Near infrared muscle spectroscopy in patients with Friedreich's ataxia

Friedreich's ataxia is a progressive neurodegenerative disorder of the afferent cerebellar pathways associated with mitochondrial dysfunction at the cellular level. We have used noninvasive continuous near infrared muscle spectroscopy (NIRS) to investigate the delivery and utilization of oxygen in response to exercise in this disorder. Patients performed an incremental treadmill walking protocol in which levels of muscle deoxygenation or oxygenation were continuously measured in the medial calf muscle. The kinetics of recovery from exercise-induced deoxygenation, called the half-time of recovery (t(1/2)) were determined. The t(1/2) was prolonged in patients with Friedreich's ataxia compared with controls, and the degree of prolongation correlated with the length of the shorter GAA repeat, a genetic measure that correlates with the age of onset of disease. The t(1/2) also correlated inversely with patient age and with the maximum treadmill speed attained. Several patients also displayed features consistent with inadequate oxygen utilization by muscle. These results suggest that NIRS may be an effective tool for monitoring the biochemical and functional features of Friedreich's ataxia in parallel.     

Anti-heparan sulfate antibodies in neurological disease

Antibodies to heparan sulfate (HS) have previously been found in association with peripheral neuropathy. We tested sera from patients with neuropathies and with other neurological diseases for antibodies to HS using an avidin-biotin enzyme-linked immunosorbent assay (ELISA) system. Increased titers of anti-HS antibodies were found in 3.4% of patients with neuropathy, and in 3% of patients with other neurological diseases. In all cases, however, an inflammatory disease was present, including chronic inflammatory neuropathy, cerebral vasculitis, or multiple sclerosis. Antibodies to HS appear not to be specific for neuropathy, as they occur in several inflammatory diseases. They might contribute to the associated breakdown of the blood-brain or blood-nerve barrier.     

Light scattering in rat neocortical slices differs during spreading depression and ischemia

Spreading depression (SD) and ischemia are different pathophysiological events but have similar characteristics. This study investigated whether similarity exists in the light scattering (LS) properties during SD and ischemia in rat neocortical slices. SD was induced by injection of K(+) while ischemia was simulated by removing oxygen and glucose. LS was simultaneously recorded with changes in extracellular direct current (DC) potential and extracellular space (ECS) volume. LS was measured using a photon counting fiber optic system and the ECS volume change was determined by measuring the ECS concentration of tetramethylammonium (TMA(+)). Slices maintained in normal artificial cerebrospinal fluid (ACSF) showed a consistent LS increase during SD, but exhibited two different LS behaviors during 6 min of ischemia. In eight slices, LS decreased and remained so until the end of the ischemic challenge. In another 10 slices, LS diminished initially but, after 2 min, suddenly reversed sign, accompanied by a rapid negative shift in extracellular DC potential. When 50 or 91% of Cl(-) in the ACSF was replaced by membrane-permeable propionate, LS retained its increase during SD, but always showed the sudden LS reversal during ischemia. In contrast, when Cl(-) was substituted with membrane-impermeant methylsulfate, the SD-induced LS increase was replaced by an LS decrease, and the sudden LS reversal during ischemia was absent. While the LS signal showed different characteristics during SD and ischemia, the DC potential always presented negative shifts and the ECS volume always exhibited similar decreases. These results suggest that the polarity of the LS signal is determined by the competition of at least two factors: cell swelling and anion influx.     

椎间盘镜手术治疗战士腰椎间盘突出症

目的　探讨脊柱后路椎间盘镜治疗战士腰椎间盘突出症的临床应用。方法　单侧或双侧入路采用椎间盘镜技术行腰椎间盘突出症髓核摘除术。术中用C型臂X线机定位、导引、准确安装 16mm工作通道 ,在影像监视系统辅助下 ,按常规开窗法完成髓核摘除和神经根减压术。结果　手术共 12例 ,随访 4～ 2 0个月 ,按照Nakai标准评定 :优 11例 ,良1例。结论　该术式具有微创手术的优势 ,不干扰腰椎的生物力学结构 ,术后恢复快 ,适合应用于战士腰椎间盘突出症。术中应注意准确定位 ,以摘除压迫神经组织的突出物为主 ,避免盲目扩大减压和过度摘除正常髓核组织     

Endoscopic percutaneous transforaminal treatment for herniated lumbar discs

Summary.  Background: The prevailing percutaneous treatment options for herniated non-contained lumbar discs have not reliably achieved the same good results as the conventional microsurgical techniques. In this study we evaluated clinical outcome and complication rate following endoscopic percutaneous transforaminal treatment of extruded or sequestrated herniated lumbar discs in 122 patients with a follow-up period of more than one year.  Method: Between October 1997 and December 2000, 86 male and 36 female patients with a median age of 55 years (range 18 to 89 years) underwent endoscopic treatment for non-contained herniated lumbar discs at our department. Neurological controls were conducted after 4 to 8 weeks routinely and the clinical result was reassessed at a follow-up of 15 to 53 months (median 35 months) according to the Macnab scale and Prolo outcome score.  Findings: On follow-up examination, 96 patients were found with permanently ameliorated or normal clinical status following endoscopy alone. The remaining 26 cases with unchanged or only temporarily improved neurological disorders were submitted to conventional microsurgical interventions. Spinal nerve root injury during endoscopic treatment occurred in two patients but no additional neurological deficits or aggravation of pre-existing disorders were observed.  Interpretation: Due to the minimal invasivity, the good functional outcome (78.7% clinical amelioration) and the low complication rate (1.6%), this procedure represents an attractive and efficient treatment alternative especially for foraminal and extraforaminal herniated lumbar discs and reduces the indications for open surgery in selected cases. Published online October 10, 2002 Correspondence: Sandro Eustacchio, M.D., Department of Neurosurgery, Karl-Franzens University, Auenbruggerplatz 29, A-8036 Graz, Austria.     

颈椎间盘突出症的手术治疗

目的探讨不同类型颈椎间盘突出的手术治疗和效果。方法回顾性分析65例颈椎间盘突出，其中脊髓型53例，神经根型12例，均行前路开槽减压植骨融合术。结果脊髓型椎间盘突出术后症状和体征消失明显较神经根型颈椎间盘突出症术后效果好，脊髓型优艮率92．45%，可、差类10例患者中，神经根型占50％。结论脊髓型椎间盘突出症患者出现症状和体征者。应积极行手术治疗，对于神经根型的行前路手术应慎重考虑。     

Feature detection of visual neurons in the nucleus of the basal optic root in pigeons

Previous studies have shown that the nucleus of the basal optic root in birds is involved in optokinetic nystagmus, and its neurons respond not only to large-field stimuli but also to a single object moving through their excitatory receptive fields. The present study provides electrophysiological evidence that basal optic neurons in pigeons respond vigorously to motion of a black leading edge. The orientation of the edge is also an essential factor affecting visual responses of these cells, showing that any deviation of the edge from the direction perpendicular to the preferred direction decreases visual responses in most cases. Furthermore, visual responses increase as the edge is lengthened within the excitatory receptive field. However, a square, semicircle and isosceles with an area ratio of 1.00: 0.39: 0.50 but with an identical leading edge elicit almost the same responses, which are not dependent on the shape and area of visual stimuli. It suggests that these feature extraction properties, similar to those of neurons in the nucleus lentiformis mesencephali, may be specialized for detecting optokinetic stimuli rich in luminance contrasts, but not for realizing pattern recognition.     

葛根素对实验性视网膜缺血-再灌注损伤后视神经的保护作用

目的探讨葛根素对实验性高眼压视网膜缺血-再灌注损伤后视神经的保护作用及其机制。方法用眼内灌注法前房灌注林格氏液制成急性高眼压视网膜缺血-再灌注损伤模型。将70只SD大鼠随机分为正常对照组(10只),葛根素治疗组(30只)和模型组(30只)。其中后2组根据再灌注的时间不同分为1d、3d、7d组,每组10只大鼠。治疗组经大鼠腹腔注射葛根素注射液(60mg·kg-1),模型组经大鼠腹腔注射生理盐水(10mL·kg-1)。利用免疫组织化学法检测各组大鼠视网膜内一氧化氮合酶(neural nitrogenoxide synthase,nNOS)的表达,以及硫代巴比妥酸法测量丙二醛(malonaldialdehyde,MDA)含量,黄嘌呤氧化酶法测超氧化物歧化酶(superoxide dismutase,SOD)活性。结果从再灌注1d开始,模型组视网膜内nNOS阳性表达明显增多,MDA水平持续升高,SOD活性持续下降,其差异与正常对照组相比,有统计学意义(P<0.01)。与模型组相比,再灌注各时段葛根素治疗组nNOS阳性神经元明显减少(P<0.01),MDA含量降低(P<0.01),SOD活性升高(P<0.01),其中nNOS阳性神经元与正常对照组相比,无统计学意义(P>0.05)。结论葛根素可通过提高视网膜组织中SOD活性,降低MDA含量,以及增加组织中nNOS表达,对大鼠实验性高眼压视网膜缺血-再灌注损伤有一定的保护作用。     

大视杯与早期青光眼视盘形态的对比研究

目的了解海德堡视网膜断层扫描(HRT-Ⅱ)视盘参数对青光眼早期视盘变化的灵敏性。设计横断面调查研究。研究对象 21例(36眼)生理性大视杯(C／D≥0．7)和27例(31眼)早期青光眼(C／D≥0.7、MD≤3dB)。方法对所有入选的患者进行视野及HRT-Ⅱ检测,对两组患者的视盘诸参数进行比较。主要指标 HRTⅡ检测的视盘诸参数,包括视盘面积、视杯面积、盘沿面积、视杯容积、盘沿容积、杯盘面积比、平均视杯深度、最大视杯深度、视杯形态测量、视杯高度变异轮廓、平均视网膜神经纤维层(RNFL)厚度和视神经纤维层横断面积。结果 HRTⅡ参数中,生理性大视杯组的盘沿面积、盘沿容积、平均RNFL厚度、RNFL 横断面积的值比早期青光眼组大,差异有显著性(t=2．247-3．714,P=0.000-0．028)。结论在鉴别早期青光眼与生理性大视杯时, 应重点关注上述HRT-Ⅱ参数。     

腰椎间盘突出症合并腰椎失稳的外科治疗

目的探讨腰椎间盘突出症合并腰椎不稳的诊断和治疗.方法1999年1月至2003年7月间对36例腰椎间盘突出症合并腰椎不稳患者,采用后路减压、椎间盘摘除、植骨融合、椎弓根系统内固定手术治疗.结果平均随访23个月（12～62月）,植骨全部愈合,优良率94.4%（34/36）.结论对术前明确存在腰椎不稳合并腰椎间盘突出症的患者,施行髓核摘除、植骨融合、内固定,重建脊柱的稳定性,临床疗效满意.