7.2%) were lost due to GKS complications. Kaplan-Meier analysis showed that each subgroup needed different time for achieving 50% favorable obliteration outcome rate: 3.5, 6.5, and 8.2 years for 10–20 mL, 20–30 mL, and > 30 mL subgroup, respectively. Total obliteration rate calculated by intention-to-treat method: 73%, 51.7%, 35.7%, respectively, 61.5% overall. Post-GKS hemorrhage and chronic encapsulated expanding hematoma (CEEH) occurred in 13.5% and 8.3% of cases, respectively.Two patients died. Dose and volume were significant prognostic factors for obliteration. Initial AVM volume was a significant prognostic factor of post-GKS hemorrhage and CEEH. Conclusion Time-staged GKS for large AVMs less than 30 mL has highly favorable long-term outcome and a tolerable complication rate.

Background: Since the long-term outcomes of 162 patients who underwent gamma knife radiosurgery (GKS) as an initial or adjuvant treatment for acoustic neuromas (ANs) with unilateral hearing loss were first reported in 1998, there has been no report of a comprehensive analysis of what has changed in GKS practice. Methods: We performed a retrospective study of the long-term outcomes of 106 patients with unilateral sporadic ANs who underwent GKS as an initial treatment. The mean patient age was 50 years, and the mean initial tumor volume was 3.68 cm 3 (range, 0.10–23.30 cm 3 ).The median marginal tumor dose was 12.5 Gy (range, 8.0–15.0 Gy) and the median follow-up duration was 153 months (range, 120–216 months). Results: The tumor volume increased in 11 patients (10.4%), remained stationary in 27 (25.5%), and decreased in 68 patients (64.2%). The actuarial 3, 5, 10, and 15-year tumor control rates were 95.3 ± 2.1%, 94.3 ± 2.2%, 87.7 ± 3.2%, and 86.6 ± 3.3%, respectively.The 10-year actuarial tumor control rate was significantly lower in the patients with tumor volumes of ≥ 8 cm 3 (P = 0.010). The rate of maintaining the same Gardner-Robertson scale grade was 28.6%, and that of serviceable hearing was 46.4%. The rates of newly developed facial and trigeminal neuropathy were 2.8% and 4.7%, respectively. The patients who received marginal doses of less than 12 Gy revealed higher tumor control failure rates (P = 0.129) and newly occurred facial or trigeminal neuropathy rates (P = 0.040 and 0.313, respectively). Conclusion GKS as an initial treatment for ANs could be helpful in terms of tumor control, the preservation of serviceable hearing, and the prevention of cranial neuropathy. It is recommended to perform GKS as soon as possible not only for tumor control in unilateral ANs with hearing loss but also for hearing preservation in those without hearing loss.

Objective: : Chronic subdural hematoma (CSDH) is a common neurosurgical disease and generally treated with burr-hole surgery alone. Tranexamic acid (TXA) is an antifibrinolytic agent that potentially reduces recurrence rates and the residual hematoma volume. However, the role of postoperative TXA medication remains unclear to date. This study aimed to verify the effectiveness of adjunctive TXA in the view of early hematoma resolution. Methods: : Between January 2018 and September 2021, patients with CSDH who underwent burr-hole trephination in a single tertiary institute were reviewed. The study population was divided into three groups, TXA, non-TXA, and antithrombotics (AT) groups, according to the medical history of cardio-cerebrovascular disease and TXA administration. The primary endpoint was CSDH recurrence, defined as re-appearance or re-accumulation of CSDH requiring neurosurgical interventions. The secondary outcome was CSDH resolution, defined as complete or near-complete resorption of the CSDH. The CSDH resolution time and serial changes of hematoma thickness were also investigated. Results: : A total of 240 patients was included in the analysis consisting of 185 male and 55 female, with a median age of 74 years. During the median imaging follow-up period of 75 days, 222 patients were reached to the primary or secondary endpoint. TXA was administered as an adjunctive therapy in 41 patients (TXA group, 16.9%) while 114 patients were included in the non-TXA group (47.9%) and 85 were in the AT group. The recurrence rate was the lowest in the TXA group (2.4%), followed by non-TXA (7.0%) and AT (8.2%) groups. However, there was no statistical significance due to the small number of patients with recurrence. CSDH resolution was achieved in 206 patients, and the median estimated time to resolution was significantly faster in the TXA group (p<0.001). Adjunctive TXA administration was a significant positive factor for achieving CSDH resolution (p<0.001). The hematoma thickness was comparable among the three groups at the initial time and after surgery. However, CSDH thickness in the TXA group decreased abruptly in a month and showed a significant difference from that in the other groups (p<0.001). There was no TXA-related adverse event. Conclusion : The adjunctive use of TXA after CSDH surgery significantly facilitated the resorption of residual CSDH and resulted in the early CSDH resolution. Adjunctive TXA may be an effective treatment option to reduce recurrence by enhancing CSDH resolution in the selective patients.

Symptomatic Rathke’s cleft cysts (RCCs) can be treated by surgical procedures, usually through an endonasal transsphenoidal corridor using either a microscope or an endoscope. We report a large suprasellar extended RCC causing obstructive hydrocephalus, which was efficiently managed by a novel surgical route named “reverse” trans-sellar approach using transventricular neuroendoscopy. A 48-yearold woman complained of persistent headache and a tendency to fall that had begun 6 months previously. The images obtained from MRI scan showed intra- and supra-sellar cystic masses occupying the third ventricle with obstruction of the foramina of Monro and the aqueduct of Sylvius. The cystic wall showed a slight enhancement, and the cystic contents showed iso-signal intensity on T1-and T2-weighted images. Instead of trans-nasal trans-sellar surgery, we decided to operate using a conventional transventricular endoscope. A thin cystic capsule, which blocked the foramina of Monro and the aqueduct of Sylvius, was fenestrated and removed and a third ventriculostomy was performed. The defect in the infundibulum between sellar and suprasellar cysts was widened and used as a corridor to drain cystic contents (reverse trans-sellar route). The final pathological finding revealed an RCC with focal metaplasia. We efficiently managed a large RCC by transventricular neuroendoscopic surgery with cyst fenestration and third ventriculostomy and simultaneously drained the sellar contents using a novel surgical route. Reverse trans-sellar neuroendoscopic surgery is a relevant treatment option for selective patients with large suprasellar extensions of RCCs.

Syncope is a common symptom in clinical practice. Rotational vertebral artery occlusion syndrome, also referred to as Bow Hunter’s syndrome (BHS), is a rare condition associated with syncope and is caused by mechanical occlusion or stenosis secondary to mechanical compression of the vertebral artery during head rotation. BHS is associated with a multifactorial etiology; however, in most cases, this condition is attributed to degenerative changes. A 53-year-old man visited our hospital for the evaluation of fainting and dizziness episodes that occurred when he turned his head. Evaluation as an outpatient in the Department of Neurology showed a positive result on the Frenzel goggle test. Transfemoral cerebral angiography performed at the Department of Neurosurgery revealed stenosis of the proximal right vertebral artery. Complete occlusion of the vertebral artery was observed, and the head was turned to the right. Decompression and fusion were performed, and the contributory lesion was completely removed. Postoperative imaging confirmed complete removal of the spur and sufficient vertebral artery decompression; the patient’s symptoms resolved postoperatively.

Radiation-induced cavernous hemangiomas (RICHs) have been increasingly reported as a late complication after conventional radiotherapy. RICH after stereotactic radiosurgery (SRS) is extremely rare and the few cases have been reported to demonstrate their properties. A 72-year-old female patient presented with progressive neurologic deficits. She underwent tumor surgery for meningioma 13 years ago and two times of SRS for treating a residual tumor. Newly-developed mass was 4.3 cm-sized heterogeneously enhancing mass with severe cerebral edema. She underwent surgical resection and the histologic examinations revealed organized hematoma. Finally, it was diagnosed as a RICH following SRS based on radiological and histological findings and a history of multiple radiosurgeries. Clinical, radiological, and histological features of a RICH following SRS were discussed in this report.

Background: This study was performed to evaluate etiologies and secular trends in primary amenorrhea in South Korea. Methods: This retrospective multi-center study analyzed 856 women who were diagnosed with primary amenorrhea between 2000 and 2016. Clinical characteristics were compared according to categories of amenorrhea (hypergonadotropic/hypogonadotropic hypogonadism, eugonadism, disorders of sex development) or specific causes of primary amenorrhea. In addition, we assessed secular trends of etiology and developmental status based on the year of diagnosis. Results: The most frequent etiology was eugonadism (39.8%). Among specific causes, Müllerian agenesis was most common (26.2%), followed by gonadal dysgenesis (22.4%). Women with hypergonadotropic hypogonadism were more likely to have lower height and weight, compared to other categories. In addition, the proportion of cases with iatrogenic or unknown causes increased significantly in hypergonadotropic hypogonadism category, but overall, no significant secular trends were detected according to etiology. The proportion of anovulation including polycystic ovarian syndrome increased with time, but the change did not reach statistical significance. Conclusion The results of this study provide useful clinical insight on the etiology and secular trends of primary amenorrhea. Further large-scale, prospective studies are necessary.

Background: Anterior choroidal artery (AchA) aneurysms are usually small in diameter because of the size of the involved artery and are often wide-necked. Coil embolization of AchA aneurysm is thus challenging because of serious risks, such as thromboembolic occlusion of artery and perforation of aneurysm dome. Therefore, aneurysmal neck clipping remains widely performed despite a recent increase in the use of coil embolization for aneurysm treatment. We report the treatment results of AchA aneurysms mostly (92.3%) treated with coil embolization at our institute. Methods: The database and medical records of patients who underwent coil embolization for AchA aneurysms were retrospectively analyzed. The clinical and imaging results and procedure-related complications were investigated after coil embolization performed between January 2006 and March 2022 at our institute. Results: In total, 96 AchA aneurysms comprising 65 unruptured and 31 ruptured aneurysms, including only 1 ruptured aneurysm (1.0%) re-embolized at postoperative day 192 because of coil compaction, were evaluated. After the initial coil embolization, complete occlusion was attained in 41, residual neck in 45, and residual aneurysm in 10 patients. Follow-up radiological studies after 6–174 months were performed for 80 aneurysms. Complete occlusion was noted in 57 patients, residual neck in 22, and residual aneurysm in 1. The dysarthria experienced by one (1.0%) patient was the only symptomatic procedure-related complication. After coil embolization, neither delayed new rupture nor re-rupture was observed. Conclusions The results of this study demonstrate that coil embolization is a safe and effective treatment option for patients with AchA aneurysms.