Worry, generalized anxiety disorder, and emotion: evidence from the EEG gamma band

The present study examined EEG gamma (35-70Hz) spectral power distributions during worry inductions in participants suffering from generalized anxiety disorder (GAD) and in control participants without a history of psychiatric illness. As hypothesized, the EEG gamma band was useful for differentiating worry from baseline and relaxation. During worry induction, GAD patients showed higher levels of gamma activity than control participants in posterior electrode sites that have been previously associated with negative emotion. Gamma fluctuations in these electrode sites were correlated with subjective emotional experience ratings lending additional support to interpretations of negative affect. Following 14 weeks of psychotherapy, the GAD group reported less negative affect with worry inductions and the corresponding gamma sites that previously differentiated the clinical from control groups changed for the GAD patients in the direction of control participants. These findings suggest converging evidence that patients suffering from GAD experience more negative emotion during worry and that the EEG gamma band is useful for monitoring fluctuations in pathological worry expected to follow successful treatment.     

肌筋膜触发点疼痛的实验动物模型研究

目的:根据肌筋膜触发点疼痛的形成机制建立实验动物模型。方法:36只雄性SD大鼠,随机分成3组,分别采用打击、离心运动和打击结合离心运动的方法进行肌筋膜触发点疼痛造模,以打击组非打击侧作为正常对照。造模组每周进行1次造模实验,连续4周。最后一次造模结束1周后,在局部解剖直视下观察局部紧张带,肌电自发电位和局部抽搐反应。结果:(1)可触及紧张带检查显示,正常对照组均为阴性。打击结合离心运动组的紧张带阳性率最高,为100%,显著高于正常对照组(P<0.01)。打击组和离心运动组阳性率分别为66.6%和33.3%,均显著高于正常对照组(P<0.01,P<0.05)。各造模组组间比较,以打击结合离心运动组阳性率最高(P<0.01)。(2)肌电图检查显示,正常对照组均为阴性。打击结合离心运动组肌电图阳性率最高,为91.7%,显著高于正常对照组(P<0.01)。打击组阳性率为58.3%,显著高于正常对照组(P<0.01)。离心运动组阳性率低,为16.7%,与正常对照组比较无显著性差异。各造模组组间比较,以打击结合离心运动组阳性率最高(P<0.05)。(3)抽搐反应结果显示,正常对照组肌肉内无局部抽搐反应,均为阴性。打击结合离心运动组抽搐反应阳性率最高,为100%,显著高于正常对照组(P<0.01)。打击组阳性率为50%,显著高于正常对照组(P<0.01)。离心运动组阳性率最低,为25%,与正常对照组比较无显著性差异(P>0.05)。各造模组组间比较,打击结合离心运动组阳性率最高(P<0.05)。结论:打击与打击结合离心运动的方法均可建立肌筋膜触发点疼痛的实验动物模型,但从临床特点上看,打击结合离心运动的方法更稳定可靠。重复同样强度的离心运动并不能有效激活触发点。     

润燥止痒胶囊联合窄谱中波紫外线治疗寻常型银屑病血虚风燥证的临床观察

目的观察润燥止痒胶囊联合窄谱中波紫外线治疗寻常型银屑病血虚风燥证的临床疗效。方法将入选的58例患者随机分为治疗组31例,采用润燥止痒胶囊口服,联合窄谱中波紫外线照射;对照组27例,仅予窄谱中波紫外线照射。2组均持续治疗8周,在第8周结束时评价临床疗效。结果治疗组有效率83.87%,对照组有效率59.26%,2组比较差异有统计学意义(P<0.05)。结论润燥止痒胶囊联合窄谱中波紫外线治疗寻常型银屑病临床疗效较好。     

双侧第一、二磨牙联合带环固定腭弓的制作及模拟增强支抗试验

双侧第一、二磨牙联合带环固定腭弓的制作及模拟增强支抗试验姜世同魏玲口外弓作为一种增强支抗措施,广泛用于方丝弓矫治技术。但口外弓使用不便,且对患者配合的依赖性较大,若使用不当还有可能发生意外事故［１］。为探索安全而可靠的支抗设计,避免使用口外弓,笔者在...     

Clinicopathological study of myocardial infarction with normal or nearly normal extracardiac coronary arteries. Quantitative analysis of contraction band necrosis,coagulation necrosis,hemorrhage, and infarct size

Summary In order to clarify the pathogenesis of acute myocardial infarction (MI) in hearts with normal coronary arteries, infarct size, and the extent of contraction band necrosis (CBN), coagulation necrosis, and hemorrhage were quantitatively examined using an image analyzer in 5 autopsy cases of MI with normal or nearly normal extracardiac coronary arteries. One patient died 40 h after acute MI. A second patient with acute MI due to severe spasm of segment 6, confirmed by cineangiography, died three days later. The third patient had already suffered a subarachnoid hemorrhage, and died 10 h after the onset of acute MI. The fourth patient had aortic stenosis and regurgitation. She developed acute MI due to total occlusion of segment 6, confirmed by cineangiography 4 h after the onset, and died 61 days later. Autopsy revealed old anteroseptal MI with normal coronary arteries and valvular thrombi. The fifth patient had a malignancy, and died one day after the onset of acute MI. Autopsy revealed multiple occlusive thrombi in the small intramural coronary arteries of the left ventricular wall supplied by segment 14, without any stenosis in the feeding vessel. Most infarcts were localized in the territory supplied by 1 or 2 of the 3 epicardial coronary arteries, and coincided with the clinically diagnosed infarct site. The infarct size ranged from 3%–26% of the left ventricular wall, and infarcts were generally localized to the inner third of the wall (67±20%). Histological examination of the four patients with acute MI revealed diffuse CBN (86±14% of the infarcted area) and/or hemorrhage. The findings suggested that MI associated with normal coronary arteries was caused by transient coronary arterial occlusion due to spasm and/or thromboembolism, with the CBN seen in these hearts representing reperfusion injury.     

Mechanism behind gamma band activity in the pedunculopontine nucleus

The pedunculopontine nucleus (PPN), part of the reticular activating system, modulates waking and paradoxical sleep. During waking and paradoxical sleep, EEG responses are characterized by low-amplitude, high-frequency oscillatory activity in the beta-gamma band range (~20-80 Hz). We have previously reported that gamma band activity may be intrinsically generated by the membrane electroresponsiveness of PPN neurons, and that the neuronal ensemble generates different patterns of gamma activity in response to specific transmitters. This study attempted to identify the voltage-gated calcium and potassium channels involved in the rising and falling phases of gamma oscillations in PPN neurons. We found that all rat (8-14 day) PPN cell types showed gamma oscillations in the presence of TTX and synaptic blockers when membrane potential was depolarized using current ramps. PPN neurons showed gamma oscillations when voltage-clamped at holding potentials above -30 mV, suggesting that their origin may be spatially located beyond voltage-clamp control. The average frequency for all PPN cell types was 23 ± 1 Hz and this increased under carbachol (47 ± 2 Hz; anova df = 64, t = 12.5, P < 0.001). The N-type calcium channel blocker ω-conotoxin-GVIA partially reduced gamma oscillations, while the P/Q-type blocker ω-agatoxin-IVA abolished them. Both ω-CgTX and ω-Aga blocked voltage-dependent calcium currents, by 56 and 52% respectively. The delayed rectifier-like potassium channel blocker α-dendrotoxin also abolished gamma oscillations. In carbachol-induced PPN population responses, ω-agatoxin-IVA reduced higher, and ω-CgTx mostly lower, frequencies. These results suggest that voltage-dependent P/Q- and, to a lesser extent, N-type calcium channels mediate gamma oscillations in PPN.     

Voluntary tic suppression and the normalization of motor cortical beta power in Gilles de la Tourette syndrome: an EEG study

Gilles de la Tourette syndrome (GTS) is a neurological condition characterized by motor and vocal tics. Previous studies suggested that this syndrome is associated with abnormal sensorimotor cortex activity at rest, as well as during the execution of voluntary movements. It has been hypothesized that this abnormality might be interpreted as a form of increased tonic inhibition, probably to suppress tics; however, this hypothesis has not been tested so far. The present study was designed to formally test how voluntary tic suppression in GTS influences the activity of the sensorimotor cortex during the execution of a motor task. We used EEG to record neural activity over the contralateral sensorimotor cortex during a finger movement task in adult GTS patients, in both free ticcing and tic suppression conditions; these data were then compared with those collected during the same task in age‐matched healthy subjects. We focused on the levels of activity in the beta frequency band, which is typically associated with the activation of the motor system, during three different phases: a pre‐movement, a movement, and a post‐movement phase. GTS patients showed decreased levels of beta modulation with respect to the healthy controls, during the execution of the task; however, this abnormal pattern returned to be normal when they were explicitly asked to suppress their tics while moving. This is the first demonstration that voluntary tic suppression in GTS operates through the normalization of the EEG rhythm in the beta frequency range during the execution of a voluntary finger movement.     

Localizing evoked and induced responses to faces using magnetoencephalography

A rich pattern of responses in frequency, time and space are known to be generated in the visual cortex in response to faces. Recently, a number of studies have used magnetoencephalography (MEG) to try to record these responses non‐invasively – in many cases using source analysis techniques based on the beamforming method. Here we sought both to characterize best practice for measuring face‐specific responses using MEG beamforming, and to determine whether the results produced by the beamformer match evidence from other modalities. We measured activity to visual presentation of face stimuli and phase‐scrambled control stimuli, and performed source analyses of both induced and evoked responses using Synthetic Aperture Magnetometry. We localized the gamma‐band response to bilateral lateral occipital cortex, and both the gamma‐band response and the M170‐evoked response to the right fusiform gyrus. Differences in the gamma‐band response between faces and scrambled stimuli were confined to the frequency range 50–90 Hz; gamma‐band activity at higher frequencies did not differ between the two stimulus categories. We additionally identified a component of the M220‐evoked response – localized to the parieto‐occipital sulcus – which was enhanced for scrambled vs. unscrambled faces. These findings help to establish that MEG beamforming can localize face‐specific responses in time, frequency and space with good accuracy (when validated against established findings from functional magnetic resonance imaging and intracranial recordings), as well as contributing to the establishment of best methodological practice for the use of the beamformer method to measure face‐specific responses.     

Individual EEG Alpha Activity Analysis for Enhancement Neurofeedback Efficiency: Two Case Studies

The hypothesis was tested of whether neurofeedback training applied in order to increase or decrease power of individual EEG frequency ranges is more efficient than neurofeedback training of standard EEG frequency ranges. The sessions of decreasing the theta/beta ratio and reinforcing alpha neurofeedback training were carried out on two outpatients with attention deficit disorder (a schoolboy) and functional pain contraction (a professional musician). The neurofeedback utilizing standard EEG frequency ranges (theta 4-8, alpha 8-12, beta 13-18) was inefficient and even resulted in aggravation of symptoms in both cases. The individualized neurofeedback that utilized individual frequency ranges resulted in substantial clinical improvement.     

Double fixation of displaced patella fractures using bioabsorbable cannulated lag screws and braided polyester suture tension bands

Purpose

To evaluate the effectiveness and safety of a new double fixation technique for displaced patellar fractures using bioabsorbable cannulated lag screws and braided polyester suture tension bands.

Methods

Fifteen patients (mean age of 46.2 years) with displaced transverse or comminuted patella fractures were enrolled in this prospective study. All of the patients were treated via the open reduction internal fixation (ORIF) procedure using bioabsorbable cannulated lag screws and braided polyester suture tension bands. The patients were followed post-surgery to evaluate (1) the time required for radiographic bone union, (2) the knee joint range of motion at the time of radiographic bone union, (3) the degree of pain assessed using the visual analogue scale (VAS), (4) the function of the knee using the Lysholm score and (5) the presence of any additional complications from the surgery.

Results

All of the patients were followed post-treatment for more than 1 year (range, 12–19 months; mean post-treatment follow up time, 14 months). The bone union of the fractures as seen radiographically occurred approximately 3 months from surgery in all cases without implant failure or redisplacement of the fractured site. The mean knee joint range of motion was from 0 to 134.6°, and the mean VAS score was 0.7 at the time of bone union. The mean Lysholm scores at the time of bone union and 12 months post-surgery were 86.7 and 95.7, respectively. No postoperative complications, such as infection, dislocation or breakage of the implants, were observed. Moreover, all of the patients returned to their previous activity level.

Conclusion

This new double fixation technique using bioabsorbable cannulated lag screws and braided polyester suture tension bands resulted in satisfactory outcomes for patella fractures without any obvious complications.