腰椎间盘突出症合并椎管内硬膜外血管畸形的解剖与临床特点

目的研究腰椎间盘突出症合并椎管内硬膜外血管畸形的解剖与临床特点。方法2001-2006年期间在我科手术治疗的7例腰椎间盘突出症合并椎管内硬膜外血管畸形,术前行MRI和选择性脊髓血管造影检查,均行椎间盘髓核摘除及畸形血管烧灼切除术。结果术中发现5例硬膜前方畸形血管,2例椎管内大量陈旧积血。术后症状消失或逐渐减轻,随访4年均无复发。根据Macnab疗效评定标准,优5例、良2例,无可及差。结论MRI、脊髓造影、手术探查是腰椎间盘突出症合并椎管内硬膜外血管畸形的主要诊断方法,充分认识其解剖与临床特点,有助于提高诊断准确率及手术疗效。     

Three‐Dimensional Reconstruction of the Optic Canal‐Based on Multislice Helical CT: A Comparison Analysis with Skull Dissection of 40 Postmortem Cases

Decompression operation of the optic canal via the nasal path under endoscope is widely used, but it is both a challenging and controversial method. Unsatisfactory results were largely associated with otolaryngologists' limited understanding of the real anatomical situations of the optic canal before operation. To provide otolaryngologists with the real situations and data preoperation, multislice helical CT was used to reconstruct the images of the optic canal. Using multislice helical CT‐aided three‐dimensional reconstructive methods in combination with direct anatomic measurement, we dissected and analyzed the shape of the optic canal and its anatomic relationship with the adjoining structures in 40 intact postmortem skull samples. The In‐Space technique clearly showed the structure and the related region of the optic canal. The virtual endoscopy technique showed superbly the spatial appearance and topography of the inner optic canal and also gave the inner structure of the optic canal optically. There was no statistic difference in three‐dimensional reconstructive data with that obtained by anatomical measurements and thus can be used to directly instruct the clinic operation. These results demonstrate that a combined In‐Space technique with virtual endoscopy can accurately define the subtle structure and the related region of the optical canal. In conclusion, multislice helical CT‐based three‐dimensional reconstruction is of important value for clinical operations. Anat Rec, 2008. © 2008 Wiley‐Liss, Inc.     

C7神经移位椎管内吻合腰神经前根重建截瘫屈髋伸膝功能的应用解剖

目的:为C7神经移位椎管内吻合腰神经前根重建截瘫患者屈髋伸膝功能提供解剖学基础。方法:在20例成人尸体标本上,观测L1阶段椎管内L1～4神经前根排列及纤维数、C7神经转移路径距离及坐骨神经可切取长度及远端纤维数。结果:一侧C7神经经椎体前通路跨越椎体中线的长度为(2.4±0.58)cm,可与对侧C7神经编织成束。在L1节段,L1～4神经前支可辨认并能编织成束供吻合。胫神经和腓总神经可切取长度(52.35±2.60)cm,(48.20±2.37)cm能够满足C7至L1段椎管的距离(48.35±3.36)cm。一侧胫神经和腓总神经远端纤维数(26856±112),(25700±156)大于一侧腰L1～4神经前支纤维数(20766±354)。结论:坐骨神经可选择为颈7神经移位重建截瘫下肢功能的桥接神经,双侧C7神经可经椎体前通路编织成束作为动力神经源,在L1阶段椎管内吻合L1～4腰神经前根的具有可行性。     

腰骶部SPR术中脊神经前后根定位的应用解剖

目的：为ＳＰＲ提供可靠的术中脊神经前、后根鉴别的解剖学依据。方法：在２０例成人脊柱标本上,去除后部结构,暴露整个马尾神经,对Ｌ１～Ｓ２节段的前后根进行形态学观察和测量。结果：脊神经后根位于马尾的后半部,前根则位于前半部。脊神经后根较相应的前根粗大,后根从Ｌ１～Ｓ１逐渐增大,以Ｓ１为最粗大;前根则以Ｌ３最粗大。相应前后根出硬脊膜前,有一段相互贴附并紧贴硬脊膜侧壁。结论：在多椎板切除ＳＰＲ术中前、后根的定位及鉴别,暴露时可根据前、后根出硬脊膜前的相互贴附;在限制性椎板切除时则可通过脊髓外侧索和Ｌ１前、后根之间的最下端的齿状韧带加以鉴别     

Filter properties of root mean square successive difference (RMSSD) for heart rate

The root mean square successive difference (RMSSD) in heart period series is a time domain measure of heart period variability. The RMSSD is sensitive to high-frequency heart period fluctuations in the respiratory frequency range and has been used as an index of vagal cardiac control. By transfer function simulations, the RMSSD statistic is shown to represent a high-pass filter that effectively captures respiratory sinus arrhythmia but also passes lower frequency fluctuations that can include sympathetic influences. These simulations, together with analysis of actual heart period series, reveal that the RMSSD is biased by basal heart period. Although between-subjects levels of RMSSD covary highly with spectral estimates of high-frequency variability, within-subject RMSSD change scores account for only 50-60% of the variance in spectral estimates. The present findings raise caveats in the applications and interpretation of the RMSSD statistic.     

Temporal response properties of lumbar-projecting vestibulospinal neurons to roll tilt in decerebrate cats

In decerebrate cats, rotation about the longitudinal axis of the animal, leading to sinusoidal stimulation of labyrinth receptors, produces a tonic contraction of limb extensors during side-down tilt ( responses) and of dorsal neck extensors during side-up tilt ( responses). These changes in posture are mediated, at least in part, by lateral vestibular nucleus (LVN) neurons, with response characteristics to stimulation of macular and/or canal receptors that have so far been evaluated at the level of either unidentified vestibulospinal (VS) neurons or vestibulo-collic neurons projecting to the upper cervical cord. In the present study we investigated the dynamics of the responses of VS neurons projecting to the lumbosacral segments of the spinal cord to increasing frequencies of tilt (from 0.026 to 0.32 Hz, ±10°). All the recorded units showed an average phase lead with respect to position of +25.6±5.5° (SE) at the tilt frequency of 0.026 Hz. Most of these neurons (n=32) were particularly activated during side-down tilt ( responses) and showed either a stable phase or an increase in phase lead of the responses with increasing frequency of tilt. At the tilt frequency of 0.026 Hz, the smaller the phase lead of the responses, the larger was the response gain. Moreover, the smaller the phase lead of the responses at that frequency of tilt, the smaller the increase in gain but the larger was the increase in lead of the responses obtained by increasing the stimulation frequency up to 0.32 Hz. Through this set of finely organized changes in unit response characteristics, the overall output of this population of neurons increased, while the phase angle of the responses reached the mean value of +64.9±2.6° (SE), thus becoming more related to the velocity than to the positional signal. The remaining units (n=7), which were mainly activated during side-up tilt ( responses), displayed an increase in phase lag of the responses to increasing frequency of stimulation, which reached the mean value of-118.9±14.5° (SE) at 0.32 Hz. The differences in the dynamic properties of these VS neurons projecting to the lumbosacral cord, with respect to those of previously recorded populations of VS neurons, are discussed.     

Microfilamentous type VI collagen in the hyalinized stroma of the hypertrophied ligamentum flavum

Summary Thickened ligamenta flava obtained from 14 patients with spinal canal stenosis were examined with special reference to type VI collagen. The characteristic histological finding in the thickened area was rupture of normal elastic fibre meshwork with resultant fibrosis which usually appeared hyaline. Using an immunohistological method, collagen types VI, I and III were found to be present in the hyaline matrix. Ultrastructural study revealed many microfilamentous structures of type VI collagen admixed in loosely packed, banded collagen fibres. With differential salt precipitation of pepsin-extracted collagen the existence of type VI collagen was confirmed by SDS-polyacrylamide gel electrophoresis analysis and Western blotting analysis using anti-type VI collagen antibody. Quantification of type VI collagen in pepsin-extracted crude collagen samples by an inhibition enzyme-linked immunosorbent assay showed an increasing amount of type VI collagen in the thickened ligamenta flava compared to the normal ligaments. Thus, increase of type VI collagen is the main contribution to the thickening of the ligamentum flavum. This may represent an adaptational and reparative process associated with disruption of elastic fibres.     

Transcerebellar inhibitory interaction between the bilateral vestibular nuclei and its modulation by cerebellocortical activity

Summary In decerebrate, unanesthetized cats, the brain stem was longitudinally cut at the midline from its dorsal to ventral surface with the cerebellum kept intact, eliminating neural interactions between the bilateral vestibular nuclei through the brain stem.Extracellular spike potentials of vestibular type I neurons identified by horizontal rotation were distinctly inhibited by contralateral vestibular nerve stimulation. This crossed inhibition was abolished by removal of the medial part of the cerebellum, indicating that the inhibition was mediated through the cerebellum. Neither aspiration of the flocculus on the recording side nor intravenous administration of picrotoxin eliminated transcerebellar crossed inhibition, suggesting that it is mediated through the cerebellar nuclei. When the fastigial, interposite and dentate nuclei were stimulated, inhibition of vestibular type I neurons was produced only from the contralateral fastigial nucleus. Cerebellocortical stimulation which inhibited fastigial type I neurons suppressed transcerebellar crossed inhibition. Effective sites for suppression of transcerebellar crossed inhibition were localized to lobules VI and VIIa in the vermal cortex on the side of labyrinthine stimulation.Intracellular recordings were made from type I neurons in the medial vestibular nucleus. Stimulation of the contralateral vestibular nerve and the contralateral fastigial nucleus produced IPSPs in these neurons with the shortest latency of 3.8 msec and 1.8 msec, respectively. The difference between these two latency values approximates the shortest latency of spike initiation of fastigial type I neurons in response to vestibular nerve stimulation. It is postulated that transcerebellar crossed inhibition is mediated through the fastigial nucleus on the side of labyrinthine stimulation.     

下颌第一前磨牙根管系统和根尖孔解剖及临床意义

采用牙髓透明法对 347颗下颌第一前磨牙根管系统的数目和形态进行观察。下颌第一前磨牙根管可分为Ⅰ、Ⅱ、Ⅲ、Ⅳ型。其中Ⅰ型 (单根单管型 )占 83 86 % ,Ⅱ型 (单根双管型 )占 4 6 1% ,Ⅲ型 (单双管混合型 )占 11 2 4 % ,Ⅳ型 (双根双管型 )占 0 2 9%。应用XTT— 3A连续变倍体视显微镜对 347颗下颌第一前磨牙的根管系统形态进行观察 ,根尖分歧出现率 15 6 3% ,根尖分叉出现率 2 4 3% ,根管侧支出现率 1 0 8%。并对 347颗下颌第一前磨牙的根尖孔与根尖顶的位置关系进行观察 ,根尖孔位于根尖顶者占 88 14 % ,位于旁侧者占 11 86 %。并就上述内容的临床意义进行了讨论。