Traumatic injuries to the craniovertebral junction: a review of rare events

The craniovertebral junction is a specific region of the spine with unique anatomical and biomechanical properties that yields a wide variety of injury patterns. Junctional traumatic fractures and/or dislocations are widely reported in clinical practice, but we could identify only a subgroup of upper cervical spine traumatic injuries with very few cases reported in the literature, and for this reason may be considered rare. In some of these cases, the absence of spinal biomechanical instability, in association with moderate clinical symptoms (neck stiffness and pain) and the difficulty in fracture identification through standard cervical radiographs, leads to a high percentage of missed injuries. In other cases, traumatic events have been commonly described only in autopsy series due to the high degree of spinal biomechanical instability. Herein, we have summarized all the relevant literature concerning this issue and also included our cases, with the aim of emphasizing prompt diagnosis and correct management. We provide a guide for correctly identifying “rare” craniovertebral junction traumatic injuries.     

Role of dynamic computed tomography scans in patients with congenital craniovertebral junction malformations

AIM To evaluate the role of dynamic computed tomography(CT)scan imaging in diagnosing craniovertebral junction(CVJ)instability in patients with congenital CVJ malformations.METHODS Patients with symptomatic congenital CVJ malformations who underwent posterior fossa decompression and had a preoperative dynamic CT scan in flexion and extended position were included in this study.Measurements of the following craniometrical parameters were taken in flexed and extended neck position:Atlanto-dental interval(ADI),distance of the odontoid tip to the Chamberlain’s line,and the clivus-canal angle(CCA).Assessment of the facet joints congruence was also performed in both positions.Comparison of the values obtained in flexion and extension were compared using a paired Student’s t-test.RESULTS A total of ten patients with a mean age of 37.9 years were included.In flexion imaging,the mean ADI was1.76 mm,the mean CCA was 125.4°and the mean distance of the odontoid tip to the Chamberlain’s line was+9.62 mm.In extension,the mean ADI was1.46 mm(P=0.29),the mean CCA was 142.2°(P0.01)and the mean distance of the odontoid tip to the Chamberlain’s line was+7.11 mm(P0.05).Four patients(40%)had facetary subluxation demonstrated in dynamic imaging,two of them with mobile subluxation(both underwent CVJ fixation).The other two patients with a fixed subluxation were not initially fixed.One patient with atlantoaxial assimilation and C23 fusion without initial facet subluxation developed a latter CVJ instability diagnosed with a dynamic CT scan.Patients with basilar invagination had a lower CCA variation compared to the whole group.CONCLUSION Craniometrical parameters,as well as the visualization of the facets location,may change significantly according to the neck position.Dynamic imaging can provide additional useful information to the diagnosis of CVJ instability.Future studies addressing the relationship between craniometrical changes and neck position are necessary.     

Magnetic resonance imaging of pseudotumors of the craniovertebral junction in long-term hemodialysis patients

BACKGROUND/AIMS: Pseudotumors of the craniovertebral junction (PTCVJ) are observed in long-term hemodialysis (HD) patients. There are neither criteria for diagnosis nor guidelines for screening. We attempted to determine magnetic resonance imaging (MRI) findings that could be used to detect PTCVJ, to determine the prevalence of PTCVJ, and to evaluate whether destructive spondyloarthropathy (DSA) might be a yardstick for selection of patients for MRI examination for PTCVJ. METHODS: MRI were examined in 19 DSA patients (8 males, 11 females, age 61.4 +/- 7.3 years, HD duration 17.0 +/- 4.4 years) and in 20 sex-, age-, and HD-duration-matched non-DSA patients (9 males, 11 females, age 57.5 +/- 6.6 years, HD duration 17.7 +/- 4.9 years). We evaluated MRI characteristics of PTCVJ according those which occur due to rheumatoid arthritis. RESULTS: PTCVJ were characterized as follows: disappearance of fat pads in the upper region (supradental PTCVJ), intensity change of the 'predental triangle' in the anterior region (predental PTCVJ), and thickening of cruciform ligaments (retrodental PTCVJ). The prevalence of PTCVJ among patients undergoing HD more than 10 years was high (26 out of 39; 66.7%). The prevalence of PTCVJ was not different between DSA and non-DSA groups. CONCLUSION: We verified that the above MRI findings might be helpful in the detection of PTCVJ. These findings were observed frequently and independently also in patients with DSA. Copyright Copyright 1999 S. Karger AG, Basel     

上颈椎韧带对寰枢椎稳定性影响的生物力学研究

 目的 探讨上颈椎韧带结构中横向韧带(横韧带)及纵向韧带对维持寰枢椎稳定性的作用。方法 新鲜成人完整上颈椎标本6具,在生物力学试验机上按序测定完整标本、横韧带切断、横韧带+纵向韧带切断状态下寰枢椎的前屈/后伸、左/右侧屈、轴向旋转幅度及前屈时的寰齿前间隙(atlantodental interval,ADI)。结果 (1)横韧带切断后,载荷10 N时平均ADI值、前屈、后伸角度与完整标本比较差异有统计学意义;载荷30～90 N时两组差异无统计学意义;载荷100 N时ADI值2.90 mm、前屈12.53°、后伸13.89°,载荷150 N时ADI值3.37 mm、前屈16.07°、后伸16.39°,与完整标本比较差异有统计学意义。载荷≤100 N时左/右侧屈、轴向旋转与完整标本比较差异无统计学意义;载荷150 N时,左侧屈8.40°、右侧屈9.67°、轴向旋转61.53°,与完整标本比较差异有统计学意义。(2)横韧带+纵向韧带切断后,不同载荷状态下的ADI值和三维运动幅度与横韧带切断及完整标本比较差异均有统计学意义。结论 单纯切断横韧带对寰枢椎稳定性可造成一定影响,表现在运动初期或载荷超出生理范围时;纵向韧带在生理载荷范围内足以维持寰枢椎的稳定性,切断纵向韧带将明显影响寰枢椎的稳定性。     

A prospective randomised controlled study of patient-controlled propofol sedation in phobic dental patients

The safety and effectiveness of patient-controlled propofol sedation was prospectively assessed in 18 healthy, phobic dental patients. Using a randomised, crossover design each patient received two sessions of equivalent dental treatment under patient-controlled or clinician-controlled propofol sedation. The patient-controlled technique used 29.8% less drug (time-weighted dose) than the clinician-controlled method (p = 0.011). There was a high correlation between number of demands and number of doses actually infused during the patient-controlled technique (r = 0.99, p < 0. 001). Clinically, the level of sedation was lighter and the degree of operator satisfaction was higher with patient-controlled sedation. Blood pressure and arterial oxygen saturation showed minimal changes and remained within normal ranges during both techniques. Patient-controlled sedation produced a greater reduction in dental and general anxiety compared with clinician-controlled sedation, but the difference did not reach statistical significance. Three times the number of patients expressed a preference for the patient-controlled, compared with the clinician-controlled, technique. Patient-controlled sedation provides safe and acceptable intra-operative anxiolysis for phobic dental patients, but with reduced propofol dosage.     

A comparative study between preoperative and postoperative pulmonary functions and diaphragmatic movements in congenital craniovertebral junction anomalies

Respiratory dysfunctions in patients with craniovertebral junction (CVJ) anomalies may occur due to compression of brainstem affecting the respiratory centers, and weakening of the muscles of respiration. We assessed pulmonary functions [forced vital capacity (FVC), forced expiratory volume in first second (FEV1), maximum mid-expiratory flow rate (FEF25%-75%), FEV1%], mouth pressures (maximum inspiratory pressure, maximum expiratory pressure), and diaphragmatic movements in 30 patients of CVJ anomalies and compared them with their mean predictive values. These parameters were also assessed in the postoperative period. It was found that the mean values of FVC, FEV1, and FEF25%-75% were significantly lower (P<0.001) than their mean predictive values (2.4+/-0.8 L, 2.0+/-0.7 L, 2.5+/-0.9 L vs. 3.7+/-0.9 L, 3.2+/-0.7 L, and 3.4+/-0.7 L, respectively). In the postoperative period there was significant reduction (P<0.05) in all these parameters (2.2+/-0.8 L, 1.7+/-0.7 L, and 2.1+/-0.8 L, respectively). The postoperative FEV1% was 78.8% compared with the preoperative value of 85.7%. A restrictive pattern of lung disease was observed which persisted in the postoperative period. The postoperative maximum inspiratory pressure and maximum expiratory pressure were comparable to their preoperative values (47.9+/-19.6 and 47.0+/-16.7 cmH2O vs. 42.6+/-17.3 and 43.9+/-18.2 cmH2O, respectively). Similarly, the diaphragmatic movements were also comparable to the preoperative values, both during quiet and deep breathing (13.7+/-3.9 and 38.0+/-9.3 mm vs. 13.8+/-3.9 and 39.0+/-9.1 mm, respectively). There was no improvement of pulmonary functions in the early postoperative period. However, a long-term follow-up is needed to determine subsequent changes of these parameters.     

Appropriate surgical procedures for Chiari type 1 malformation and associated syrinx based on radiological characteristics of the craniovertebral junction

Neurosurgical Review - Several surgical procedures can be applied for syrinx associated with Chiari type 1 malformation; however, it remains controversial as to which approach is the most...     

Congenital lung malformation patients experience respiratory infections after resection: A population-based cohort study

PurposeThe benefit of elective resection of congenital lung malformations continues to be debated. Proponents of resection endorse a decreased risk of respiratory complications as one indication for surgery. Our study aimed to compare the prevalence of respiratory infections in cases, before and after resection of congenital lung malformations, to controls without a history of congenital lung malformation.MethodsWe performed a retrospective cohort study of children born from 1991 to 2007 who underwent congenital lung malformation resection. Patients were identified from Winnipeg´s Surgical Database of Outcomes and Management (WiSDOM), and a 10:1 date-of-birth matched control group was generated from a population-based administrative data repository. International Classification of Disease codes were used to assess pulmonary infection outcomes. Relative rates (RR) were calculated to compare the frequency of pneumonia, respiratory infections and influenza between cases and controls.ResultsWe included 31 congenital lung malformation cases and 310 controls. Cases consisted of 14 (45.16%) congenital pulmonary airway malformations, 9 (29.03%) bronchopulmonary sequestrations and 8 (25.81%) hybrid lesions. Before resection, pneumonia was more common in cases than controls (RR 6.85; 95%CI 3.89, 11.9), while the risk of acute respiratory infections (RR 1.21; 95%CI 0.79, 1.79) and influenza (RR 0.46; 95%CI 0.01, 3.22) were similar to controls. Post-resection, the risk of pneumonia (RR 9.75; 5.06, 18.50) was still higher in cases than controls, and respiratory infections (RR 1.77; 95%CI 1.20, 2.53) and influenza (RR 3.98; 95%CI 1.48, 9.36) were more common in cases than controls.ConclusionOur study demonstrated that after resection of congenital lung malformations, children experience more frequent respiratory infections compared to the general population. Resection does not eliminate the increased risk of pneumonia.     

颅颈交界畸形中寰枢椎脱位的个体化治疗

目的 分析颅颈交界畸形中寰枢椎脱位的特点,探讨其手术策略制定.方法 分析2009年4月至2011年11月手术治疗的56例颅颈交界畸形伴寰枢椎脱位患者资料,包括2例可复性脱位和54例难复性脱位;其中男性22例,女性34例,年龄9 ～56岁,平均34岁.14例采用后路固定达到直接复位或部分复位,41例进行了经口前路减压和后路固定融合术,1例经后路行齿状突磨除和固定融合术.结果 53例患者获得随访,3例失访(出院时症状较术前改善);随访时间6 ～36个月,平均20个月.术后7例患者出现并发症,包括脑脊液漏2例、肺部感染2例、局部肉芽肿样病变1例、切口延期愈合1例,经对症处理后均恢复;1例出现不可逆性颈髓损伤,遗留四肢肌力下降.末次随访时Nurick分级,6例(11.3％)较术前改善3级,30例(56.6％)改善2级,13例(24.5％)改善1级,3例(5.7％)无明显改善,1例(1.9％)加重.结论 可复性寰枢椎脱位行后路固定即可达到复位效果,难复性寰枢椎脱位治疗方式要个体化,依据病情、影像学表现和临床经验采用直接复位固定术或经口齿状突磨除及后路固定融合术.     

枕颈结合部肿瘤诊断和外科治疗

枕颈结合部位于颅底和颈椎交界区域,位置深在,解剖结构复杂.该区域一旦发生肿瘤,早期诊断往往困难,而手术治疗更具风险性和挑战性.随着近年影像诊断技术的不断提高,特别是枕颈部外科技术的不断发展,枕颈结合部肿瘤的诊断和外科治疗水平正逐步提高.该文就诊断步骤和治疗策略作一综述.     

N-terminal-pro-BNP in critically ill patients with acute respiratory failure: a prospective cohort study

Background: The aim of this study was to evaluate the prognostic value of plasma N‐terminal pro‐B‐type natriuretic peptide (NT‐pro‐BNP) in unselected critically ill patients with acute respiratory failure (ARF). Methods: Prospective, observational cohort study in 25 intensive care units in Finland. This study included a total of 602 patients with laboratory samples from 958 consecutive patients with ARF treated either with invasive or with non‐invasive ventilatory support (the FINNALI study). Plasma NT‐pro‐BNP samples were drawn after the onset of ventilatory support (day 0) and on the morning of the second day. Results: The median [interquartile ranges (IQR)] NT‐pro‐BNP‐values were significantly higher at baseline in 90‐day non‐survivors than the survivors, 4378 pg/ml (1400–13,943 pg/ml) vs. 1052 pg/ml (232–4076 pg/ml), respectively. The median (IQR) NT‐pro‐BNP values were significantly higher in patients with chronic cardiac disease or cardiac surgery than in non‐cardiac patients, 1947 pg/ml (801–4687 pg/ml) vs. 417 pg/ml (153–1735 pg/ml), respectively, if renal function was normal. With deteriorating renal function, the NT‐pro‐BNP values showed a significant increase. The area under curve for baseline NT‐pro‐BNP predicting 90‐day mortality was moderate: 0.718 (95% confidence interval 0.674–0.761). Baseline NT‐pro‐BNP over 1765 pg/ml was independently associated with 90‐day mortality by logistic regression analysis (P<0.001). Conclusions: NT‐pro‐BNP on admission is commonly elevated and independently associated with 90‐day mortality in critically ill ARF patients. However, the routine use of NT‐pro‐BNP for prognostic purpose does not seem to add value to clinical data in ARF patients.     

三种经口入路处理颅颈交界区病变的解剖及比较

目的观察3种经口咽入路达到颅颈交界区的解剖特点。方法通过在尸体标本上模拟各种经口咽入路手术,观察解剖层次,测量手术深度、横向和纵向显露范围,重点对椎动脉与颅、颈神经的位置关系以及各段椎动脉的参数进行测量。结果单纯经口入路能显露从斜坡下1/3到C2椎体下缘的范围,水平向和纵向的显露范围分别为（39.4±2.2）mm和（52.1±3.5）mm。软腭切开后纵向显露范围增加到了（66.7±3.9）mm,能显露到从斜坡中部到C2/C3间隙的范围。上颌骨截骨后能将纵向显露提高到（74.6±5.1）mm,能显露至斜坡上1/3及蝶窦,足够暴露椎-基底动脉汇合点。椎动脉颅外段最宽处在C1横突孔内为（25.5±4.5）mm,最窄处在C2/C3间隙内为（11.2±1.5）mm。结论通过改良经口入路手术能直接将显露范围扩展至斜坡上段和蝶窦,椎动脉的解剖特点使其能作为该术式安全边界的标志。