Correlation Between Single-Pulse and Pulse-Train Stimulation During Neuromonitoring of Thoracic Pedicle Screws in Scoliosis Surgery.

BACKGROUND: The use of thoracic pedicle screws (TPSs) during scoliosis surgery entails an inherent risk of neurological deficit. Triggered electromyography (t-EMG) is an accurate neuromonitoring test for detection of malpositioned TPSs. However, single-pulse (SP) t-EMG stimulation has shown variable capability for detecting medial pedicle breaches, while pulse-train (PT) t-EMG could be more accurate. The aim of this study was to analyze the correlation between SP t-EMG and PT t-EMG. METHODS: This retrospective study included 20 patients who underwent scoliosis correction with 294 TPSs placed. A total of 588 tests with both SP t-EMG and PT t-EMG were performed, analyzed, and compared. The results of both t-EMG techniques were stratified into 3 different groups according to threshold obtained: group 1 (≤6 mA), group 2 (6.1-11.9 mA), and group 3 (12 mA). A generalized linear model was used to analyze the correlation between the methods. RESULTS: SP t-EMG elicited response in 5 screws (1.7%) at ≤6 mA, 28 screws (9.5%) at 6.1-11.9 mA, and 261 screws (88.8%) at 12 mA. PT t-EMG elicited response in 16 screws (5.4%) at ≤6 mA, 30 screws (10.2%) at 6.1-11.9mA, and 248 screws (84.4%) at 12 mA. There is a strong positive and significant association between SP t-EMG and PT t-EMG with a decrease ratio of 2% (95% confidence interval 1% to 3%). CONCLUSIONS: SP t-EMG and PT t-EMG stimulation techniques had similar results when the stimuli were applied to TPSs, but PT t-EMG may have better efficacy in low-threshold group.

Effects of Circuit Weight-Interval Training on Physical Fitness, Cardiac Autonomic Control, and Quality of Life in Sedentary Workers.

Sedentary behaviors, those that involve sitting and low levels of energy expenditure, have been associated with several adverse cardiometabolic effects. This study evaluated the chronic effects of a combined circuit weight interval training (CWIT) on physical fitness, quality of life, and heart rate variability (HRV), and compared the effects of CWIT-induced autonomic adaptations on different postures in adult sedentary workers. Twenty-seven sedentary workers (age 36.9 ± 9.2 years old, 13 men and 14 women) were divided into two groups: control, who continued their sedentary behavior, and experimental, who were submitted to a CWIT for 12 weeks, completing two ~40 min sessions per week. Monitoring of 8th, 16th, and 24th sessions revealed a moderate training load during sessions. Participants exhibited an improved aerobic capacity (VO2max, 34.03 ± 5.36 vs. 36.45 ± 6.05 mL/kg/min, p < 0.05) and flexibility (22.6 ± 11.4 vs. 25.3 ± 10.1 cm, p < 0.05) after the training period. In addition, they showed greater quality of life scores. However, the CWIT did not change body composition. Interestingly, more HRV parameters were improved in the seated position. The CWIT used in the current study was associated with improvements in several fitness and quality of life parameters, as well as in cardiac autonomic control of HR in adult sedentary workers. Examination of different body positions when evaluating changes in HRV appears to be a relevant aspect to be considered in further studies. Future randomized controlled trials (RCTs) with larger samples of both sexes should confirm these promising results.