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Background: Obtaining sufficient tumor tissue for genomic profiling is challenging in pancreaticobiliary cancer (PBCA). We determined the utility of molecular barcoding (MB) of liquid biopsies (bile, duodenal fluid, and plasma) for highly sensitive genomic diagnosis and detection of druggable mutations for PBCA., Methods: Two in-house panels of 60 genes (non-MB panel) and 21 genes using MB (MB panel) were used for the genomic analysis of 112 DNA samples from 20 PBCA patients. We measured the yield of DNA and compared the genomic profiles of liquid samples obtained using the non-MB panel and the MB panel. The utility of the panels in detecting druggable mutations was investigated., Results: A significantly greater amount of DNA was obtained from bile supernatants and precipitates compared to tumor samples (P < 0.001 and P = 0.001, respectively). The number of mutations per patient was significantly higher using the MB panel than using the non-MB panel (2.8 vs. 1.3, P = 0.002). Tumor-derived mutations were detected more frequently using the MB panel than the non-MB panel (P = 0.023). Five drug-matched mutations were detected in liquid samples., Conclusions: Liquid biopsy with MB may have utility in providing genomic information for the prognosis of patients with PBCA., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Hiroshi Ohyama reports financial support was provided by Japan Society for the Promotion of Science. Yosuke Hirotsu reports financial support was provided by Japan Society for the Promotion of Science. Rintaro Mikata reports financial support was provided by Japan Society for the Promotion of Science. Hiroshi Ohyama reports financial support was provided by the Pancreas Research Foundation of Japan. Hiroshi Ohyama reports financial support was provided by the Chiba Foundation for Health Promotion and Disease Prevention. Yosuke Hirotsu reports financial support was provided by Yasuda Memorial Medical Foundation. Yosuke Hirotsu reports financial support was provided by Uehara Memorial Foundation. Yosuke Hirotsu reports financial support was provided by The Takeda Foundation. Yosuke Hirotsu reports financial support was provided by Genome Research Project from Yamanashi Prefecture. Masao Omata reports financial support was provided by Genome Research Project from Yamanashi Prefecture., (Copyright © 2023. Published by Elsevier Inc.)

Objectives: Recently, the Omicron strain of SARS-CoV-2 has spread and replaced the previously dominant Delta strain. Several Omicron sublineages (BA.1, BA.1.1, and BA.2) have been identified, with in vitro and preclinical reports showing that the pathogenicity and therapeutic efficacy differs between BA.1 and BA.2. We sought to develop a TaqMan assay to identify these subvariants., Methods: A TaqMan assay was constructed for rapid identification and genotyping of Omicron sublineages with 171 samples. We analyzed three characteristic mutations of the spike gene, Δ69-70, G339D, and Q493R, by TaqMan assay. The accuracy of the TaqMan assay was examined by comparing its results with the results of whole genome sequencing (WGS) analysis., Results: A total of 171 SARS-CoV-2 positive samples were analyzed by WGS and TaqMan assay. The 127 samples determined as BA.1/BA.1.1 by WGS were all positive for Δ69-70, G339D and Q493R by TaqMan assay. A total of 42 samples, determined as BA.2 by WGS, were negative for Δ69-70 but positive for G339D and Q493R by TaqMan. Two samples with G339N were determined to be inconclusive by the TaqMan method. Except for these two samples, the concordance rate between WGS and the TaqMan assay was 100% (169/169)., Conclusion: TaqMan assays targeting characteristic mutations are useful for identification and discrimination of Omicron sublineages., Competing Interests: Conflict of interest The authors have no competing interests to declare., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

The ALK inhibitors are promising therapeutic agents against lung cancer harboring ALK fusion genes and are currently under development up to the third generation. However, its therapeutic effects are reported to be affected by differences in ALK variants and co-occurrent mutations. Materials and Methods; We experienced an autopsy case of an ALK-positive lung cancer patient who showed primary resistance to three generations of ALK inhibitors. The poor survival time of the case was 14 months. To reveal the mechanism of primary resistance to three generations of ALK inhibitors, we performed next generation sequencing for 12 specimes obtained from an autopsy with covering whole exons of 53 significantly mutated, lung cancer-associated genes and amplicon-based target RNA sequenceing for the ALK fusion gene. The NGS analysis revealed a rare variant.3 of ALK fusion, in which 30 bp of base was inserted at the end of ALK intron.19 and was associated with EML exon.6 [E6&#95;ins30A20] and a co-occurrent oncogenic PIK3CA E542K mutation in all specimens. Structural analysis of the fusion protein ALK [E6&#95;ins30A20] showed no interferance with the binding of ALK inhibitors to the kinase domain. The NGS analysis of primary and metastatic lesions obtained from an autopsy revealed a co-occurrent oncogenic PIK3CA E542K mutation in all specimens. The constitutive activation of PI3K-Akt signal by PIK3CA E542K mutation occurred downstream of ALK signaling pathway, could lead to primary resistance to ALK inhibitors in all generations., Competing Interests: Disclosure statement The all authors report no conflict of interest., (Copyright © 2021. Published by Elsevier Inc.)

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to spread worldwide. Here, we evaluated the performance of two quantitative antigen (Ag) tests, the Roche and Lumipulse Ag tests, using automated platforms., Methods: We collected 637 nasopharyngeal swab samples from 274 individuals. Samples were subjected to quantitative reverse transcription PCR (RT-qPCR), the Roche Ag test and Lumipulse Ag test., Results: When RT-qPCR was used as a reference, the overall concordance rate of the Roche Ag test was 77.1% (491/637) with 70.0% (341/487) sensitivity and 100% specificity (150/150). When inconclusive results of the Lumipulse Ag test were excluded, the overall concordance rate of the Lumipulse Ag test was 88.3% (467/529) with 84.8% (330/389) sensitivity and 97.9% (137/140) specificity. The overall concordance rate between the Roche and Lumipulse Ag tests was 97.9% (518/529) with 96.7% (322/333) sensitivity and 100% (196/196) specificity. Quantitative Ag levels determined using the Roche and Lumipulse Ag tests were highly correlated (R 2 = 0.922). The Roche and Lumipulse Ag tests showed high concordance up to nine days after symptom onset, with progressively lower concordance after that., Conclusions: The Roche and Lumipulse Ag tests showed equivalent assay performance and represent promising approaches for diagnosing coronavirus disease 2019., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Reverse transcription polymerase chain reaction (RT-PCR) is the gold standard for detection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Previously, the accuracy of the quantitative LUMIPULSE SARS-CoV-2 antigen test was demonstrated using samples collected retrospectively. In this study, the LUMIPULSE antigen test was clinically validated using prospective samples., Methods: In total, 1033 nasopharyngeal swab samples were collected from 1033 individuals, and an additional 275 follow-up samples were collected from 43 patients who subsequently tested positive for coronavirus disease 2019 (COVID-19). All 1308 samples were subjected to quantitative RT-PCR (RT-qPCR) and the antigen test. The antibody response was investigated for patients with discordant results to clarify if seroconversion had occurred., Results: RT-qPCR identified 990 samples as negative and 43 as positive, while the antigen test identified 992 samples as negative, 37 as positive and four as inconclusive. The overall concordance rate was 99.7% (1026/1029). Sensitivity, specificity, positive predictive value and negative predictive value of the antigen test were 92.5% (37/40), 100% (989/989), 100% (37/37) and 99.7% (989/992), respectively, after exclusion of the four inconclusive results. The kappa coefficient was 0.960 (95% confidence interval 0.892-0.960), suggesting excellent agreement between the two tests. Seropositivity in five of seven patients with discordant results suggested that the discrepancy was caused by samples collected during the late phase of infection. Using follow-up samples, correlation was observed between the antigen level and the viral load or cycle threshold value. The concordance rate between these test results tended to be high among samples collected 0-9 days after symptom onset, but this decreased gradually in samples collected thereafter., Conclusions: This prospective study demonstrated that the LUMIPULSE antigen test is a highly accurate diagnostic test for SARS-CoV-2., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Various diagnostic tests utilizing different principles are currently under development for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, these tests can occasionally produce discrepant results, causing confusion in their interpretation. Here, we evaluated the performance and features of three diagnostic assays: quantitative reverse transcription polymerase chain reaction (RT-qPCR), FilmArray Respiratory Panel (RP) v2.1, and the LUMIPULSE antigen test. Twenty-seven serial nasopharyngeal swabs were collected from a prolonged viral shedding patient who had been hospitalized for 51 days. We examined the SARS-CoV-2 detection rates of the three tests. The overall agreement rate was 81% between RT-qPCR and FilmArray RP v2.1, 63% between the antigen test and FilmArray RP v2.1, and 59% between the antigen test and RT-qPCR. We obtained concordant results in samples with high viral loads (low threshold cycle values) by all three tests. RT-qPCR and FilmArray RP v2.1 accurately detected SARS-CoV-2 at the early to intermediate phases of infection, but the results varied at the late phase. The antigen test also produced a positive result at the early phase but varied at the intermediate phase and consistently produced negative results at late phase of infection. These results demonstrated FilmArray RP v2.1 could detect SARS-CoV-2 with accuracy comparable to RT-qPCR. Further, there were discrepant results using different types of diagnostic tests during the clinical course of prolonged viral shedding patient. We provided insights into how to utilize different types of kits to assess and manage SARS-CoV-2 infections., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2020 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

In routine clinical practice, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is determined by reverse-transcription PCR (RT-PCR). In the current pandemic, a more rapid and high-throughput method is in growing demand. Here, we validated the performance of a new antigen test (LUMIPULSE) based on chemiluminescence enzyme immunoassay. A total of 313 nasopharyngeal swabs (82 serial samples from 7 infected patients and 231 individual samples from 4 infected patients and 215 uninfected individuals) were analyzed for SARS-CoV-2 with quantitative RT-PCR (RT-qPCR) and then subjected to LUMIPULSE. We determined the cutoff value for antigen detection using receiver operating characteristic curve analysis and compared the performance of the antigen test with that of RT-qPCR. We also compared the viral loads and antigen levels in serial samples from seven infected patients. Using RT-qPCR as the reference, the antigen test exhibited 55.2% sensitivity and 99.6% specificity, with a 91.4% overall agreement rate (286/313). In specimens with > 100 viral copies and between 10 and 100 copies, the antigen test showed 100% and 85% concordance with RT-qPCR, respectively. This concordance declined with lower viral loads. In the serially followed patients, the antigen levels showed a steady decline, along with viral clearance. This gradual decline was in contrast with the abrupt positive-to-negative and negative-to-positive status changes observed with RT-qPCR, particularly in the late phase of infection. In summary, the LUMIPULSE antigen test can rapidly identify SARS-CoV-2-infected individuals with moderate to high viral loads and may be helpful for monitoring viral clearance in hospitalized patients., (Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: The evaluation of neurological examination in clinical practice still remains qualitative or semi-quantitative, and the results often vary depending on an examiner's skill level and are less objective. In this study, we developed a smartphone-based application to investigate quantifying neurological examinations using hand-drawn spirals and diagnose patients with tremor using artificial intelligence (AI)., Methods: This study included 24 and 26 patients with essential tremor (ET) and cerebellar disease (CD), respectively, and 41 age-matched normal controls (NCs). We obtained 69, 46, and 56 hand-drawn spirals from the NC, ET, and CD groups, respectively, as image data captured by smartphones. The patients traced a printed reference spiral. The length of this spiral was compared with the reference spiral length (% of spiral length) and the total deviation area between these spirals was calculated. The server also estimates the diagnostic probability through AI., Results: The quantified spiral analysis (% of spiral length and deviation area) significantly correlated with disease severity in each disease group, and significant differences in the deviation area were observed among all groups. The AI diagnosis showed 79%, 70%, and 73% accuracies for the NC, ET, and CD groups, respectively., Conclusion: This study indicates the possibility of using a smartphone as a medical examination tool and demonstrates the application of AI in neurological examinations., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Microsatellite instability (MSI) occurs in solid tumors and is a predictive biomarker for remarkable response to immune checkpoint inhibitors. Detection of MSI status has been conventionally conducted by PCR-electrophoresis-based assay (MSI-PCR) and immunohistochemistry (IHC) of mismatch repair proteins. However, these approaches require visual confirmation and involve some difficulties in determining MSI statuses from equivocal results., Methods: We performed amplicon-based targeted sequencing of 76 microsatellite loci (MSI-NGS) in 184 formalin-fixed paraffin-embedded (FFPE) tumor tissues and baseline control samples. A bioinformatics tool, MSIcall, was used to calculate the quantitative values based on the aligned sequence reads and evaluated MSI status. Furthermore, we examined the concordance between the results from MSI-NGS and MSI-PCR/IHC. Diagnostic accuracy, sensitivity, and specificity were estimated by receiver operating characteristic (ROC) curve analysis. For validation cohort, we studied additional 50 tumor samples to determine the MSI status., Results: Of 184 tumor samples, MSI-PCR and IHC analysis classified 161 tumors as MSS/pMMR and 23 as MSI-H/dMMR. Using MSI-NGS combined with MSIcall, we predicted MSI status with high accuracy (98.9%), specificity (91.3%), and sensitivity (100%) in 25 types of cancers. This method achieved an area under the ROC curve (AUC) value of 0.9986. Furthermore, we achieved the 100% concordant results using additional 50 samples for validation., Conclusion: We demonstrated newly developed MSI-NGS with MSIcall accurately determines the MSI status of FFPE tumor tissues thorough sequencing of tumor samples alone without patient-matched normal controls. This approach can be applied to all types of solid tumors to determine responders to immune-oncology therapy., Competing Interests: Declaration of Competing Interest The authors declare no potential conflicts of interest., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Introduction: Next-generation sequencing (NGS) of multiple metastases in an advanced cancer patient reveals the evolutional history of the tumor. The evolutionary model is clinically valuable because it reflects the future course of the tumorigenic process and prognosis of the patient., Materials and Methods: We experienced two lung cancer patients whose clinical courses were abruptly deteriorating resulting in very poor prognosis. To investigate the evolutionary model of these patients, we performed targeted sequencing covering whole exons of 53 significantly mutated genes associated with lung cancer of multiple metastases by autopsy. We conducted PyClone analysis to infer subclonal archtecture of multi-lesional samples., Results: The NGS analysis revealed both patients harboring multiple clonal driver mutations. In Case.1, KRAS Q61H, KEAP1 G333C, STK11 K312*, RBM10 Q320* and MGA I1429V and in Case.2, TP53 R337L, TP53 Q192*, PTEN W274C, RB1 P29fs and CREBBP P696L with high allele fraction were detected in all lesions. These mutations were clustered and occupied major population across multi-lesional tumor samples. Our data suggested their lung cancers progressed with punctuated and big bang evolutional model., Conclusion: We should pay attention to clinical course of lung cancer patients harboring multiple clonal driver mutations in their primary lesions. Their punctuated and big bang evolutionary process could develop systemic clinically undetectable metastases with an unexpected speed., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest to disclose concerning the study., (Copyright © 2019. Published by Elsevier Inc.)

To evaluate the spinal cord atrophy that occurs in HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), we conducted magnetic resonance imaging (MRI) and pathological analyses. In the MRI study, 15 patients with HAM/TSP and 20 age-matched normal control subjects were enrolled. Anteroposterior and transverse distances and cross-sectional areas were measured and calculated at the C2, C4, C6, T2, and T6 vertebral levels. In the pathological study, spinal cord autopsy specimens were compared between a HAM/TSP case and an adult T cell leukemia/lymphoma case. In both the MRI and pathological studies, HAM/TSP spinal cords demonstrated more severe atrophy in the anteroposterior direction than those of controls. The spinal cord atrophy and pathological changes in HAM/TSP occurred predominantly in the white matter, especially in the lateral columns. This is the first report indicating spinal cord atrophy in the anteroposterior direction using MRI. In pathological analysis, atrophy and pathological changes were prominent in areas of the spinal cord with slow blood flow. Hemodynamic and anatomical factors are speculated to be among the main mechanisms of atrophy in the anteroposterior direction., (Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Many patients from Toroku, Japan, who have chronic arsenic exposure demonstrate whole-body sensory disturbance that is slightly more pronounced in the extremities. Although previous research in this population showed a mild peripheral neuropathy, it is unknown whether these patients have central nervous system impairment. To investigate the lesion sites underlying sensory disturbance related to chronic arsenic poisoning, we analyzed somatosensory evoked potentials (SEP)., Methods: Clinical features, nerve conduction study results, and median and/or tibial SEP were analyzed in patients with chronic arsenic exposure (total, 13 patients; median & tibial, 4; median, 5; tibial, 4) retrospectively. The SEP findings in patients were compared with those in normal controls., Results: The median SEP results indicated a conduction delay between the proximal brachial plexus and the primary sensory cortex, and tibial SEP findings indicated a delay between the dorsal gray matter of the lumbosacral cord and the primary sensory cortex., Conclusion: This is the first study to identify an impairment of the central somatosensory pathway in patients with chronic arsenic exposure. Sensory disturbance in these patients is related not only to peripheral neuropathy but also to impairment of the central nervous system., (Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.)

Objective: In patients with benign myoclonus epilepsy (ME), giant sensory-evoked potential (SEP) reflects the hyperexcitability of the sensory cortex. The aim of this study was to compare the effect of quadripulse transcranial magnetic stimulation (QPS) on the median nerve SEP between ME patients and healthy subjects., Methods: Ten healthy volunteers and six ME patients with giant SEP participated in this study. QPSs at interpulse intervals (IPIs) of 5, 30, 50, 100, 500 and 1250 ms were applied over the left primary motor cortex (M1) for 30 min. The peak-to-peak amplitudes of N20 to P25 (N20-P25) and P25 to N33 (P25-N33) components were measured at the left somatosensory cortex., Results: In healthy participants, the P25-N33 was bidirectionally modulated by QPS over M1, following the Bienenstock-Cooper-Munro (BCM) theory. The N20-P25 was not affected by any QPSs. In ME patients, the giant P25-N33 was potentiated after any QPSs. Furthermore, the N20-P25 was also potentiated after QPS at IPIs of 5, 30, 50 100 or 500 ms., Conclusions: In ME patients, the cascade for long-term depression-like effects may be impaired., Significance: The giant SEP was furthermore enhanced by QPS., (Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

Background: Imaging studies investigating repetitive transcranial magnetic stimulation (rTMS) mediated hemodynamic consequences revealed inconsistent results, mainly due to differences in rTMS parameters and technical difficulties with simultaneous recordings during rTMS., Objective/hypothesis: Quadri-pulse rTMS (QPS) induces bidirectional long-term plasticity of the human primary motor cortex (M1). To evaluate its on-line effects, near infrared spectroscopy (NIRS) recordings were performed during QPS. We hypothesized that on-line effects during QPS are different from long-term aftereffects., Methods: Using a novel TMS - on-line multi-channel NIRS setup we recorded hemoglobin concentration [Hb] changes at the stimulated M1 and adjacent sensory-motor areas during QPS protocols inducing oppositely directed aftereffects (QPS-5: interstimulus interval (ISI) 5 ms, potentiation; QPS-50: ISI 50 ms, depression). In two experiments we studied NIRS changes during either single or repeated QPS bursts., Results: The repetitive QPS-5 bursts significantly decreased oxyhemoglobin concentration ([oxy-Hb]) in the ipsilateral M1. A single QPS-5 burst decreased [oxy-Hb] in the M1 and premotor cortex. QPS-50 induced no significant NIRS changes at any sites., Conclusions: QPS can significantly alter cortical hemodynamics depending on the stimulation frequency. While bidirectional long-term aftereffects of QPS reflect synaptic efficacy changes, unidirectional on-line effects during QPS may represent pure electrophysiological property changes within the cell membrane or synapse. Since neuronal postexcitatory inhibitory postsynaptic potentials typically peak within the first 10-20 ms, only pulses delivered at higher frequencies may lead to summation of the inhibitory effects, resulting in [oxy-Hb] decrease only after QPS-5. Our new TMS-NIRS setup may be valuable to investigate TMS induced neurovascular coupling mechanisms in humans., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Objective: Quadripulse transcranial magnetic stimulation (QPS) is a newly designed patterned repetitive transcranial magnetic stimulation (TMS). Previous studies of QPS showed bidirectional effects on the primary motor cortex (M1), which depended on its inter-stimulus interval (ISI): motor evoked potentials (MEPs) were potentiated at short ISIs and depressed at long ISIs (homotopic effects). These physiological characters were compatible with synaptic plasticity. In this research, we studied effects of QPS on the primary sensory cortex (S1)., Methods: One burst consisted of four monophasic TMS pulses at an intensity of 90% active motor threshold. The ISI of four pulses was set at 5 ms (QPS-5) or at 50 ms (QPS-50). Same bursts were given every 5s for 30 min. QPS-5 and QPS-50 were performed over three areas (M1, S1 and dorsal premotor cortex (dPMC)). One sham stimulation session was also performed. Excitability changes of S1 were evaluated by timeline of somatosensory evoked potentials (SEPs)., Results: QPS-5 over M1 or dPMC enhanced the P25-N33 component of SEP, and QPS-50 over M1 depressed it. By contrast, QPSs over S1 had no effects on SEPs., Conclusions: QPSs over motor cortices modulated the S1 cortical excitability (heterotopic effects). Mutual connections between dPMC or M1 and S1 might be responsible for these modulations., Significance: QPSs induced heterotopic LTP or LTD-like cortical excitability changes., (Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

Background: Skeletal muscle metabolism is a major determinant of resting energy expenditure (REE). Although the severe muscle loss that characterizes Duchenne muscular dystrophy (DMD) may alter REE, this has not been extensively investigated., Methods: We studied REE in 77 patients with DMD ranging in age from 10 to 37 years using a portable indirect calorimeter, together with several clinical parameters (age, height, body weight (BW), body mass index (BMI), vital capacity (VC), creatine kinase, creatinine, albumin, cholinesterase, prealbumin), and assessed their influence on REE. In addition, in 12 patients maintaining a stable body weight, the ratio of energy intake to REE was calculated and defined as an alternative index for the physical activity level (aPAL)., Results: REE (kcal/day, mean±SD) in DMD patients was 1123 (10-11 years), 1186±188 (12-14 years), 1146±214 (15-17 years), 1006±136 (18-29 years) and 1023±97 (≥30 years), each of these values being significantly lower than the corresponding control (p<0.0001). VC (p<0.001) was the parameter most strongly associated with REE, followed by BMI (p<0.01) and BW (p<0.05). The calculated aPAL values were 1.61 (10-11 years), 1.19 (12-14 years), 1.16 (15-17 years), and 1.57 (18-29 years)., Conclusion: The REE in DMD patients was significantly lower than the normal value in every age group, and strongly associated with VC. Both the low REE and PAL values during the early teens, resulting in a low energy requirement, might be related to the obesity that frequently occurs in this age group. In contrast, the high PAL value in the late stage of the disease, possibly due to the presence of respiratory failure, may lead to a high energy requirement, and thus become one of the risk factors for development of malnutrition., (Copyright © 2011 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

In the last decade, combined transcranial magnetic stimulation (TMS)-neuroimaging studies have greatly stimulated research in the field of TMS and neuroimaging. Here, we review how TMS can be combined with various neuroimaging techniques to investigate human brain function. When applied during neuroimaging (online approach), TMS can be used to test how focal cortex stimulation acutely modifies the activity and connectivity in the stimulated neuronal circuits. TMS and neuroimaging can also be separated in time (offline approach). A conditioning session of repetitive TMS (rTMS) may be used to induce rapid reorganization in functional brain networks. The temporospatial patterns of TMS-induced reorganization can be subsequently mapped by using neuroimaging methods. Alternatively, neuroimaging may be performed first to localize brain areas that are involved in a given task. The temporospatial information obtained by neuroimaging can be used to define the optimal site and time point of stimulation in a subsequent experiment in which TMS is used to probe the functional contribution of the stimulated area to a specific task. In this review, we first address some general methodologic issues that need to be taken into account when using TMS in the context of neuroimaging. We then discuss the use of specific brain mapping techniques in conjunction with TMS. We emphasize that the various neuroimaging techniques offer complementary information and have different methodologic strengths and weaknesses.

Objective: To study differences in the long-term after-effect between high-frequency, monophasic and biphasic repetitive transcranial magnetic stimulation (rTMS)., Methods: Ten hertz rTMS was delivered over the left primary motor cortex and motor evoked potentials (MEPs) were recorded from the right first dorsal interosseous muscle. To probe motor cortex excitability we recorded MEPs at several timings before, during and after several types of conditioning rTMSs. We also recorded F-waves to probe spinal excitability changes. Thousand pulses were given in total, with a train of 10 Hz, 100 pulses delivered every minute (ten trains for 10min). The intensity was fixed at 90% active motor threshold (AMT) or 90% resting motor threshold (RMT) for both monophasic and biphasic rTMS. In addition, we performed a monophasic rTMS experiment using a fixed intensity of 90% RMT for biphasic pulses., Results: At 90% AMT, MEPs were enhanced for a few minutes after both monophasic and biphasic rTMS. On the other hand, at 90% RMT, a larger and longer enhancement of MEPs was evoked after monophasic rTMS than after biphasic rTMS. Monophasic rTMS at an intensity adjusted to biphasic 90% RMT elicited a great enhancement similar to that after monophasic rTMS at monophasic 90% RMT. Neither F-wave amplitude nor its occurrence rate was significantly altered by 90% RMT monophasic rTMS., Conclusions: These results suggest that enhancement after rTMS occurs at the motor cortex. Monophasic rTMS has a stronger after-effect on motor cortical excitability than biphasic rTMS. This is probably because monophasic pulses preferentially activate a relatively uniform population of neurons oriented in the same direction and their effects summate more readily than biphasic rTMS activating differently oriented neurons at slight different timings altogether., Significance: The present results suggest that when using rTMS as a therapeutic tool or in research fields, the waveforms of magnetic pulses may affect the results profoundly.

Objective: We investigated the effects on occipital cortex, of two newly developed methods of repetitive transcranial magnetic stimulation (rTMS): continuous and intermittent theta burst stimulation (cTBS and iTBS), that lead to long lasting changes in excitability when applied over primary motor cortex., Methods: Phosphene threshold to a single TMS pulse was measured before and after application of either continuous or intermittent theta burst stimulation (cTBS/iTBS; 600 total pulses at 80% phosphene threshold)., Results: In our cohort, cTBS increased phosphene threshold by an average of 10%. In contrast, iTBS, which transiently increases motor cortex excitability, had no effect on phosphene threshold., Conclusions: cTBS can be applied successfully to non-motor areas of cortex, but iTBS may need modification to produce maximal effects., Significance: cTBS maybe a new useful tool in disorders characterized by an abnormal state of activity of the visual cortex.

People who have a Glu487Lys mutation (single nucleotide polymorphism) in the aldehyde dehydrogenase-2 (ALDH2) gene are slow to metabolize the alcohol breakdown product acetaldehyde. The P13/14-N20 interval of the median nerve somatosensory evoked potential was significantly longer in alcoholic patients with a hypoactive ALDH2 (n = 27) than in those with an active ALDH2 (n = 43). This suggests that acetaldehyde accumulation due to hypoactive ALDH2 is associated with a prolongation of the central sensory conduction time between pons and primary sensory cortex. The present result indicates that an elevated blood concentration of acetaldehyde must cause the central sensory tract involvement and that acetaldehyde is one of factors producing brain damage in alcoholics.

To evaluate recovery function of and effects of hyperventilation (HV) on high-frequency oscillations (HFOs) of median nerve somatosensory evoked potential (SEP), we recorded SEPs in 8 Parkinson's disease (PD) patients with enlarged HFOs, 4 myoclonus epilepsy (ME) patients and 10 healthy volunteers (N). SEP was recorded from the hand sensory area contralateral to the median nerve stimulated at the wrist. Responses were amplified with filters set at 0.5 and 3000 Hz. HFOs were obtained by digitally filtering raw SEPs from 500 to 1000 Hz. We measured amplitudes of the N20 onset-peak (N20o-p), N20 peak-P25 peak (N20p-P25p), P25 peak-N33 peak (P25p-N33p), the early (1st-2nd) and late (3rd) HFOs. For the recovery function study, paired-pulse stimuli at various interstimulus intervals (20, 50, 100, 150, 200 and 300 ms) were given. To investigate effects of HV, amplitudes of several components of SEPs recorded after HV were compared with those before HV. In PD and ME, the N20o-p recovery curve showed significantly less suppression as compared with those of N. The P25p-N33p recovery curve of ME showed longer suppression than those of N and PD. There were no significant differences in the early or late HFOs recovery curves among three groups. At the dysinhibited state after HV, the late HFO was reduced in association with a significant enlargement of the N20p-P25p amplitude in normal subjects. This suggests that the late HFOs should reflect bursts of inhibitory interneurons. In the ME patients, the early HFOs significantly decreased by HV. The pattern in ME patients may be explained by a kind of compensation for already enhanced SEPs (giant SEP) in the dysinhibited situation. We conclude that (1) Giant HFOs are normally regulated by inhibitory neuronal systems involving in paired stimulation SEP. (2) The late HFOs must reflect bursts of GABAergic inhibitory interneurons.