Theta burst transcranial magnetic stimulation is associated with increased EEG synchronization in the stimulated relative to unstimulated cerebral hemisphere

Theta burst transcranial magnetic stimulation (TBS) may induce behavioural changes that outlast the stimulation period. The neurophysiological basis of these behavioural changes are currently under investigation. Given the evidence that cortical information processing relies on transient synchronization and desynchronization of neuronal assemblies, we set out to test whether TBS is associated with changes of neuronal synchronization as assessed by surface EEG. In four healthy subjects one TBS train of 600 pulses (200 bursts, each burst consisting of 3 pulses at 30 Hz, repeated at intervals of 100 ms) was applied over the right frontal eye field and EEG synchronization was assessed in a time-resolved manner over 60 min by using a non-overlapping moving window. For each time step the linear cross-correlation matrix for six EEG channels of the right and for the six homotopic EEG channels of the left hemisphere were computed and their largest eigenvalues used to assess changes of synchronization. Synchronization was computed for broadband EEG and for the delta, theta, alpha, beta and gamma frequency bands. In all subjects EEG synchronization of the stimulated hemisphere was significantly and persistently increased relative to EEG synchronization of the unstimulated hemisphere. This effect occurred immediately after TBS for the theta, alpha, beta and gamma frequency bands and 10-20 min after TBS for broadband and delta frequency band EEG. Our results demonstrate that TBS is associated with increased neuronal synchronization of the cerebral hemisphere ipsilateral to the stimulation site relative to the unstimulated hemisphere. We speculate that enhanced synchronization interferes with cortical information processing and thus may be a neurophysiological correlate of the impaired behavioural performance detected previously.     

木通马兜铃化学成分研究

从木通马兜铃(Aristolochia manshuriensis Kom)茎皮中分得一个新化合物(5),经光谱(IR,UV,HRMS,^{1HNMR,NOEDS)鉴定为3,4-二甲氧基-10-硝基菲-1-羧酸甲酯,命名为马兜铃酸BII甲酯。另11个已知化合物是马兜铃酸Ⅰ,Ⅱ,Ⅲa,Ⅳ,Ⅳa,对羟基桂皮酸,β-谷甾醇,豆甾烷-3,6-二酮,6-羟基-豆甾-4-烯-3-酮,胡萝卜甙,二十八酸甘油单酯;其中二十八酸甘油单酯为首次从该属植物中分得。}     

大环骨架结构的倍半萜化合物——Ⅵ.马兜铃新内酯的化学结构测定

自绵毛马兜铃(Aristolochia mollissima Hance)根茎中分得九个化合物,其中已报道的七个化合物是尿囊素、马兜铃内酯、绵毛马兜铃内酯、β-谷甾醇、马兜铃酸A、9-乙氧基马兜铃内酯和9-乙氧基马兜铃内酰胺,本文报道结晶K₃的化学结构,经光谱分析(IR,¹H-NMR,¹³C-NMR,2D-NMR和MS),化学反应及X-衍射晶体分析,确证K₃为一个新骨架结构的倍半萜化合物,命名为马兜铃新内酯。     

Predictors and management of post-banding ulcer bleeding in cirrhosis: A systematic review and meta-analysis

Background and Aims

Post-banding ulcer bleeding (PBUB) is an understudied complication of oesophageal varices endoscopic band ligation (EBL). This systematic review with meta-analysis aimed at: (a) evaluating the incidence of PBUB in patients with cirrhosis treated with EBL in primary or secondary prophylaxis or urgent treatment for acute variceal bleeding and (b) identifying predictors of PBUB.

Methods

We conducted a systematic review of articles in English published in 2006–2022 using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Searches were made in eight databases including Embase, PubMed and Cochrane Library. Random-effects meta-analysis was used to determine the incidence, mean interval and predictors of PBUB.

Results

Eighteen studies (9034 patients) were included. The incidence of PBUB was 5.5% (95% CI 4.3–7.1). The mean time for it to occur was 11 days (95% CI 9.94–11.97). Model for End-stage Liver Disease (MELD) score (OR 1.162, 95% CI 1.047–1.291) and EBL done in emergency setting (OR 4.902, 95% CI 2.99–8.05) independently predicted post-ligation ulcer bleeding. Treatment included drugs, endoscopic procedures and transjugular intrahepatic portosystemic shunt. Refractory bleeding was treated with self-expandable metallic stents or balloon tamponade. Mortality was on average 22.3% (95% CI 14.1–33.6).

Conclusions

Patients with high MELD score and receiving EBL in an emergency setting are more prone to develop PBUB. Prognosis is still poor and the best therapeutic strategy to address remains to be ascertained.     

注射用右兰索拉唑治疗急性胃和/或十二指肠溃疡引起的上消化道出血的有效性及安全性

目的：以注射用兰索拉唑为对照,评价注射用右兰索拉唑15 mg q12 h治疗急性胃和/或十二指肠溃疡引起的上消化道出血的有效性及安全性。方法：选取全国31家研究中心的急性胃和/或十二指肠溃疡引起的上消化道出血患者共202例,按照1∶1随机分配至试验组（注射用右兰索拉唑组）和对照组（注射用兰索拉唑组）。主要疗效终点为72 h有效止血率。对主要疗效终点采用非劣效评价,非劣效性界值δ是10%。结果：有效性方面,全分析数据集分析结果显示：用药72 h后,注射用右兰索拉唑组有效止血率为96.08%(98/102);注射用兰索拉唑组有效止血率为98.00%(98/100),两组率差为-1.92%(95%CI-6.58,2.74)。两组72 h有效止血率差异无统计学意义（P=0.682 9）。两组率差的双侧界值均低于δ(10%),注射用右兰索拉唑非劣于注射用兰索拉唑。安全性方面,试验组的不良事件及不良反应发生率与对照组差异无统计学意义,无非预期不良反应和严重不良反应。主要的不良反应为白细胞计数降低、中性粒细胞计数降低等。结论：注射用右兰索拉唑15 mg q12 h在治疗急性胃和/或十二指肠溃疡引起的...     

Timing of antibiotics in febrile children meeting sepsis criteria at a paediatric emergency department

Objective

Delay in antibiotic administration in paediatric sepsis is associated with increased mortality and prolonged organ dysfunction. This pre-intervention study evaluated performance in paediatric sepsis management.

Methods

Retrospective cohort study of febrile children admitted through the ED at The Children's Hospital at Westmead, Sydney, between 1 May and 31 July 2017. Participants were children aged 29 days to 60 months excluding children with simple febrile seizures, neonates and children who had received intravenous antibiotics elsewhere. We assessed the timing of antibiotic administration in children meeting local sepsis guidelines. We conducted a survey of clinicians in ED in 2018 to describe contributing factors.

Results

There were 160 febrile children admitted and 144 presentations were included in the analysis. Male 53% (n = 76); median age 20.1 months (interquartile range [IQR] 3.9–37 months). Thirty-seven (26%) febrile children met local sepsis criteria. The median time from triage to first dose of intravenous antibiotic was 109 min (IQR 62–183 min). Delay (>60 min) occurred in 26 (76%) children. Reported reasons contributing to delay included high patient load, long waiting times, difficult intravenous access, delayed prescribing, inadequate staffing and difficulty distinguishing between a viral infection and serious bacterial infection.

Conclusion

There was frequent delay in administering antibiotics in children meeting local sepsis criteria, more commonly in young infants. Reasons contributing to delay were specific to young children along with departmental factors that will require addressing through targeted quality improvement interventions.     

Multiple sclerosis as a model to investigate SARS-CoV-2 effect on brain atrophy

Introduction

Data on structural brain changes after infection with SARS-CoV-2 is sparse. We postulate multiple sclerosis as a model to study the effects of SARS-CoV-2 on brain atrophy due to the unique availability of longitudinal imaging data in this patient group, enabling assessment of intraindividual brain atrophy rates.

Methods

Global and regional cortical gray matter volumes were derived from structural MRIs using FreeSurfer. A linear model was fitted to the measures of the matching pre-SARS-CoV-2 images with age as an explanatory variable. The residuals were used to determine whether the post-SARS-CoV-2 volumes differed significantly from the baseline.

Results

Fourteen RRMS patients with a total of 113 longitudinal magnetic resonance images were retrospectively analyzed. We found no acceleration of brain atrophy after infection with SARS-CoV-2 for global gray matter volume (p = 0.17). However, on the regional level, parahippocampal gyri showed a tendency toward volume reduction (p = 0.0076), suggesting accelerated atrophy during or after infection.

Conclusions

Our results illustrate the opportunity of using longitudinal MRIs from existing MS registries to study brain changes associated with SARS-CoV-2 infections. We would like to address the global MS community with a call for action to use the available cohorts, reproduce the proposed analysis, and pool the results.     

Subthalamic Nucleus Stimulation–Induced Local Field Potential Changes in Dystonia

Background

Subthalamic nucleus (STN) stimulation is an effective treatment for Parkinson's disease and induced local field potential (LFP) changes that have been linked with clinical improvement. STN stimulation has also been used in dystonia although the internal globus pallidus is the standard target where theta power has been suggested as a physiomarker for adaptive stimulation.

Objective

We aimed to explore if enhanced theta power was also present in STN and if stimulation-induced spectral changes that were previously reported for Parkinson's disease would occur in dystonia.

Methods

We recorded LFPs from 7 patients (12 hemispheres) with isolated craniocervical dystonia whose electrodes were placed such that inferior, middle, and superior contacts covered STN, zona incerta, and thalamus.

Results

We did not observe prominent theta power in STN at rest. STN stimulation induced similar spectral changes in dystonia as in Parkinson's disease, such as broadband power suppression, evoked resonant neural activity (ERNA), finely-tuned gamma oscillations, and an increase in aperiodic exponents in STN-LFPs. Both power suppression and ERNA localize to STN. Based on this, single-pulse STN stimulation elicits evoked neural activities with largest amplitudes in STN, which are relayed to the zona incerta and thalamus with changing characteristics as the distance from STN increases.

Conclusions

Our results show that STN stimulation–induced spectral changes are a nondisease-specific response to high-frequency stimulation, which can serve as placement markers for STN. This broadens the scope of STN stimulation and makes it an option for other disorders with excessive oscillatory peaks in STN. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.