ABSTRACT
In this paper we propose a novel neurostimulation protocol that provides an intervention-based assessment to distinguish the contributions of different motor control networks in the cortico-spinal system. Specifically, we use a combination of non-invasive brain stimulation and neuromuscular stimulation to probe neuromuscular system behavior with targeted impulse-response system identification. In this protocol, we use an in-house developed human-machine interface (HMI) for an isotonic wrist movement task, where the user controls a cursor on-screen. During the task, we generate unique motor evoked potentials based on triggered cortical or spinal level perturbations. Externally applied brain-level perturbations are triggered through TMS to cause wrist flexion/extension during the volitional task. The resultant contraction output and related reflex responses are measured by the HMI. These movements also include neuromodulation in the excitability of the brain-muscle pathway via transcranial direct current stimulation. Colloquially, spinal-level perturbations are triggered through skin-surface neuromuscular stimulation of the wrist muscles. The resultant brain-muscle and spinal-muscle pathways perturbed by the TMS and NMES, respectively, demonstrate temporal and spatial differences as manifested through the human-machine interface. This then provides a template to measure the specific neural outcomes of the movement tasks, and in decoding differences in the contribution of cortical- (long-latency) and spinal-level (short-latency) motor control. This protocol is part of the development of a diagnostic tool that can be used to better understand how interaction between cortical and spinal motor centers changes with learning, or injury such as that experienced following stroke.
ABSTRACT
INTRODUCTION: Ovarian cancer is associated with a venous thromboembolism risk of at least 7.2% by 2 years from diagnosis, and although patients undergoing surgery benefit from routine thromboprophylaxis, those undergoing neoadjuvant chemotherapy do not. This study aims to determine the venous thromboembolism incidence in patients with ovarian cancer undergoing neoadjuvant chemotherapy, and explore whether any subset is at higher risk, in order to evaluate whether thromboprophylaxis is justified in some or all of these patients. MATERIAL AND METHODS: This was a retrospective review of all women undergoing neoadjuvant chemotherapy for FIGO radiological stages III and IV primary ovarian, fallopian tube, and primary peritoneal cancer, between 2000 and 2015, in a London tertiary cancer center. The primary outcome was venous thromboembolism rate among women undergoing neoadjuvant chemotherapy. The secondary outcomes were patient or treatment factors associated with venous thromboembolism risk, including age, body mass index, smoking status, performance status, and tumor stage. RESULTS: We identified 278 eligible women from the ovarian cancer database. Fifty-eight women (20.9%) developed venous thromboembolism between initial presentation and the immediate postoperative period, of which 45 (77.6%) developed a pulmonary embolism. In all, 15.1% of women developed venous thromboembolism from the start of neoadjuvant chemotherapy. Age, body mass index, smoking, or other comorbidities were not significantly associated with venous thromboembolism risk. One woman died from massive pulmonary embolism, 27 women underwent inferior vena cava filter insertion, and 10 had surgery delayed. CONCLUSIONS: This study demonstrates an unacceptably high rate of avoidable venous thromboembolism including pulmonary embolism in these women, which complicates and delays treatment. Thromboprophylaxis during neoadjuvant chemotherapy should now be assessed prospectively.
