Neurophysiological assessment of spinal cord stimulation in failed back surgery syndrome

Despite good clinical results, the mechanisms of action of spinal cord stimulation (SCS) for the treatment of chronic refractory neuropathic pain have not yet been elucidated. In the present study, the effects of SCS were assessed on various neurophysiological parameters in a series of 20 patients, successfully treated by SCS for mostly unilateral, drug-resistant lower limb pain due to failed back surgery syndrome. Plantar sympathetic skin response (SSR), F-wave and somatosensory-evoked potentials (P40-SEP) to tibial nerve stimulation, H-reflex of soleus muscle, and nociceptive flexion (RIII) reflex to sural nerve stimulation were recorded at the painful lower limb. The study included two recording sets while SCS was switched ‘ON’ or ‘OFF’ for 1 h. Significant changes in ‘ON’ condition were as follows: SSR amplitude, H-reflex threshold, and RIII-reflex threshold and latency were increased, whereas SSR latency, F-wave latency, H-reflex amplitude, P40-SEP amplitude, and RIII-reflex area were reduced. Analgesia induced by SCS mainly correlated with RIII attenuation, supporting a real analgesic efficacy of the procedure. This study showed that SCS is able to inhibit both nociceptive (RIII-reflex) and non-nociceptive (P40-SEP, H-reflex) myelinated sensory afferents at segmental spinal or supraspinal level, and to increase cholinergic sympathetic skin activities (SSR facilitation). Complex modulating effects can be produced by SCS on various neural circuits, including a broad inhibition of both noxious and innocuous sensory information processing.     

The constituents of Anisomeles indica and their anti-inflammatory activities

Ethnopharmacological relevance

Anisomeles indica (L.) Kuntze. (Labiatae), popularly known as ‘yu-chen-tsao’, has been traditionally used as anti-inflammatory agent.

Aim of the study

Investigate the chemical constituents from the whole plants of Anisomeles indica, and evaluate their in vitro anti-inflammatory activities.

Results

The combined MeOH extract was successively partitioned with CHCl₃ and n-butanol, then submitted to several column chromatographic, and HPLC purification procedures which led to the isolation of one cembrane-type diterpenoid (3), two benzenoids (4 and 5), five flavonoids (1, 2, 6, 7 and 14), and six phenyl propanoids (8–13). The compounds 1–14 were examined for their inhibitory effects on inflammatory mediator's enhanced production from LPS/IFN-γ-stimulated macrophages. Among these, ovatodiolide (3) exhibited potent inhibition on NO, TNF-α and IL-12 enhanced production at a concentration of 5 μM, followed by pedalitin (1), scutellarein 7-O-β-d-glucuronide methyl ester (6), and acteoside (12) at 40 μM (P < 0.05). Furthermore, 2 μM of 3, and 20 μM of 1 and 6 significantly (P < 0.05) arrested the cell cycle of Con A-stimulated spleen cells at the G0/G1 stage.

Conclusion

This is the first report on the presence of compounds 1 and 4–13 in this plant and of the potent anti-inflammatory activity of 1, 3, 6 and 12in vitro. These compounds may account for the use of Anisomeles indica in folk medicine to treat inflammation.     

Scoliosis circa 2000: radiologic imaging perspective

Plain film imaging remains important for the diagnosis and surveillance of scoliosis, as well as for the detection of complications after surgery. Advances in CT and MR imaging have greatly improved the ability to detect or confirming nonidiopathic causes of scoliosis, including abnormalities within the spinal canal. Three-dimensional thinking has become more important in evaluating and understanding scoliosis.     

后柱切除后伸压缩中柱矫治胸腰段骨质疏松性重度椎体压缩骨折伴后凸畸形

【摘要】 目的：评价后柱切除后伸压缩中柱矫治胸腰段骨质疏松性重度椎体压缩骨折伴后凸畸形的安全性和临床效果。方法：2009年7月～2012年1月经后入路行后柱切除后伸压缩中柱矫治胸腰段骨质疏松性重度椎体压缩骨折伴后凸畸形患者14例,男2例,女12例;年龄62～81岁,平均68岁。骨折均位于T11～L2,其中单椎体骨折12例,两个椎体骨折2例;椎体高度压缩78.5%～92.4%,平均82.5%。后凸畸形的顶椎均位于胸腰段,其中L1 7例,T12 5例,L2 2例。后凸畸形Cobb角39°～59°,平均45°;脊柱矢状位C7铅垂线偏移距离为0.4～2.8cm,平均1.6cm;腰椎前凸41°～62°,平均58.4°,9例出现腰椎前凸代偿性加大。均有腰背部疼痛及疲劳感,疼痛视觉模拟评分（VAS）8.5分（7.5～9分）。神经功能按Frankel分级：E级12例,D级2例。其中10例采用注射型聚甲基丙烯酸甲酯骨水泥强化钉道。结果：手术时间187～221min,平均190min;术中出血量372～463ml,平均420ml。1例术中硬脊膜破裂,予以修补,术后未发生脑脊液漏。术后胸腰椎后凸Cobb角0°～9°,平均5°,平均矫正率达88.9%;矢状位C7铅垂线偏移距离0～0.8cm,平均0.3cm;腰椎前凸角28°～43°,平均37°。随访12～33个月,平均21个月。末次随访时,胸腰椎后凸Cobb角0～11°,平均7°;矢状位C7铅垂线偏移距离为0～1.2cm,平均0.4cm;腰椎前凸29°～45°,平均39°;神经功能按Frankel分级均为E级;腰背疼痛消失11例,明显缓解3例,VAS为1.9（0~3.5）分,与术前比较差异有统计学意义（P<0.05）;均植骨融合及骨折愈合良好,内固定无松动及拔出,固定邻近节段无继发骨折。结论：后柱切除后伸压缩中柱矫治胸腰段骨质疏松性重度椎体压缩骨折伴后凸畸形,与经椎弓根截骨术比较手术操作简单、创伤小。当骨质疏松性重度椎体压缩骨折伴后凸难以施行椎体成形术时,此技术是一种安全有效的补充方法。     

经后路全脊椎切除治疗结核治愈型胸腰椎角状后凸畸形

【摘要】 目的：探讨经后路全脊椎切除术治疗结核治愈型胸腰椎角状后凸畸形的有效性和安全性。方法：2008年１月~2012年１月,采用后路全脊椎切除手术治疗17例结核治愈型胸腰椎角状后凸畸形患者,男5例,女12例,年龄9～40岁,平均23.6岁。病程16～122个月,平均37.5个月,其中2例病例既往有经肋横突入路结核病灶清除手术史。病灶累及1～2个椎体8例,≥3个椎体9例。后凸畸形顶椎位于胸椎（T5～T10）5例,胸腰段（T11～L1）10例,腰椎2例。术前Cobb角60°～90°者13例,＞90°者4例,最大为102°,平均81.3°±12.8°。所有患者均可见驼背畸形,无低热、盗汗等结核中毒症状。术前、术后和末次随访时分别测量患者后凸Cobb角,并评估神经功能ASIA分级。结果：本组病例手术均顺利完成,手术时间330～450min,平均364min;术中出血量1600～2500ml,平均2218ml;术中输血1000～2000ml,平均1863ml。术中2例患者出现胸膜破裂,及时予以修补,经观察未发现气胸或血气胸。所有病例术后伤口均一期愈合,无窦道形成,内固定未见松动,未见神经功能加重者。术后Cobb角矫正至10°～28°,平均17.3°±3.6°,较术前明显改善（P<0.01）,后凸畸形矫正率平均为（68.7±6.5）%;术后随访13～34个月,平均18.7个月,末次随访时后凸Cobb角10°～32°,平均20.6°±3.9°,较术后平均丢失3.3°（P>0.05）,但与术前相比仍有明显改善（P<0.01）;植骨融合时间5～9个月,平均6.5个月;术前神经功能为D级的5例患者,4例恢复到E级,另1例仍为D级,但后凸畸形及局部疼痛已明显好转。结论：经后路全脊椎切除可安全有效地用于结核治愈型胸腰椎角状后凸畸形的矫形手术。     

后路全椎节切除、双轴旋转矫形手术治疗重度陈旧结核性后凸的疗效分析

目的:分析后路全椎节切除、双轴旋转矫形手术治疗重度陈旧结核性后凸的手术效果,探讨影响疗效的因素。方法:2004年5月~2011年9月,采用后路全椎节切除、双轴旋转矫形固定融合术治疗重度陈旧结核性后凸畸形患者33例。男15例,女18例;平均年龄34.7±14.1岁(11~63岁),其中年龄≥35岁18例,35岁15例;术前平均后凸角98.9°±18.2°(70.0°~130.0°),其中≥100°者17例,100°者16例;后凸顶点位于上中胸椎(T10及以上)19例,胸腰段及腰椎(T11及以下)14例。脊髓损伤Frankel分级A、B级各1例,C级5例,D级12例,E级14例。ODI术前平均19.5±9.4分。根据年龄、后凸顶点位置、后凸角度、术前Frankel分级、有无并发症等情况进行分组。对所有患者行手术前后及末次随访时的后凸局部和全脊柱正侧位X线摄片,测量后凸Cobb角,对合并侧凸的患者测量侧凸Cobb角。对手术前和随访时的患者进行脊柱矢状位平衡测量、实际身高测量、Frankel神经功能分级、Oswestry评分、VAS评分和手术PSI满意指数的评定。总结患者术中和术后并发症,并积极采取相应处理。结果:所有患者术前平均后凸Cobb角98.9°±18.2°,术后平均为30.9°±11.3°,矫正率为69.1%,末次随访时平均为34.8°±15.1°,矫正率为65.3%。患者脊柱矢状位平衡、身高测量、神经功能Frankel分级、生活质量Oswestry评分、腰背痛VAS评分均改善,手术总体满意率为87.9%。并发症发生率为54.5%,其中术中并发症12例、术后短期并发症2例、术后中远期并发症4例。所有并发症均及时采取相应处理。发生并发症者的总体后凸矫正率与未发生并发症者相当,但严重神经并发症发生者在神经功能恢复和生活质量改善方面均明显不如无并发症者。结论:后路全椎节切除、双轴旋转矫形手术是治疗重度陈旧结核性后凸畸形的有效方法,可以获得较好的手术效果,但需要尽量防止严重神经并发症的发生。     

大剂量氨甲环酸用于脊柱矫形手术的安全性和有效性

目的:评价大剂量氨甲环酸(TXA)应用于脊柱矫形手术尤其是经后路全脊椎切除术(PVCR)的安全性及有效性。方法:2009年2月~2010年10月收治脊柱畸形患者共66例,术前凝血功能检查异常及长期服用影响凝血功能药物的患者共7例被排除,最终59例患者纳入本研究。其中严重僵硬性脊柱畸形患者均接受一期PVCR,其余患者均接受一期单纯后路矫形融合术,所有手术均由同一位医师主刀完成。患者被分为TXA组和对照组。TXA组中8例接受PVCR,18例接受非PVCR矫形手术;对照组中9例接受PVCR,24例接受非PVCR矫形手术。TXA组患者在切皮前20min静脉输入100mg/kg剂量的TXA,随后给予维持量10mg·kg~(-1)·h~(-1)的TXA直到切口关闭;对照组给予等量的生理盐水替代。统计患者的术中失血量、真实失血量、输血量等数据,并监测患者围手术期的凝血功能、血红蛋白、红细胞比容等,同时监测药物相关并发症,包括潜在的肝、肾功能损伤,上/下肢静脉血栓,肺栓塞,心肌梗死及癫痫等。结果:TXA组中接受PVCR的患者术中失血量(4219±1386ml)、真实失血量[(134.2±36.4)%]及输血量(2986±1458ml)均少于对照组接受PVCR手术的患者[分别为9906±5251ml,(332.9±191.8)%,6255±3401ml,均P0.05]。TXA组中接受非PVCR矫形手术患者的术中失血量、真实失血量及输血量也均小于对照组非PVCR矫形手术患者(P0.05)。TXA组中PVCR术中失血量较对照组PVCR减少57.4%,而非PVCR手术术中失血量减少39.8%,大剂量TXA减少术中失血的作用在PVCR术中更为明显。TXA组及对照组围手术期肝、肾功能指标无明显差异(P0.05)。TXA组中未出现上/下肢静脉血栓、肺栓塞、心肌梗死、癫痫及急性肾功能衰竭。结论:大剂量TXA可有效减少脊柱矫形手术的术中失血与输血,尤其在PVCR手术中大剂量TXA的效果更为突出;大剂量TXA在脊柱矫形手术中的使用是安全的。     

椎体切除截骨矫形术治疗胸腰段脊柱后凸的疗效观察

目的观察椎体切除截骨矫形术治疗胸腰段脊柱后凸的矫正效果。方法2004年8月至2008年7月,采用后路椎体切除截骨矫形椎弓根钉棒固定植骨融合术治疗15例脊柱后凸患者,男10例,女5例;年龄12～62岁,平均32.3岁;后凸角度45°～110°,平均78.5°。病因：椎体肿瘤术后3例,先天性脊柱畸形5例,创伤后脊椎后凸4例,椎体结核术后3例。受累节段：均位于胸腰段,T_（11） 3例,T_（12） 5例,L_1 5例,L_2 2例。椎体切除：部分切除4例,单节段切除8例,2节段切除2例,4节段切除1例。术前,术后1周、3个月、1年摄全脊柱X线片,同时行MR及CT检查。结果全部获得随访,随访时间为10个月～3年,平均26个月。术后后凸角为0°～40°,平均20°,平均改善68.5°。术后患者腰痛均消失。脊髓功能：13例E级无明显变化,1例由Frankel C级恢复至D级,另1例由D级恢复至E级。8～12个月X线片示截骨融合,无一例出现钉棒松动、断裂、假关节形成及矫正度数丢失等。结论椎体切除截骨矫形是治疗脊柱后凸畸形的有效手段,能达到矢状面和冠状面的同时矫正且矫形彻底。     

Leaching of Titanium Dioxide Nanomaterials from Agricultural Soil Amended with Sewage Sludge Incineration Ash: Comparison of a Pilot Scale Simulation with Standard Laboratory Column Elution Experiments

Nanoscale titanium dioxide (nTiO₂ (Hombikat UV 100 WP)) was applied to sewage sludge that was incinerated in a large-scale waste treatment plant. The incineration ash produced was applied to soil as fertilizer at a realistic rate of 5% and investigated in pilot plant simulations regarding its leaching behavior for nTiO₂. In parallel, the applied soil material was subject to standard column leaching (DIN 19528) in order to test the suitability of the standard to predict the leaching of nanoscale contaminants from treated soil material. Relative to the reference material (similar composition but without nTiO₂ application before incineration) the test material had a total TiO₂ concentration, increased by a factor of two or 3.8 g/kg, respectively. In contrast, the TiO₂ concentration in the respective leachates of the simulation experiment differed by a factor of around 25 (maximum 91.24 mg), indicating that the added nTiO₂ might be significantly mobilisable. Nanoparticle specific analysis of the leachates (spICP-MS) confirmed this finding. In the standard column elution experiment the released amount of TiO₂ in the percolates between test and reference material differed by a factor of 4 to 6. This was also confirmed for the nTiO₂ concentrations in the percolates. Results demonstrate that the standard column leaching, developed and validated for leaching prediction of dissolved contaminants, might be also capable to indicate increased mobility of nTiO₂ in soil materials. However, experiments with further soils are needed to verify those findings.     

Somatostatin selectively ablates post-inspiratory activity after injection into the Bötzinger complex

Somatostatin (SST) neurons in the ventral respiratory column (VRC) are essential for the generation of normal breathing. Little is known about the neuromodulatory role of SST on ventral respiratory neurons other than that local administration induces apnoea. Here, we describe the cardiorespiratory effects of microinjecting SST into the preBötzinger and Bötzinger complexes which together elaborate a normal inspiratory augmenting and expiratory respiratory pattern, and on spinally projecting respiratory subnuclei (rostral ventral respiratory group; rVRG). Microinjections (20–50 nl) of SST (0.15, 0.45, 1.5 mM) were made into respiratory subnuclei of urethane-anaesthetized, paralysed, vagotomized and artificially ventilated Sprague–Dawley rats (n=46). Unilateral microinjection of SST into the Bötzinger complex converted the augmenting activity of phrenic nerve discharge into a square-wave apneustic pattern associated with a lengthening of inspiratory period and shortening of expiratory time. Following bilateral microinjection the apneusis became pronounced and was associated with a dramatic variability in inspiratory duration. Microinjection of SST into the Bötzinger complex also abolished the post-inspiratory (post-I) motor activity normally observed in vagal and sympathetic nerves. In the preBötzinger complex SST caused bradypnoea and with increasing dose, apnoea. In the rVRG SST reduced phrenic nerve amplitude, eventually causing apnoea. In conclusion, SST powerfully inhibits respiratory neurons throughout the VRC. Of particular interest is the finding that chemical inhibition of the Bötzinger complex with SST ablates the post-I activity that is normally seen in respiratory activity and leads to apneusis. This loss of post-I activity is a unique feature of inhibition with SST and is not seen following inhibition with other agents such as galanin, GABA and endomorphin. The effect seen on post-I activity is similar to the effect of inhibiting the Kölliker–Fuse nucleus in the pons. The mechanism by which SST exerts this effect on Bötzinger neurons remains to be determined.