Gelastic seizure (GS) is a type of epilepsy characterized primarily by inappropriate bursts of laughter, with or without other epileptic events. Based on the timing of symptoms, the presence of emotional changes, and disturbances of consciousness, GS is classified into simple and complex types. The generation of laughter involves two major neural pathways: the emotional pathway and the volitional pathway. The neural network involved in GS includes structures such as the frontal lobe, insula, cingulate gyrus, temporal lobe, and brainstem.The most common cause of GS is a hypothalamic hamartoma, and stereotactic electroencephalography can record discharges from the lesion itself. Surgical removal of the hypothalamic hamartoma can result in immediate cessation of GS in the majority of patients, while some may experience partial improvement with persistent epileptic-like discharges detectable on scalp electroencephalography (EEG). Early surgical intervention may improve prognosis.In cases of non-hypothalamic origin of GS with no apparent imaging abnormalities, focal discharges are often observed on EEG and these cases respond well to antiepileptic drugs. Conversely, patients with structural abnormalities suggested by imaging studies tend to have multifocal discharges and a poorer response to medication. In a small subset of medically refractory non-hypothalamic GS, surgical intervention can effectively control symptoms.This article provides a comprehensive review of the etiology, neural networks involved, EEG characteristics, and treatment options for GS, with the goal of improving understanding of this relatively rare type of epileptic seizure.
The objective of this study was to determine the visco-hyperelastic constitutive law of brain tissue under dynamic impacts. A method combined by finite element simulations and optimization algorithm was employed for the determination of material variables. Firstly, finite element simulations of brain tissue dynamic uniaxial tension, with a maximum stretch rate of 1.3 and strain rates of 30 s–1 and 90 s–1, were developed referring to experimental data. Then, fitting errors between the engineering stress-strain curves predicted by simulations and experimental average curves were assigned as objective functions, and the multi-objective genetic algorithm was employed for the optimation solution. The results demonstrate that the brain tissue finite element models assigned with the novel obtained visco-hyperelastic material law could predict the brain tissue’s dynamic mechanical characteristic well at different loading rates. Meanwhile, the novel material law could also be applied in the human head finite element models for the improvement of the biofidelity under dynamic impact loadings.
Alveolar bone reconstruction simulation is an effective means for quantifying orthodontics, but currently, it is not possible to directly obtain human alveolar bone material models for simulation. This study introduces a prediction method for the equivalent shear modulus of three-dimensional random porous materials, integrating the first-order Ogden hyperelastic model to construct a computed tomography (CT) based porous hyperelastic Ogden model (CT-PHO) for human alveolar bone. Model parameters are derived by combining results from micro-CT, nanoindentation experiments, and uniaxial compression tests. Compared to previous predictive models, the CT-PHO model shows a lower root mean square error (RMSE) under all bone density conditions. Simulation results using the CT-PHO model parameters in uniaxial compression experiments demonstrate more accurate prediction of the mechanical behavior of alveolar bone under compression. Further prediction and validation with different individual human alveolar bone samples yield accurate results, confirming the generality of the CT-PHO model. The study suggests that the CT-PHO model proposed in this paper can estimate the material properties of human alveolar bone and may eventually be used for bone reconstruction simulations to guide clinical treatment.
ObjectiveTo evaluate the effectiveness of titanium elastic nails for severe displaced proximal humeral fractures in older children.
MethodsBetween April 2009 and July 2012, 31 cases of severe displaced proximal humeral fractures were treated with closed or open reduction and fixation with 2 titanium elastic nails, and the clinical data were retrospectively analyzed. There were 23 boys and 8 girls, aged from 10 to 15 years (mean, 12.8 years). The causes of injury were sports injury (16 cases), traffic accident (11 cases), and falling from height (4 cases). The interval from injury to operation was 6 hours to 7 days (mean, 72 hours). According to Neer-Horwitz classification, 17 cases were rated as type III fracture and 14 cases as type IV fracture. There were 21 cases of metaphyseal fractures and 10 cases of epiphyseal fractures.
ResultsSatisfactory reduction of fracture and stable fixation were obtained in all patients (closed reduction in 23 cases and open reduction in 8 cases). Primary healing was achieved in all incisions; no infection and neurovascular injury occurred. All patients were followed up 12-36 months with an average of 20 months. X-ray films showed that all fractures healed at 7-10 weeks (mean, 8 weeks). During follow-up, no disturbance of development or angulation deformity caused by premature physeal closure or bone bridge formation was observed. At last follow-up, the average Neer score of the shoulder was 95.7 (range, 83-100). The appearance and motion of the shoulder were normal. There was no significant difference in the upper extremity length between affected side and contralateral side[(67.68±2.56) cm vs. (67.61±2.54) cm; t=-1.867,P=0.072].
ConclusionTitanium elastic nails for severe displaced humeral fractures in older children is a safe and effective method with a low complication incidence.
Objective To investigate the surgical technique and effectiveness of titanium elastic nail (TEN) assisted retrograde channel screw implantation of superior pubic branch. Methods The clinical data of 31 patients with pelvic or acetabular fractures treated with retrograde channel screw implantation in superior pubic branch between January 2021 and April 2022 were retrospectively analyzed. Among them, 16 cases were implanted with assistance of TEN (study group) and 15 cases were implanted under the guidance of C-arm X-ray machine (control group). There was no significant difference in gender, age, cause of injury, Tile classification of pelvic fracture, Judet-Letournal classification of acetabular fracture, and time from injury to operation between the two groups (P>0.05). The operation time, fluoroscopy times, and intraoperative blood loss of each superior pubic branch retrograde channel screw were recorded during operation. X-ray films and three-dimensional CT were reexamined after operation, the quality of fracture reduction was evaluated by Matta score standard, and the position of channel screw was evaluated by screw position classification standard. The fracture healing time was recorded during the follow-up, and the postoperative functional recovery was evaluated by Merle D’Aubigne Postel score system at last follow-up. Results Nineteen and 20 retrograde channel screws of superior pubic branch were implanted in the study group and the control group, respectively. The operation time, fluoroscopy times, and intraoperative blood loss of each screw in the study group were significantly less than those in the control group (P<0.05). According to the postoperative X-ray films and three-dimensional CT, none of the 19 screws in the study group penetrated out of the cortical bone or into the joint, and the excellent and good rate was 100% (19/19); in the control group, there were 4 screws of cortical bone penetration, and the excellent and good rate was 80% (16/20); the difference between the two groups was significant (P<0.05). Matta score standard was used to evaluate the quality of fracture reduction, there was no patient in the two groups with poor reduction results, and the difference was not significant between the two groups (P>0.05). The incisions of the two groups healed by first intention, and there was no complication such as incision infection, skin margin necrosis, and deep infection. All patients were followed up 8-22 months, with an average of 14.7 months. There was no significant difference in healing time between the two groups (P>0.05). At last follow-up, the difference in functional recovery evaluated by the Merle D’Aubigne Postel scoring system between the two groups was not significant (P>0.05). Conclusion TEN assisted implantation technique can significantly shorten the operation time of retrograde channel screw implantation of superior pubic branch, reduce the times of fluoroscopy, and have less intraoperative blood loss and accurate screw implantation, which provides a new safe and reliable method for minimally invasive treatment of pelvic and acetabular fractures.
Objective
To investigate the elasticity of demand for health care services in China, and to provide suggestions for further studies.
Methods
Databases including PubMed, The Cochrane Library (Issue 10, 2015), EMbase, CNKI, VIP and WanFang Data were searched from inception to December 2015 to collect studies about price elasticity or income elasticity of demand for health care services. Literatures were screened and related information was independently extracted by two reviewers. Then qualitative approaches were applied to describe the elasticity.
Results
A total of 31 studies were included. Estimates of the own-price elasticity of demand for health care services ranged from –2.520 to 2.944 in 25 studies; 2 studies estimated cross-price elasticity between outpatient and inpatient service and one study estimated cross-price elasticity between different levels of inpatient services and all estimates were positive; Estimates of the income elasticity ranged from –0.020 to 2.480 in 28 studies. Demand for inpatient services was more income sensitive than the demand for outpatient services and urban citizens were more sensitive to income than their rural counterparts.
Conclusion
Health service is insensitive to price and belongs to necessity; inpatient service and outpatient service are substitutes for each other and different levels of inpatient services are substitutes for each other; government are supposed to tackle with the unbalanced increase of the demand of outpatient and inpatient services along with the increase of income to guide rational health-seeking behaviors.
The mechanical behavior modeling of human soft biological tissues is a key issue for a large number of medical applications, such as surgery simulation, surgery planning, diagnosis, etc. To develop a biomechanical model of human soft tissues under large deformation for surgery simulation, the adaptive quasi-linear viscoelastic (AQLV) model was proposed and applied in human forearm soft tissues by indentation tests. An incremental ramp-and-hold test was carried out to calibrate the model parameters. To verify the predictive ability of the AQLV model, the incremental ramp-and-hold test, a single large amplitude ramp-and-hold test and a sinusoidal cyclic test at large strain amplitude were adopted in this study. Results showed that the AQLV model could predict the test results under the three kinds of load conditions. It is concluded that the AQLV model is feasible to describe the nonlinear viscoelastic properties of in vivo soft tissues under large deformation. It is promising that this model can be selected as one of the soft tissues models in the software design for surgery simulation or diagnosis.
ObjectiveTo investigate the effectiveness of Nice knot combined with elastic intramedullary nailing fixation in treatment of Robinson type 2B midshaft clavicular fracture in adults.MethodsBetween March 2016 and January 2018, 20 patients with Robinson type 2B midshaft clavicular fractures were treated with reduction and internal fixation by Nice knot and elastic intramedullary nailing. There were 13 cases and 7 cases, with an average age of 43 years (range, 18-56 years). The causes of injury included the traffic accident in 6 cases, falling in 12 cases, and falling from height in 2 cases. The interval between injury and admission ranged from 1 hour to 2 days (mean, 3.2 hours). The fractures were classified as Robinson type 2B1 in 16 cases and type 2B2 in 4 cases. The length of incision, the operation time, the visual analogue scale (VAS) score on the 2nd day after operation, the fracture healing time, the postoperative shoulder function and the Disability of Arm Shoulder and Hand (DASH) score, the complications, and the time of second surgical removal of internal fixator and incision length were recorded.ResultsThe length of incision was 2-6 cm (mean, 4.7cm). The operation time was 45-120 minutes (mean, 77.2 minutes). The VAS score was 1-5 (mean, 3.2) on the 2nd day after operation. All incisions healed by first intention and no infection or nerve injury occurred. All patients were followed up 12-32 months (mean, 18.6 months). All fractures healed with the healing time of 10-15 weeks (mean, 12.1 weeks). The Constant score was 92-98 (mean, 96.3) and DASH score was 0-6.4 (mean, 3.1). The elastic intramedullary nailing bending and hypertrophic nonunion occurred in 1 case and the skin stimulated by elastic nail tail in 1 case after operation. The internal fixators were removed at 12-26 months (mean, 14.6 months) after operation. And the length of incision was 1-2 cm (mean, 1.3 cm) and the operation time was 5-15 minutes (mean, 9.0 minutes). ConclusionFor the midshaft clavicular fracture in adults, the procedure of the Nice knot combined with elastic intramedullary nail has advantages of small incision, light pain, rapid fracture healing, small secondary operation injury, and avoiding the risk of clavicular epithelial nerve injury, and can obtain good effectiveness.
Objective
To compare the effectiveness of titanium elastic nail (TEN) and locking compression plate fixation in treating femoral subtrochanteric fracture in older children.
Methods
Between April 2015 and September 2016, 35 older children (aged 7-13 years) with femoral subtrochanteric fractures were treated, the clinical data were retrospectively reviewed. TEN fixation was used in 19 cases (group A) and locking compression plate fixation in 16 cases (group B). There was no significant difference in age, gender, sides, fracture causes, type of fracture, and time from injury to operation between 2 groups (P>0.05). The fluoroscopy times, operation time, intraoperative blood loss, fracture healing time were recorded and compared between 2 groups. The limb function was evaluated according to the Sanders scores and Flynnet al. outcome score.
Results
All the patients were followed up 6-24 months (mean, 11.46 months). The operation time, intraoperative blood loss, and fracture healing time of group A were significantly less than those of group B, but the fluoroscopy times of group A was significantly more than that of group B (P<0.05). All the fractures were healed, no breakage of screw, infection of deep tissue, nerve injury, osteonecrosis of the femoral head, or other complication occurred. At last follow-up, according to the Sanders scores, the results were excellent in 14 cases, good in 4 cases, and fair in 1 case in group A with an excellent and good rate of 94.74%; the results were excellent in 12 cases, good in 3 cases, and fair in 1 case in group B with an excellent and good rate of 93.75%; showing no significant difference between 2 groups (χ2=0.400, P=0.980). According to the Flynn et al. outcome score, the results were excellent in 13 cases, good in 5 cases, and fair in 1 case in group A with an excellent and good rate of 94.74%; the results were excellent in 11 cases, good in 3 cases, and fair in 2 cases in group B with an excellent and good rate of 87.50%; showing no significant difference between 2 groups (χ2=0.748, P=0.688).
Conclusion
Both TEN and locking compression plate have satisfactory outcomes for treating pediatric femoral subtrochanteric fractures. TEN method has minimally trauma, security, and faster fracture healing when compared with locking compression plate.
The mechanical properties of the cornea in corneal ectasia disease undergo a significant reduction, yet the alterations in mechanical properties within distinct corneal regions remain unclear. In this study, we established a rabbit corneal ectasia model by employing collagenase II to degrade the corneal matrix within a central diameter of 6 mm. Optical coherence tomography was employed for the in vivo assessment of corneal morphology (corneal thickness and corneal curvature) one month after operation. Anisotropy and viscoelastic characteristics of corneal tissue were evaluated through biaxial and uniaxial testing, respectively. The results demonstrated a marked decrease in central corneal thickness, with no significant changes observed in corneal curvature. Under different strains, the elastic modulus of the cornea exhibited no significant differences in the up-down and naso-temporal directions between the control and model groups. However, the cornea in the model group displayed a significantly lower elastic modulus compared to the control group. Specifically, the elastic modulus of the central region cornea in the model group was significantly lower than that of the entire cornea within the same group. Moreover, in comparison to the control group, the cornea in the model group exhibited a significant increase in both creep rate and overall deformation rate. The instantaneous modulus and equilibrium modulus were significantly reduced in the model cornea. No significant differences were observed between the entire cornea and the central cornea concerning these parameters. The results indicate that corneal anisotropy remains unchanged in collagenase-induced ectatic cornea. However, a significant reduction in viscoelastic properties is noticed. This study provides valuable insights for investigating changes in corneal mechanical properties within different regions of ectatic corneal disease.
