Disorders of consciousness (DoCs) are a frequent complication of brain injury disease, and effective treatments are currently lacking. Transauricular vagus nerve stimulation (tVNS) has been proposed as a promising therapeutic method for neurological disorders such as epilepsy and depression. In our previous study, we demonstrated that vagus nerve stimulation promoted recovery in rats with DoCs caused by traumatic brain injury. However, the clinical effect of vagus nerve stimulation on consciousness disorders is unclear. We aimed to investigate the therapeutic efficacy and safety of tVNS in patients with DoCs.We conducted a randomized, double-blinded, sham-controlled trial. Patients (N = 60) with DoCs, including minimally conscious state (MCS) and vegetative state/unresponsive wakefulness syndrome, were enrolled and randomized to groups receiving either active or sham tVNS. A frequency of 20 Hz and pulse wave of 200 us was used in the active-tVNS protocol, which was performed in the auricular branch of the vagus nerve in the left outer ear. The sham-tVNS protocol was the same as the active-tVNS protocol although without current input. Both groups of patients also received conventional treatments. Consciousness was evaluated according to the Coma Recovery Scale-Revised before and after the 4-week intervention. We also recorded the type and number of behavioral responses. Safety was primarily assessed according to the incidence of treatment-emergent adverse events. Each patient's heart rate and blood pressure were monitored during all treatment sessions.Ultimately, 57 patients completed the study: 28 patients underwent active tVNS and 29 patients underwent sham tVNS. No significant differences were observed in Coma Recovery Scale-Revised scores between the active- and sham-tVNS groups before the tVNS sessions. Compared with patients in the sham-tVNS group (9.28 ± 4.38), patients with DoCs treated with active tVNS showed improved consciousness (10.93 ± 4.99), although not statistically significant. Further analysis revealed obvious differences between patients with MCS receiving active and sham tVNS, but no significant difference in patients with vegetative state/unresponsive wakefulness syndrome in both groups. All side effects were considered common medical conditions with no obvious correlation to tVNS.These preliminary data provide early evidence that tVNS may be an effective and safe approach for promoting the recovery of consciousness, especially in patients with MCS.https://www.chictr.org.cn/edit.aspx?pid=175938&htm=4, identifier: ChiCTR2200066629.
Abstract Introduction Combining transcranial magnetic stimulation with electroencephalography (TMS‐EEG), oscillatory reactivity can be measured, allowing us to investigate the interaction between local and distant cortical oscillations. However, the extent to which human consciousness is related to these oscillatory effective networks has yet to be explored. Aims We tend to investigate the link between oscillatory effective networks and brain consciousness, by monitoring the global transmission of TMS‐induced oscillations in disorders of consciousness (DOC). Results A cohort of DOC patients was included in this study, which included 28 patients with a minimally conscious state (MCS) and 20 patients with vegetative state/unresponsive wakefulness syndrome (VS/UWS). Additionally, 25 healthy controls were enrolled. The oscillatory reactivity to single‐pulse TMS of the frontal, sensorimotor and parietal cortex was measured using event‐related spectral perturbation of TMS‐EEG. The temporal–spatial properties of the oscillatory reactivity were illustrated through life time, decay gradients and accumulative power. In DOC patients, an oscillatory reactivity was observed to be temporally and spatially suppressed. TMS‐EEG of DOC patients showed that the oscillations did not travel as far in healthy controls, in terms of both temporal and spatial dimensions. Moreover, cortical theta reactivity was found to be a reliable indicator in distinguishing DOC versus healthy controls when TMS of the parietal region and in distinguishing MCS versus VS/UWS when TMS of the frontal region. Additionally, a positive correlation was observed between the Coma Recovery Scale‐Revised scores of the DOC patients and the cortical theta reactivity. Conclusions The findings revealed a breakdown of oscillatory effective networks in DOC patients, which has implications for the use of TMS‐EEG in DOC evaluation and offers a neural oscillation viewpoint on the neurological basis of human consciousness.
According to previous case reports, trigeminal nerve stimulation (TNS) can be successfully used to wake a non-responsive unconscious patient. However, no studies have comprehensively investigated the effect of TNS on patients with disorders of consciousness (DOC). Therefore, the present study aimed to assess the safety and efficacy of TNS in DOC patients recruited at the First Affiliated Hospital of Nanchang University. We used Coma Recovery Scale-Revised (CRS-R) scores to assess patients at baseline and after 1–4 weeks of TNS. The patients were further followed up for 4 weeks after the last stimulation to evaluate the safety of the procedure. The participant group comprised 21 DOC patients with an acquired brain injury who were more than 3 months post-injury. The participants were 44.29 ± 12.55 years old and 5.52 ± 1.83 months post-DOC onset, and included 12 patients who were in a vegetative state or had unresponsive wakefulness syndrome and 9 patients who were in a minimally conscious state. Compared with CRS-R scores at baseline, those at weeks 4 and 8 showed no significant improvements in any of the DOC patients. Nonetheless, CRS-R scores improved throughout the study period in 8 out of the 21 DOC patients. Among those with improved scores, two patients in a minimally conscious state had improved CRS-R scores at week 4, while five had improved scores at 4 weeks later. Only one patient with vegetative state/unresponsive wakefulness syndrome had recovered to a minimally conscious state at week 4. Importantly, no obvious treatment-related adverse events were considered to be related to TNS. Taken together, these data provide early evidence that TNS may be an effective and safe approach for promoting the recovery of consciousness in patients with neurological disorders.
In this study, rats were put into traumatic brain injury-induced coma and treated with median nerve electrical stimulation. We explored the wake-promoting effect, and possible mechanisms, of median nerve electrical stimulation. Electrical stimulation upregulated the expression levels of orexin-A and its receptor OX1R in the rat prefrontal cortex. Orexin-A expression gradually increased with increasing stimulation, while OX1R expression reached a peak at 12 hours and then decreased. In addition, after the OX1R antagonist, SB334867, was injected into the brain of rats after traumatic brain injury, fewer rats were restored to consciousness, and orexin-A and OXIR expression in the prefrontal cortex was downregulated. Our findings indicate that median nerve electrical stimulation induced an up-regulation of orexin-A and OX1R expression in the prefrontal cortex of traumatic brain injury-induced coma rats, which may be a potential mechanism involved in the wake-promoting effects of median nerve electrical stimulation.
Brain responses to transcranial magnetic stimulation (TMS) can be recorded with electroencephalography (EEG) and comprise TMS-evoked potentials and TMS-induced oscillations. Repetitive TMS may entrain endogenous brain oscillations. In turn, ongoing brain oscillations prior to the TMS pulse can influence the effects of the TMS pulse. These intricate TMS-EEG and EEG-TMS interactions are increasingly attracting the interest of researchers and clinicians. This review surveys the literature of TMS and its interactions with brain oscillations as measured by EEG in health and disease.
Objective
To evaluate the dosimetry accuracy and clinical efficacy of 125I radioactive seed implantation using coplanar template (CPT) in the treatment of metastatic or recurrent chest wall tumor.
Methods
Thirty-one patients with metastasis or recurrence of chest wall tumor, who had been diagnosed with pathology between July 2005 and July 2015, were retrospectively studied. All patients underwent CPT-assisted 125I radioactive seed implantation. Brachytherapy radiation treatment planning system (BTPS) was used to make preoperative plans, and the prescribed dose (PD) was 110 Gy. CPT was used to assist CT guided 125I radioactive seeds implantation. Dose evaluation was performed immediately after implantation. The difference of dose parameters was compared between preoperation and postoperation, including D90, D100, V90, V100 and the numbers of seeds. Postoperative chest CT was conducted regularly to assess the treatment efficacy based on the response evaluation criteria in solid tumors (RECIST Version 1.1). The patients were followed up till July 2016.
Results
All patients went through implantation procedure successfully and there was no significant statistical difference between preoperative and postoperative dose parameters (P>0.05). The conformal index(CI) was 0.951±0.13, external index(EI) was 6.5%±0.9%. Six months after implantation, CR, PR, SD and PD were 25.8% (8/31), 51.6% (16/31), 6.5% (2/31) and 16.1% (5/31), respectively. The effective rate was 77.4%, and local control rate was 83.9% (26/31). Skin pigmentation occurred in 13 patients during the follow-up period, without any special treatment.
Conclusions
The auxiliary of CPT in the treatment of metastatic or recurrent chest wall tumor under the guiding of CT could achieve quality control, safety and effectiveness.
Key words:
Coplanar template; Radioactive seeds; Chest wall malignant tumor; Metastatic tumor; Recurrent tumor
Purpose: Scatter correction in cone-beam computed tomography (CBCT) has obvious effect on the removal of image noise, the cup artifact and the increase of image contrast. Several methods using a beam blocker for the estimation and subtraction of scatter have been proposed. However, the inconvenience of mechanics and propensity to residual artifacts limited the further evolution of basic and clinical research. Here, we propose a rotating collimator-based approach, in conjunction with reconstruction based on a discrete Radon transform and Tchebichef moments algorithm, to correct scatter-induced artifacts. Methods: A rotating-collimator, comprising round tungsten alloy strips, was mounted on a linear actuator. The rotating-collimator is divided into 6 portions equally. The round strips space is evenly spaced on each portion but staggered between different portions. A step motor connected to the rotating collimator drove the blocker to around x-ray source during the CBCT acquisition. The CBCT reconstruction based on a discrete Radon transform and Tchebichef moments algorithm is performed. Experimental studies using water phantom and Catphan504 were carried out to evaluate the performance of the proposed scheme. Results: The proposed algorithm was tested on both the Monte Carlo simulation and actual experiments with the Catphan504 phantom. From the simulation result, the mean square error of the reconstruction error decreases from 16% to 1.18%, the cupping (τcup) from 14.005% to 0.66%, and the peak signal-to-noise ratio increase from 16.9594 to 31.45. From the actual experiments, the induced visual artifacts are significantly reduced. Conclusion: We conducted an experiment on CBCT imaging system with a rotating collimator to develop and optimize x-ray scatter control and reduction technique. The proposed method is attractive in applications where a high CBCT image quality is critical, for example, dose calculation in adaptive radiation therapy. We want to thank Dr. Lei Xing and Dr. Yong Yang in the Stanford University School of Medicine for this work. This work was jointly supported by NSFC (61471226), Natural Science Foundation for Distinguished Young Scholars of Shandong Province (JQ201516), and China Postdoctoral Science Foundation (2015T80739, 2014M551949).
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