Mental fatigue is an important factor of human health and safety. It is important to achieve dynamic mental fatigue detection by using electroencephalogram (EEG) signals for fatigue prevention and job performance improvement. We in our study induced subjects' mental fatigue with 30 h sleep deprivation (SD) in the experiment. We extracted EEG features, including relative power, power ratio, center of gravity frequency (CGF), and basic relative power ratio. Then we built mental fatigue prediction model by using regression analysis. And we conducted lead optimization for prediction model. Result showed that R2 of prediction model could reach to 0.932. After lead optimization, 4 leads were used to build prediction model, in which R2 could reach to 0.811. It can meet the daily application accuracy of mental fatigue prediction.
In order to investigate the features of multidetector CT (MDCT) and magnetic resonance imaging (MRI) as well as the corresponding pathogic basis of solitary fibrous tumor (SFT) in the pelvis, we collected the clinical data of 13 patients with pathologically confirmed SFT in pelvis, and retrospectively reviewed the MDCT and MRI appearances. Of these enrolled patients, 6 received MDCT scans, 5 underwent MRI scans, and 2 underwent both MDCT and MRI examinations. Shown on the MDCT and MRI, the maximum diameters of the masses ranged from 4.0 to 25.2 cm (averaged 11.8 cm). Six masses were lobulated, and seven were round or oval. In addition, all masses were well-defined and displaced the adjacent structures to some degrees. On the computed tomography, all masses were of isodensity on unenhanced scans in general, among which five masses were demonstrated with hypodense areas. On the MRI T1-weighted image, all lesions were isointense, of which patchy hypointense areas were detected in 3 cases and radial hypointense areas were in 3 cases, and the other one was presented with homogenous intensity. On T2-weighted images, most of the lesions were mixed hyperintense, of which 3 cases were of heterogenous hyperintesity, radial hypointense areas were detected in 3 patients, and the other one was homogenously intense. On enhanced computed tomography and MRI, large supplying vessels were found in 4 cases; 12 cases showed moderate to conspicuous enhancement, and the other one was presented with mild homogenous enhancement. Of the patients with moderate to conspicuous enhancement, patchy areas of non-enhancement were detected in 7 cases, radial areas of progressive enhancement were detected in 3 cases, and the remained 2 cases showed homogenous enhancement. On pathology, the radial area presented as progressive enhancement was fibrosis. During the follow-ups after surgery, 2 patients had local recurrence and 1 had metastasis to liver. In conclusion, the SFT in the pelvis are commonly presented as a large solid, well-defined and hypervascular mass with necrosis or cystic changes at some extents together with the displacement of adjacent structures. The radial area with hypointensity on T2-weighted image and with progressive enhancement on enhanced magnetic resonance imaging is an important feature of SFT, which can be helpful for the diagnosis of this mass.
ObjectiveTo explore the effect of spinal dural release on the effectiveness of expansive cervical laminoplasty for treating multi-segmental cervical myelopathy with ossification of posterior longitudinal ligament. MethodsA retrospective analysis was made on the clinical data of 32 patients with multi-segmental cervical myelopathy with cervical ossification of posterior longitudinal ligament who underwent expansive cervical laminoplasty and spinal dural release between February 2011 and October 2013 (group A); and 36 patients undergoing simple expansive cervical laminoplasty between January 2010 and January 2011 served as controls (group B). There was no significant difference in gender, age, disease duration, affected segments, combined internal disease, preoperative cervical curvature, Japanese Orthopaedic Association (JOA) score, and visual analogue scale (VAS) score between 2 groups (P>0.05). Postoperative JOA score and improvement rate, VAS score, posterior displacement of the spinal cord, and the change of cervical curvature were compared between 2 groups. ResultsSpinal dural tear occurred in 3 cases (2 cases in group A and 1 case in group B) during operation. Cerebrospinal fluid leakage occurred in 3 cases (2 cases in group A and 1 case in group B) after operation. The patients were followed up 12-46 months (mean, 18.7 months). At last follow-up, the JOA score and VAS score were significantly improved in 2 groups when compared with preoperative scores (P<0.05). JOA score and improvement rate of group A were significantly higher than those of group B (P<0.05), but VAS score of group A was significantly lower than that of group B (P<0.05). At last follow-up, no significant difference in cervical curvature was found between 2 groups (P>0.05); posterior displacement of the spinal cord of group A was significantly larger than that of group B (P<0.05). No reclosed open-door was observed during follow-up. ConclusionFor patients with multi-segmental cervical myelopathy with ossification of posterior longitudinal ligament, full spinal dural release during expansive cervical laminoplasty can increase the posterior displacement of spinal cord, and significantly improve the effectiveness.
Somatosensory vibration can stimulate somatosensory area of human body, and this stimulation is tranferred to somatosensory nerves, and influences the somatic cortex, which is on post-central gyrus and paracentral lobule posterior of cerebral cortex, so that it alters the functional status of brain. The aim of the present study was to investigate the neural mechanism of brain state induced by somatosensory vibration. Twelve subjects were involved in the 20 Hz vibration stimulation test. Linear and nonlinear methods, such as relative change of relative power (RRP), Lempel-Ziv complexity (LZC) and brain network based on cross mutual information (CMI), were applied to discuss the change of brain under somatosensory vibration stimulation. The experimental results showed the frequency following response (FFR) by RRP of spontaneous electroencephalogram (EEG) in 20 Hz vibration, and no obvious change by LZC. The information transmission among various cortical areas enhanced under 20 Hz vibration stimulation. Therefore, 20 Hz somatosensory vibration may be able to adjust the functional status of brain.
We applied Lempel-Ziv complexity (LZC) combined with brain electrical activity mapping (BEAM) to study the change of alertness under sleep deprivation in our research. Ten subjects were involved in 36 hours sleep deprivation (SD), during which spontaneous electroencephalogram (EEG) experiments and auditory evoked EEG experiments-Oddball were recorded once every 6 hours. Spontaneous and evoked EEG data were calculated and BEAMs were structured. Results showed that during the 36 hours of SD, alertness could be divided into three stages, i.e. the first 12 hours as the high stage, the middle 12 hours as the rapid decline stage and the last 12 hours as the low stage. During the period SD, LZC of Spontaneous EEG decreased over the whole brain to some extent, but remained consistent with the subjective scales. By BEAMs of event related potential, LZC on frontal cortex decreased, but kept consistent with the behavioral responses. Therefore, LZC can be effective to reflect the change of brain alertness. At the same time LZC could be used as a practical index to monitor real-time alertness because of its simple computation and fast calculation.
Vigilance is defined as the ability to maintain attention for prolonged periods of time. In order to explore the variation of brain vigilance in work process, we designed addition and subtraction experiment with numbers of three digits to induce the vigilance to change, combined it with psychomotor vigilance task (PVT) to measure this process of electroencephalogram (EEG), extracted and analyzed permutation entropy (PE) of 11 cases of subjects' EEG and made a brief comparison with nonlinear parameter sample entropy (SE). The experimental results showed that:PE could well reflect the dynamic changes of EEG when vigilance decreases, and has advantages of fast arithmetic speed, high noise immunity, and low requirements for EEG length. This can be used as a measure of the brain vigilance indicators.
ObjectiveTo analyze the value of internal mammary lymph node biopsy via intercostal space in staging and adjuvant therapy of breast cancer. MethodsThe clinical data of 305 breast cancer patients received any kind of radical mastectomy from may 2003 to January 2014 in the Jinan Military General Hospital of PLA were analyzed retrospectively. The patient age, axillary lymph node, and internal mammary lymph node status were integrated to investigate the changing of staging and postoperative adjuvant therapy of the breast cancer. ResultsThese 305 patients were divided into neoadjuvant chemotherapy group and non-neoadjuvant therapy group. There were 67 patients in the neoadjuvant chemotherapy group, including 45(67.2%) patients with axillary lymph node positive, 23(34.3%) patients with internal mammary lymph node positive. There were 23(34.3%) patients who had a change of pathology lympy node (pN) staging and 8(11.9%) patients who had a change of the pTNM staging. Meanwhile, there were 238 patients in the non-neoadjuvant chemotherapy group, including 155(65.1%) patients with axillary lymph node positive, 30(12.6%) patients with internal mammary node positive. There were 30(12.6%) patients who had a change of the pN staging and 23(9.66%) patients who had a change of the pTNM staging. There was a significant difference in the metastasis rate of the internal mammary lymph node (χ2=15.7, P < 0.05) or the changing ratio of the pTNM staging (χ2=5.3, P < 0.05) in two groups. ConclusionsInternal mammary lymph node status could affect pN staging of breast cancer, so do the pTNM staging (TNM, pathology tumor, lymph node, metastasis). The internal mammary lymph node status could guide the postoperative adjuvant radiative therapy by reducing excessive treatment of the internal mammary lymph node area, also could enhance the individual accurate therapy.