Commonly used antiemetics for prophylaxis of postoperative nausea and vomiting after Caesarean delivery with neuraxial morphine: a network meta-analysis.

BACKGROUND: Dopamine antagonists, 5-HT3 antagonists, and dexamethasone are frequently used in obstetrics to prevent postoperative nausea and vomiting (PONV). However, the superiority of any drug class is yet to be established. This network meta-analysis aimed to compare the efficacy of these antiemetics for PONV prophylaxis in women receiving neuraxial morphine for Caesarean delivery. METHODS: We searched PubMed, Embase, CENTRAL, Web of Science, and Wanfang Data for eligible randomised controlled trials. Primary outcomes were the incidences of postoperative nausea (PON) and postoperative vomiting (POV) within 24 h after surgery. We used a Bayesian random-effects model and calculated odds ratios with 95% credible intervals for dichotomous data. We performed sensitivity and subgroup analyses for primary outcomes. RESULTS: A total of 33 studies with 4238 women were included. In the primary analyses of all women, 5-HT3 antagonists, dopamine antagonists, dexamethasone, and 5-HT3 antagonists plus dexamethasone significantly reduced PON and POV compared with placebo, and 5-HT3 antagonists plus dexamethasone were more effective than monotherapy. In the subgroup analyses, similar results were seen in women receiving epidural morphine or intrathecal morphine alone but not in women receiving intrathecal morphine with fentanyl or sufentanil. However, most included studies had some concerns or a high risk of bias, and the overall certainty of the evidence was low or very low. CONCLUSIONS: Combined 5-HT3 antagonists plus dexamethasone are more effective than monotherapy in preventing PONV associated with neuraxial morphine after Caesarean delivery. Future studies are needed to determine the role of prophylactic antiemetics in women receiving intrathecal morphine and lipophilic opioids. SYSTEMATIC REVIEW PROTOCOL: PROSPERO CRD42023454602.

Brainmask: an ultrasoft and moist micro-electrocorticography electrode for accurate positioning and long-lasting recordings.

Bacterial cellulose (BC), a natural biomaterial synthesized by bacteria, has a unique structure of a cellulose nanofiber-weaved three-dimensional reticulated network. BC films can be ultrasoft with sufficient mechanical strength, strong water absorption and moisture retention and have been widely used in facial masks. These films have the potential to be applied to implantable neural interfaces due to their conformality and moisture, which are two critical issues for traditional polymer or silicone electrodes. In this work, we propose a micro-electrocorticography (micro-ECoG) electrode named "Brainmask", which comprises a BC film as the substrate and separated multichannel parylene-C microelectrodes bonded on the top surface. Brainmask can not only guarantee the precise position of microelectrode sites attached to any nonplanar epidural surface but also improve the long-lasting signal quality during acute implantation with an exposed cranial window for at least one hour, as well as the in vivo recording validated for one week. This novel ultrasoft and moist device stands as a next-generation neural interface regardless of complex surface or time of duration.

Ultrasonic neuromodulation mediated by mechanosensitive ion channels: current and future.

Ultrasound neuromodulation technology is a promising neuromodulation approach, with the advantages of noninvasiveness, high-resolution, deep penetration and good targeting, which aid in circumventing the side effects of drugs and invasive therapeutic interventions. Ultrasound can cause mechanical effects, activate mechanosensitive ion channels and alter neuronal excitability, producing biological effects. The structural determination of mechanosensitive ion channels will greatly contribute to our understanding of the molecular mechanisms underlying mechanosensory transduction. However, the underlying biological mechanism of ultrasonic neuromodulation remains poorly understood. Hence, this review aims to provide an outline of the properties of ultrasound, the structures of specific mechanosensitive ion channels, and their role in ultrasound neuromodulation.

Effects of EMG-based robot for upper extremity rehabilitation on post-stroke patients: a systematic review and meta-analysis.

Objective: A growing body of research shows the promise and efficacy of EMG-based robot interventions in improving the motor function in stroke survivors. However, it is still controversial whether the effect of EMG-based robot is more effective than conventional therapies. This study focused on the effects of EMG-based robot on upper limb motor control, spasticity and activity limitation in stroke survivors compared with conventional rehabilitation techniques. Methods: We searched electronic databases for relevant randomized controlled trials. Outcomes included Fugl-Meyer assessment scale (FMA), Modified Ashworth Scale (MAS), and activity level. Result: Thirteen studies with 330 subjects were included. The results showed that the outcomes post intervention was significantly improved in the EMG-based robot group. Results from subgroup analyses further revealed that the efficacy of the treatment was better in patients in the subacute stage, those who received a total treatment time of less than 1000 min, and those who received EMG-based robotic therapy combined with electrical stimulation (ES). Conclusion: The effect of EMG-based robot is superior to conventional therapies in terms of improving upper extremity motor control, spasticity and activity limitation. Further research should explore optimal parameters of EMG-based robot therapy and its long-term effects on upper limb function in post-stroke patients. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/; Identifier: 387070.

The interaction between changes of muscle activation and cortical network dynamics during isometric elbow contraction: a sEMG and fNIRS study.

Objective: The relationship between muscle activation during motor tasks and cerebral cortical activity remains poorly understood. The aim of this study was to investigate the correlation between brain network connectivity and the non-linear characteristics of muscle activation changes during different levels of isometric contractions. Methods: Twenty-one healthy subjects were recruited and were asked to perform isometric elbow contractions in both dominant and non-dominant sides. Blood oxygen concentrations in brain from functional Near-infrared Spectroscopy (fNIRS) and surface electromyography (sEMG) signals in the biceps brachii (BIC) and triceps brachii (TRI) muscles were recorded simultaneously and compared during 80% and 20% of maximum voluntary contraction (MVC). Functional connectivity, effective connectivity, and graph theory indicators were used to measure information interaction in brain activity during motor tasks. The non-linear characteristics of sEMG signals, fuzzy approximate entropy (fApEn), were used to evaluate the signal complexity changes in motor tasks. Pearson correlation analysis was used to examine the correlation between brain network characteristic values and sEMG parameters under different task conditions. Results: The effective connectivity between brain regions in motor tasks in dominant side was significantly higher than that in non-dominant side under different contractions (p < 0.05). The results of graph theory analysis showed that the clustering coefficient and node-local efficiency of the contralateral motor cortex were significantly varied under different contractions (p < 0.01). fApEn and co-contraction index (CCI) of sEMG under 80% MVC condition were significantly higher than that under 20% MVC condition (p < 0.05). There was a significant positive correlation between the fApEn and the blood oxygen value in the contralateral brain regions in both dominant or non-dominant sides (p < 0.001). The node-local efficiency of the contralateral motor cortex in the dominant side was positively correlated with the fApEn of the EMG signals (p < 0.05). Conclusion: In this study, the mapping relationship between brain network related indicators and non-linear characteristic of sEMG in different motor tasks was verified. These findings provide evidence for further exploration of the interaction between the brain activity and the execution of motor tasks, and the parameters might be useful in evaluation of rehabilitation intervention.

Electromyography-Force Relation and Muscle Fiber Conduction Velocity Affected by Spinal Cord Injury.

A surface electromyography (EMG) analysis was performed in this study to examine central neural and peripheral muscle changes after a spinal cord injury (SCI). A linear electrode array was used to record surface EMG signals from the biceps brachii (BB) in 15 SCI subjects and 14 matched healthy control subjects as they performed elbow flexor isometric contractions from 10% to 80% maximum voluntary contraction. Muscle fiber conduction velocity (MFCV) and BB EMG-force relation were examined. MFCV was found to be significantly slower in the SCI group than the control group, evident at all force levels. The BB EMG-force relation was well fit by quadratic functions in both groups. All healthy control EMG-force relations were best fit with positive quadratic coefficients. In contrast, the EMG-force relation in eight SCI subjects was best fit with negative quadratic coefficients, suggesting impaired EMG modulation at high forces. The alterations in MFCV and EMG-force relation after SCI suggest complex neuromuscular changes after SCI, including alterations in central neural drive and muscle properties.

Convalescent or standard plasma versus standard of care in the treatment of COVID-19 patients with respiratory impairment: short and long-term effects. A three-arm randomized controlled clinical trial.

BACKGROUND: The efficacy of early treatment with convalescent plasma in patients with COVID-19 is debated. Nothing is known about the potential effect of other plasma components other than anti-SARS-CoV-2 antibodies. METHODS: To determine whether convalescent or standard plasma would improve outcomes for adults in early phase of Covid19 respiratory impairment we designed this randomized, three-arms, clinical trial (PLACO COVID) blinded on interventional arms that was conducted from June 2020 to August 2021. It was a multicentric trial at 19 Italian hospitals. We enrolled 180 hospitalized adult patients with COVID-19 pneumonia within 5 days from the onset of respiratory distress. Patients were randomly assigned in a 1:1:1 ratio to standard of care (n = 60) or standard of care + three units of standard plasma (n = 60) or standard of care + three units of high-titre convalescent plasma (n = 60) administered on days 1, 3, 5 after randomization. Primary outcome was 30-days mortality. Secondary outcomes were: incidence of mechanical ventilation or death at day 30, 6-month mortality, proportion of days with mechanical ventilation on total length of hospital stay, IgG anti-SARS-CoV-2 seroconversion, viral clearance from plasma and respiratory tract samples, and variations in Sequential Organ Failure Assessment score. The trial was analysed according to the intention-to-treat principle. RESULTS: 180 patients (133/180 [73.9%] males, mean age 66.6 years [IQR 57-73]) were enrolled a median of 8 days from onset of symptoms. At enrollment, 88.9% of patients showed moderate/severe respiratory failure. 30-days mortality was 20% in Control arm, 23% in Convalescent (risk ratio [RR] 1.13; 95% confidence interval [CI], 0.61-2.13, P = 0.694) and 25% in Standard plasma (RR 1.23; 95%CI, 0.63-2.37, P = 0.544). Time to viral clearance from respiratory tract was 21 days for Convalescent, 28 for Standard plasma and 23 in Control arm but differences were not statistically significant. No differences for other secondary endpoints were seen in the three arms. Serious adverse events were reported in 1.7%, 3.3% and 5% of patients in Control, Standard and Convalescent plasma arms respectively. CONCLUSIONS: Neither high-titer Convalescent nor Standard plasma improve outcomes of COVID-19 patients with acute respiratory failure. Trial Registration Clinicaltrials.gov Identifier: NCT04428021. First posted: 11/06/2020.

The development path of the medical profession in China's engineering universities from the perspective of the 'four new' disciplines.

In recent years, China has actively promoted the construction of first-class universities and disciplines of the world ('Double First-Class'), and built a new model of university development to solve Chinese problems and support high-quality economic and social development. In the context of China's efforts to promote the construction of new engineering, new medicine, new agriculture, and new liberal arts (referred to as the 'four new' disciplines), these disciplines are developing rapidly. As a specialty dealing with major life issues, medical education has become increasingly prominent. To enhance the comprehensive strength of universities, corresponding to the 'four new' disciplines strategy, engineering universities are building and developing medical specialties one after another. At present, the greatest problem in the medical specialty of engineering universities is the tendency to blindly follow trends and integrate new concepts with traditional methods. However, to date, the integration of medical and nonmedical specialties has been superficial and thus has not been successful. To address this problem, this paper, guided by the policies aimed at developing the 'four new' disciplines, analyses the current situation of traditional medicine education and professional development in engineering universities and proposes measures to enhance the competitiveness of new medicine in engineering universities, thereby promoting the development of universities.KEY MESSAGESThe implementation of the 'four new' disciplines is a strategic choice for higher education.Engineering technology is an efficient path and hands-on approach to solving medical problems.Interdisciplinary and comprehensive educational approaches play an important role in the development of medical science.

Transcranial ultrasound stimulation applied in ischemic stroke rehabilitation: A review.

Ischemic stroke is a serious medical condition that is caused by cerebral vascular occlusion and leads to neurological dysfunction. After stroke, patients suffer from long-term sensory, motor and cognitive impairment. Non-invasive neuromodulation technology has been widely studied in the field of stroke rehabilitation. Transcranial ultrasound stimulation (TUS), as a safe and non-invasive technique with deep penetration ability and a tiny focus, is an emerging technology. It can produce mechanical and thermal effects by delivering sound waves to brain tissue that can induce the production of neurotrophic factors (NFs) in the brain, and reduce cell apoptosis and the inflammatory response. TUS, which involves application of an acoustic wave, can also dissolve blood clots and be used to deliver therapeutic drugs to the ischemic region. TUS has great potential in the treatment of ischemic stroke. Future advancements in imaging and parameter optimization will improve the safety and efficacy of this technology in the treatment of ischemic stroke.

Effects of Non-Invasive Brain Stimulation on Post-Stroke Spasticity: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

In recent years, the potential of non-invasive brain stimulation (NIBS) for the therapeutic effect of post-stroke spasticity has been explored. There are various NIBS methods depending on the stimulation modality, site and parameters. The purpose of this study is to evaluate the efficacy of NIBS on spasticity in patients after stroke. This systematic review and meta-analysis was conducted according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. PUBMED (MEDLINE), Web of Science, Cochrane Library and Excerpta Medica Database (EMBASE) were searched for all randomized controlled trials (RCTs) published before December 2021. Two independent researchers screened relevant articles and extracted data. This meta-analysis included 14 articles, and all included articles included 18 RCT datasets. The results showed that repetitive transcranial magnetic stimulation (rTMS) (MD = −0.40, [95% CI]: −0.56 to −0.25, p < 0.01) had a significant effect on improving spasticity, in which low-frequency rTMS (LF-rTMS) (MD = −0.51, [95% CI]: −0.78 to −0.24, p < 0.01) and stimulation of the unaffected hemisphere (MD = −0.58, [95% CI]: −0.80 to −0.36, p < 0.01) were beneficial on Modified Ashworth Scale (MAS) in patients with post-stroke spasticity. Transcranial direct current stimulation (tDCS) (MD = −0.65, [95% CI]: −1.07 to −0.22, p < 0.01) also had a significant impact on post-stroke rehabilitation, with anodal stimulation (MD = −0.74, [95% CI]: −1.35 to −0.13, p < 0.05) being more effective in improving spasticity in patients. This meta-analysis revealed moderate evidence that NIBS reduces spasticity after stroke and may promote recovery in stroke survivors. Future studies investigating the mechanisms of NIBS in addressing spasticity are warranted to further support the clinical application of NIBS in post-stroke spasticity.

Case Management Improves Satisfaction, Anxiety, and Depression of Patients with Pregnancy Loss after In Vitro Fertilization and Embryo Transfer.

Objective: Pregnancy loss has negative impacts on both the physical and the mental health of expectant mothers, which calls for an in-depth investigation. In this study, we examined the effects of case management on patients with pregnancy loss after in vitro fertilization and embryo transfer (IVF-ET). Methods: 100 participants that had suffered pregnancy loss after IVF-ET-assisted pregnancy from January 2019 to March 2020 were divided into routine care and case management groups, each with 50 cases. For the routine care group, a doctor led the diagnostic and treatment processes and a nurse assisted with the treatment. For the case management group, a nurse led the patient diagnostic and treatment processes and a doctor controlled the diagnosis and treatment plan formulation. Case management models were established according to the comprehensive peripregnancy loss care of patients with pregnancy loss after IVF-ET-assisted pregnancy. The participants' outcomes (satisfaction, anxiety, and depression) were assessed at the time of pregnancy loss and 1 and 3 months after pregnancy loss during follow-up of the routine care and case management groups. Results: There was no statistical difference between the patients in the two groups with regard to their general information statistics (P > 0.05) or their satisfaction, anxiety, and depression at the time of pregnancy loss (P > 0.05). One month after pregnancy loss, there was no statistical difference in anxiety between the two groups (P > 0.05), but satisfaction was greater and depression was significantly reduced in the case management group compared with the routine care group (P < 0.05). Conclusion: Case management care can have a positive effect on improving the satisfaction, anxiety, and depression of patients that have had pregnancy loss after IVF-ET.

Interrater and Intrarater Reliability of Electrical Impedance Myography: A Comparison between Large and Small Handheld Electrode Arrays.

The objective of this study was to evaluate the interrater and intrarater reliability of electrical impedance myography (EIM) using handheld sensors of different sizes. Electrical impedance myography of the biceps brachii muscle of twenty healthy individuals was performed by two raters using both large and small sensors. The procedures were also repeated 5 to 8 days after the first recording session. The repeatability of the resistance, reactance, and phase angle at two different current frequencies (50 and 100 kHz) was assessed by the intraclass correlation coefficient (ICC). The ICCs of the large sensor were higher than those of the small sensor for both the intrarater and interrater reliabilities. High-frequency current tended to improve the ICC for the small sensor. These results indicate reasonable repeatability of the handheld electrode arrays for EIM measurements. The findings suggest that electrode array should be selected appropriately according to the size of the tested muscle.

Quantifying the Changes of Mechanical and Electrical Properties of Paralyzed Muscle in Survivors With Cervical Spinal Cord Injury.

Background: Survivors with spinal cord injury (SCI) have neuromuscular deficits such as muscle atrophy that lead to functional impairments. This study utilized myotonometry and electrical impedance myography (EIM) to quantitatively evaluate the changes in muscle mechanical properties and compositions after SCI. Methods: This study adopted a cross-sectional design. Eighteen SCI patients and 18 healthy individuals were recruited. The outcome measures were: (1) The myotonometer measured muscle mechanical parameters of oscillation frequency (freq), dynamic stiffness, logarithmic decrement (decr), mechanical stress relaxation time, and indication of creep. (2) The electrical impedance myography measured parameters of resistance (R), reactance (X), and phase angle (θ). (3) muscle strength (maxForce); (4) clinical scales of Manual Muscle Testing (MMT) and modified Ashworth scale (MAS). All outcome measures were compared between the bicep brachii muscle of the weaker side of the SCI group and the non-dominate side of the healthy group. Correlation analysis was performed at quantitative data and clinical scales. Results: Freq, stiffness, and maxForce of the SCI group were significantly lower (p < 0.01) than those of the healthy control. The relaxation time and creep were significantly higher in the SCI group than in the control group. Significant differences of R and Xc were observed between the two groups. Significant correlation was observed between freq, stiffness, and months past injury, and between Xc, creep, and relaxation time. Conclusions: Reduced muscle tone and stiffness might relate to muscle atrophy, and higher relax time and creep may be caused by poor contractile ability. The changes in EIM parameters could indirectly reflect the muscle cell size, and fatty and connective tissue alterations. These findings support the feasibility of myotonometer and EIM to quantify muscle mechanical and intrinsic properties in patients with SCI. The results could facilitate the understanding of neuromuscular changes that are related to functional impairments.

Norepinephrine for the prevention of spinal-induced hypotension during caesarean delivery under combined spinal-epidural anaesthesia: Randomised, double-blind, dose-finding study.

BACKGROUND: During caesarean delivery under spinal anaesthesia hypotension may be managed by norepinephrine in preference to phenylephrine due a perception of less bradycardia and fewer reductions in cardiac output. OBJECTIVE: As the optimum prophylactic dose of norepinephrine is unclear, we aimed to investigate its dose-response for preventing postspinal hypotension in caesarean delivery. DESIGN: A randomised, double-blinded, dose-finding study. SETTING: Jiaxing University affiliated Women and Children Hospital, Jiaxing, China. PATIENTS: Ninety-nine patients undergoing elective caesarean delivery from 1 February to 5 August: excluding patients with ASA III or above, preeclampsia or hypertension, pre-existing or gestational diabetes, BMI more than 35 kg m, height less than 150 cm or with more than 175 cm, or with contraindications to local anaesthesia. INTERVENTIONS: Patients received 0, 0.04, 0.05, 0.06 or 0.07 µg kg min preventive norepinephrine infusions immediately after intrathecal injection of 10 mg bupivacaine with 5 µg sufentanil. MAIN OUTCOME MEASURES: The norepinephrine (Median effective dose) or (95% effective dose) ED50 and ED95, which were estimated using Probit analysis to compare haemodynamic changes associated with the different doses. RESULTS: The incidence of hypotension was 70, 47.4, 40, 20 and 15% in the 0, 0.04, 0.05, 0.06 and 0.07 µg kg min groups, respectively. The ED50, ED80 and ED95 values were 0.029 (95% CI 0.008 to 0.042 µg kg min), 0.068 (95% CI 0.055 to 0.099 µg kg min) and 0.105 µg kg min (95% CI 0.082 to 0.172 µg kg min), respectively. Apgar scores or umbilical arterial pH were similar among groups. CONCLUSION: The ED50, ED80 and ED95 were 0.029, 0.068 and 0.105 µg kg min respectively. A 0.07 µg kg min norepinephrine infusion may be optimum for preventing postspinal hypotension after intrathecal injection of 10 mg bupivacaine combined with 5 µg sufentanil. TRIAL REGISTRATION: Chinese Clinical Trial Registry (identifier: ChiCTR-TRC-1800014614).

Correlation Between Muscle Structures and Electrical Properties of the Tibialis Anterior in Subacute Stroke Survivors: A Pilot Study.

Electrical impedance myography (EIM) is a non-invasive diagnostic tool that assesses the muscle inherent properties, whereas ultrasonography can assess the alteration in muscle architecture. This study aimed to combine EIM with ultrasonography to assess the changes of the tibialis anterior (TA) muscle properties during passive plantar/dorsiflexion in stroke survivors. Fifteen patients with subacute stroke were recruited. The muscle structures were simultaneously assessed by EIM and ultrasonography at five different extension angles (-10°, 0°, 10°, 20°, and 30°) of the ankle joint. The EIM parameters measured were resistance (R), reactance (X), and phase angle (θ). The parameters recorded by ultrasonography were pennation angle (PA), muscle thickness (MT), and fascicle length (FL). Two-way repeated ANOVA was performed to compare the differences between the affected and unaffected sides as well as the parameters that changed with joint angle. Linear correlation analysis was conducted to assess the association between muscle parameters and clinical scores. The results showed that as the ankle was passively plantarflexed, the θ (P = 0.003) and PA (P < 0.001) values decreased, and the X (P < 0.001), R (P < 0.001), and FL (P < 0.001) values increased. Significant correlations were found between the FL and R values (r = 0.615, P = 0.015), MT and R values (r = 0.522, P = 0.046), and FL and θ values (r = 0.561, P = 0.03), as well as between the PA and the Fugl-Meyer Assessment of Lower Extremity score (r = 0.615, P = 0.015), the R and the Modified Ashworth Scale (MAS) score (r = 0.58, P = 0.023), and the PA and the manual muscle testing (MMT) score (r = -0.575, P = 0.025). This study demonstrated a correlation between the EIM and the ultrasonography parameters at different joint angles. Therefore, both methods could jointly be applied in patients with stroke to detect changes in the muscle inherent properties and muscle architecture. This could assist clinicians to quantitatively evaluate the muscle condition in people with subacute stroke. The study was registered on the Chinese Clinical Trial Registry (trial registration number: ChiCTR-IOR-17012299, http://www.chictr.org.cn/showprojen.aspx?proj=19818). Clinical Trial Registration Number: ChiCTR-IOR-17012299.

Identify the Alteration of Balance Control and Risk of Falling in Stroke Survivors During Obstacle Crossing Based on Kinematic Analysis.

This study aims to compare the differences in the kinematic characteristics of crossing obstacles of different heights between stroke survivors and age-matched healthy controls and to identify the changes of balance control strategy and risk of falling. Twelve stroke survivors and twelve aged-matched healthy controls were recruited. A three-dimensional motion analysis system and two force plates were used to measure the kinematic and kinetic data during crossing obstacles with heights of 10, 20, and 30% leg length. The results showed that during leading and trailing limb clearance, (AP) center of mass (COM) velocities of the stroke group were smaller than those of the healthy controls for all heights. The decreased distances between COM and center of pressure (COP) in the AP direction during the both trailing and leading limb support period were also found between stroke survivors and healthy controls for all heights. The COM velocity and COM-COP distance significantly correlated with the lower limb muscle strength. In addition, stroke survivors showed greater lateral pelvic tilt, greater hip abduction, and larger peak velocity in the medio-lateral (ML) direction. There was a positive correlation between the COM-COP distance in the AP direction and the clinical scales. These results might identify that the stroke survivors used a conservative strategy to negotiate the obstacles and control balance due to a lack of muscle strength. However, the abnormal patterns during obstacle crossing might increase the risk of falling. The findings could be used to design specific rehabilitation training programs to enhance body stability, reduce energy cost, and improve motion efficiency.

Design and basic research on accuracy of a novel individualized three-dimensional printed navigation template in atlantoaxial pedicle screw placement.

OBJECTIVE: To design and evaluate the accuracy of a novel navigation template suitable for posterior cervical screw placement surgery by using 3D printing technology to improve the existing guiding template design. METHODS: The researchers (including spine surgeons and technicians) used CT to perform thin-slice scanning on 12 cases of normal upper cervical vertebral specimens and defined the screw channels that were completely located in the pedicle without penetrating the cortex as ideal screw channels, then designed the ideal channel of the upper cervical vertebral (atlantoaxial) pedicle screw by computer software which was regarded as the preset values, and recorded the screw entrance point, transverse angle and sagittal angle of the ideal channel. Then, researchers designed the novel navigation templates for placement pedicle screw according to the ideal screw channel preset values and manufactured them with one for every single vertebra by 3D printer. A senior spine surgeon performed the posterior surgery to implant pedicle screw on the specimens by the novel navigation templates, then performed CT thin-slice scanning on the specimens again after removing the screws, and reconstructed the actual screws channel by computer software, recorded the screw entrance point, transverse angle and sagittal angle of the actual channels which were defined as the actual values and evaluated them according to Kawaguchi's pedicle screw evaluation standard finally. The differences between the preoperative preset values of ideal screw channel and the postoperative actual values of actual screw channel were compared by a nonparametric paired rank test. RESULTS: 48 screws were placed on 12 cases of upper cervical vertebral specimens in total. It showed that the grade 0, I, II, III channels in this study were 47, 1, 0, 0, respectively. The grade 0 channels accounted for 97.92% of the total number of channels. There was no significant difference with regard to the screw entrance point, the transverse angle, and the sagittal angle between the preoperative preset values of ideal screw channels and the postoperative actual values of actual screw channels. CONCLUSION: To implant pedicle screw assisted with the novel individually navigation template designed by 3D printed in the posterior cervical surgery can improve accuracy of pedicle screw placement and safety of the surgery.

Motor Unit Properties of the First Dorsal Interosseous in Chronic Stroke Subjects: Concentric Needle and Single Fiber EMG Analysis.

The purpose of this study was to better understand changes in motor unit electrophysiological properties in people with chronic stroke based on concentric needle electromyography (EMG) and single fiber EMG recordings. The first dorsal interosseous (FDI) muscle was studied bilaterally in eleven hemiparetic stroke subjects. A significant increase in mean fiber density (FD) was found in the paretic muscle compared with the contralateral side based on single fiber EMG (1.6 ± 0.2 vs. 1.3 ± 0.1, respectively, P = 0.003). There was no statistically significant difference between the paretic and contralateral sides in most concentric needle motor unit action potential (MUAP) parameters, such as amplitude (768.7 ± 441.7 vs. 855.0 ± 289.9 µV), duration (8.9 ± 1.8 vs. 8.68 ± 0.9 ms) and size index (1.2 ± 0.5 vs. 1.1 ± 0.3) (P > 0.18), nor was there a significant difference in single fiber EMG recorded jitter (37.0 ± 9.6 vs. 39.9 ± 10.6 µs, P = 0.45). The increase in FD suggests motor units of the paretic FDI have enlarged due to collateral reinnervation. However, sprouting might be insufficient to result in a statistically significant change in the concentric needle MUAP parameters. Single fiber EMG appears more sensitive than concentric needle EMG to reflect electrophysiological changes in motor units after stroke. Both single fiber and concentric needle EMG recordings may be necessary to better understand muscle changes after stroke, which is important for development of appropriate rehabilitation strategies. The results provide further evidence that motor units are remodeled after stroke, possibly in response to a loss of motoneurons.

Aging and Sex Influence Cortical Auditory-Motor Integration for Speech Control.

It is well known that acoustic change in speech production is subject to age-related declines. How aging alters cortical sensorimotor integration in speech control, however, remains poorly understood. The present event-related potential study examined the behavioral and neural effects of aging and sex on the auditory-motor processing of voice pitch errors. Behaviorally, older adults produced significantly larger vocal compensations for pitch perturbations than young adults across the sexes, while the effects of sex on vocal compensation did not exist for both young and older adults. At the cortical level, there was a significant interaction between aging and sex on the N1-P2 complex. Older males produced significantly smaller P2 amplitudes than young males, while young males produced significantly larger N1 and P2 amplitudes than young females. In addition, females produced faster N1 responses than males regardless of age, while young adults produced faster P2 responses than older adults across the sexes. These findings provide the first neurobehavioral evidence that demonstrates the aging influence on auditory feedback control of speech production, and highlight the importance of sex in understanding the aging of the neuromotor control of speech production.