Radiofrequency Ablation of Re-entrant Atrial Tachycardia Originating from the Superior Vena Cava with a High-resolution, 3-dimensional Mapping System.

An 80-year-old man with no previous history of catheter ablation or cardiac surgery underwent catheter ablation for atrial tachycardia (AT). We suspected that the mechanism causing AT was re-entry indicated by the entrainment phenomenon during AT and through activation mapping with a 3-dimensional mapping system (EnSite™ X EP system; Abbott, Chicago, IL, USA). We used a multipolar catheter (Advisor™ HD Grid Mapping Catheter; Abbott) inserted into the superior vena cava (SVC) to accomplish activation mapping. The AT circuit was localized inside the SVC with a fractionated potential recorded on its right lateral wall. A similar fractionated potential was observed in the surrounding area. These areas functioned as the critical isthmus of the AT. Radiofrequency (RF) catheter ablation at these sites eliminated the tachycardia. After RF delivery, no tachycardia was induced by programmed stimulation, even during isoproterenol infusion. Consequently, there was no recurrence of tachycardia even after catheter ablation.

Histopathological characteristics of the arrhythmogenic right ventricular cardiomyopathy presenting the electrocardiographic characteristics with Brugada syndrome.

INTRODUCTION: The histopathological characteristics of the overlapping disease states of Brugada syndrome (BrS) and arrhythmogenic right ventricular cardiomyopathy (ARVC) have not been fully elucidated. METHODS: A 71-year-old man showed coved-type ST-segment elevation with the right precordial leads, and the echocardiography demonstrated right ventricular (RV) dilatation. After 11 months, he died of a polymorphic VT storm. RESULTS: The pathological tissue demonstrated fibrofatty degeneration in the free wall of the RV outflow tract based on the heart autopsy. CONCLUSION: The overlapping disease states of BrS and ARVC showed histopathological characteristics consistent with ARVC.

Connectivity alteration in thalamic nuclei and default mode network-related area in memory processes in mesial temporal lobe epilepsy using magnetoencephalography.

This work aimed to investigate the involvement of the thalamic nuclei in mesial temporal lobe epilepsy (MTLE) and identify the influence of interictal epileptic discharges on the neural basis of memory processing by evaluating the functional connectivity (FC) between the thalamic nuclei and default mode network-related area (DMNRA) using magnetoencephalography. Preoperative datasets of nine patients with MTLE with seizure-free status after surgery and those of nine healthy controls were analyzed. The FC between the thalamic nuclei (anterior nucleus [ANT], mediodorsal nucleus [MD], intralaminar nuclei [IL]), hippocampus, and DMNRA was examined for each of the resting, pre-spike, spike, and post-spike periods in the delta to ripple bands using magnetoencephalography. The FC between the ANT, MD, hippocampus, and medial prefrontal cortex increased in the gamma to ripple bands, whereas the FC between the ANT, IL, and DMNRA decreased in the delta to beta bands, compared with that of the healthy controls at rest. Compared with the rest period, the pre-spike period had significantly decreased FC between the ANT, MD, and DMNRA in the ripple band. Different FC changes between the thalamic nuclei, hippocampus, and DMNRA of specific connections in a particular band may reflect impairment or compensation in the memory processes.

Clinical Impacts of Stereotactic Electroencephalography on Epilepsy Surgery and Associated Issues in the Current Situation in Japan.

Stereotactic electroencephalography (SEEG) is receiving increasing attention as a safe and effective technique in the invasive evaluation for epileptogenic zone (EZ) detection. The main clinical question is whether the use of SEEG truly improves outcomes. Herein, we compared outcomes in our patients after three types of intracranial EEG (iEEG): SEEG, the subdural electrode (SDE), and a combined method using depth and strip electrodes. We present here our preliminary results from two demonstrative cases. Several international reports from large epilepsy centers found the following clinical advantages of SEEG: 1) three-dimensional analysis of structures, including bilateral and multilobar structures; 2) low rate of complications; 3) less pneumoencephalopathy and less patient burden during postoperative course, which allows the initiation of video-EEG monitoring immediately after implantation and does not require resection to be performed in the same hospitalization; and 4) a higher rate of good seizure control after resection. In other words, SEEG more accurately identified the EZ than the SDE method. We obtained similar results in our preliminary experiences under limited conditions. In Japan, as of August 2022, dedicated electrodes and SEEG accessories have not been approved and the use of the robot arm is not widespread. The Japanese medical community is hopeful that these issues will soon be resolved and that the experience with SEEG in Japan will align with that of large epilepsy centers internationally.

Magnetic resonance-guided focused ultrasound thalamotomy restored distinctive resting-state networks in patients with essential tremor.

OBJECTIVE: Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy ameliorates symptoms in patients with essential tremor (ET). How this treatment affects canonical brain networks has not been elucidated. The purpose of this study was to clarify changes of brain networks after MRgFUS thalamotomy in ET patients by analyzing resting-state networks (RSNs). METHODS: Fifteen patients with ET were included in this study. Left MRgFUS thalamotomy was performed in all cases, and MR images, including resting-state functional MRI (rsfMRI), were taken before and after surgery. MR images of 15 age- and sex-matched healthy controls (HCs) were also used for analysis. Using rsfMRI data, canonical RSNs were extracted by performing dual regression analysis, and the functional connectivity (FC) within respective networks was compared among pre-MRgFUS patients, post-MRgFUS patients, and HCs. The severity of tremor was evaluated using the Clinical Rating Scale for Tremor (CRST) score pre- and postoperatively, and its correlation with RSNs was examined. RESULTS: Preoperatively, ET patients showed a significant decrease in FC in the sensorimotor network (SMN), primary visual network (VN), and visuospatial network (VSN) compared with HCs. The decrease in FC in the SMN correlated with the severity of tremor. After MRgFUS thalamotomy, ET patients still exhibited a significant decrease in FC in a small area of the SMN, but they exhibited an increase in the cerebellar network (CN). In comparison between pre- and post-MRgFUS patients, the FC in the SMN and the VSN significantly increased after treatment. Quantitative evaluation of the FCs in these three groups showed that the SMN and VSN increased postoperatively and demonstrated a trend toward those of HCs. CONCLUSIONS: The SMN and CN, which are considered to be associated with the cerebello-thalamo-cortical loop, exhibited increased connectivity after MRgFUS thalamotomy. In addition, the FC of the visual network, which declined in ET patients compared with HCs, tended to normalize postoperatively. This could be related to the hypothesis that visual feedback is involved in tremor severity in ET patients. Overall, the analysis of the RSNs by rsfMRI reflected the pathophysiology with the intervention of MRgFUS thalamotomy in ET patients and demonstrated a possibility of a biomarker for successful treatment.

Cutoff values for the best management strategy for magnetic resonance-guided focused ultrasound ablation for essential tremor.

OBJECTIVE: The efficacy of magnetic resonance-guided focused ultrasound (MRgFUS) ablation for essential tremor (ET) is well known; however, no prognostic factors have been established. The authors aimed to retrospectively investigate MRgFUS ablation outcomes and associated factors and to define the cutoff values for each prognostic factor. METHODS: Sixty-four Japanese patients who underwent unilateral ventral intermediate nucleus thalamotomy with MRgFUS for ET were included. Follow-up evaluations were performed at 1 week and 1, 3, 6, 12, and 24 months postoperatively. Tremor suppression was evaluated using the Clinical Rating Scale for Tremor (CRST), and adverse effects were recorded postoperatively. Outcome-associated factors were examined preoperatively, intraoperatively, and postoperatively using multivariate analyses. The cutoff values for the prognostic factors were calculated using receiver operating characteristics. RESULTS: Percentage improvements in the CRST scores of the affected upper limb were 82.4%, 72.2%, 68.6%, and 65.9% at 1, 3, 6, and 12 months, respectively. Preoperatively, a high skull density ratio (SDR) (p ≤ 0.047), low CRST part B score (used to assess tremors during several tasks) (cutoff value 25, p ≤ 0.041), and nonoccurrence of resting tremors (p = 0.027) were significantly associated with improved tremor control. An intraoperatively high maximum mean temperature (cutoff value 52.5°C, p ≤ 0.047), postoperatively large lesion (cutoff value 3.9 mm in the anterior-posterior direction, p ≤ 0.002; cutoff value 5.0-5.55 mm in the superior-inferior direction, p ≤ 0.026), and small transducer focus correction (p ≤ 0.015) were also associated with improved tremor control. No valid cutoff value was found for SDR. Adverse effects (limb weakness, sensory disturbance, ataxia/walking disturbance, dysgeusia, dysarthria, and facial swelling) occurred transiently and were associated with high SDR, high temperature, high number of sonication sessions, large lesion, and occurrence of resting tremor. Patients who developed leg weakness experienced greater percentage improvement in tremors at 3 months postoperatively than those who did not. CONCLUSIONS: MRgFUS ablation could be used to achieve good tremor control with acceptable adverse effects in Japanese patients with ET. The relatively low SDR in Asian ethnic groups as compared with that of Western populations makes treatment difficult; however, the cutoff values obtained in this study may be useful for achieving good treatment outcomes even in such patients. Clinical trial registration no.: UMIN000026952 (University Hospital Medical Information Network). ABBREVIATIONS: ACPC = anterior commissure-posterior commissure; AP = anterior to posterior; CRST = Clinical Rating Scale for Tremor; ET = essential tremor; MRgFUS = magnetic resonance-guided focused ultrasound; PC = posterior commissure; PSA = posterior subthalamic area; RL = right to left; ROC = receiver operating characteristic; SDR = skull density ratio; SI = superior to inferior; T2WI = T2-weighted imaging; VIM = ventral intermediate nucleus.

A case report: Dual-lead deep brain stimulation of the posterior subthalamic area and the thalamus was effective for Holmes tremor after unsuccessful focused ultrasound thalamotomy.

Holmes tremor is a symptomatic tremor that develops secondary to central nervous system disorders. Stereotactic neuromodulation is considered when the tremors are intractable. Targeting the ventral intermediate nucleus (Vim) is common; however, the outcome is often unsatisfactory, and the posterior subthalamic area (PSA) is expected as alternative target. In this study, we report the case of a patient with intractable Holmes tremor who underwent dual-lead deep brain stimulation (DBS) to stimulate multiple locations in the PSA and thalamus. The patient was a 77-year-old female who complained of severe tremor in her left upper extremity that developed one year after her right thalamic infarction. Vim-thalamotomy using focused ultrasound therapy (FUS) was initially performed but failed to control tremor. Subsequently, we performed DBS using two leads to stimulate four different structures. Accordingly, one lead was implanted with the aim of targeting the ventral oralis nucleus (Vo)/zona incerta (Zi), and the other with the aim of targeting the Vim/prelemniscal radiation (Raprl). Electrode stimulation revealed that Raprl and Zi had obvious effects. Postoperatively, the patient achieved good tremor control without any side effects, which was maintained for two years. Considering that she demonstrated resting, postural, and intention/action tremor, and Vim-thalamotomy by FUS was insufficient for tremor control, complicated pathogenesis was presumed in her symptoms including both the cerebellothalamic and the pallidothalamic pathways. Using the dual-lead DBS technique, we have more choices to adjust the stimulation at multiple sites, where different functional networks are connected. Intractable tremors, such as Holmes tremor, may have complicated pathology, therefore, modulating multiple pathological networks is necessary. We suggest that the dual-lead DBS (Vo/Raprl and Vim/Zi) presented here is safe, technically feasible, and possibly effective for the control of Holmes tremor.

Multitier Network Analysis Using Resting-state Functional MRI for Epilepsy Surgery.

Resting-state functional MRI (rs-fMRI) has been utilized to visualize large-scale brain networks. We evaluated the usefulness of multitier network analysis using rs-fMRI in patients with focal epilepsy. Structural and rs-fMRI data were retrospectively evaluated in 20 cases with medically refractory focal epilepsy, who subsequently underwent surgery. First, structural changes were examined using voxel-based morphometry analysis. Second, alterations in large-scale networks were evaluated using dual-regression analysis. Third, changes in cortical hubs were analyzed and the relationship between aberrant hubs and the epileptogenic zone (EZ) was evaluated. Finally, the relationship between the hubs and the default mode network (DMN) was examined using spectral dynamic causal modeling (spDCM). Dual-regression analysis revealed significant decrease in functional connectivity in several networks including DMN in patients, although no structural difference was seen between groups. Aberrant cortical hubs were observed in and around the EZ (EZ hubs) in 85% of the patients, and a strong degree of EZ hubs correlated to good seizure outcomes postoperatively. In spDCM analysis, facilitation was often seen from the EZ hub to the contralateral side, while inhibition was seen from the EZ hub to nodes of the DMN. Some cognition-related networks were impaired in patients with focal epilepsy. The EZ hub appeared in the vicinity of EZ facilitating connections to distant regions in the early phase, which may eventually generate secondary focus, while inhibiting connections to the DMN, which may cause cognitive deterioration. Our results demonstrate pathological network alterations in epilepsy and suggest that earlier surgical intervention may be more effective.

Techniques, Indications, and Outcomes in Magnetic Resonance-guided Focused Ultrasound Thalamotomy for Tremor.

Magnetic resonance (MR)-guided focused ultrasound surgery (MRgFUS) is the latest minimally invasive stereotactic procedure, and thalamotomy using this novel modality has demonstrated its effectiveness and safety, especially for patients with essential tremor (ET) and Parkinson's disease (PD). In Japan, the application of MRgFUS to treat ET and PD has recently been covered by health insurance. Technically, the transducer with 1024 elements emits ultrasound beams, which are then focused on the target with a phase control, resulting in optimal ablation by thermal coagulation. The technical advantages of MRgFUS are continuous intraoperative monitoring of clinical symptoms and MR images and fine adjustment of the target by the steering function. Postoperative tremor control is compatible with other modalities, although long-term follow-up is necessary. The adverse effects are usually transient and acceptable. Prognostic factors for good tremor control include high temperature and large lesion size. A high skull density ratio is a factor to achieve high temperature and large lesioning, but it may not be necessary and sufficient for clinical outcomes. For patients with advanced symptoms such as bilateral tremor or head/neck tremor, deep brain stimulation may be recommended because of the adjustability of stimulation and the possibility of bilateral treatment. Patients have high expectations of MRgFUS because of its non-invasiveness. To perform this treatment safely and effectively, physicians need to understand the technological aspects, the physiological principles. To choose the appropriate modality, physicians also should recognize the clinical advantages and disadvantages of MRgFUS compared to other modalities.

[Magnetic Resonance-guided Focused Ultrasound Ablation:Techniques and Neurological Applications].

Magnetic resonance(MR)-guided focused ultrasound ablation(FUS)is a minimally invasive technique for targeted tissue thermo-ablation and is promising for neuromodulation in various neurological disorders. The effectiveness and safety of this technique have been recognized worldwide. In Japan, the applications of FUS for the treatment of essential tremors and Parkinson's disease have recently been covered under health insurance. The FUS system is composed of a phased-array transducer with 1024 elements, with a beam of ultrasound emerging from each element. The phase and amplitude of the beam are computed and controlled to focus on the target with the calculation of computed tomography(CT)profiles, resulting in optimal thermo-ablation. To utilize FUS safely and effectively, a deep understanding of the physics of this technology is necessary. Furthermore, the technique should be compared with other options including deep brain stimulation(DBS)and radiofrequency thermo-ablation. Although FUS has received attention because of minimally invasive characteristics and a possibility of procedural target refinement, DBS has some advantages on bilateral implantation, a potential of postoperative adjustment, and control of head/leg tremors. In this article, we first reviewed the physics of FUS and demonstrated the typical treatment protocols. Second, we reviewed the outcomes from the existing literature, and revealed the advantages and disadvantages of this procedure, with the evaluation of the optimal condition for FUS.

[A Case of Unilateral Multiple Cerebral Edema 4 Weeks after Coil Embolization].

Coil embolization for cerebral aneurysms can lead to various complications, such as aneurysm rupture and cerebral embolism. In recent years, foreign substance embolisms-caused by peeling off of coating materials from therapeutic devices-have been described. We report here a case of unilateral multiple cerebral edema four weeks after coil embolization. A 44-year-old woman presented with a subarachnoid hemorrhage from a right internal carotid-posterior communicating artery aneurysm, for which coil embolization was performed. Four weeks after the embolization, she developed numbness in the left side of her mouth and in her left upper extremity. Magnetic resonance images showed multiple edematous lesions in the right cerebral hemisphere. Subsequent treatment with steroids improved her symptoms and edematous cerebral lesions. Although definitive diagnosis by biopsy was not performed, her clinical course and imaging findings resembled a foreign substance embolism by hydrophilic coating. It is important to note that delayed cerebral edema due to foreign substance embolisms might occur after endovascular treatments.

Repeated Intracranial Hemorrhage After Delivery Induced by Coagulopathy Associated with Multiple Venous Malformations.

BACKGROUND: Venous malformations are classified as slow-flow vascular malformations. Coagulation abnormalities are known to be frequent among patients with venous malformations. We report a case of repeated intracranial hemorrhage after delivery, induced by coagulopathy associated with multiple venous malformations. CASE DESCRIPTION: A 28-year-old woman presented with left chronic subdural hematoma 1 month after successfully giving birth. She had a history of multiple venous malformations around the pubic region and hips. The hematoma was evacuated by burr hole surgery. Three hours later, her level of consciousness rapidly deteriorated and computed tomography showed acute epidural hematoma. The hematoma was removed immediately by craniotomy under general anesthesia. No bleeding points were apparent in the operative field. Continuous bleeding around the dura mater and subdural space were encountered, and hemostasis was not achieved by electrocoagulation. After using fresh frozen plasma, hemostasis was achieved. Level of consciousness and neurologic symptoms improved postoperatively. Magnetic resonance imaging revealed multiple venous malformations in bilateral lower extremities and the pelvis. Disseminated intravascular coagulopathy was diagnosed, and thrombomodulin and blood coagulation factor XIII were administered. She was discharged home without any neurologic deficits. CONCLUSIONS: The delivery activated localized intravascular coagulopathy in the venous malformations and induced chronic subdural hematoma. Surgical interventions then resulted in progression of the coagulopathy to disseminated intravascular coagulopathy, inducing acute epidural hematoma.

Long-Term Outcomes for Pediatric Patients with Brain Arteriovenous Malformations Treated with Gamma Knife Radiosurgery, Part 2: The Incidence of Cyst Formation, Encapsulated Hematoma, and Radiation-Induced Tumor.

OBJECTIVE: Long-term data about the incidence of late adverse radiation effects (AREs) in pediatric brain arteriovenous malformations (AVMs) treated with Gamma Knife radiosurgery (GKRS) are lacking. This study addresses the incidence of late AREs, including cyst formation (CF), chronic encapsulated hematoma (CEH), and radiation-induced tumor, in pediatric patients with AVM treated with GKRS. METHODS: This is a single-institutional study involving pediatric patients with AVM who underwent GKRS between 1991 and 2014. Among 201 pediatric patients with AVM (age ≤15 years), 189 who had at least 12 months of follow-up were assessed in this study. The median treatment volume was 2.2 cm3, and the median marginal dose was 20 Gy. RESULTS: The mean follow-up period was 136 months. During the follow-up period, symptomatic radiation-induced perilesional edema was found in 5 patients (3%), CFs in 7 patients (4%), CEHs in 7 patients (4%), and radiation-induced tumors in 2 patients (1%). The cumulative incidences of late AREs including CF, CEH, and radiation-induced tumor were 1.2% at 5 years, 5.2% at 8 years, 6.1% at 10 years, 7.2% at 15 years, and 17.0% at 20 years. In the multivariate analysis, treatment volume alone was a significant factor for late AREs (P < 0.001; hazard ratio, 1.111). CONCLUSIONS: GKRS is a reasonable treatment option for pediatric AVMs to prevent future intracranial hemorrhages, particularly in the eloquent regions. However, considerable attention should be paid to late AREs such as CFs, CEHs, and radiation-induced tumors because of longer life expectancy in pediatric patients.

Long-Term Outcomes for Pediatric Patients with Brain Arteriovenous Malformations Treated with Gamma Knife Radiosurgery, Part 1: Analysis of Nidus Obliteration Rates and Related Factors.

OBJECTIVE: Little is known about long-term outcomes for pediatric brain arteriovenous malformations (AVMs) treated with Gamma Knife radiosurgery (GKRS). This study investigated annual hemorrhage rates and nidus obliteration rates, and the factors affecting them, in pediatric AVMs treated with GKRS. METHODS: We examined 189 pediatric AVM patients (age ≤15 years) who underwent GKRS and had at least 12 months of follow-up. The Spetzler-Martin (S-M) grade was I in 29 patients (15%), II in 57 (30%), III in 82 (43%), IV in 16 (9%), and V in 5 (3%). The median treatment volume was 2.2 cm3, and the median marginal dose was 20 Gy. RESULTS: The mean follow-up period was 136 months. During a cumulative latency period to nidus obliteration of 813 years, 23 hemorrhages occurred, resulting in an annual post-GKRS hemorrhage rate of 2.8%. The cumulative hemorrhage rates after GKRS were 3.3%, 8.5%, and 11.9% at 3, 5, and 10 years, respectively. Higher S-M grade was significantly associated with intracranial hemorrhages during the latency period (P < 0.001). The actuarial nidus obliteration rates with repeated GKRS were 64% and 81% at 5 and 10 years, respectively. Absence of pre-GKRS embolization (P = 0.023) and higher marginal dose (P = 0.029) were significant factors predicting nidus obliteration. CONCLUSIONS: GKRS is a reasonable treatment option in pediatric AVMs to prevent future hemorrhages. Because higher S-M grade AVMs are more likely to hemorrhage during the latency period, a combined therapy with endovascular embolization should be considered to prevent AVM rupture.

[Meteorological Factors that Affect Stroke Onset].

BACKGROUND: To date, there have been many publications concerning relationship of meteorological condition and stroke onset. However, little is known about detailed meteorological factors that affect stroke onset. With hospital characteristics that most inpatients at our institution lived around Komaki, we examined the relationship between stroke onset and meteorological factors based on detailed meteorological data of Komaki. MATERIALS AND METHODS: Between April 1, 2012 and March 31, 2015, 1351 stroke patients admitted to Komaki City Hospital were enrolled in this study. These patients were classified into hypertensive intracranial hemorrhage(ICH), subarachnoid hemorrhage(SAH), and cerebral infarction(CI). Meteorological conditions such as season, weather, temperature, atmospheric pressure, and humidity were evaluated as factors that affect stroke onset. RESULTS: The incidence of ICH was lower in summer, and the minimum daily temperature was significantly related to ICH onset. The incidence of SAH was significantly related to the temperature difference compared to that on the previous day. When the mean temperature was lower than that on the previous day, the incidence of SAH was higher. No meteorological factor was found to affected the incidence of CI in this study. CONCLUSIONS: This study indicated that seasons and temperatures affect stroke onset.

Long-term hearing outcomes after gamma knife surgery in patients with vestibular schwannoma with hearing preservation: evaluation in 92 patients with serial audiograms.

The treatment strategy for patients with vestibular schwannoma (VS) is controversial, and data concerning the long-term hearing outcomes > 5 years after gamma knife surgery (GKS) are limited. The long-term hearing outcomes after GKS were evaluated in VS patients with hearing preservation. Ninety-two VS patients with a pure tone average (PTA) ≤ 50 dB were evaluated. The median age was 54 years; the median tumor volume was 1.5 cm3. The tumors were treated with a median margin dose of 12 Gy and a median mean cochlear dose of 4.0 Gy. At the time of GKS, 65 patients retained a PTA of 0-30 dB, and 27 had a PTA of 31-50 dB. The median follow-up period was 106 months. At the final follow-up, 2 (2%) developed tumor progression. During the median audiogram follow-up of 83 months, the PTA was ≤ 30 dB in 22 patients (24%) and 31-50 dB in 27 patients (29%); 43 patients (47%) worsened to a PTA > 50 dB. Hearing preservation rates were 66, 57, and 44% at 3, 5, and 10 years, respectively. In multivariate analysis, the mean cochlear dose (P < 0.001) and pre-GKS PTA (P = 0.045) were significant for hearing preservation. GKS was an effective treatment option for VS patients with a PTA ≤ 50 dB. As a lower cochlear dose and better pre-GKS PTA contributed to long-term hearing preservation, prophylactic GKS before hearing deterioration or tumor growth would be a treatment of choice if patients provided informed consent.

The dose and risk factors for radiation exposure to medical staff during endobronchial ultrasonography with a guide sheath for peripheral pulmonary lesions under X-ray fluoroscopy.

OBJECTIVE: Therapy for lung cancer has recently evolved to include molecular targeted therapy and adequate amounts of lung cancer tissue are needed to identify particular phenotypes. For this purpose, quite a number of investigations on diagnostic bronchoscopy have been undertaken. Corollary to the increasing number of transbronchial biopsies for peripheral pulmonary nodules is the increased chances of radiation exposure during fluoroscopy. Our aim was to determine the dose and risk factors of radiation exposure to medical staff. METHODS: Endobronchial ultrasonography with a guide sheath under X-ray fluoroscopy was performed on 132 cases of peripheral pulmonary lesions. The radiation exposure dose to medical staff (operator physicians, assistant physicians, nurses and radiological technologists) was measured. RESULTS: The median time of fluoroscopy was 7.6 min (range 1.5-23.9). The median radiation exposure dose to operator physicians was 12 µSv/exam (range 1-99), while that of the other medical staff was lower. In a multivariate analysis, body mass index and the location of the radial ultrasound probe had significantly higher odds ratios. CONCLUSIONS: The risk factors for an increased radiation exposure dose were patients' BMI and the location of the radial ultrasound probe. But even then, the radiation exposure dose to medical staff during endobronchial ultrasonography with a guide sheath was very low, especially for nurses and radiological technologists in whom the exposure dose was negligible.

The value of chest tomosynthesis in locating a ground glass nodule (GGN) during endobronchial ultrasonography with a guide sheath: a case report.

A 74-year-old man was referred to our department for work-up of a pure ground glass nodule (GGN) on computed tomography (CT). He was suspected to have lung cancer by CT scan, but no lesion was visible on chest X-ray. Chest tomosynthesis was performed before bronchoscopy, showing a clear GGN. We could not detect a tumor signal on endobronchial ultrasonography so we relied on the chest tomosynthesis image as a guide during transbronchial biopsy. The diagnosis of adenocarcinoma was confirmed on histopathology. In this case, transbronchial biopsy under the guidance of chest tomosynthesis was useful for the diagnosis of GGN.

Repeated treatment with nicotine induces phosphorylation of NMDA receptor NR2B subunit in the brain regions involved in behavioral sensitization.

Protein phosphorylation is an important mechanism for the post-translational modulation of N-methyl-d-aspartate (NMDA) receptor functions. In the present study, we investigated the levels of NR2B phosphorylation at Tyr1472 and Ser1303 in the nucleus accumbens, striatum, frontal cortex, and hippocampus of rats that exhibit behavioral sensitization to nicotine. Repeated treatment of rats with nicotine (0.6mg/kg, s.c., for 7 days) produced locomotor sensitization accompanied by increased NR2B phosphorylation at Tyr1472 in the nucleus accumbens and striatum, brain regions involved in behavioral sensitization. In contrast, no changes in NR2B phosphorylation were observed after a single treatment with nicotine in these brain regions. In addition, no changes in NR2B phosphorylation at Ser1303 were observed after repeated treatment with nicotine in any examined brain regions. These results suggest that repeated treatment with nicotine induces NR2B phosphorylation at Tyr1472 in the nucleus accumbens and striatum, which might contribute to the development of synaptic and behavioral plasticity in response to nicotine.