【作者】 吴涛；

【导师】 邱勇；

【作者基本信息】 南京大学 ， 外科学， 2012， 博士

【摘要】 第一章双足直立小鼠模型高中枢瘦素水平对脊柱侧凸影响研究目的：研究中枢高瘦素水平对双足直立鼠模型脊柱侧凸发生率及严重程度的影响,从动物实验层次上验证脊柱侧凸中枢高瘦素水平假说。方法：选取3周龄雌性C3He/ej小鼠50只,于麻醉状态下切除小鼠前肢及尾部,建立双足直立鼠模型。建模成功后三天,将双足直立小鼠模型随机分成两组：一组通过颅内注射方式将瘦素过表达慢病毒载体注入小鼠下丘脑,建立中枢高瘦素水平双足直立鼠模型；另一种则通过颅内注射方式将空白慢病毒载体注入小鼠下丘脑,建立对照双足直立鼠模型。两组小鼠模型均于相同条件下饲养于鼠笼中并通过高位饮食诱导其直立体态。成功建模20周后,通过X-ray评估两组小鼠模型脊柱侧凸发生率及严重程度。然后处死小鼠取外周血液样本,通过ELISA试剂盒评估两组小鼠外周血中瘦素水平。结果：本研究结果显示中枢高瘦素水平组双足直立小鼠外周瘦素水平明显高于对照组(p<0.05),但中枢高瘦素水平组体重较对照组虽有所减少,但未见显著差异(p>0.05)。影像学结果显示25只中枢高瘦索水平组双足直立鼠中23只发生脊柱侧凸,平均Cobb角29.9°,而对照组25只小鼠中只有13只发生脊柱侧凸,平均Cobb角18.3°。上述结果显示中枢高瘦素水平组小鼠脊柱侧凸发生率明显高于对照组。而发生脊柱侧凸的小鼠中,中枢高瘦素水平组小鼠模型脊柱侧凸平均Cobb角显著高于对照组。结论：本研究结果显示中枢高瘦素水平不仅能够提高双足直立小鼠脊柱侧凸发生率,而且可能引起脊柱侧凸进一步进展,提示中枢高瘦素水平可能是导致脊柱侧凸发生的重要影响因素。第二章(第一节)青少年特发性脊柱侧凸患者小脑扁桃体位置与后颅窝容积间相关性研究目的：本研究通过磁共振(Magnetic Resonance Imaging, MRI)测量特发性脊柱侧凸(Idiopathic Scoliosis, IS)患者与年龄匹配正常对照后颅窝各骨性标志间线性距离,比较两组后颅窝容积差异,并分析IS患者后颅窝发育异常与小脑扁桃体生理性下疝间相关性。方法：从2009年1月至2011年6月我科收治500例IS患者中选取研究对象,入选标准为：(1)患者年龄16-20岁,Risser征均为5级。(2)患者术前行站立位全脊柱正侧位X线片及颈枕部MRI检查。选取年龄匹配正常对照组。测量两组研究对象头颈正中矢状位MRI中小脑扁桃体下缘超出BO线的距离(d值),枕骨大孔径(AB),斜坡长度(AD),枕上长度(BC)以及后颅窝矢状径(CD)等指标,比较两组小脑扁桃体位置及后颅窝容积差异。然后根据MRI影像学表现,再将IS患者按照是否伴发生理性小脑扁桃体下疝进行分组,分析后颅窝容积与小脑扁桃体生理性下疝间关系及主弯Cobb角与小脑扁桃体生理性下疝程度间相关性。结果：IS患者共70例,平均年龄17.2±1.5岁,男48例(68.6%),女22例(31.2%),平均Cobb角51.2土14.1。。对照组共58例,平均年龄17.3±1.4岁,男27例,女31例。研究结果显示IS患者的小脑扁桃体下缘超出BO线的距离(d值)明显大于正常对照组(p=0.009),其生理性小脑扁桃体下疝发生率为22.9%。IS患者枕骨大孔径明显大于正常对照组(p<0.001),而斜坡长度(AD),枕上长度(BC)以及后颅窝矢状径(CD)均明显小于正常对照组(p<0.001)。此外,IS患者d值与主弯Cobb角无显著相关性(p=0.585)。生理性下疝组IS患者枕上长度(BC)长度显著小于对照IS患者(p=0.008),而其他三项后颅窝线性指标两组间均未见显著性差异。结论：IS患者小脑扁桃体位置明显低于正常青少年,生理性小脑扁桃体下疝发生率为22.9%,这可能是由于IS患者后颅窝枕骨大孔增大而斜坡、枕骨发育受限有关,其病理机制尚需进一步研究探讨,提示IS患者颅骨发育过程中也存在成骨异常。第二章(第二节)Chiari畸形伴脊柱侧凸患者后颅窝线性容积研究目的：本研究通过MRI测量Chiari畸形Ⅰ型(Chiari Malformation Type Ⅰ, CMI)患者与年龄匹配正常青少年后颅窝各骨性标志间线性距离,比较两组后颅窝容积差异,分析CMI患者后颅窝容积与小脑扁桃体下疝程度及脊髓空洞间相关性。方法：患者选自2003年至2010年CMI患者,入选标准为：(1)年龄16-20岁,Risser征5级。(2)经头颈部MRI确诊为Chiari畸形Ⅰ型伴或不伴脊髓空洞。入选CMI患者均排除可致继发性CMI及颅骨破坏相关疾病。选取年龄匹配正常青少年作为对照组。测量两组研究对象头颈正中矢状位MRI中枕骨大孔径(AB),斜坡长度(AD),枕上长度(BC)以及后颅窝矢状径(CD)等指标,并将两组按性别分组后比较后颅窝容积差异。根据MRI影像学表现,将CMI患者按照小脑扁桃体下疝严重程度及是否伴发脊髓空洞进行分组,分析后颅窝容积与小脑扁桃体下疝程度及脊髓空洞间关系。结果：本研究中CMI患者共37例,平均年龄17.2岁,其中男23例(62.2%),女14例(37.8%)。对照组青少年共49例,平均年龄17.5岁,其中男24例(49.0%),女25例(51.0%)。结果显示CMI患者后颅窝各骨性标志间线性距离均明显小于同性别、年龄匹配对照组青少年。此外,本研究还发现Ⅰ度扁桃体下疝CMI患者斜坡长度(AD)明显大于Ⅱ、Ⅲ度扁桃体下疝CMI患者,余指标未见明显差异。CMI伴脊髓空洞患者与单纯CMI患者后颅窝各骨性标志间线性距离亦未见显著性差异。结论：本研究显示CMI患者存在明显的颅骨发育障碍,支持了CMI是由中胚层旁叶发育受限所致这一假说。此外,本研究还发现斜坡发育受限可能是促使CMI患者小脑扁桃体下疝加重的重要因素之一,而颅骨发育受限并非脊髓空洞的主要致病因素。第二章(第三节)儿童Chiari畸形伴脊柱侧凸的影像学特点与临床意义目的：通过对于Chiari畸形伴脊柱侧凸患儿的临床及影像学特征进行研究,探讨其临床意义。方法：研究对象选自2001年7月至2008年12月在我院就诊的儿童(年龄<10岁)Chiari畸形伴脊柱侧凸患者。通过分析其临床及影像学资料,测量胸椎后凸、腰椎前凸、MRI上小脑扁桃体下疝程度、空洞形态和长度以及空洞与脊髓的最大比值(S/C最大比值),对以上测量指标进行比较分析。结果：共有患儿40例入选,其中男23例(57.5%),女17例(42.5%)。本组患儿中累及胸弯37例(92.5%),单胸腰弯2例(5%),单腰弯1例(2.5%),不典型侧凸的发生率47.5%(19/40例),其中左胸弯的发生率为22.5%(9/40例)。典型侧凸模式中不典型特征发生率为72.7%(16/21例)。胸椎后凸角平均25.40,胸椎正常后凸与过度后凸占总患者的60%,腰椎前凸角平均53.1°,MRI发现其中36例(90%)伴有脊髓空洞。结论：儿童Chiari畸形患者以胸弯累及多见,不典型弯型及典型弯型中不典型特征较多见,胸椎后凸角较大,对于具有上述特征的低龄脊柱侧凸患儿,建议行全脊柱MRI排除神经系统异常。第二章(第四节)Chairi畸形脊髓空洞枕大孔减压术后脊髓空洞的自然转归目的：研究儿童Chiari畸形伴脊柱侧凸患者接受枕骨大孔减压术(PFD)术后脊髓空洞的自然转归,探索脊髓空洞PFD术后转归的相关影响因素。方法：研究对象选自2000至2009年于本院接受PFD术的Chiari畸形伴脊髓空洞合并脊柱侧凸患者。入选标准为：(1)患者年龄均小于或等于18岁；(2)经MRI确诊为Chiari畸形伴脊髓空洞；(3)以脊柱侧凸为首诊主诉；(4)入选患者均接受术前及术后MRI随访进行评估Chiari畸形及脊髓空洞状态。此外,本研究入选对象均排除继发性Chiari畸形或接受脊髓空洞引流术的可能。本研究采用最大脊髓空洞/脊髓比(S/C ratio)及脊髓空洞长度作为评估术前及术后随访脊髓空洞状况的影像学指标。根据末次术后随访资料,脊髓空洞S/C ratio或长度较术前减少超过20%定义为脊髓空洞明显缓解,而脊髓空洞完全消失则定义为脊髓空洞完全缓解。结果：共有44例患者入选本研究。44例患者术前及术后6月均接受MRI检查。其中37例患者术后2年接受MRI随访,26例患者术后4年接受MRI随访,15例患者术后6年接受MRI随访。根据末次随访MRI影像学资料,97.7%(43/44)的患者PFD术后脊髓空洞明显缓解。本研究结果显示小脑扁桃体下疝距离(mm)与PFD术对脊髓空洞的疗效间存在显著相关性(r=0.116,p=0.013)。同时我们发现脊髓空洞PFD术后缓解主要发生在术后6月内,6月之后脊髓空洞缓解虽然仍持续进行,但是缓解速度明显减低。结论：绝大多数Chiari畸形伴脊髓空洞合并脊柱侧凸患者接受枕骨大孔减压术术后脊髓空洞显著改善。而这种脊髓空洞的显著改善主要发生在枕骨大孔减压术术后6月内,其后脊髓空洞缓缓改善。同时我们发现小脑扁桃体下疝严重程度可能是影响枕骨大孔减压术对脊髓空洞疗效的重要潜在因素。更多还原

【Abstract】 Chapter1Role of high central leptin activity in a scoliosis model created in bipedal amputated miceObjective:To validate this hypothesis that leptin dysfunction might be involved in the etiopathogenesis of AIS.Method:In this study, a scoliosis model of bipedal amputated mice with high central leptin activity was established. Amputation of forelimbs and tails was performed at the age of3-week on50C3H/HeJ mice. Three days after bipedal amputation, the mice were randomly divided into two groups:then25mice were injected in the hypothalamus with lentivirus vectors which overexpressed leptin, whereas the remaining25were injected with lentivirus vectors expressing GFP (control vector). X-rays were obtained at20th week to determine the development of spinal deformity. After that all mice were sacrificed, and blood samples were collected. Then peripheral leptin levels were measured by an ELISA kit. Comparisons for the incidence of scoliosis and the severity of the curves were performed between groups. Results:The body weight was found to be slightly lower in the leptin-vector-treated C3H/HeJ mice when compared with control mice. Significantly higher peripheral serum leptin level was found in leptin-vector-treated mice than control mice. Scoliosis was observed in23/25of leptin-vector-treated mice with an average Cobb angle of29.9°, and in13/25of control with an average Cobb angle of18.3°. Both the incidence of scoliosis and curve severity was significantly higher in leptin-vector-treated mice than in control group.Conclusion:The results of this study indicated that the high central leptin activity might not only increase the risk of developing a scoliosis in bipedal mice but also contribute to the progression of scoliosis. The high central leptin activity might play an important role in the etiopathogenesis of scoliosis.Chapter2(section1) A morphometric analysis on the correlation between position of cerebellar tonsil and posterior fossa volume in the patients with idiopathic scoliosisObjective:To compare the posterior fossa volume of idiopathic scoliosis (IS) patients with that of age-matched controls and to determine the correlation between location of cerebellar tonsil and posterior fossa volume in IS patients.Methods:A retrospective radiographic study was performed on500patients with IS who received surgical treatment at our center between January2009to June2011. The recruited patients were selected with the following inclusion criteria:(1) age ranged from16to20years, and the Risser sign was5;(2) each patient had a posteroanterior standing X-ray and a combined head, cervical spine MRI scan. Age-matched healthy adolescents were recruited as controls. On sagittal MRI images, the position of the cerebellar tonsil was evaluated by the distance (d) between the inferior pole of cerebellar tonsil and the line connecting the basion and opisthion (BO line). And the anteroposterior diameter of the foramen magnum (AB), the length of supraocciput (BC), the anteroposterior diameter of the posterior fossa (CD) and the length of the clivus (AD) were measured on mid-sagittal MRI images to make a comparison of the posterior fossa volume between the IS patients and controls. Then a further analysis was performed to determine whether there was significant difference of the posterior fossa volume between IS patients with and without physiological tonsillar ectopia.Results:Totally,70IS patients were recruited with the mean age of17.2year. Of them, there were48males and22females.58normal adolescents were recruited with the mean age of17.3years. Of them, there were27males and31females. It was shown that the positions of cerebellar tonsils in IS patients were significantly lower than the positions in controls (p=0.009). The incidence of physiological tonsillar ectopia in IS was found to be22.9%. Significant increment in anteroposterior diameter of the foramen magnum (AB) was found in IS patients compared to the control group (p<0.001), while significant decrement were also found in the three remaining indexes (P<0.001). However, Cobb angles of the main curve in IS patients were found to be not correlated with positions of cerebellar tonsils. Significant difference in no index but the length of supraocciput (BC) was found in IS patients with physiological tonsillar ectopia compared to IS patients without physiological tonsillar ectopia.Conclusion:It was shown that the positions of cerebellar tonsils in IS patients were lower than the positions in controls. The incidence of physiological tonsillar ectopia in IS was found to be22.9%. It might be caused by the heteroplasia of posterior fossa in IS patients, indicating that abnormal growth kinetics of endochondral and membranous ossification could be found in the development of posterior fossa. Chapter2(section2) A morphometric analysis of the posterior fossa volume in patients with Chiari malformationsObjective:To determine whether posterior fossa volumes of patients with Chiari malformation type I (CMI) are smaller than those of the age-matched healthy adolescents through the measurement of linear distances between bony landmarks in posterior fossa and to document whether the small posterior fossa volume in CMI patient is a key point that leads to the aggravation of tonsillar displacement and syrinx formation.Methods:A retrospective radiographic study was performed on patients with CMI. The recruited patients were selected with the following inclusion criteria, including (1) age ranged from16to20years, Risser sign was5;(2)The diagnosis of CMI in each patient was confirmed by a combined head, cervical spine MRI scan. And age-matched healthy adolescents were recruited as controls. On mid-sagittal MRI images, the anteroposterior diameter of the foramen magnum (AB), the length of supraocciput (BC), the anteroposterior diameter of the posterior fossa (CD) and the length of the clivus (AD) were measured to make a comparison of the posterior fossa volume between CMI patients and controls. The severity of tonsillar descent was classified and the presence of syrinx was identified on the sagittal MRI image. Then a further analysis was performed to determine whether the posterior fossa volume in CMI patients was correlated with the severity of tonsillar displacement and syrinx formation.Results:37CMI patients were recruited with the mean age of17.2year. Of them, there were23males and14females.49normal adolescents were recruited with the mean age of17.5years. Of them, there were24males and25females. Significant decrement was found in terms of all four indexes in CMI patients compared to control group. CMI patients with tonsillar hernia of I degree were found to have longer clivus than those with tonsillar descent of Ⅱ or Ⅲ degree. No significant difference was found in terms of all four indexes between CMI patients with syrinx and those without syrinx.Conclusion:The results of the current study suggested that the bony components of posterior fossa were underdeveloped in CMI patients, supporting the current concept that CMI is caused by the underdevelopment of the para-axial mesoderm, leading to a small posterior fossa. Besides above, we found that the underdevelopment of clivus might lead to the aggravation of cerebellar tonsillar displacement and the small posterior fossa had no association with syrinx formation.Chapter2(section3) The radiological features and clinical relevance of pediatric population with scoliosis secondary to Chiari malformation Type I.Objective:To analyze the clinical and imaging features of scoliosis secondary to Chiari malformation Type I in pediatric population and to discuss their clinical significance.Methods:We reviewed the records of children(age<10years old) diagnosed as scoliosis secondary to Chiari malformation Type I from2001to2008.These indexes were measured as follow:thoracic kyphotic angle, lumbar lordotic angle, degree of cerebellar tonsillar descent, configuration, length of syrinx, the maximal ratio of syrinx to cord (S/C ratio). The correlation among them were investigated.Results:In this study,40pediatric patients with Chiari I malformation were included. There were23male and17female patients with a mean age of7.4years (range:4-10 years). In these patients, there were37(92.5%) children who had a thoracic curve,2with a thoracolumbar curve and1(2.5%) child with a lumbar curve. The overall frequency of atypical curve patterns was47.5%(19/40) in our series. Left-sided thoracic curve patterns occurred in22.5%patients(9/40). Sixteen of twenty-one (72.7%) patients had typical curve patterns with atypical features in this study. The average thoracic kyphotic angle was25.4°. A total of60%of patients had a normal to hyperkyphotic thoracic spine. The average lumbar lordotic angle was53.1°. A total of36(90%) patients were identified to have a syrinx.Conclusion:Thoracic curve,atypical curve patterns, atypical features in typical curve patterns and a normal to hyperkyphotic thoracic spine are usually found in pediatric population with scoliosis secondary to Chiari malformation Type Ⅰ. We suggest it is necessary for scoliotic children with the above features to have a MRI scan.Chapter2(section4) Syrinx resolution after posterior fossa decompression in patients with scoliosis secondary to Chiari malformation type ⅠObjective:to investigate the outcome of PFD in patients with scoliosis secondary to CMI and to identify potential predictive factors for better outcome after PFD.Methods:Patients with scoliosis secondary to CMI and SM, who had undergone PFD during the period2000through2009. were recruited. Inclusion criteria were (1) age≤18years,(2) diagnosis of SM associated with CMI,(3) scoliosis as the first complaint,(4) having undergone preoperative and follow-up magnetic resonance imaging (MRI). Patients with acquired CMI anomalies or who had received syringosubarachnoid shunting were excluded. The maximal S/C ratio and syrinx length were measured to evaluate syrinx resolution after PFD. A20%decrease in S/C ratio or length at the latest follow-up was defined as a significant radiographic improvement and complete resolution was used to describe the syrinx disappearing after PFD.Results:44patients were recruited. Follow-up MRI was conducted for all44patients at6±3months postoperatively, for37patients at2years±3months, for26patients at4years±3months, and for15patients at6years±3months.97.7%(43of44) of patients showed significant radiographic improvement by MRI. The distance of tonsillar descent (mm) was correlated significantly with the surgical outcome (r=0.116, P=0.013). Significant improvement was observed within6months postoperatively, with continued slow improvement after that.Conclusion:Syringes showed significant improvement after PFD in most patients with scoliosis secondary to CMI. Resolution generally occurred within6months follow-up and continued at a slow rate for several years. In addition, the severity of tonsillar descent is a potential predictor for better improvement after standard PFD.更多还原