Factors affecting reasonable duration of continuous electrocardiographic monitoring to detect atrial fibrillation in acute ischemic stroke.

BACKGROUND: To examine the reasonable duration of continuous electrocardiographic monitoring (CEM) to detect AF at acute ischemic stroke. MATERIALS AND METHOD: 811 consecutive patients admitted to Tsuruga Municipal Hospital by acute ischemic stroke between April 2013 and December 2021 were enrolled in this study. Excluding 78 patients, 733 patients were analyzed by cluster analysis with SurvCART algorithm, followed by Kaplan-Meier analysis. RESULTS: The analysis provided step graphs for 8 subgroups. The duration of CEM to achieve the sensitivity of 0.8, 0.9, and 0.95 in each could be calculated. The duration of CEM to achieve the sensitivity of 0.8 are 18 days in female patients with heart failure (HF) (subgroup 1), 24 days in male patients with HF (subgroup 2), 22 days in patients without HF with arterial occlusion and pulse rate (PR) more than 91 (subgroup 3), 24 days in patients without HF with occlusion with PR less than 91 (subgroup 4), 18 days in patients without HF without occlusion with lacuna (subgroup 5), 26 days in patients without HF, occlusion, and lacuna, with arterial stenosis (subgroup 6), 15 days in patients without HF, occlusion, lacuna, and stenosis with BMI more than 21%(subgroup 7), and 44 days in patients without HF, occlusion, lacuna, stenosis and with BMI less than 21% (subgroup 8). CONCLUSIONS: Duration of CEM with the sensitivity of 0.8, 0.9, and 0.95 could be determined by presence of HF, female sex, arterial occlusion, PR more than 91/minute, presence of lacuna, presence of stenosis, and BMI more than 21%. (250).

[Monitoring of the Floor of the 4th Ventricle for Brainstem Surgery].

The brainstem is densely aggregated with important cranial nerve nuclei and nerve tracts. Surgery in this area is, therefore, risky. Not only anatomical knowledge but also electrophysiological monitoring is essential for brainstem surgery. The facial colliculus, obex, striae medullares, and medial sulcus are important visual anatomical landmarks at the floor of the 4th ventricle. As cranial nerve nuclei and nerve tracts deviate by lesion, it is important to have a firm image of the cranial nerve nuclei and nerve tracts before making an incision in the brainstem. The entry zone into the brainstem is selected where the parenchyma is the thinnest due to the lesions. The suprafacial or infrafacial triangle is often used as an incision site for the floor of the 4th ventricle. In this article, we introduce the electromyographic method of observing the external rectus muscle; orbicularis oculi muscle; orbicularis oris muscle; and tongue; and two cases in which monitoring was used(the pons and medulla cavernoma cases). By examining surgical indications in this way it may be possible to improve the safety of such operations.

Functional Outcomes of Microsurgical Resection for Cavernous Malformations of the Brainstem.

Long-term functional outcomes of microsurgical resection for cavernous malformations of the brainstem (CMB) have been largely unknown. Favorable outcomes after CMB surgery might be related to the achievement of complete resection and mRS at 1 month after the surgery. Preoperative sensory, cerebellar, trigeminal nerve, and lower cranial nerve symptoms tended to improve after surgery.We evaluated 25 consecutive patients with CMB surgically treated at our center between 2006 and 2021. The subjects included 11 men and 14 women, with ages ranging from 13 to 61 years (mean ± SD = 37 ± 12 years). Modified Rankin Scale (mRS) scores and neurological symptoms of the patients were evaluated before surgery, 1 month after surgery, and at the final follow-up at the outpatient clinic. The mean number of previous hemorrhages was 7 ± 1.0 and the mean lesion size was 21 ± 8 mm. The mRS scores on admission and at the final follow-up were 2.9 points and 1.7 points, respectively. The mRS scores at the final follow-up were significantly improved compared to those on admission. There was no statistical difference between the preoperative mRS and mRS at 1 month after the operation. Multivariable analysis indicated that mRS scores at 1 month after surgery were the most significant predictive factors for favorable outcomes. Complete resection was achieved in 24 of 33 operations. Incomplete resection was significantly related to the frequency of subsequent recurrent hemorrhage and high mRS scores at the final follow-up. Preoperative sensory, cerebellar, trigeminal nerve, and lower cranial nerve symptoms improved significantly after surgery.

Factors affecting global neurocognitive status and frontal executive functions in the early stage after surgical clipping of unruptured anterior circulation aneurysms with respect to keyhole clipping and conventional clipping.

PURPOSE: This study investigated the most significant factor for the preservation of the global neurocognitive status and frontal executive functions in the surgical clipping of unruptured anterior circulation aneurysms, specifically in keyhole and conventional clipping procedures. METHODS: The prospective study that was performed to examine the effects of aneurysm surgery on the patient's global neurocognitive status and frontal executive functions started on April 2016. After exclusion posterior circulation aneurysms, anterior communicating aneurysms treated by interhemispheric approach, giant aneurysms, and paraclinoid aneurysms, 23 patients who were enrolled before May 2017 were treated by conventional clipping, and 18 patients who were enrolled after June 2017 were treated by keyhole clipping. Two patients were excluded from each group due to missing data. Finally, 21 and 16 patients in each group were analyzed, respectively. Three-tesla magnetic resonance imaging was performed before and after surgery to detect the presence of perioperative cerebral infarctions and brain edema. The Mini-Mental State Examination, Frontal Assessment Battery, and Self-Rating Depression Scale scores were obtained before and 1 month after surgery. RESULTS: Logistic regression analyses indicated that anterior communicating and internal carotid artery aneurysms were the most significant factors for poor outcomes and that keyhole clipping for these two types of aneurysm was the most significant factor for the preservation of patient global neurocognitive status. Keyhole clipping was also the most significant factor for the preservation of frontal executive functions in patients. CONCLUSIONS: Keyhole clipping may be more favorable than conventional clipping for the preservation of the global neurocognitive status and frontal executive functions. Moreover, it may be the most effective factor for preservation of global neurocognitive status when it is indicated for anterior communicating or internal carotid artery aneurysms.

[Optic Neuropathy Secondary to Compression by the Internal Carotid Artery Concomitant with an Inflammatory Granuloma:A Case Report].

A 77-year-old man presented with a 6-month history of progressive right optic neuropathy secondary to compression by the ipsilateral internal carotid artery(ICA). We performed anterior clinoidectomy and optic canal unroofing. Subsequently, we wrapped the ICA with a polytetrafluoroethylene tape, pulled the vessel laterally, and sutured the tape to the dura mater at the anterior skull base for optimal decompression. An inflammatory mass lesion was observed around the ICA, which led to further compression of the optic nerve. Histopathological examination of the resected specimen showed an inflammatory granuloma. The patient's visual field deficit showed partial improvement postoperatively. Transposition using a tape might be an effective surgical alternative for compressive optic neuropathy.

Deflation of a Rathke cleft cyst triggered rupture of a superior hypophyseal artery aneurysm: a case report.

A 57-year-old woman was diagnosed as a Rathke cleft cyst (RCC). Endoscopic transsphenoidal surgery (TSS) was performed uneventfully. She developed subarachnoid haemorrhage on postoperative day 3. The vessels adhered the cyst had been pulled into the pituitary fossa, causing an aneurysm.

Mitogen-activated protein kinase in gliosis and pilocytic astrocytoma.

Pilocytic astrocytoma (PA), featuring activation of the mitogen-activated protein kinase (MAPK) pathway, is the most common tumor of the pediatric central nervous system. However, it remains unknown whether MAPK activation is present in the reactive gliosis of non-neoplastic lesions. Therefore, we investigated the expression of MAPK in reactive gliosis associated with cavernous angiomas. Immunohistochemical expression and the extent of BRAF, ERK, p38, and JNK were investigated in 10 patients with gliosis surrounding cavernous angiomas (GS group) and 10 patients with PA (PA group). Evaluation of these parameters was scored as 0, none; 1, scarce; 2, moderate; 3, global. In the GS group, histopathologic features of PA (piloid cells, Rosenthal fibers, microcysts with eosinophilic granular bodies) were identified. Expression of ERK, and p38 was shown in all patients in the GS and PA group. Expression of BRAF was identified in 5 patients (50%) in the GS group and in 8 (80%) in the PA group. The mean score of BRAF expression in the PA group was significantly higher than that in the GS group (p = 0.019). Reactive gliosis may resemble PA in histological findings and MAPK activation. Therefore, PA could be indistinguishable from reactive gliosis with classic histopathologic and/or immunohistochemical methods.
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[Vestibular Schwannoma Surgery with Continuous Intraoperative Monitoring of Evoked Facial Nerve Electromyograms].

Preservation of facial nerve function is crucial during vestibular schwannoma surgery. Here, we report the utility of continuous intraoperative monitoring of evoked facial nerve electromyograms(EMGs)for preservation of facial nerve function during vestibular schwannoma surgery. A 64-year-old man presented with left ear hearing disturbance. CT and MRI revealed a tumor mass(4cm)with cyst formation in the left cerebellopontine angle. Microsurgical removal was performed with continuous intraoperative monitoring of evoked facial nerve EMGs. An electrode with Ag wire and absorbable gelatin sponge, which we developed, was used for continuous monitoring. It could be placed and fixed more easily on the root exit zone of the facial nerve than the previously reported electrodes and provide reliable information during surgery. The tumor mass could be removed safely without inducing facial nerve palsy. Continuous intraoperative monitoring of evoked facial nerve EMGs with this newly developed electrode could facilitate successful schwannoma surgery.

Evaluation of obliteration of arteriovenous malformations after stereotactic radiosurgery with arterial spin labeling MR imaging.

PURPOSE: Complete obliteration of treated arteriovenous malformations (AVMs) can be diagnosed only by confirming the disappearance of arterio-venous (A-V) shunts with invasive catheter angiography. The authors evaluated whether non-invasive arterial spin labeling (ASL) magnetic resonance (MR) imaging can be used to diagnose the obliteration of AVMs facilitate the diagnosis of AVM obliteration after treatment with stereotactic radiosurgery (SRS). MATERIAL AND METHODS: Seven patients with a cerebral AVM treated by SRS were followed up with ASL images taken with a 3T-MR unit, and received digital subtraction angiography (DSA) after the AVM had disappeared on ASL images. Three patients among the seven received DSA also after the postradiosurgical AVM had disappeared on conventional MR images but A-V shunt was residual on ASL images. Four patients among the seven received contrast-enhanced (CE) MR imaging around the same period as DSA. RESULTS: ASL images could visualize postradiosurgical residual A-V shunts clearly. In all seven patients, DSA after the disappearance of A-V shunts on ASL images demonstrated no evidence of A-V shunts. In all three patients, DSA after the AVM had disappeared on conventional MR images but not on ASL images demonstrated residual A-V shunt. CE MR findings of AVMs treated by SRS did not correspond with DSA findings in three out of four patients. CONCLUSIONS: Findings of radiosurgically treated AVMs on ASL images corresponded with those on DSA. The results of this study suggest that ASL imaging can be utilized to follow up AVMs after SRS and to decide their obliteration facilitate to decide the precise timing of catheter angiography for the final diagnosis of AVM obliteration after SRS.

Predictive Factors for the Occurrence of Visual and Ischemic Complications After Open Surgery for Paraclinoid Aneurysms of the Internal Carotid Artery.

OBJECTIVE: To investigate the predictive factors for visual and ischemic complications after open surgery for paraclinoid aneurysms of the internal carotid artery (ICA). MATERIALS AND METHODS: Thirty-eight consecutive patients with unruptured paraclinoid aneurysms of ICA operated on between 2009 and 2013 were included in this study. The male:female ratio was 6:32 and the ages ranged from 33 to 81 (mean: 60 ± 2). Twenty cases were asymptomatic and 18 had ophthalmological symptoms. The sizes of the aneurysms ranged from 2 to 35 mm (mean: 10.6 ± 9 mm). Twenty-three patients were treated by clipping and 15 by trapping with bypass (high-flow bypass in 11, and low-flow in 4). Twenty-four patients underwent removal of the anterior clinoid process. Among them, 8 underwent en bloc anterior clinoidectomy with a high-speed drill, and 16 had piecemeal excision with a microrongeur or ultrasonic bone curette. Intraoperative monitoring was performed using motor-evoked potentials (MEP) and visual-evoked potentials (VEP) in 27 and 15 cases, respectively. RESULTS: Complete obliteration of the aneurysm was achieved in 37 cases (97.4 %). The patency rate of bypass was 100 %. Postoperative worsening of visual acuity, including one case of blindness, was observed in six cases (11 %). Worsening of visual field defects occurred in 14 cases (38 %), but 10 of them were transient. Transient oculomotor nerve palsy occurred in six cases (15 %). Postoperative stroke was detected by diffusion-weighted imaging (DWI) in five cases (13 %), four of which were symptomatic. Statistical analysis showed that piecemeal anterior clinoidectomy was significantly safer than en bloc removal in preserving visual function. Trapping with high-flow bypass had a significantly greater risk of postoperative stroke than direct clipping. CONCLUSIONS: Intraoperative VEP monitoring might be useful for preventing postoperative worsening of visual function. Two-stage treatment with bypass and endovascular trapping might be safer than single-stage trapping alone.

Long-term follow-up of cryopreservation with glycerol of autologous bone flaps for cranioplasty after decompressive craniectomy.

BACKGROUND: Autologous bone flaps adequately preserved can be used successfully for repair of cranial bone defects with biological and economic advantages. However, the effect or advantages of cryopreservation of autologous bone flaps using cryoprotectant solutions have not been investigated. The aim of this study was to investigate the utility of autologous bone flaps frozen with glycerol in cranioplasty after decompressive craniectomy. METHODS: We evaluated postoperative complications and clinical and aesthetic results in 40 consecutive patients who underwent delayed cranioplasty using autologous bone flaps frozen with glycerol following decompressive craniectomy between 2001 and 2010. Bone flaps removed at the time of external decompression were dipped in 20 % glycerol solution with a sterilized plastic vessel and stored at -84 °C in an ultra-low temperature freezer. The bone flaps were thawed in the vessel at room temperature for 12 h. The bone flaps were taken out of melting glycerol, replaced in their original positions, and fixed with silk sutures or titanium plates. Follow-up periods ranged from 35 to 3745 days (median, 558 days). RESULTS: Mild resorption of the bone flap occurred in one case. However, there were no cases with local infection and no cases requiring reoperation for complications during the follow-up period. CONCLUSIONS: Cryopreservation with glycerol is a simple and safe method for preservation of autologous bone grafts. The clinical and aesthetic results of delayed cranioplasty using autologous bone flaps frozen with glycerol solution were satisfactory.

Anatomy of the Frontal Sinus Drainage Pathway Evaluated in 247 Cadavers to Prevent Cerebrospinal Fluid Leakage After Frontobasal Craniotomy.

BACKGROUND AND OBJECTIVES: The frontal sinus (FS) drainage pathway (FSDP) may be a conduit for cerebrospinal fluid leakage after frontobasal craniotomy. In this cadaveric study, we aimed to evaluate the anatomy of the FSDP. METHODS: The FSs and FSDPs of 247 cadavers were investigated. We counted the number of FSs and FSDPs in each half-head, verified the presence of a narrowing section in each FSDP, and evaluated the depth, shape, and size of each narrowing FSDP section. RESULTS: We investigated 494 sides and 472 FSDPs of 247 cadavers. FSs were unilaterally undeveloped in 13 of 247 cadavers (5.3%) and bilaterally in 8 (3.2%). FSs were unilaterally duplicated in 7 of 247 cadavers (2.8%), and no FSs were bilaterally duplicated or triplicated. No FSs had 2 or more FSDPs, and all 472 investigated FSDPs were invariably narrowed at various depths. The narrowing FSDP sections were elliptical (78.6%), circular (18.1%), triangular (1.8%), or crescent-shaped (1.4%) and of varying thickness and orientation. Although FSDPs were asymmetric in 92.2% of cadavers and narrowing FSDP sections were located deep (8.9 ± 4.4 mm from the anterior skull base), the narrowing FSDP sections were typically small (area: 5.9 ± 3.3 mm 2 ) or thin (short diameter: 2.1 ± 0.7 mm). CONCLUSION: Each FS had only one FSDP, all FSDPs were invariably narrowed at various depths, and the narrowing FSDP sections were sufficiently small or thin to allow local closure, facilitating prevention of cerebrospinal fluid leakage after frontobasal craniotomy.

Prediction of Occurrence of Cerebral Infarction After Successful Mechanical Thrombectomy for Ischemic Stroke in the Anterior Circulation by Arterial Spin Labeling.

PURPOSE: The overall goal of our study is to create modified Alberta Stroke Program Early Computed Tomography Score (ASPECTS) determined by the findings on arterial spin labeling imaging (ASL) to predict the prognosis of patients with acute ischemic stroke after successful mechanical thrombectomy (MT). Prior to that, we examined predictive factors including the value of cerebral blood flow (CBF) measured by ASL for occurrence of cerebral infarction at the region of interest (ROI) used in the ASPECTS after successful MT. METHODS: Of the 92 consecutive patients with acute ischemic stroke treated with MT at our institution between April 2013 and April 2021, a total of 26 patients who arrived within 8 h after stroke onset and underwent MT resulting in a thrombolysis in cerebral infarction score of 2B or 3 were analyzed. Magnetic resonance imaging, including diffusion-weighted imaging (DWI) and ASL, was performed on arrival and the day after MT. The asymmetry index (AI) of CBF by ASL (ASL-CBF) before MT was calculated for 11 regions of interest using the DWI-Alberta Stroke Program Early CT Score. RESULTS: Occurrence of infarction after successful MT for ischemic stroke in the anterior circulation can be expected when the formula 0.3211â€¯× history of atrial fibrillation +0.0096â€¯× the AI of ASL-CBF before MT (%) +0.0012â€¯× the time from onset to reperfusion (min) yields a value below 1.0 or when the AI of ASL-CBF before MT is below 61.5%. CONCLUSION: The AI of ASL-CBF before MT or a combination of a history of atrial fibrillation, the AI of ASL-CBF before MT, and the time from onset to reperfusion can be used to predict the occurrence of infarction in patients arriving within 8 h after stroke onset in which reperfusion with MT was successful.

The Utility of Arterial Transit Time Measurement for Evaluating the Hemodynamic Perfusion State of Patients with Chronic Cerebrovascular Stenosis or Occlusive Disease: Correlative Study between MR Imaging and 15O-labeled H2O Positron Emission Tomography.

PURPOSE: To verify whether arterial transit time (ATT) mapping can correct arterial spin labeling-cerebral blood flow (ASL-CBF) values and to verify whether ATT is a parameter that correlates with positron emission tomography (PET)-oxygen extraction fraction (OEF) and PET-mean transit time (MTT). METHODS: Eleven patients with unilateral major cerebral artery stenosis or occlusion underwent MRI and PET in the chronic or asymptomatic phase. ASL-MRI acquisitions were conducted with each of two post-label delay (PLD) settings (0.7s and 2.0s) using a pseudo-continuous ASL pulse sequence and 3D-spin echo spiral readout with vascular crusher gradient. ATT maps were obtained using a low-resolution pre-scan approach with five PLD settings. Using the ASL perfusion images and ATT mapping, ATT-corrected ASL-CBF images were obtained. Four kinds of ASL-CBF methods (PLD 0.7s with or without ATT correction and PLD 2.0s with or without ATT correction) were compared to PET-CBF, using vascular territory ROIs. ATT and OEF were compared for all ROIs, unaffected side ROIs, and affected side ROIs, respectively. ATT and MTT were compared by the ratio of the affected side to the unaffected side. Transit time-based ROIs were used for the comparison with ATT. RESULTS: Comparing ASL-CBF and PET-CBF, the correlation was higher with ATT correction than without correction, and for a PLD of 2.0s compared with 0.7s. The best correlation was for PLD of 2.0s with ATT correction (R2 = 0.547). ROIs on the affected side showed a low but significant correlation between ATT and PET-OEF (R2 = 0.141). There was a low correlation between the ATT ratio and the MTT ratio (R2 = 0.133). CONCLUSION: Low-resolution ATT correction may increase the accuracy of ASL-CBF measurements in patients with unilateral major cerebral artery stenosis or occlusion. In addition, ATT itself might have a potential role in detecting compromised hemodynamic state.

Assessment of Arterial Transit Time and Cerebrovascular Reactivity in Moyamoya Disease by Simultaneous PET/MRI.

We investigated the relationship between MRI-arterial spin labeling (ASL) parameters and PET-cerebral blood flow (CBF)/cerebrovascular reactivity (CVR) simultaneously obtained by PET/MRI in Moyamoya disease. Twelve patients underwent 15O-water PET/MRI with the acetazolamide (ACZ) challenge test. PET-CBF and PET-CVR were measured using 15O-water PET. Pseudo-continuous ASL obtained the robust arterial transit time (ATT) and ASL-CBF estimation. ASL parameters were compared with PET-CBF and PET-CVR. Before ACZ loading, absolute and relative ASL-CBF were significantly correlated with absolute and relative PET-CBF (r = 0.44, p < 0.0001, and r = 0.55, p < 0.0001, respectively). After ACZ loading, absolute and relative ASL-CBF were significantly correlated with absolute and relative PET-CBF (r = 0.56, p < 0.001, and r = 0.75, p < 0.0001, respectively), and ΔASL-CBF was significantly correlated with ΔPET-CBF (r = 0.65, p < 0.0001). Baseline ASL-ATT had strong negative correlations with ΔPET-CBF and PET-CVR (r = -0.72, p < 0.0001, and r = -0.66, p < 0.0001, respectively). Baseline ASL-ATT of MCA territories with CVR <30% (1546 ± 79 ms) was significantly higher than that with CVR > 30% (898 ± 197 ms). ASL-ATT ratio of MCA territories with CVR < 30% (94.0 ± 10.5%) was significantly higher than that with CVR > 30% (81.4 ± 11.3%). ATT correction using multiple postlabeling delays increased the accuracy of ASL-CBF quantitation. Baseline ASL-ATT is a hemodynamic parameter and may represent an efficient alternative to PET-CVR.

Effect of newly developed scissors-attached micro-forceps on the recipient clamp time and occurrence of anastomotic site infarction after bypass surgery for moyamoya disease.

Introduction: This study aimed to examine the effect of newly developed scissors-attached micro-forceps in superficial temporal artery-to-middle cerebral artery (STA-MCA) anastomosis for moyamoya disease (MMD). Materials and methods: Of 179 consecutive STA-MCA anastomoses on 95 hemispheres of 71 MMD patients at the University of Fukui Hospital between 2009 and 2023, 49 anastomoses on 26 hemispheres of 21 patients were enrolled in this retrospective cohort clinical trial intraoperative indocyanine green video-angiography did not demonstrate bypass patency in three anastomoses in two patients who were excluded. Twenty-one anastomosis in 19 hemispheres of 16 patients were performed using the conventional micro-forceps (conventional group, CG), and 25 anastomoses in 22 hemispheres of 19 patients were performed using scissors-attached micro-forceps (scissors group, SG). A small infarction near the anastomotic site detected using postoperative diffusion-weighted imaging was defined as anastomotic site infarction (ASI). Factors affecting the occurrence of ASI were examined by univariate, logistic regression, and receiver operating curve (ROC) analysis. Results: There were no significant differences in clinical parameters such as age, sex, number of sacrificed branches, number of sacrificed large branches, and number of sutures between the CG and SG. However, the clamp time and occurrence of ASI were significantly lower in the SG than in the CG. Logistic regression analysis revealed that the clamp time was the only significant factor predicting the occurrence of ASI. A receiver operating curve analysis also revealed that the clamp time significantly predicted the occurrence of ASI (area under the curve, 0.875; cutoff value, 33.2 min). Conclusion: The newly developed scissors-attached micro-forceps could significantly reduce the clamp time and occurrence of ASI in STA-MCA anastomosis for MMD.

Cross-tissue correlations of genome-wide DNA methylation in Japanese live human brain and blood, saliva, and buccal epithelial tissues.

Neuroepigenetics considers genetic sequences and the interplay with environmental influences to elucidate vulnerability risk for various neurological and psychiatric disorders. However, evaluating DNA methylation of brain tissue is challenging owing to the issue of tissue specificity. Consequently, peripheral surrogate tissues were used, resulting in limited progress compared with other epigenetic studies, such as cancer research. Therefore, we developed databases to establish correlations between the brain and peripheral tissues in the same individuals. Four tissues, resected brain tissue, blood, saliva, and buccal mucosa (buccal), were collected from 19 patients (aged 13-73 years) who underwent neurosurgery. Moreover, their genome-wide DNA methylation was assessed using the Infinium HumanMethylationEPIC BeadChip arrays to determine the cross-tissue correlation of each combination. These correlation analyses were conducted with all methylation sites and with variable CpGs, and with when these were adjusted for cellular proportions. For the averaged data for each CpG across individuals, the saliva-brain correlation (r = 0.90) was higher than that for blood-brain (r = 0.87) and buccal-brain (r = 0.88) comparisons. Among individual CpGs, blood had the highest proportion of CpGs correlated to the brain at nominally significant levels (19.0%), followed by saliva (14.4%) and buccal (9.8%). These results were similar to the previous IMAGE-CpG results; however, cross-database correlations of the correlation coefficients revealed a relatively low (brain vs. blood: r = 0.27, saliva: r = 0.18, and buccal: r = 0.24). To the best of our knowledge, this is the fifth study in the literature initiating the development of databases for correlations between the brain and peripheral tissues in the same individuals. We present the first database developed from an Asian population, specifically Japanese samples (AMAZE-CpG), which would contribute to interpreting individual epigenetic study results from various Asian populations.

Quantitative Analysis of the Far-Lateral, Supra-Articular Transcondylar Transtubercular Approach Using Cadaveric Computed Tomography and Magnetic Resonance Imaging.

BACKGROUND: Removing the jugular tubercle (JT) is regarded as an important step in the far-lateral approach; however, few cadaveric studies have objectively evaluated it. OBJECTIVE: To quantitatively analyze the effect of JT removal in the far-lateral approach, using cadaveric computed tomography (CT) and magnetic resonance (MR) imaging. METHODS: The far-lateral, supra-articular transcondylar transtubercular approach was employed on 23 sides of 13 formalin-fixed cadaveric heads. CT bone images were obtained before and after JT removal, and MR images were obtained before dissection and were merged with the CT bone images. The angles of attack used to approach the ventral region of the medulla, the distances between the medulla and the bony structure, and the volume of the paramedullary space were measured at the level of the JT on axial CT-MR fusion images. The values obtained after JT removal were compared with those obtained before JT removal. RESULTS: All evaluated values were significantly increased after JT removal, including the angle of attack at the level of the JT (29.8 ± 7.4° vs 58.2 ± 15.5°, P < .001), the distance between the olive and the JT (6.4 ± 2.0 mm vs 9.5 ± 5.0 mm, P = .01), and the volume of the space around the medulla (0.28 ± 0.04 cm3 vs 0.47 ± 0.09 cm3, P < .001). CONCLUSION: The paramedullary surgical working space widened by JT removal was quantitatively demonstrated in the cadaveric CT and MR imaging study. The measurement methods in this study can be applied to clinical cases and other skull base cadaveric studies.

No significant difference found in PET/MRI CBF values reconstructed with CT-atlas-based and ZTE MR attenuation correction.

BACKGROUND: Accurate attenuation correction (AC) is one of the most important issues to be addressed in quantitative brain PET/MRI imaging. Atlas-based MRI AC (AB-MRAC), one of the representative MRAC methods, has been used to estimate the skull attenuation in brain scans. The zero echo time (ZTE) pulse sequence is also expected to provide a better MRAC estimation in brain PET scans. The difference in quantitative measurements of cerebral blood flow (CBF) using H215O-PET/MRI was compared between the two MRAC methods, AB and ZTE. METHOD: Twelve patients with cerebrovascular disease (4 males, 43.2 ± 11.7 years) underwent H215O-PET/MRI studies with a 3-min PET scan and MRI scans including the ZTE sequence. Eleven of them were also studied under the conditions of baseline and 10 min after acetazolamide administration, and 2 of them were followed up after several months interval. A total of 25 PET images were reconstructed as dynamic data using 2 sets of reconstruction parameters to obtain the image-derived input function (IDIF), the time-activity curves of the major cerebral artery extracted from images, and CBF images. The CBF images from AB- and ZTE-MRAC were then compared for global and regional differences. RESULTS: The mean differences of IDIF curves at each point obtained from AB- and ZTE-MRAC dynamic data were less than 5%, and the differences in time-activity curves were very small. The means of CBF from AB- and ZTE-MRAC reconstructions calculated using each IDIF showed differences of less than 5% for all cortical regions. CBF images from AB-MRAC tended to show greater values in the parietal region and smaller values in the skull base region. CONCLUSION: The CBF images from AB- and ZTE-MRAC reconstruction showed no significant differences in regional values, although the parietal region tended to show greater values in AB-MRAC reconstruction. Quantitative values in the skull base region were very close, and almost the same IDIFs were obtained.

Correlation between reduction in microvascular transit time after superficial temporal artery-middle cerebral artery bypass surgery for moyamoya disease and the development of postoperative hyperperfusion syndrome.

OBJECTIVE Hyperperfusion syndrome (HPS) is a notable complication that causes various neurological symptoms after superficial temporal artery (STA)-middle cerebral artery (MCA) bypass surgery for moyamoya disease (MMD). The authors used intraoperative indocyanine green (ICG) videoangiography to measure the change in microvascular transit time (MVTT) after bypass surgery. An analysis was then conducted to identify the correlation between change in MVTT and presence of postoperative HPS. METHODS This study included 105 hemispheres of 81 patients with MMD who underwent STA-MCA single bypass surgery between January 2010 and January 2015. Intraoperative ICG videoangiography was performed before and after bypass surgery. The MVTT was calculated from the ICG time intensity curve recorded in the pial arterioles and venules. Multivariate logistic regression analysis was conducted to test the effect of multiple variables, including the change in MVTT after bypass surgery, on postoperative HPS. RESULTS Postoperative HPS developed in 28 (26.7%) of the 105 hemispheres operated on. MVTT was reduced significantly after bypass surgery (prebypass 5.34 ± 2.00 sec vs postbypass 4.12 ± 1.60 sec; p < 0.001). The difference between prebypass and postbypass MVTT values, defined as ΔMVTT, was significantly greater in the HPS group than in the non-HPS group (2.55 ± 2.66 sec vs 0.75 ± 1.78 sec; p < 0.001). Receiver operating characteristic curve analysis revealed that the optimal cutoff point of ΔMVTT was 2.6 seconds (sensitivity 46.4% and specificity 85.7% as a predictor of postoperative HPS). A ΔMVTT > 2.6 seconds was an independent predictor of HPS in multivariate analysis (hazard ratio 4.88, 95% CI 1.76-13.57; p = 0.002). CONCLUSIONS MVTT in patients with MMD was reduced significantly after bypass surgery. Patients with a ΔMVTT > 2.6 seconds tended to develop postoperative HPS. Because ΔMVTT can be easily measured during surgery, it is a useful diagnostic tool for identifying patients at high risk for HPS after STA-MCA bypass surgery for MMD.