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2.
PLoS One ; 15(1): e0216185, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31929531

RESUMO

The ability to interpret transcranial magnetic stimulation (TMS)-evoked electroencephalography (EEG) potentials (TEPs) is limited by artifacts, such as auditory evoked responses produced by discharge of the TMS coil. TEPs generated from direct cortical stimulation should vary in their topographical activity pattern according to stimulation site and differ from responses to sham stimulation. Responses that do not show these effects are likely to be artifactual. In 20 healthy volunteers, we delivered active and sham TMS to the right prefrontal, left primary motor, and left posterior parietal cortex and compared the waveform similarity of TEPs between stimulation sites and active and sham TMS using a cosine similarity-based analysis method. We identified epochs after the stimulus when the spatial pattern of TMS-evoked activation showed greater than random similarity between stimulation sites and sham vs. active TMS, indicating the presence of a dominant artifact. To do this, we binarized the derivatives of the TEPs recorded from 30 EEG channels and calculated cosine similarity between conditions at each time point with millisecond resolution. Only TEP components occurring before approximately 80 ms differed across stimulation sites and between active and sham, indicating site and condition-specific responses. We therefore conclude that, in the absence of noise masking or other measures to decrease neural artifact, TEP components before about 80 ms can be safely interpreted as stimulation location-specific responses to TMS, but components beyond this latency should be interpreted with caution due to high similarity in their topographical activity pattern.

3.
Sci Rep ; 9(1): 18305, 2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31797890

RESUMO

The beta rhythm (15-30 Hz) is a prominent signal of sensorimotor cortical activity. This rhythm is not sustained but occurs non-rhythmically as brief events of a few (1-2) oscillatory cycles. Recent work on the relationship between these events and sensorimotor performance suggests that they are the biologically relevant elements of the beta rhythm. However, the influence of these events on corticospinal excitability, a mechanism through which the primary motor cortex controls motor output, is unknown. Here, we addressed this question by evaluating relationships between beta event characteristics and corticospinal excitability in healthy adults. Results show that the number, amplitude, and timing of beta events preceding transcranial magnetic stimulation (TMS) each significantly predicted motor-evoked potential (MEP) amplitudes. However, beta event characteristics did not explain additional MEP amplitude variance beyond that explained by mean beta power alone, suggesting that conventional beta power measures and beta event characteristics similarly captured natural variation in human corticospinal excitability. Despite this lack of additional explained variance, these results provide first evidence that endogenous beta oscillatory events shape human corticospinal excitability.

4.
Aust J Gen Pract ; 48(12): 856-857, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31774989
5.
J Emerg Med ; 57(4): 574, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31739912
7.
J Card Surg ; 34(5): 305-311, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30908754

RESUMO

BACKGROUND: Cardiac surgery patients are at high risk for postoperative bleeding. Intravenous (IV) tranexamic acid (TxA) is a commonly used antifibrinolytic drug, but is associated with postoperative seizures. We conducted this pilot randomized controlled trial (RCT) to determine the feasibility of a larger trial that will be designed to investigate the impact of TxA administration route, intrapericardial (IP) vs IV, on postoperative bleeding and seizures. METHODS: In this single-center, double-blinded, pilot RCT we enrolled adult patients undergoing nonemergent on-pump cardiac operations through a median sternotomy. Participants were randomized to IP or IV TxA groups. The primary outcomes were cumulative chest tube drainage, transfusion requirements, and incidence of postoperative seizures. RESULTS: A total of 97 participants were randomized to the intervention and control groups. Baseline characteristics were similar in both groups. Most participants underwent a CABG and/or aortic valve replacement. There was no statistical difference. The IP TxA group was found to have a tendency for less chest tube drainage in comparison to the IV TxA group, 500.5 (370.0-700.0) and 540.0 (420.0-700.0) mL, respectively, which was not statistically significant (P = 0.2854). Fewer participants in the IP TxA group with cardiac tamponade and/or required a reoperation for bleeding and fewer packed red blood cell transfusions. None of the IP TxA group developed seizure vs one from the IV TxA group. CONCLUSION: This is the first known pilot RCT to investigate the role of TxA route of administration in open cardiac surgery. Intrapericardial TxA shows promising results with decreased bleeding, transfusion requirements, reoperations, and postoperative seizures. A larger RCT is needed to confirm these results and lead to a change in practice.


Assuntos
Antifibrinolíticos/administração & dosagem , Perda Sanguínea Cirúrgica/prevenção & controle , Procedimentos Cirúrgicos Cardíacos , Hemorragia Pós-Operatória/prevenção & controle , Ácido Tranexâmico/administração & dosagem , Administração Tópica , Idoso , Valva Aórtica/cirurgia , Ponte de Artéria Coronária , Método Duplo-Cego , Emulsões , Ácidos Graxos , Feminino , Implante de Prótese de Valva Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Fosfolipídeos , Projetos Piloto , Vitamina A , Vitamina D
8.
Cardiol Young ; 29(1): 67-70, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30511604

RESUMO

BACKGROUND: A wide variety of surgical strategies are used in tetralogy of Fallot repair. We sought to describe the international contemporary practice patterns for surgical management of tetralogy of Fallot. METHODS: Surgeons from 18 international paediatric cardiac surgery centres (representing over 1800 tetralogy of Fallot cases/year) completed a Research Electronic Data Capture-based survey. Participating countries include: China (4), India (2), Nepal (1), Korea (1), Indonesia (1), Saudi Arabia (3), Japan (1), Turkey (1), Australia (1), United States of America (2), and Canada (1). Summary measures were reported as means and counts (percentages). Responses were weighted based on case volume/centre. RESULTS: Primary repair is the prevalent strategy (83%) with variation in age at elective repair (range). Approximately 47% of sites use patient age as a factor in determining the strategy, with age 90% of all trans-annular repairs. CONCLUSIONS: In this cohort representing 11 countries, there is variation in tetralogy of Fallot surgical management with no consensus on standard of practice. A large international prospective cohort study would allow analysis of impact of underlying anatomy and repair strategy on early and late outcomes.


Assuntos
Procedimentos Cirúrgicos Cardíacos/métodos , Tetralogia de Fallot/cirurgia , Cirurgia Torácica/estatística & dados numéricos , Fatores Etários , Estudos de Coortes , Humanos , Lactente , Recém-Nascido , Internacionalidade , Inquéritos e Questionários
9.
Cereb Cortex ; 29(9): 3766-3777, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-30496352

RESUMO

Oscillatory activity within sensorimotor networks is characterized by time-varying changes in phase and power. The influence of interactions between sensorimotor oscillatory phase and power on human motor function, like corticospinal output, is unknown. We addressed this gap in knowledge by delivering transcranial magnetic stimulation (TMS) to the human motor cortex during electroencephalography recordings in 20 healthy participants. Motor evoked potentials, a measure of corticospinal excitability, were categorized offline based on the mu (8-12 Hz) and beta (13-30 Hz) oscillatory phase and power at the time of TMS. Phase-dependency of corticospinal excitability was evaluated across a continuous range of power levels using trial-by-trial linear mixed-effects models. For mu, there was no effect of PHASE or POWER (P > 0.51), but a significant PHASE × POWER interaction (P = 0.002). The direction of phase-dependency reversed with changing mu power levels: corticospinal output was higher during mu troughs versus peaks when mu power was high while the opposite was true when mu power was low. A similar PHASE × POWER interaction was not present for beta oscillations (P > 0.11). We conclude that the interaction between sensorimotor oscillatory phase and power gates human corticospinal output to an extent unexplained by sensorimotor oscillatory phase or power alone.

10.
BMJ Case Rep ; 20182018 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-30317200

RESUMO

A young man previously diagnosed with Kleine-Levin syndrome (KLS) presented with abnormal behaviour over the last 8 days. This included decreased sleeping hours and appetite, hypersexuality, aggressiveness and visual hallucinations. All blood tests and investigations in the emergency department yielded normal results. A preliminary diagnosis of a KLS episode with psychosis was made and the patient was started on a regimen of aripiprazole 10 mg once daily along with lorazepam 2 mg intravenously in two divided doses in the event of agitation or insomnia. On discharge 5 days later, the patient had returned to his premorbid level of functioning and was willing to follow up in the neurology clinic. He was discharged on aripiprazole 10 mg once daily and lorazepam 2 mg two times daily as needed for 2 weeks to help with his agitation and insomnia, as well as lithium carbonate 400 mg at night.


Assuntos
Síndrome de Kleine-Levin/diagnóstico , Distúrbios do Início e da Manutenção do Sono/diagnóstico , Adolescente , Antimaníacos/administração & dosagem , Antimaníacos/uso terapêutico , Diagnóstico Diferencial , Alucinações/etiologia , Humanos , Síndrome de Kleine-Levin/complicações , Síndrome de Kleine-Levin/tratamento farmacológico , Carbonato de Lítio/administração & dosagem , Carbonato de Lítio/uso terapêutico , Masculino , Distúrbios do Início e da Manutenção do Sono/complicações , Distúrbios do Início e da Manutenção do Sono/tratamento farmacológico
11.
BMJ Case Rep ; 20182018 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-30262540

RESUMO

A 5-month-old baby presented with a low-grade fever and tachypnoea and was found to have right upper lobe consolidation on chest radiograph. He was admitted with the diagnosis of bronchopneumonia and the treatment protocol for pneumonia was initiated. Blood culture samples were collected, and he was started on a course of intravenous amoxicillin-clavulanate. Blood culture results displayed pansensitive Gemella morbillorum bacteraemia and he was continued on intravenous antibiotic to which he responded in a short period and was discharged in good condition on the fourth day.


Assuntos
Infecções por Bactérias Gram-Positivas/diagnóstico , Pneumonia Bacteriana/diagnóstico , Administração Intravenosa , Combinação Amoxicilina e Clavulanato de Potássio/administração & dosagem , Antibacterianos/administração & dosagem , Bacteriemia/sangue , Gemella/isolamento & purificação , Infecções por Bactérias Gram-Positivas/sangue , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Humanos , Lactente , Pulmão/diagnóstico por imagem , Masculino , Pneumonia Bacteriana/sangue , Pneumonia Bacteriana/tratamento farmacológico
13.
Turk J Emerg Med ; 18(2): 78-79, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29922736

RESUMO

An elderly, bed ridden patient with a history of stroke was admitted for management of aspiration pneumonia. Two days after insertion of a nasopharyngeal airway, sudden respiratory distress prompted further investigations which led to the eventual diagnosis and removal of the nasopharyngeal airway that had been aspirated. The device was removed under conscious sedation with fiber optic bronchoscopy.

14.
J Neurophysiol ; 117(6): 2085-2087, 2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28228580

RESUMO

Paired-pulse transcranial magnetic stimulation (TMS) and peripheral stimulation combined with TMS can be used to study cortical interneuronal circuitry. By combining these procedures with concurrent transcranial alternating current stimulation (tACS), Guerra and colleagues recently showed that different cortical interneuronal populations are differentially modulated by the phase and frequency of tACS-imposed oscillations (Guerra A, Pogosyan A, Nowak M, Tan H, Ferreri F, Di Lazzaro V, Brown P. Cerebral Cortex 26: 3977-2990, 2016). This work suggests that different cortical interneuronal populations can be characterized by their phase and frequency dependency. Here we discuss how combining TMS and tACS can reveal the frequency at which cortical interneuronal populations oscillate, the neuronal origins of behaviorally relevant cortical oscillations, and how entraining cortical oscillations could potentially treat brain disorders.


Assuntos
Córtex Cerebral/fisiologia , Interneurônios/fisiologia , Estimulação Transcraniana por Corrente Contínua/métodos , Estimulação Magnética Transcraniana/métodos , Humanos
16.
J Foot Ankle Res ; 9: 43, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27843491

RESUMO

BACKGROUND: The ankle is an important component of the human kinetic chain, and deficits in ankle strength can negatively impact functional tasks such as balance and gait. While peak torque is influenced by joint angle and movement velocity, ankle strength is typically reported for a single angle or movement speed. To better identify deficits and track recovery of ankle strength after injury or surgical intervention, ankle strength across a range of movement velocities and joint angles in healthy adults is needed. Thus, the primary goals of this study were to generate a database of strength values and 3-dimensional strength surface models for plantarflexion (PF) and dorsiflexion (DF) ankle strength in healthy men and women. Secondary goals were to develop a means to estimate ankle strength percentiles as well as examine predictors of maximal ankle strength in healthy adults. METHODS: Using an isokinetic dynamometer, we tested PF and DF peak torques at five joint angles (-10° [DF], 0° [neutral], 10° [PF], 20° [PF] and 30° [PF]) and six velocities (0°/s, 30°/s, 60°/s, 90°/s, 120°/s and 180°/s) in 53 healthy adults. These data were used to generate 3D plots, or "strength surfaces", for males and females for each direction; surfaces were fit using a logistic equation. We also tested predictors of ankle strength, including height, weight, sex, and self-reported physical activity levels. RESULTS: Torque-velocity and torque-angle relationships at the ankle interact, indicating that these relationships are interdependent and best modeled using 3D surfaces. Sex was the strongest predictor of ankle strength over height, weight, and self-reported physical activity levels. 79 to 97 % of the variance in mean peak torque was explained by joint angle and movement velocity using logistic equations, for men and women and PF and DF directions separately. CONCLUSIONS: The 3D strength data and surface models provide a more comprehensive dataset of ankle strength in healthy adults than previously reported. These models may allow researchers and clinicians to quantify ankle strength deficits and track recovery in patient populations, using angle- and velocity-specific ankle strength values and/or strength percentiles from healthy adults.


Assuntos
Articulação do Tornozelo/fisiologia , Artrometria Articular/métodos , Amplitude de Movimento Articular/fisiologia , Adulto , Exercício/fisiologia , Feminino , Humanos , Contração Isométrica/fisiologia , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Força Muscular/fisiologia , Dinamômetro de Força Muscular , Músculo Esquelético/fisiologia , Valores de Referência , Torque , Adulto Jovem
17.
Brain Stimul ; 9(4): 584-93, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27117281

RESUMO

BACKGROUND: The theory of homeostatic metaplasticity has significant implications for human motor cortical plasticity and motor learning. Previous work has shown that the extent of recent effector use before exogenously-induced plasticity can affect the direction, magnitude and variability of aftereffects. However, the impact of recent effector use on motor learning and practice-dependent plasticity is not known. HYPOTHESIS: We hypothesized that reducing effector use for 8 hours via hand/wrist immobilization would facilitate practice-dependent changes in corticospinal excitability and TMS-evoked thumb movement kinematics, while also promoting 24-hour retention of a ballistic motor skill. METHODS: Subjects participated in a crossover study involving two conditions. During the immobilization condition, subjects wore a splint that restricted motion of the left hand and thumb for 8 hours. While wearing the splint, subjects were instructed to avoid using their left hand as much as possible. During the control condition, subjects did not wear a splint at any time nor were they instructed to avoid hand use. After either an 8 hour period of immobilization or normal hand use, we collected MEP and TMS-evoked thumb movement recruitment curves, and subjects practiced a ballistic motor skill involving rapid thumb extension. After motor practice, MEP and TMS-evoked thumb movement recruitment curves were re-tested. Retention of the motor skill was tested 30 minutes and 24 hours after motor practice. RESULTS: Reduced effector use did not impact pre-practice corticospinal excitability but did facilitate practice-dependent changes in corticospinal excitability, and this enhancement was specific to the trained muscle. In contrast, reducing effector use did not affect practice-dependent changes in TMS-evoked thumb movements nor did it promote acquisition or retention of the skill. Finally, we detected some associations between pre-practice excitability levels, plasticity effects and learning effects, but these did not reach our adjusted criterion for significance. CONCLUSION: Experimentally enhancing practice-dependent changes in corticospinal excitability is not sufficient to promote learning or memory of a ballistic motor skill.


Assuntos
Potencial Evocado Motor/fisiologia , Imobilização/fisiologia , Atividade Motora/fisiologia , Plasticidade Neuronal/fisiologia , Tratos Piramidais/fisiologia , Estimulação Magnética Transcraniana/métodos , Adulto , Feminino , Homeostase , Humanos , Masculino , Adulto Jovem
18.
Ann Thorac Surg ; 101(3): 996-1004, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26830224

RESUMO

BACKGROUND: Potential surgical strategies for hypoplastic branch pulmonary arteries (BPAs) during tetralogy of Fallot repair include (1) extensive patch augmentation to the hilum (PATCH), (2) limited extension arterioplasty to the proximal pulmonary artery (EXTENSION), or (3) leaving the native vessels unaugmented (NATIVE). We explored the effect of these strategies on reintervention and BPA growth. METHODS: From 2000 to 2012, 434 children underwent complete tetralogy of Fallot repair. Risk-adjusted parametric models were used to analyze the risk of BPA reintervention for (1) all children, (2) children with BPAs of 4 mm or smaller, and (3) children with BPAs of 3 mm or smaller. Repeated-measures analysis of more than 2,000 echocardiograms was used to characterize postoperative BPA growth and right ventricular pressure by using nonlinear mixed models. RESULTS: Overall survival (99% [3 deaths]) was excellent. The 10-year freedom from BPA reintervention was 84%. In risk-adjusted models (including baseline BPA z-score), PATCH had a decreased freedom from reintervention (73%; p < 0.01) vs EXTENSION (87%) or NATIVE (91%). For children with BPAs of 4 mm or smaller (28 PATCH, 60 EXTENSION, 75 NATIVE), baseline characteristics were similar. The risk-adjusted 5-year freedom from reintervention was 68% for PATCH, 76% for EXTENSION, and 85% for NATIVE. PATCH trended toward an increased risk of reintervention (p = 0.07). For children with BPAs of 4 mm or smaller left in their NATIVE state, only ∼15% required reintervention. After adjustment for baseline BPA z-score, the time-related BPA growth was decreased (p < 0.014) and right ventricular pressure was increased (p = 0.03) for the PATCH group. CONCLUSIONS: Aggressive PATCH augmentation of hypoplastic BPAs improves the short-term geometry but may lead to late stenosis and higher rates of reintervention. Hypoplastic BPAs in tetralogy of Fallot tend (∼85%) to grow well without instrumentation.


Assuntos
Anormalidades Múltiplas , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Complicações Pós-Operatórias/cirurgia , Artéria Pulmonar/anormalidades , Retalhos Cirúrgicos , Tetralogia de Fallot/cirurgia , Procedimentos Cirúrgicos Vasculares/métodos , Adolescente , Criança , Pré-Escolar , Ecocardiografia , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Masculino , Ontário/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Artéria Pulmonar/diagnóstico por imagem , Artéria Pulmonar/cirurgia , Reoperação , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Tetralogia de Fallot/diagnóstico , Tetralogia de Fallot/mortalidade , Fatores de Tempo , Resultado do Tratamento
19.
PLoS One ; 10(6): e0129543, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26053288

RESUMO

Caffeine is widely consumed throughout the world and appears to indirectly facilitate learning and memory through effects on attention and motivation. Animal work indicates that post-training caffeine administration augments inhibitory avoidance memory, spatial memory, and object memory. In humans, post-training caffeine administration enhances the ability to discern between familiar images and new, similar images. However, the effect of post-training caffeine administration on motor memory has not been examined. Therefore, we tested two groups of low caffeine consumers (average weekly consumption ≤500 mg) in a double-blind, placebo-controlled study involving acquisition of a continuous isometric visuomotor tracking skill. On Day 1, subjects completed 5 blocks (150 repetitions) of training on the continuous isometric visuomotor skill and subsequently ingested either 200 mg of caffeine or placebo. On day 2, subjects completed an additional 5 blocks of training. Day 1 mean performance and performance variability were both similar between groups, suggesting that both groups acquired the motor skill similarly. For mean performance on Day 2, patterns of re-learning, mean performance learning magnitudes, mean performance learning rates, and mean performance retention magnitudes were all similar between groups. For performance variability on Day 2, there was a small trend towards increased variability in the caffeine group during re-learning, but performance variability learning magnitudes and performance variability retention magnitudes did not differ between groups. Because motor skill acquisition can also be conceptualized as a reduction in performance variability, these results suggest that there may be a small negative effect of post-practice caffeine administration on memory of a newly-learned visuomotor skill. Overall, we found no evidence to suggest that post-training caffeine administration enhances 24-hour retention of a newly-learned continuous visuomotor skill, and these results support the notion that memory-enhancing effects of post-training caffeine ingestion may be task-specific.


Assuntos
Cafeína/administração & dosagem , Destreza Motora/efeitos dos fármacos , Desempenho Psicomotor/efeitos dos fármacos , Adulto , Feminino , Humanos , Masculino , Sono/efeitos dos fármacos , Adulto Jovem
20.
J Atr Fibrillation ; 8(4): 1175, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27957219

RESUMO

Syncope and atrial fibrillation are both common entities and frequently occur together in an acute clinical scenario. Treatment of each in this presentation requires acquiring a good history and understanding the presentation of the patient. In this manuscript, there are 5 case studies that demonstrate common misperceptions when attempting to treat syncope when it presents with the arrhythmia atrial fibrillation. Rarely, does atrial fibrillation cause syncope. However, when a patient presents in atrial fibrillation, it becomes the focus of therapy rather than trying to define the etiology of the syncopal episode. It may be that well thought out algorithms to treat atrial fibrillation in an acute setting are replacing deductive thinking particularly when it comes to diagnosing the cause of a syncopal spell.

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