应用多点刺激法运动单位数目估计评定平山病病情

目的 探讨多点刺激法运动单位数目估计( MUNE)在平山病病情判定中的意义.方法 采用病例对照研究,记录35例健康人和69例平山病患者拇短展肌和小指展肌MUNE数值.结果 (1)平山病组左侧拇短展肌MUNE为145.66±126.10,左侧小指展肌MUNE为102.20±112.67,右侧拇短展肌MUNE为149.72±117.80,右侧小指展肌MUNE为64.23±69.27,较对照组显著降低(P＜0.01).(2)在临床尚未出现明显症状的肌肉也可见到MUNE明显下降,尤其在症状不显著侧(P＜0.05).结论 多点刺激法MUNE检测可客观监测疾病自然过程,早期了解病情及定量评价肌肉的失神经支配情况.     

An electrophysiologic evaluation of whether open and laparoscopic techniques used in pediatric inguinal hernia repairs affect the genitofemoral nerve

Background

A prospective study was performed to evaluate the effect of inguinal hernia repairs on the genitofemoral nerve (GFN), and to compare postoperative electrophysiologic changes in the GFN of patients who had undergone either open or laparoscopic surgery.

Methods

Seventy patients with a mean age of 6.48 ± 3.49 were enrolled in the study. Either open or laparoscopic techniques were used to operate on the patients' inguinal hernias. In all cases, bilateral GFN motor responses were investigated electrophysiologically using surface electrodes on three occasions: preoperatively, in the first month, and third month postoperatively. t-Tests were used to compare changes in the GFN.

Results

Preoperative mean latency of the GFN in all groups was found to be significantly prolonged on the hernia side, compared with the non-hernia side (P = 0.01). Although no difference was observed in the latency levels of the GFN on the operated side at the preoperative and early postoperative stages, GFN latency levels decreased significantly in the late postoperative period in the laparoscopic group (P < 0.05). In the late postoperative period, amplitudes of GFN motor responses were significantly higher in the laparoscopic group than the open repair group (0.91 ± 0.11 mV and 0.57 ± 0.053 mV, respectively; P < 0.05).

Conclusion

Preoperative prolonged latency of GFN on the hernia side is likely to occur due to the pressure on the nerve caused by the hernia mass. By surgically removing the hernia mass, this buildup of pressure is prevented, decreasing the latency of the GFN. The significantly higher motor response amplitudes and decreased latency in the late postoperative stage for the laparoscopic group may be due to the fact that this technique is less invasive.     

心房颤动肺静脉前庭和左房内连续碎裂电位的电生理特点

目的探讨阵发性和持续性心房颤动(简称房颤)患者肺静脉前庭(PVO)和左房(LA)内连续碎裂电位(CFEAs)的电生理特点。方法入选24例药物治疗无效的房颤患者,依房颤节律分为阵发性房颤(PAF)组与持续性房颤(PeAF)组,每组各12例,根据距离肺静脉口远近,将肺静脉分成距肺静脉5～10 mm(Ⅰ区)与10～20 mm(Ⅱ区)两区。在房颤时,应用EnSite NavX标测系统高密度标测PVO和LA,比较两组平均CFE值(碎裂间期)≤70ms的CFAEs的电生理特点。结果①PeAF组LA内径大于PAF组(P<0.05),PAF组LA后壁CFAES分布比例最低,顶部最高,PeAF组前后壁最低,左心耳最高;PAF组PVO较LA高(P<0.05),PeAF组PVO和LA无差异。②两组间总PVO区域连续CFAEs比例无差异,PeAF组LA明显高于PAF组(P<0.05),PAF左下PVO连续CFAEs分布比例高于PeAF(P=0.02),另三支PVO无明显差别。除顶部PAF组连续CFAEs分布高于PeAF组(P=0.02)外,PeAF组下壁、左心耳及二尖瓣环均显著高于PAF组(P均<0.001)。③PAF组各支Ⅰ区连续CFAEs分布高于Ⅱ区(P<0.05),PeAF组左下PVOⅠ区高于Ⅱ区(P<0.05),右上PVOⅡ区高于Ⅰ区(P<0.05),另两支PVO无差异。④PAF组PVO平均CFE明显低于LA(P<0.0001),PeAF组两区域及两组间PVO则无差异;PeAF组LA平均CFE值较低,连续CFAEs数量较多,房颤周长较短。结论 LA电解剖重构在房颤维持中起重要作用,PeAF LA内连续CFAEs分布较PAF广泛,碎裂程度更高,房颤周长较短。PVO绝大多数连续CFAEs位于5～10 mm区域。     

换瓣术后左侧旁道的导管消融

目的报道机械瓣膜置换术后患者左侧旁道射频消融的经验。方法分析瓣膜置换术后患者左侧旁道射频消融的影像学和导管操作的特点,以及消融术前后的注意事项。结果 3例患者(男1例,女2例),年龄为32,46,46岁,分别为二尖瓣置换术后(2例)和主动脉瓣与二尖瓣联合换瓣术后(1例),均行心内电生理检查诊断为经左侧旁道折返的顺向型房室折返性心动过速,分别经主动脉逆行法(2例)和穿房间隔法(1例)射频消融治疗成功。结论换瓣术后患者的左侧旁道可考虑经导管射频消融治疗。     

以双向阻滞作为阵发性心房颤动肺静脉电隔离终点的临床研究

目的 评价以左心房-肺静脉电联系双向阻滞作为环肺静脉消融电隔离术终点对阵发性心房颤动(房颤)导管消融疗效的影响.方法 在76例阵发性房颤患者导管消融达到左心房-肺静脉传入阻滞后,分别于每根肺静脉内起搏评价肺静脉-左心房传导情况.据此分为双向阻滞组(传入与传出均阻滞)和传入阻滞组,随访观察房颤导管消融的临床疗效.结果 76例均完成导管消融术,306根肺静脉(2例患者存在右中肺静脉)均达到左心房-肺静脉电学传入阻滞之传统终点.18例消融术后左心房-肺静脉传导呈双向阻滞,58例仅传入阻滞.平均随访(6.85±1.08)个月,1次消融成功率为77.63％.其中,双向阻滞组为83.33％,传入阻滞组为75.86％,两组相比差异无统计学意义(P＞0.05).术后房性心动过速发生率5.26％(4/76),无心脏压塞、脑栓塞、左心房食管瘘等并发症以及死亡发生.结论 以左心房-肺静脉传导双向阻滞为房颤导管消融终点治疗阵发性房颤的策略似乎临床疗效较好.     

Neural processing stages during object-substitution masking and their relationship to perceptual awareness

The extent of visual perceptual processing that occurs in the absence of awareness is as yet unclear. Here we examined event-related-potential (ERP) indices of visual and cognitive processes as awareness was manipulated through object-substitution masking (OSM), an awareness-disrupting effect that has been hypothesized to result from the disruption of reentrant signaling to low-level visual cortical areas. In OSM, a visual stimulus array is briefly presented that includes a parafoveal visual target denoted by a cue, typically consisting of several surrounding dots. When the offset of the target-surrounding cue dots is delayed relative to the rest of the array, a striking reduction in the perception of the target image surrounded by the dots is observed. Using faces and houses as the target stimuli, we found that successful OSM reduced or eliminated all the measured electrophysiological indices of visual processing stages after 130 ms post-stimulus. More specifically, when targets were missed within the masked condition (i.e., on trials with effective OSM that disrupted awareness), we observed fully intact early feed-forward processing up through the visual extrastriate P1 ERP component peaking at 100 ms, followed by reduced low-level activity over the occipital pole 130–170 ms post-stimulus, reduced ERP indices of lateralized shifts of attention toward the parafoveal target, reduced object-generic visual processing, abolished object-category-specific (face-specific) processing, and reduced late visual short-term-memory processing activity. The results provide a comprehensive electrophysiological account of the neurocognitive underpinnings of effective OSM of visual-object images, including evidence for central roles of early reentrant signal disruption and insufficient visual attentional deployment.     

Enhanced short-latency responses in the ventral posterior medial (VPM) thalamic nucleus following whisker trimming in the adult rat

This study examined the effects of whisker trimming on the functional organization of the adult somatosensory thalamus. In vivo extracellular unit recordings were made on ventral posterior medial (VPM) thalamic neurons in urethane anaesthetised adult rats. Neuronal response properties to controlled whisker deflection were recorded in untrimmed control animals and in animals where one row of whiskers had been trimmed for a median of 18 days. Trimming significantly increased short-latency responses to stimulation of the centre receptive field whisker (mean increase of 36%, p<.001). Longer latency responses to surround receptive field whiskers were unaffected. Spontaneous firing was significantly decreased in trimmed animals. A condition-test paradigm indicated that thalamic inhibition was reduced following whisker trimming, although this effect failed to reach statistical significance. These results demonstrate a capacity of the adult somatosensory thalamus to undergo functional reorganization in response to non-traumatic and innocuous whisker trimming.     

Effects of stimulus frequency and duration on somatosensory discrimination responses

Somatosensory processing of duration and frequency changes was investigated using event-related potentials to vibrotactile stimuli. Intermittent vibration to the fingertips of either hand was presented using a two-stimulus odd-ball paradigm (deviant P = 0.10). One group (N = 12, 18–38 years) was presented with stimulus pairs of 20/70, 50/150 and 170/250 ms. A second group (N = 10, 19–34 years) was tested using frequency pairs of 200/70 Hz. A psychophysical study examined the subjects’ ability to discriminate between different stimulus pairs. A clear negative shift in the response to the deviant stimulus was recorded with all the stimulus conditions used in both experiments. Both frequency changes and duration increments/decrements revealed an initial negativity in the subtraction waveform with a mean onset of 90–170 ms and a following positivity, both of which were dependent on the duration of the stimulus used. A significant decrease in the amplitude of both components was observed with the 170/250 ms pairing, coinciding with a positive correlation between individual discrimination performance and amplitude. These results support the existence of a somatosensory mismatch response with features similar to those of the aMMN and highlight the relevance of the somatosensory-specific positivity. Results from the duration experiment also resolve some of the discrepancies between previous studies.