Elimination of the check-valve mechanism of the sacral Tarlov cyst using a rotation flap technique in a pediatric patient: technical note.

OBJECTIVE: Symptomatic Tarlov cysts in children are not sufficiently reported and treatment methods for Tarlov cysts are still controversial. The goal of this manuscript is to introduce a new variation of the surgical technique. METHODS: We performed surgery to eliminate the one-way check valve mechanism of the Tarlov cyst in a 7-year-old female who presented with urinary and fecal incontinence. A relatively large S3 nerve root cyst showed a one-way check valve on computed tomography myelography. The inlet of the check valve was enlarged with rotation flap reconstruction. RESULTS: Two months after surgery, the patient had established normal sphincter control. MRI performed two years later showed that the treated cyst was collapsing, and no recurrence occurred. CONCLUSIONS: Rotation flap enlargement of the check valve inlet is a safe and efficacious option for the treatment of pediatric patients with sacral Tarlov cysts.

A case of pediatric moyamoya disease with severe cerebral vasospasm and delayed cerebral infarction following an intraventricular hemorrhage.

Reports on patients with moyamoya disease presenting cerebral ischemic complications after the onset of intraventricular hemorrhage (IVH) and/or intracerebral hemorrhage (ICH) are limited. Herein, we report a case of a 7-year-old girl with moyamoya disease with severe cerebral vasospasm and delayed cerebral infarction following an IVH. Although the case is rare, the potential for vasospasm-induced cerebral infarction should be carefully considered and thus, intensive treatment should be immediately initiated.

Hemorrhagic stroke associated with essential thrombocythemia: Case report and literature review.

Hemorrhagic stroke associated with essential thrombocythemia (ET) is very infrequent. Herein, we report a case of a 33-year-old woman with a 2-year history of ET who developed intracerebral and subarachnoid hemorrhage. Angiography demonstrated severe vessel irregularity in the bilateral cerebral arteries. Molecular genetic testing revealed a calreticulin mutation. To our knowledge, hemorrhagic stroke has been reported in only six other patients with ET, and this is the first report of hemorrhagic stroke in an ET patient with a calreticulin mutation. We review the current literature and discuss the possible underlying mechanisms.

Association between extracranial internal carotid artery tortuosity and thromboembolic complications during coil embolization of anterior circulation ruptured aneurysms.

BACKGROUND: The most frequent neurological complication during coil embolization of a ruptured cerebral aneurysm is a thromboembolic event. The association between the tortuosity of the internal carotid artery (ICA) and thromboembolic events (TEEs) during coil embolization of ruptured cerebral aneurysms remains unclear. The present study aimed to investigate the association between extracranial ICA tortuosity and thromboembolic complications during coil embolization of anterior circulation ruptured aneurysms. METHODS: A cohort of 57 patients with 57 anterior circulation ruptured aneurysms who underwent endovascular embolization at a single institution was retrospectively investigated. Patients were divided into two groups, those who experienced TEEs and those who did not that were compared and analyzed based on patient baseline characteristics, procedural factors, and anatomical factors including those of aneurysms and extracranial ICA tortuosity. The anatomical factors of the aneurysms included maximum dome size, neck width, dome-to-neck ratio, and dome-to-neck aspect ratio. Extracranial ICA angles in the proximal and distal curvature were evaluated as ICA tortuosity. RESULTS: Three of the 57 patients were excluded because of unavailability of data regarding ICA tortuosity; 54 patients were finally evaluated. TEEs occurred in six patients with five anterior cerebral and one internal carotid aneurysms. The extracranial distal ICA angle was significantly larger in patients with TEEs than in those without. Procedural factors and anatomical factors of the aneurysms were not associated with TEEs. CONCLUSIONS: Extracranial ICA tortuosity was significantly associated with an increased incidence of thromboembolic events during endovascular coiling of anterior circulation ruptured aneurysms.

Stabilization of vulnerable carotid plaques with proprotein convertase subtilisin/kexin type 9 inhibitor alirocumab.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, a novel class of monoclonal antibodies, reduce low-density lipoprotein cholesterol levels and improve outcomes of myocardial infarction and stroke. However, the effects of PCSK9 inhibitors on carotid plaques remain unclear. We describe three patients treated with PCSK9 inhibitor alirocumab for progressive carotid stenosis despite lipid-lowering statin therapy. All three patients had vulnerable plaques on magnetic resonance (MR) plaque imaging. After alirocumab treatment initiation, no patients suffered stroke or adverse events, and the stabilization of the carotid plaques was observed on MR plaque imaging.

A compact and facile microfluidic droplet creation device using a piezoelectric diaphragm micropump for droplet digital PCR platforms.

We have exploited a compact and facile microfluidic droplet creation device consisting of a poly(dimethylsiloxane) microfluidic chip possessing T-junction channel geometry, two inlet reservoirs, and one outlet reservoir, and a piezoelectric (PZT) diaphragm micropump with controller. Air was evacuated from the outlet reservoir using the PZT pump, reducing the pressure inside. The reduced pressure within the outlet reservoir pulled oil and aqueous solution preloaded in the inlet reservoirs into the microchannels, which then merged at the T-junction, successfully forming water-in-oil emulsion droplets at a rate of ∼1000 per second with minimal sample loss. We confirmed that the onset of droplet formation occurred immediately after turning on the pump (<1 s). Over repeated runs, droplet formation was highly reproducible, with droplet size purity (polydispersity, <4%) comparable to that achieved using other microfluidic droplet preparation techniques. We also demonstrated single-molecule PCR amplification in the created droplets, suggesting that the device could be used for effective droplet digital PCR platforms in most laboratories without requiring great expense, space, or time for acquiring technical skills.

Dural arteriovenous fistula manifesting as pontine hemorrhage at the craniocervical junction.

Craniocervical junction (CCJ) dural arteriovenous fistula (DAVF) manifesting as intracerebral hemorrhage is extremely rare. We report the first case of CCJ-DAVF manifesting as pontine hemorrhage. A 69-year-old male presented with a pontine hemorrhage manifesting as a sudden onset of right hemiparesis and dysarthria. Digital subtraction angiography revealed a CCJ-DAVF fed by the meningeal branches of the right vertebral artery. The patient underwent surgical ligation of the cerebral draining veins to prevent re-bleeding. The postoperative course was uneventful. The patient had no neurological deficit after 1 month rehabilitation.

Phase I study of nintedanib in Japanese patients with advanced hepatocellular carcinoma and liver impairment.

This phase I, dose-escalation study evaluated the safety, preliminary efficacy and pharmacokinetics of nintedanib, a triple angiokinase inhibitor, in Japanese patients with advanced hepatocellular carcinoma and mild/moderate liver impairment. Thirty patients with unresectable hepatocellular carcinoma were enrolled to groups, depending on whether liver impairment was mild (group I, aspartate aminotransferase and alanine aminotransferase ≤2× upper limit of normal and Child-Pugh score 5 [n = 14] or 6 [n = 2]) or moderate (group II, Child-Pugh score 5-6 and aspartate aminotransferase or alanine aminotransferase >2× to ≤5× upper limit of normal [n = 7] or Child-Pugh score 7 [n = 7]); 22 patients had prior sorafenib treatment. Nintedanib was given twice daily in 28-day cycles until disease progression or unacceptable adverse events, starting at 150 mg (group I) or 100 mg (group II) and escalating to 200 mg. The primary objective was to define the maximum tolerated dose based on occurrence of dose-limiting toxicities during cycle 1 (grade ≥3 non-hematological and grade 4 hematological adverse events). No dose-limiting toxicities were reported during cycle 1 and the maximum tolerated dose for both groups was 200 mg twice daily. The most frequent adverse events were gastrointestinal (diarrhea, nausea, vomiting, and decreased appetite). No patients discontinued nintedanib due to adverse events; 31% of group I and 21% of group II had dose reductions. Median time to progression was 2.8 months (95% confidence interval, 1.05-5.52) for group I and 3.2 months (95% confidence interval, 0.95-6.70) for group II. Nintedanib showed a manageable safety profile and efficacy signals, including in patients previously treated with sorafenib. Clinical trial registration NCT01594125; 1199.120 (ClinicalTrials.gov).

Phase I trial of volasertib, a Polo-like kinase inhibitor, in Japanese patients with advanced solid tumors.

PURPOSE: This trial evaluated the maximum tolerated dose (MTD), safety, pharmacokinetics, and clinical effects of volasertib, a selective Polo-like kinase inhibitor that induces mitotic arrest and apoptosis, in Japanese patients with advanced solid tumors (NCT01348347; 1230.15). METHODS: In this phase I, open-label, dose-escalation trial, sequential patient cohorts (3 + 3 dose-escalation design) received volasertib (200-350 mg) as a single dose by intravenous infusion over 2 h on day 1 every 21 days until disease progression or unacceptable toxicity. The primary endpoint was the MTD of volasertib in Japanese patients with an advanced solid tumor; secondary endpoints included safety, pharmacokinetics, and clinical benefit. RESULTS: Fifteen patients with an advanced solid tumor were treated. Dose-limiting toxicities of grade 4 neutropenia for ≥7 days and grade 4 thrombocytopenia were both experienced by 2/6 patients in the 350 mg cohort. The MTD of volasertib in Japanese patients was 300 mg. The most common (≥3 patients) drug-related non-hematologic adverse events included fatigue, decreased appetite, and nausea. Exposure to volasertib and its metabolite increased with increasing doses. A partial response in a patient with gastric cancer and stable disease in eleven patients were observed. CONCLUSIONS: Volasertib had a manageable safety profile up to the MTD determined as 300 mg. Exposure to volasertib and its metabolite increased with increasing doses. The safety profile of volasertib in Japanese patients is comparable with those previously obtained in Caucasian patients. These data support enrollment of Japanese patients in global clinical trials without dose modification.

Effect of empagliflozin monotherapy on postprandial glucose and 24-hour glucose variability in Japanese patients with type 2 diabetes mellitus: a randomized, double-blind, placebo-controlled, 4-week study.

BACKGROUND: This study evaluated the effect of empagliflozin on postprandial glucose (PPG) and 24-hour glucose variability in Japanese patients with type 2 diabetes mellitus (T2DM). METHODS: Patients (N = 60; baseline mean [SD] HbA1c 7.91 [0.80]%; body mass index 24.3 [3.2] kg/m(2)) were randomized to receive empagliflozin 10 mg (n = 20), empagliflozin 25 mg (n = 19) or placebo (n = 21) once daily as monotherapy for 28 days. A meal tolerance test and continuous glucose monitoring (CGM) for 24 hours were performed at baseline and on days 1 and 28. The primary endpoint was change from baseline in area under the glucose concentration-time curve 3 hours after breakfast (AUC1-4h for PPG) at day 28. RESULTS: Adjusted mean (95%) differences versus placebo in changes from baseline in AUC1-4h for PPG at day 1 were -97.1 (-126.5, -67.8) mg · h/dl with empagliflozin 10 mg and -91.6 (-120.4, -62.8) mg · h/dl with empagliflozin 25 mg (both p < 0.001 versus placebo) and at day 28 were -85.5 (-126.0, -45.0) mg · h/dl with empagliflozin 10 mg and -104.9 (-144.8, -65.0) mg · h/dl with empagliflozin 25 mg (both p < 0.001 versus placebo). Adjusted mean (95% CI) differences versus placebo in change from baseline in 24-hour mean glucose (CGM) at day 1 were -20.8 (-27.0, -14.7) mg/dl with empagliflozin 10 mg and -23.9 (-30.0, -17.9) mg/dl with empagliflozin 25 mg (both p < 0.001 versus placebo) and at day 28 were -24.5 (-35.4, -13.6) mg/dl with empagliflozin 10 mg and -31.7 (-42.5,-20.9) mg/dl with empagliflozin 25 mg (both p < 0.001 versus placebo). Changes from baseline in mean amplitude of glucose excursions (MAGE; CGM) were not significantly different with either empagliflozin dose versus placebo at either timepoint. Curves of mean glucose (CGM) did not change between baseline and day 1 or 28 with placebo, but shifted downward with empagliflozin. Percentage of time with glucose ≥70 to <180 mg/dl increased from 52.0% at baseline to 77.0% at day 28 with empagliflozin 10 mg and from 55.0% to 81.1% with empagliflozin 25 mg, without increasing time spent with hypoglycemia. CONCLUSION: Empagliflozin for 28 days reduced PPG from the first day and improved daily blood glucose control in Japanese patients with T2DM. TRIAL REGISTRATION: Clinicaltrials.gov NCT01947855.

Anatomy of the superior petrosal veins and their exposure and management during petrous apex meningioma surgery using the lateral suboccipital retrosigmoid approach.

During surgeries in the upper cerebellopontine angle (CPA), the superior petrosal veins (SPVs) often act as obstacles; and their sectioning sometimes causes serious complications. In this study, we introduced a classification system for the SPVs wherein their tributaries were classified into four groups on the basis of their courses and draining areas. We furthermore explained the detailed anatomy of the vein of the cerebellopontine fissure, which is the largest tributary. In surgeries of petrous apex meningioma, the knowledge of the displacement pattern of the vein is very helpful for avoiding major venous complications. Therefore, we elucidated its anatomical situation in relation to the original portion of the meningioma and the natural draining point of the vein into the superior petrosal sinus (SPS) in each patient. In addition, we described the methods and techniques used to expose and manage the vein of the cerebellopontine fissure during surgery using the lateral suboccipital retrosigmoid approach. Presenting two illustrative cases, we recommend that the initial exposure of the tumor should be performed through the infratentorial lateral supracerebellar route and that the suprafloccular cistern is the best area to find the vein of the cerebellopontine fissure. We emphasized the importance of the preservation of the vein of the cerebellopontine fissure and also proposed the order for exposure of SPV tributaries during upper CPA surgery using the retrosigmoid approach.

Chromosome aberrations in normal human fibroblasts analyzed in G0/G1 and G2/M phases after exposure in G0 to radiation with different linear energy transfer (LET).

We have studied the induction of chromosome aberrations in human fibroblasts exposed in G0/G1 to X-rays or heavy ions to study the influence of G1 cell cycle arrest. Confluent normal fibroblasts were exposed to X-rays or accelerated particles with different LET values and chromosome aberrations were investigated in the first G0/G1 and G2//M phase. The particles used here were 490MeV/nucleon Si, 500MeV/nucleon Fe, and 200MeV/nucleon Fe ions. Cells were subcultured 24h after exposure and premature chromosome condensation (PCC) was performed by fusion-induced method for analysis of G0/G1 cells, and chemically-induced method for analysis of G2 and metaphase cells. Chromosome damage was assessed in chromosomes 1 and 3 using whole chromosome fluorescence in situ hybridization (FISH). Cell cycle was analyzed by flow cytometry at different incubation times following subculture. After irradiation with 2Gy of high-LET particles, the yields of chromosome aberrations and fragments were significantly higher in G0/G1 phase than in G2/M phase, whereas similar yields of damage were measured in both phases after exposure to X-rays. In contrast, the yield of misrepair, assessed by the number of color junctions, was similar in the G0/G1 and G2/M phases after exposure to either X-rays or high-LET particles. The yields of chromosome aberrations, fragments, and color junctions in both the G0/G1 and the G2/M phases, increased with LET up to 200keV/µm, then decreased for 440keV/µm Fe particles. A good correlation was found between chromosome aberrations in both G0/G1 and G2/M cells and survival fractions after 2Gy of different LET radiations, although the slopes were steeper for the G0/G1 cells. Flow cytometry analysis indicated that high-LET particles induce more non cycling G0/G1 cells within 48h of subculture than X-rays, suggesting that chromosome aberrations scored at the G2/M phase may not accurately describe the true radiation effect.

Obstructive hydrocephalus following aqueductal stenosis caused by supra- and infratentorial developmental venous anomaly: case report.

OBJECTIVE: We report a rare case of hydrocephalus following aqueductal stenosis caused by developmental venous anomaly (DVA). METHODS: Four years after the incidental discovery of asymptomatic DVA, the 10-year-old boy presented with symptoms of hydrocephalus. Enhanced computed tomographic scans and magnetic resonance images showed supra- and infratentorial DVAs with caput medusae appearances in the right basal ganglia and cerebellum. Three dilated collector veins in the right basal ganglia, floor of the third ventricle, and floor of the fourth ventricle gathered together to drain into the great vein of Galen. Three-dimensional fusion images showed that the serpentine dilated vein from the posterior fossa coursed in the aqueduct and caused the aqueductal stenosis, which was confirmed by operative endoscopy. RESULTS: Endoscopic third ventriculostomy was performed and the hydrocephalus was relieved. CONCLUSIONS: Although aqueductal stenosis caused by DVA is rare, it is important to be considered in the differential diagnosis of hydrocephalus. Three-dimensional reconstruction and fusion images are very useful.

Order Space-Based Morphology for Color Image Processing.

Mathematical morphology is a fundamental tool based on order statistics for image processing, such as noise reduction, image enhancement and feature extraction, and is well-established for binary and grayscale images, whose pixels can be sorted by their pixel values, i.e., each pixel has a single number. On the other hand, each pixel in a color image has three numbers corresponding to three color channels, e.g., red (R), green (G) and blue (B) channels in an RGB color image. Therefore, it is difficult to sort color pixels uniquely. In this paper, we propose a method for unifying the orders of pixels sorted in each color channel separately, where we consider that a pixel exists in a three-dimensional space called order space, and derive a single order by a monotonically nondecreasing function defined on the order space. We also fuzzify the proposed order space-based morphological operations, and demonstrate the effectiveness of the proposed method by comparing with a state-of-the-art method based on hypergraph theory. The proposed method treats three orders of pixels sorted in respective color channels equally. Therefore, the proposed method is consistent with the conventional morphological operations for binary and grayscale images.

Pituitary adenoma presenting as isolated oculomotor nerve palsy.

Background: Isolated oculomotor nerve palsy is a relatively uncommon symptom of pituitary adenoma that usually occurs in association with pituitary apoplexy or cavernous sinus (CS) invasion. Case Description: We report two cases of relatively small pituitary adenomas with neither apoplexy nor CS invasion presenting as isolated oculomotor nerve palsy. Both patients presented with gradually worsening diplopia, without headache or visual field defects. Magnetic resonance imaging (MRI) showed a pituitary tumor with no evidence of intratumoral hemorrhage. Computed tomography revealed a lateroposterior extension of the tumor with the erosion of the posterior clinoid process. Constructive interference in steady-state MRI revealed compression of the oculomotor nerve by the tumor at the oculomotor triangle. The patients underwent endoscopic transsphenoidal surgery, and the intraoperative findings showed that the tumors did not invade the CS. The tumors were completely resected, and the oculomotor palsies resolved fully. Conclusion: These cases illustrate the need to consider isolated oculomotor nerve palsy as an initial manifestation of a relatively small pituitary adenoma with neither apoplexy nor CS invasion. Based on the characteristic radiological findings, early surgical treatment is recommended to preserve oculomotor function.

[Brain natriuretic peptide in subarachnoid hemorrhage].

Because of the known correlation between the brain natriuretic peptide (BNP) level and the severity of cardiac failure, cardiac function assessment often involves measuring BNP levels. In addition, BNP is produced in the hypothalamus; high BNP levels are reported in patients with subarachnoid hemorrhage (SAH), although the details of this mechanism remain to be clarified. Furthermore, there are unconfirmed reports of high BNP levels during follow up in cases of post-SAH cerebral vasospasm (CVS). In the present study, we retrospectively investigated the correlation between plasma BNP levels and severity of SAH at onset and the utility of the BNP level as a predictor for CVS. Of 149 SAH cases treated as inpatients at our institution between November 2008 and March 2010, our subjects comprised 28 SAH cases in which the plasma BNP level was measured at the time of hospitalization (≦48 hours after SAH onset). There was no significant correlation between BNP levels and SAH severity at the onset, but BNP levels tended to be high in cases accompanied by intracerebral hematoma, particularly in patients with an anterior communicating aneurysm rupture. This is thought to be the result of direct damage to the hypothalamus. The cases with normal BNP levels at the onset of SAH were apt to have favorable outcomes. The incidence of delayed ischemic neurological deficit (DIND) was investigated in 15 cases in which the BNP level was measured multiple times during follow up. The ratio of BNP at SAH onset compared to at days 3 to 7 of the illness was not significant; however, BNP levels tended to be high in cases with DIND complications. BNP levels may constitute a useful early marker for CVS, despite BNP susceptibility to surgical invasion and perioperative management.

Local Contrast-Based Pixel Ordering for Exact Histogram Specification.

Histogram equalization is one of the basic image processing tasks for contrast enhancement, and its generalized version is histogram specification, which accepts arbitrary shapes of target histograms including uniform distributions for histogram equalization. It is well known that strictly ordered pixels in an image can be voted to any target histogram to achieve exact histogram specification. This paper proposes a method for ordering pixels in an image on the basis of the local contrast of each pixel, where a Gaussian filter without approximation is used to avoid the duplication of pixel values that disturbs the strict pixel ordering. The main idea of the proposed method is that the problem of pixel ordering is divided into small subproblems which can be solved separately, and then the results are merged into one sequence of all ordered pixels. Moreover, the proposed method is extended from grayscale images to color ones in a consistent manner. Experimental results show that the state-of-the-art histogram specification method occasionally produces false patterns, which are alleviated by the proposed method. Those results demonstrate the effectiveness of the proposed method for exact histogram specification.

Concomitant Nephrotic Syndrome and Cryoglobulinemia in a Case of Malignant Mesothelioma.

Malignant pleural mesothelioma is rarely associated with nephrotic syndrome. Cryoglobulinemia is found in various pathological statuses, such as hepatitis C virus infection but rarely in malignant neoplasms. We recently encountered a patient with malignant mesothelioma coincident with nephrotic syndrome and cryoglobulinemia in the course of chemotherapy. A 60-year-old man employed as a building painter was diagnosed with malignant mesothelioma by lung biopsy two years earlier and was started on chemotherapy. Nivolumab seemed effective in controlling mesothelioma, but skin immune-related adverse events occurred during the course of treatment. After discontinuation of nivolumab and administration of gemcitabine as an alternative therapy, the patient was referred to a nephrologist because of the subsequent development of edema, renal injury, and proteinuria. Following the investigation, he was diagnosed with nephrotic syndrome and cryoglobulinemia with C4-dominant cold activation. However, a percutaneous renal biopsy could not be performed due to persistent severe cough induced by pleural involvement. The patient died a little over three years after the pathological diagnosis of pleural mesothelioma. Our case had three key features nephrotic syndrome was possibly associated with malignant mesothelioma; cryoglobulinemia occurred in malignant mesothelioma; and concomitant nephrotic syndrome and cryoglobulinemia occurred after chemotherapy. Unfortunately, our rare case lacks a basis in renal pathology or evidence of links between the pathogenesis of malignant mesothelioma, cryoglobulinemia, and nephrotic syndrome. This case does not provide a causal mechanism, but may be worth adding to the case list as one of the rare renal involvement in a patient with malignant mesothelioma.

POEMS Syndrome with Biclonal Gammopathy and Renal Involvement.

Polyneuropathy, Organomegaly, Endocrinopathy, M-protein and Skin changes (POEMS) syndrome manifests as elevated levels of vascular endothelial growth factor (VEGF) and monoclonal gammopathy. We treated a case of POEMS syndrome showing monoclonality in both IgA-λ and IgG-κ. Serial renal biopsies before treatment and after normalization of the VEGF levels suggested that glomerular microangiopathy had developed due to VEGF, while biclonal gammopathy was not eliminated. The renal pathology, proteinuria, and renal function all clearly improved. Although severe polyneuropathy limited activities of daily living and enforced a bedridden state, the patient dramatically regained his motor function, achieving crutch walking after induction of remission. This case is highly notable due to the presence of biclonality and repeated biopsies.

Microsurgical Approach for True Posterior Communicating Artery Aneurysms: Literature Review and Illustrative Case.

True posterior communicating artery (PCoA) aneurysms are rare. Although true PCoA aneurysms have been reported to be located close to the internal carotid artery, at the middle part of PCoA, or close to the posterior cerebral artery; the best surgical approach to treat true PCoA aneurysms in each location remains unclear. We conducted a literature review using data from PubMed. Data on demographics, location, and projecting direction of the aneurysm, surgical approach, and surgical complications were collected. A total of 47 true PCoA aneurysms were included. Twenty-nine aneurysms originated from the proximal portion, 10 from the middle portion, and 6 from the distal portion; there were two giant aneurysms. The ipsilateral pterional approach was used for 37 true PCoA aneurysms (27 in proximal portion, 8 in middle portion, and 2 in distal portion of PCoA). The anterior temporal approach was used for two distal-portion aneurysms and one giant aneurysm. The anterior subtemporal approach was used for one distal-portion aneurysm. The subtemporal approach was used for two middle-portion aneurysms and one giant aneurysm. The contralateral pterional approach was used for two proximal-portion and one distal-portion aneurysms. Although most true PCoA aneurysms can be treated by the pterional approach, other means such as anterior temporal and subtemporal approaches can be applicable for aneurysms in the middle and distal portions of the PCoA or giant aneurysms. Surgeons should select an appropriate approach for each aneurysm while considering the advantages and disadvantages of each technique.