Comparison of EUS and ERCP-guided tissue sampling in suspected biliary stricture.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS) are commonly used diagnostic modalities in biliary strictures. We compared the diagnostic yield of EUS and ERCP-based tissue sampling in intrinsic biliary strictures without extrinsic mass outside the bile duct. METHODS: A total of 85 patients who underwent ERCP and EUS for diagnosis of suspected biliary strictures confined to the bile duct were analyzed retrospectively at Samsung Medical Center, Seoul, Korea, between 2010 and 2018. RESULTS: Seventy-one patients were diagnosed with malignancy and 14 patients were diagnosed with benign strictures. EUS-based tissue sampling was more sensitive and accurate than ERCP-based tissue sampling (p = 0.038). The overall sensitivity and accuracy were 67.6% (95% confidence interval (CI) 56.1-77.3) and 72.9% (95% CI 62.7-81.2) for ERCP-based sampling, and 80.3% (95% CI 69.6-87.9) and 83.5% (95% CI 74.2-89.9) for EUS-based sampling, respectively. EUS-based sampling was superior to ERCP-based sampling in distal bile duct strictures (accuracy: 87.0% vs. 72.5%, p = 0.007), but not in perihilar strictures. In cases without intraductal mass, EUS-based tissue sampling was also superior to ERCP-based sampling (accuracy: 83.3% vs. 69.7%, p = 0.029), but not in cases with mass. CONCLUSION: EUS-based tissue sampling was superior to ERCP-based method in intrinsic biliary stricture with no mass outside the bile duct, particularly in those without intraductal mass or those with strictures located in distal bile duct. Therefore, EUS-based sampling should be considered for making a pathological diagnosis of suspected distal bile duct strictures even in lesions without definite mass.

Neural correlates of implicit agency during the transition from adolescence to adulthood: An ERP study.

Sense of agency (SoA), the experience of being in control of our voluntary actions and their outcomes, is a key feature of normal human experience. Frontoparietal brain circuits associated with SoA undergo a major maturational process during adolescence. To examine whether this translates to neurodevelopmental changes in agency experience, we investigated two key neural processes associated with SoA, the activity that is leading to voluntary action (Readiness Potential) and the activity that is associated with the action outcome processing (attenuation of auditory N1 and P2 event related potentials, ERPs) in mid-adolescents (13-14), late-adolescents (18-20) and adults (25-28) while they perform an intentional binding task. In this task, participants pressed a button (action) that delivered a tone (outcome) after a small delay and reported the time of the tone using the Libet clock. This action-outcome condition alternated with a no-action condition where an identical tone was triggered by a computer. Mid-adolescents showed greater outcome binding, such that they perceived self-triggered tones as being temporally closer to their actions compared to adults. Suggesting greater agency experience over the outcomes of their voluntary actions during mid-adolescence. Consistent with this, greater levels of attenuated neural response to self-triggered auditory tones (specifically P2 attenuation) were found during mid-adolescence compared to older age groups. This enhanced attenuation decreased with age as observed in outcome binding. However, there were no age-related differences in the readiness potential leading to the voluntary action (button press) as well as in the N1 attenuation to the self-triggered tones. Notably, in mid-adolescents greater outcome binding scores were positively associated with greater P2 attenuation, and smaller negativity in the late readiness potential. These findings suggest that the greater experience of implicit agency observed during mid-adolescence may be mediated by a neural over-suppression of action outcomes (auditory P2 attenuation), and over-reliance on motor preparation (late readiness potential), which we found to become adult-like during late-adolescence. Implications for adolescent development and SoA related neurodevelopmental disorders are discussed.

Functional and Structural Connectivity of the Cerebellar Nuclei With the Striatum and Cerebral Cortex in First-Episode Psychosis.

OBJECTIVE: Evidence suggests that the cortico-striatal-thalamo-cortical circuitry plays an important role in schizophrenia pathophysiology. Cerebellar contribution from deep cerebellar nuclei to the circuitry has not yet been examined. The authors investigated resting-state functional connectivity (RSFC) of cerebellar output nuclei with striatal-thalamic-cortical regions in relation to white-matter integrity and regional gray-matter volumes in first-episode psychosis (FEP). Methods: Forty FEP patients and 40 age- and gender-matched healthy control subjects (HCs) participated. RSFC between cerebellar nuclei and striatal-thalamic-cortical regions was examined. Diffusion tensor imaging and volumetric scans were examined for possible structural constraints on RSFC. The authors also examined relationships between neuroimaging variables and cognitive and clinical measures. Results: FEP patients, compared with HCs, exhibited decreased RSFC between the left fastigial nucleus and right putamen, which was associated with poor letter fluency performance and lower global assessment of functioning scores. By contrast, patients showed widespread increased accumbens network connectivity in the left nucleus. The authors further observed both hypo- and hyper-RSFC between the cerebellar nuclei and fronto-parietal areas in patients, independent of striatal activity. Finally, the authors found impaired integrity of the left superior cerebellar peduncle and decreased bilateral putamen volume in patients, whereas structural-functional relationships found in HCs were absent in patients. Conclusions: This study provides evidence of disordered RSFC of cerebellar output nuclei to the striatum and neocortex at the early stage of schizophrenia. Furthermore, dysfunctional cerebellar influences on fronto-parietal areas that are independent of striatal dysfunction in patients with FEP were observed. The results suggest that cortico-striatal abnormalities in patients with FEP are produced by abnormal cerebellar influences.

Inverse Prognostic Relationships of 18F-FDG PET/CT Metabolic Parameters in Patients with Distal Bile Duct Cancer Undergoing Curative Surgery.

PURPOSE: As there were few previous studies with a small number of subjects, the purpose of this was to evaluate the prognostic significance of 18F-FDG PET/CT in patients with distal bile duct cancer undergoing curative surgery. METHODS: The study included 40 patients (M/F = 24:16; age 68.0 ± 8.0 years) who underwent preoperative 18F-FDG PET/CT followed by curative surgical resection. The participant's age, sex, Eastern Cooperative Oncology Group performance-status score, baseline serum CA 19-9 level, stage, pathologic T and N stages, tumor size, tumor grade, tumor growth pattern, R0 resection, and adjuvant therapy were included as clinicopathological variables for predicting overall survival. The PET variables were maximum standardized uptake value (SUVmax), average SUV (SUVavg), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the tumor. The Kaplan-Meyer method and Cox proportional hazards model were used for the survival analysis. RESULTS: A total of 15 of 40 patients (37.5%) died during the follow-up period. In univariate analysis, low SUVmax (≤ 2.7, p = 0.0005) and low SUVavg (≤ 2.6, p = 0.0034) were significant predictors of poor overall survival. In multivariate analyses, only low SUVmax (HR = 6.7016, 95% CI 1.9961-22.4993, p = 0.0047) was an independent prognostic factor associated with poor overall survival. CONCLUSION: The SUVmax of the primary tumor measured by 18F-FDG PET/CT was an independent significant prognostic factor for overall survival in patients with distal bile duct cancer. However, different results from a previous study warrant further large sample-sized study.

Cerebellar Structural Abnormalities Associated With Cognitive Function in Patients With First-Episode Psychosis.

Introduction: The fundamental role of the cerebellum in higher cognitive processing has recently been highlighted. However, inconsistent findings exist in schizophrenia with respect to the exact nature of cerebellar structural abnormalities and their associations with cognitive and clinical features. Materials and Methods: We undertook a detailed investigation of cerebellar lobular volumes in 40 patients with first-episode psychosis (FEP) and 40 healthy controls (HCs) using the spatially unbiased atlas template of the cerebellum (SUIT). We examined the functional significance of cerebellar structural abnormalities in relation to cognitive and clinical outcomes in patients. Results: We found that left cerebellar lobules VI and X volumes were lower in FEP patients, compared to HCs. Smaller left lobules VI and X volumes were associated with fewer number of categories completed on the Wisconsin Card Sorting Test (WCST) in patients. In addition, smaller left lobule X volume was related to performance delay on the Trail Making Test (TMT) Part B in patients. Conclusion: Our results demonstrate that cerebellar structural abnormalities are present at the early stage of schizophrenia. We suggest functional associations of cerebellar structural changes with non-verbal executive dysfunctions in FEP.

Prevalence and detection of low-allele-fraction variants in clinical cancer samples.

Accurate detection of genomic alterations using high-throughput sequencing is an essential component of precision cancer medicine. We characterize the variant allele fractions (VAFs) of somatic single nucleotide variants and indels across 5095 clinical samples profiled using a custom panel, CancerSCAN. Our results demonstrate that a significant fraction of clinically actionable variants have low VAFs, often due to low tumor purity and treatment-induced mutations. The percentages of mutations under 5% VAF across hotspots in EGFR, KRAS, PIK3CA, and BRAF are 16%, 11%, 12%, and 10%, respectively, with 24% for EGFR T790M and 17% for PIK3CA E545. For clinical relevance, we describe two patients for whom targeted therapy achieved remission despite low VAF mutations. We also characterize the read depths necessary to achieve sensitivity and specificity comparable to current laboratory assays. These results show that capturing low VAF mutations at hotspots by sufficient sequencing coverage and carefully tuned algorithms is imperative for a clinical assay.

Clinical outcomes of everolimus in patients with advanced, nonfunctioning pancreatic neuroendocrine tumors: a multicenter study in Korea.

PURPOSE: Everolimus is a standard treatment option for advanced pancreatic neuroendocrine tumors (pNETs). This multicenter study evaluated the efficacy and safety of everolimus in low and intermediate grade advanced pNETs. METHODS: Tumors were graded according to the World Health Organization 2010 classification system. Patients with low or intermediate grade pNETs who received everolimus as first- or second-line chemotherapy between 2002 and 2014 were included. RESULTS: A total of 40 patients with metastatic or recurrent pNETs were included in this study. The median age was 54.5 years (range 19-83 years). Twelve patients (30%) experienced recurrence. There were 11 patients (27.5%) with low grade pNETs and 29 (72.5%) with intermediate. Everolimus was administered as first-line therapy in 30 patients (75%) and as second-line therapy in 10 patients (25%). The median progression-free survival (PFS) of patients with low and intermediate grade pNETs was significantly different (median not reached vs. 11 months, P = 0.015). On multivariate analysis, tumor grade (intermediate grade; HR 6.52, 95% CI 1.31-32.27, P = 0.022) was the only independent prognostic factor for PFS in pNETs. The most common adverse events were stomatitis, skin rash, and anemia. CONCLUSIONS: World Health Organization 2010 grade is the most important determinant for PFS in patients undergoing everolimus treatment for pNETs with an acceptable incidence of adverse events.

Is There an Association Between Mismatch Negativity and Cortical Thickness in Schizophrenia Patients?

INTRODUCTION: Mismatch negativity (MMN) is thought to reflect preattentive, automatic auditory processing. Reduced MMN amplitude is among the most robust findings in schizophrenia research. MMN generators have been shown to be located in the temporal and frontal cortices, which are key areas in the pathophysiology of schizophrenia. This study investigated whether frontotemporal cortical thickness was associated with reduced MMN current source density (CSD) strength in patients with schizophrenia. METHODS: Sixteen schizophrenia patients and 18 healthy controls (HCs) were examined using magnetoencephalography while they performed a passive auditory oddball paradigm. All participants underwent a T1 structural magnetic resonance imaging scan in a separate session. We evaluated MMN CSD and cortical thickness, and their associations, in the superior and transverse temporal gyri, as well as in the inferior and middle frontal gyri. RESULTS: Patients exhibited significantly reduced CSD strength in all temporal and frontal areas of interest relative to HCs. There was a positive correlation between CSD strength and cortical thickness in both temporal and frontal areas in HCs. However, schizophrenia patients showed negative correlations between CSD strength and cortical thickness in the bilateral inferior frontal gyri. Additionally, we found positive correlations between frontal cortical thickness and negative and total scores on the Positive and Negative Syndrome Scale (PANSS). CONCLUSIONS: Our findings provide evidence for deficient temporal and frontal MMN generators and a disruption of normal structure-function relationship in patients with schizophrenia.

Brain Structural Networks Associated with Intelligence and Visuomotor Ability.

Increasing evidence indicates that multiple structures in the brain are associated with intelligence and cognitive function at the network level. The association between the grey matter (GM) structural network and intelligence and cognition is not well understood. We applied a multivariate approach to identify the pattern of GM and link the structural network to intelligence and cognitive functions. Structural magnetic resonance imaging was acquired from 92 healthy individuals. Source-based morphometry analysis was applied to the imaging data to extract GM structural covariance. We assessed the intelligence, verbal fluency, processing speed, and executive functioning of the participants and further investigated the correlations of the GM structural networks with intelligence and cognitive functions. Six GM structural networks were identified. The cerebello-parietal component and the frontal component were significantly associated with intelligence. The parietal and frontal regions were each distinctively associated with intelligence by maintaining structural networks with the cerebellum and the temporal region, respectively. The cerebellar component was associated with visuomotor ability. Our results support the parieto-frontal integration theory of intelligence by demonstrating how each core region for intelligence works in concert with other regions. In addition, we revealed how the cerebellum is associated with intelligence and cognitive functions.

Differential sensory cortical involvement in auditory and visual sensorimotor temporal recalibration: Evidence from transcranial direct current stimulation (tDCS).

Adaptation to delayed sensory feedback following an action produces a subjective time compression between the action and the feedback (temporal recalibration effect, TRE). TRE is important for sensory delay compensation to maintain a relationship between causally related events. It is unclear whether TRE is a sensory modality-specific phenomenon. In 3 experiments employing a sensorimotor synchronization task, we investigated this question using cathodal transcranial direct-current stimulation (tDCS). We found that cathodal tDCS over the visual cortex, and to a lesser extent over the auditory cortex, produced decreased visual TRE. However, both auditory and visual cortex tDCS did not produce any measurable effects on auditory TRE. Our study revealed different nature of TRE in auditory and visual domains. Visual-motor TRE, which is more variable than auditory TRE, is a sensory modality-specific phenomenon, modulated by the auditory cortex. The robustness of auditory-motor TRE, unaffected by tDCS, suggests the dominance of the auditory system in temporal processing, by providing a frame of reference in the realignment of sensorimotor timing signals.

Clinicopathological characteristics of biliary neuroendocrine neoplasms: a multicenter study.

OBJECTIVES: This study assessed the clinicopathological features, therapeutic approaches, and prognosis of patients with biliary neuroendocrine neoplasm (NENs). MATERIALS AND METHODS: Multicenter retrospective study of patients with biliary tract NENs in the gallbladder, the extrahepatic bile duct, or the ampulla of Vater between 2005 and 2014. RESULTS: Total of 43 patients were included in the study. The median age was 62 years (range: 29-84 years) and 58.1% of the patients were male. The tumors occurred in the gallbladder (n = 11), the extrahepatic bile duct (n = 5) or the ampulla of Vater (n = 27). The liver was the most common metastatic site. Based on the 2010 World Health Organization classification, more patients with gallbladder NENs (11/11 (100%)) had neuroendocrine carcinoma G3 than those with NENs in the ampulla of Vater (10/27 (37.1%)). The median progression free survival time (39.3 vs 5.1 months, p = 0.001) and median overall survival time (46.9 vs 7.9 months, p < 0.001) were significantly longer in patients with ampulla of Vater NENs than gallbladder NENs. A 2010 World Health Organization classification of neuroendocrine carcinoma G3 was independently related to poor overall survival (hazard ratio (HR), 27.1; 95% confidence intervals (CI), 2.81-260.68; p = 0.004). CONCLUSION: The 2010 World Health Organization classification of neuroendocrine carcinoma G3 was the only factor related to poor prognosis in patients with biliary neuroendocrine neoplasms.

Contingent negative variation (CNV) associated with sensorimotor timing error correction.

INTRODUCTION: Detection and subsequent correction of sensorimotor timing errors are fundamental to adaptive behavior. Using scalp-recorded event-related potentials (ERPs), we sought to find ERP components that are predictive of error correction performance during rhythmic movements. METHOD: Healthy right-handed participants were asked to synchronize their finger taps to a regular tone sequence (every 600 ms), while EEG data were continuously recorded. Data from 15 participants were analyzed. Occasional irregularities were built into stimulus presentation timing: 90 ms before (advances: negative shift) or after (delays: positive shift) the expected time point. A tapping condition alternated with a listening condition in which identical stimulus sequence was presented but participants did not tap. RESULTS: Behavioral error correction was observed immediately following a shift, with a degree of over-correction with positive shifts. Our stimulus-locked ERP data analysis revealed, 1) increased auditory N1 amplitude for the positive shift condition and decreased auditory N1 modulation for the negative shift condition; and 2) a second enhanced negativity (N2) in the tapping positive condition, compared with the tapping negative condition. In response-locked epochs, we observed a CNV (contingent negative variation)-like negativity with earlier latency in the tapping negative condition compared with the tapping positive condition. This CNV-like negativity peaked at around the onset of subsequent tapping, with the earlier the peak, the better the error correction performance with the negative shifts while the later the peak, the better the error correction performance with the positive shifts. DISCUSSION: This study showed that the CNV-like negativity was associated with the error correction performance during our sensorimotor synchronization study. Auditory N1 and N2 were differentially involved in negative vs. positive error correction. However, we did not find evidence for their involvement in behavioral error correction. Overall, our study provides the basis from which further research on the role of the CNV in perceptual and motor timing can be developed.

Reduced attention-driven auditory sensitivity in hallucination-prone individuals.

BACKGROUND: Evidence suggests that auditory hallucinations may result from abnormally enhanced auditory sensitivity. AIMS: To investigate whether there is an auditory processing bias in healthy individuals who are prone to experiencing auditory hallucinations. METHOD: Two hundred healthy volunteers performed a temporal order judgement task in which they determined whether an auditory or a visual stimulus came first under conditions of directed attention ('attend-auditory' and 'attend-visual' conditions). The Launay-Slade Hallucination Scale was used to divide the sample into high and low hallucination-proneness groups. RESULTS: The high hallucination-proneness group exhibited a reduced sensitivity to auditory stimuli under the attend-auditory condition. By contrast, attention-directed visual sensitivity did not differ significantly between groups. CONCLUSIONS: Healthy individuals prone to hallucinatory experiences may possess a bias in attention towards internal auditory stimuli at the expense of external sounds. Interventions involving the redistribution of attentional resources would have therapeutic benefit in patients experiencing auditory hallucinations.

Self-harm in schizophrenia is associated with dorsolateral prefrontal and posterior cingulate activity.

Self-harm, such as self-cutting, self-poisoning or jumping from height, regardless of intentions, is common among people with schizophrenia. We wished to investigate brain activations relating to self-harm, in order to test whether these activations could differentiate between schizophrenia patients with self-harm and those without. We used event-related functional MRI with a go/no-go response inhibition paradigm. Fourteen schizophrenia patients with a history of self-harm were compared with 14 schizophrenia patients without a history of self-harm and 17 healthy control participants. In addition, we used standard clinical measures and neuropsychological tests to assess risk factors associated with self-harm. The right dorsolateral prefrontal cortex (DLPFC) and the left posterior cingulate cortex differentiated all three groups; brain activation in these regions being greatest in the control group, and the self-harm patient group being greater than in the non-self-harm patient group. In the self-harm patient group, right DLPFC activity was positively correlated with severity of suicidal thinking. In addition, both patient groups showed less activation in the right orbitofrontal cortex, left ventral anterior cingulate cortex and right thalamus. This is the first study to report right DLPFC activation in association with self-harm and suicidal thinking in patients with schizophrenia. This area could be a target for future neuromodulation studies to treat suicidal thinking and self-harm behaviors in patients with schizophrenia.

South Korean endoscopists' attitudes toward endoscopic ultrasound for the evaluation of gastrointestinal diseases.

BACKGROUND/AIMS: Despite the common use of endoscopic ultrasound (EUS) for various gastrointestinal diseases in Asia, little is known about Asian endoscopists' attitudes toward the practice. The aim of our study was to provide a profile of Korean endoscopists' attitudes toward EUS use. MATERIALS AND METHODS: Self-administered questionnaires were distributed to endoscopists who attended the 4th EndoFest symposium of the Korean Society of Gastrointestinal Endoscopy on March 24, 2012. We evaluated opinions on the need for EUS for assessing gastrointestinal diseases and the perceived barriers to widespread EUS use. RESULTS: Data from 214 (32.4%) responders were analyzed. Positive opinions (agree plus strongly agree) were given on the need for EUS in the evaluation of the following gastrointestinal diseases were: subepithelial tumor (94.9%), early esophageal cancer (88.8%), early gastric cancer (86%), pancreatic cancer (84.1%), early rectal cancer (83.6%), gallbladder polyp (73.4%), advanced esophageal cancer (47.7%), colon cancer (32.2%), advanced gastric cancer (31.8%), and advanced rectal cancer (28.5%). Significant differences were observed when they were asked about the need for EUS with respect to early versus advanced cancers of the esophagus, stomach, and rectum (all p<0.001). The most commonly cited barrier to widespread use of EUS was lack of experienced endosonographers (66.2%). CONCLUSION: This is the first study to assess Korean attitudes toward using EUS for evaluating gastrointestinal diseases. Korean endoscopists highly value the use of EUS in the evaluation of early esophageal, gastric, and rectal cancers, as well as subepithelial lesions.

How to interpret the bile culture results of patients with biliary tract infections.

BACKGROUND/GOALS: Bile is normally sterile, but the presence of organisms in the bile does not necessarily imply an active infection. We wonder what the significance of bile culture results on antibiotics choice in cholangitis with negative blood culture. The aim of this study was to compare organisms cultured from bile with those from blood in bacteremic biliary tract infection and to evaluate factors associated with concordance between blood and bile isolates. METHODS: Between 2000 and 2010, 266 positive blood cultures with concomitant bile culture in bacteremic biliary tract infection were identified. Follow-up bile specimens obtained after negative conversion of blood culture and clinical recovery from acute infection were collected for supplementary analysis. RESULTS: Of the 266 events, 258 showed positive bile culture. Of the 258 bile samples, 80 yielded the same organisms with blood, 129 showed partial agreement and 49 yielded completely different organisms with blood. Only the number of organism was found to be independently associated with concordance. Of the 529 organisms isolated from bile, 227 were found in blood and gram-negative organisms showed higher rate of coincidence than gram-positive organisms. Of the 84 follow-up bile sample, 94% showed persistent positive culture and higher rate of antibiotics resistance than initial bile culture. CONCLUSIONS: More than half of the organisms isolated from bile, especially gram-positive organisms, are not likely to be true pathogens. But single organism cultured from bile has clinical significance. Routine follow-up bile culture in patients showing clinical improvement is not necessary.

Self-harm and homeless adults.

BACKGROUND: Homelessness is associated with an increased incidence of mental illness and risk of self-harm, including suicide. AIMS: To assess the prevalence of self-harm (including nonsuicidal self-injury and attempted suicide) among a UK sample of homeless adults and to compare demographic, clinical, and homeless-related variables to determine which are linked to self-harm in this population. METHOD: A sample of 80 homeless adults were interviewed regarding history of self-harm, mental health history, demographic, and homeless-related information. RESULTS: Sixty-eight percent of the sample reported past acts of self-harm. Those with histories of self-harm started using significantly more substances since becoming homeless and were younger when they first became homeless. They were also significantly more likely to have a past psychiatric admission and thoughts of self-harm in the past year. CONCLUSION: Self-harm is common among homeless adults and linked to long-term and enduring social and mental health concerns.

Prediction of carcinoma after resection in subjects with ampullary adenomas on endoscopic biopsy.

BACKGROUND/GOALS: The endoscopic treatment of ampullary adenomas is established; however, the false-negative rate of endoscopic biopsy for carcinoma is 20% to 30%, and it remains uncertain whether identifiable features predict malignancy. Our aim in this study was to evaluate the predictable factors of malignancy in ampullary adenomas on endoscopic biopsy. STUDY: Ninety-one subjects diagnosed with ampullary adenoma on endoscopic biopsy were confirmed after endoscopic or surgical resection of ampullary lesions between 1995 and 2011 respectively. Clinical, laboratory, radiologic, and endoscopic findings were compared between patients with adenoma and carcinoma after resection. We examined the predictors of malignancy in ampullary adenoma on endoscopic biopsy. RESULTS: The malignancy rate in ampullary adenomas on endoscopic biopsy was 26.4%. Univariate analysis revealed that presence of symptoms, villous components, high-grade dysplasia (HGD), papilla enlargement on computed tomography, duct dilatation on radiologic imaging, bilirubin>2 mg/dL, aspartate aminotransferase>40 IU/L, alanine aminotransferase>40 IU/L, and alkaline phosphatase>90 U/L were associated with malignancy in patients over 65 years of age. HGD [odds ratio, 6.86 (95% confidence interval, 1.58-29.79)] and ductal dilatation [odds ratio, 11.12 (95% confidence interval, 2.27-54.37)] were independently associated with malignancy in multivariate analysis. The sensitivity and negative predictive value for ≥1 risk factors were 95.83% and 96.77%, respectively. The presence of 2 risk factors resulted in a high specificity (96%) and positive predictive value (84%) for malignancy. CONCLUSIONS: HGD and ductal dilatation are significant predictors of malignancy in ampullary adenomas. When these risk factors are present, precautions should be taken in the consideration of malignancy in patients with ampullary adenoma.

The effect of head orientation on subarachnoid cerebrospinal fluid distribution and its implications for neurophysiological modulation and recording techniques.

Gravitational forces may lead to local changes in subarachnoid cerebrospinal fluid (CSF) layer thickness, which has important implications for neurophysiological modulation and recording techniques. This study examines the effect of gravitational pull associated with different head positions on the distribution of subarachnoid CSF using structural magnetic resonance imaging. Images of seven subjects in three different positions (supine, left lateral and prone) were statistically compared. Results suggest that subarachnoid CSF volume decreases on the side of the head closest to the ground, due to downward brain movement with gravity. These findings warrant future research into currently unexplored gravitation-induced changes in regional subarachnoid CSF thickness.

Where does transcranial magnetic stimulation (TMS) stimulate? Modelling of induced field maps for some common cortical and cerebellar targets.

Computational models have been be used to estimate the electric and magnetic fields induced by transcranial magnetic stimulation (TMS) and can provide valuable insights into the location and spatial distribution of TMS stimulation. However, there has been little translation of these findings into practical TMS research. This study uses the International 10-20 EEG electrode placement system to position a standard figure-of-eight TMS coil over 13 commonly adopted targets. Using a finite element method and an anatomically detailed and realistic head model, this study provides the first pictorial and numerical atlas of TMS-induced electric fields for a range of coil positions. The results highlight the importance of subject-specific gyral folding patterns and of local thickness of subarachnoid cerebrospinal fluid (CSF). Our modelling shows that high electric fields occur primarily on the peaks of those gyri which have only a thin layer of CSF above them. These findings have important implications for inter-individual generalizability of the TMS-induced electric field. We propose that, in order to determine with accuracy the site of stimulation for an individual subject, it is necessary to solve the electric field distribution using subject-specific anatomy obtained from a high-resolution imaging modality such as MRI.