Dural ossification associated with ossification of posterior longitudinal ligament in the cervical spine: a retrospective analysis.

OBJECTIVE: Dural ossification (DO) is common in patients with ossification of the posterior longitudinal ligament (OPLL). The existence of DO makes surgery challenging and increases the risk of complications. The aim of this study was to investigate the incidence, distribution and radiological characteristics of DO associated with OPLL. METHODS: From January 2017 to January 2019, 55 patients with cervical OPLL were treated in our single center using an anterior cervical approach microsurgery. Preoperative CT images of decompressed segments were evaluated to identify imaging signs of DO. The 'double-layer sign' (DLS), 'parenthese sign' (PS) and 'hook sign' (HS) were considered to be characteristic imaging findings of DO in OPLL. Two kinds of confusing signs (false double-layer) were identified. RESULTS: Nineteen segments from 15 patients with OPLL had DO related to OPLL. The incidence of DO in OPLL segments was 30.16% (19/63), and the incidence of DO in patients with OPLL was 27.27% (15/55). DO occurred at the intervertebral space level in 14 cases and at the posterior level of the vertebral body in 5 cases. The sensitivity and specificity of imaging diagnosis were 89.47% (17/19) and 81.82% (36/44), respectively. The positive predictive value was relatively low, 68.00% (17/25), due to the false-positive double-layer sign. The negative predictive value was 94.74% (36/38). CONCLUSION: DO was relatively common in cervical OPLL. DLS might be misdiagnosed. PS and HS can vividly and intuitively describe the imaging features of DO and have high diagnostic accuracy.

A novel classification and its clinical significance in Chiari I malformation with syringomyelia based on high-resolution MRI.

BACKGROUND: The existing classification in Chiari I malformation (CM-I) has limited significance for the selection of surgical methods. OBJECTIVE: The purpose of this study was to investigate the surgery of CM-I with syringomyelia based on the high-resolution MR imaging (HRMRI) findings. METHODS: Data from 115 patients were collected and retrospectively analyzed. For those with syringomyelia up to the level of C1, HRMRI was performed and according to the communication status between the fourth ventricle and the syringomyelia, patients can be divided into four types, namely Type A: classic communicating; Type B: partial communicating; Type C: non-communicating; Type D: atrophic. All operations were performed with Foramen magnum and Magendie dredging (FMMD), and all intradural factors that may have induced the obstruction of CSF circulation were recorded. The efficiency of operation on syringomyelia was evaluated by mJOA, imaging findings, and complications in the follow-up periods. RESULTS: The postoperative follow-up period was from 12 to 24 months, with an average of 14.3 months. At 1 year, the mJOA of 115 patients was significantly higher than that before the operations (before surgery 12.1 ± 2.3 vs. after surgery 14. 2 ± 1.4, P < 0.05). In addition, postoperative re-examination showed that the size of the syringomyelia was reduced or completely resolved in patients of Type A, 100% (2/2); Type B, 81% (9/11); Type C, 84% (81/97); and Type D, 20% (1/5). CONCLUSIONS: According to our new classification based on HRMRI, FMMD is the key to surgical treatment, especially for Type A and Type B patients.

Cloning, Expression and Inhibitory Effects on Lewis Lung Carcinoma Cells of rAj-Tspin from Sea Cucumber (Apostichopus japonicus).

In recent years, sea cucumber has become a favorite healthcare food due to its characteristic prevention of cardiovascular diseases, suppression of tumors, as well as enhancement of immunity. In order to screen the anti-tumoral proteins or peptides from sea cucumber (Apostichopus japonicus), its cDNA library was analyzed, and a disintegrin-like and metalloproteinase with thrombospondin type 1 motif, member 13 (ADAMTS13)-like was found. ADAMTS13-like contains 10 thrombospondin 1 (TSP1) domains. Based on analysis of bioinformatics, the third TSP1 domain of this protein, which is further named Aj-Tspin, contains an arginine-glycine-aspartate (RGD) motif. Since our previous studies showed that the recombinant RGD-containing peptide from lampreys showed anti-tumoral activity, the third TSP1 domain of ADAMTS13-like was chosen to evaluate it's effect on tumor proliferation and metastasis, despite the fact it shares almost no homologue with disintegrins from other species. After artificial synthesis, its cDNA sequence, Aj-Tspin, which is composed of 56 amino acids, was subcloned into a pET23b vector and expressed as a recombinant Aj-Tspin (rAj-Tspin) in a soluble form with a molecular weight of 6.976 kDa. Through affinity chromatography, rAj-Tspin was purified as a single protein. Both anti-proliferation and immunofluorescence assays showed that rAj-Tspin suppressed the proliferation of Lewis lung carcinoma (LLC) cells through apoptosis. Adhesion assay also displayed that rAj-Tspin inhibited the adhesion of LLC cells to ECM proteins, including fibronectin, laminin, vitronectin and collagen. Lastly, rAj-Tspin also suppressed the migration and invasion of LLC cells across the filter in transwells. Thus, the above indicates that rAj-Tspin might act as a potential anti-tumoral drug in the future and could also provide information on the nutritional value of sea cucumber.

Long-Term Impairment of the Blood-Spinal Cord Barrier in Patients With Post-Traumatic Syringomyelia and its Effect on Prognosis.

STUDY DESIGN: Cohort study. OBJECTIVE: The aim of this study was to explore the association between blood-spinal cord barrier (BSCB) markers and other factors associated with an unfavorable outcome among patients with post-traumatic syringomyelia (PTS) who achieved successful intradural adhesion lysis (IAL). SUMMARY OF BACKGROUND DATA: Only approximately half of PTS patients receiving IAL have a favorable outcome. PATIENTS AND METHODS: Forty-six consecutive patients with PTS and 19 controls (CTRL) were enrolled. All PTS patients underwent physical and neurological examinations and spinal magnetic resonance imaging before and 3 to 12 months after IAL. All patients underwent myelography before surgery. BSCB disruption was detected by increased intrathecal and serum concentrations of albumin, immunoglobulin (Ig)G, IgA, and IgM. A multivariable analysis was performed with a logistic regression model to identify factors associated with unfavorable outcomes. Receiver operating characteristic curves were calculated to investigate the diagnostic value of biomarkers. RESULTS: The ages and general health of the PTS and CTRL groups did not differ significantly. QAlb, IGAQ, IGGQ, and IGMQ was significantly higher in PTS patients than in controls ( P =<0.001). The degree of intradural adhesion was significantly higher in the unfavorable outcome group than in the favorable outcome group ( P <0.0001). QAlb, immunoglobulin (Ig)AQ, IGGQ, and IGMQ was significantly correlated with clinical status ( R =-0.38, P <0.01; R =-0.47, P =0.03; R =-0.56, P =0.01; R =-0.43, P =0.05, respectively). Higher QAlb before surgery (odds ratio=2.66; 95% CI: 1.134-6.248) was significantly associated with an unfavorable outcome. The receiver operating characteristic curve analysis demonstrated a cutoff for QAlb higher than 10.62 with a specificity of 100% and sensitivity of 96.3%. CONCLUSION: This study is the first to detect increased permeability and BSCB disruption in PTS patients. QAlb>10.62 was significantly associated with unfavorable clinical outcomes following intradural decompression. LEVEL OF EVIDENCE: Level III-prognostic.

Role of Preoperative Albumin Quotient in Surgical Planning for Posttraumatic Syringomyelia: A Comparative Cohort Study.

OBJECTIVE: Surgical procedures for patients with posttraumatic syringomyelia (PTS) remain controversial. Until now, there have been no effective quantitative evaluation methods to assist in selecting appropriate surgical plans before surgery. METHODS: We consecutively enrolled PTS patients (arachnoid lysis group, n = 42; shunting group, n = 14) from 2003 to 2023. Additionally, 19 intrathecal anesthesia patients were included in the control group. All patients with PTS underwent physical and neurological examinations and spinal magnetic resonance imaging preoperatively, 3-12 months postoperatively and during the last follow-up. Preoperative lumbar puncture was performed and blood-spinal cord barrier disruption was detected by quotient of albumin (Qalb, cerebrospinal fluid/serum). RESULTS: The ages (p = 0.324) and sex (p = 0.065) of the PTS and control groups did not differ significantly. There were also no significant differences in age (p = 0.216), routine blood data and prognosis (p = 0.399) between the arachnoid lysis and shunting groups. But the QAlb level of PTS patients was significantly higher than that of the control group (p < 0.001), and the shunting group had a significantly higher QAlb (p < 0.001) than the arachnoid lysis group. A high preoperative QAlb (odds ratio, 1.091; 95% confidence interval, 1.004-1.187; p = 0.041) was identified as the predictive factor for the shunting procedure, with the receiver operating characteristic curve showing 100% specificity and 80.95% sensitivity for patients with a QAlb > 12.67. CONCLUSION: Preoperative QAlb is a significant predictive factor for the types of surgery. For PTS patients with a QAlb > 12.67, shunting represents the final recourse, necessitating the exploration and development of novel treatments for these patients.

A novel scoring system for assessing adult syringomyelia associated with CM I treatment outcomes.

BACKGROUND: A specific scoring system for syringomyelia is lacking. Our objective was to investigate the value of a novel scoring system (Syringomyelia Outcome Scale of Xuanwu hospital, SOS-XW) in assessing surgical outcomes in the treatment of syringomyelia (SM) associated with Chiari malformation type I (CM I). METHODS: A quantitative evaluation system (SOS-XW) of SM includes 4 parameters: pain (P), sensation (S), movement (M), and syringomyelia tension index (STI). The clinical data of 88 patients with CM I-related syringomyelia treated by foramen magnum and Magendie dredging (FMMD) from January 2018 to January 2019 were retrospectively analysed with a mean follow-up of 14.3 months, and the SOS-XW score was used to assess the efficacy. RESULTS: The higher the SOS-XW score, the more severe was the SM and related symptoms. The mean preoperative score was 5.97, and the postoperative score was 2.66. The symptom improvement rates were 77.78% for P, 69.01% for S, 31.82% for M, and 95.06% for the syringomyelia tension index (STI). The symptom improvement rate of the PSM score was weakly correlated with the improvement rate of STI, R2 = 0.0016. The percentage of PSM (P + S + M) improvement was lower in patients with an STI of 0. The postoperative SOS-XW score was positively correlated with the postoperative JOA score, R2 = 0.8314. The positive detection rate of SOS-XW was higher than that of the JOA score. CONCLUSIONS: To evaluate the surgical procedure efficacy in the treatment of syringomyelia, the SOS-XW score can provide a more objective, detailed, and comprehensive analysis, especially STI. A reduction in STI is the practical standard for assessing the effectiveness of surgery.

Rapid progression of acute cervical syringomyelia: A case report of delayed complications following spinal cord injury.

Context: Post-traumatic syringomyelia treatment usually focuses on restoring normal cerebrospinal fluid (CSF) flow. Herein, the first-reported case of delayed post-traumatic syringomyelia associated with an L2 compression fracture 30 years prior to syringomyelia symptoms that rapidly progressed to the brainstem within 5 months, leading to respiratory and circulatory impairments, is summarized. The improvement in symptoms and significant decrease in size of the syringomyelia/syringobulbia achieved in this patient suggest that the initial treatment of choice in such acute cases should be posterior fossa decompression (PFD). Intradural exploration in order to restore the normal CSF flow at the level of trauma can then be planned in a later time.Findings: A retrospective analysis of clinical manifestations and findings obtained from magnetic resonance (MR) imaging, including pre-operative and post-operative follow-up data acquired 6 months later, provided adequate comparisons of the neurological deficits and syrinx size. Interestingly, serial MR images showed that a cervical syrinx acutely progressed to the brainstem within 5 months. PFD and sectioning of the thick veil completely obstructing the foramen of Magendie resulted in partial resolution of the neurological deficits and syringomyelia regression after surgery.Conclusions: To our knowledge, this is the first case report to summarize the delayed complications of a spinal cord injury and acute syringomyelia progression to the brainstem in a short period. The symptoms were relieved by an emergency PFD, chosen due to the rapid progression of symptoms. An atypical treatment strategy is described for extremely rare cases, but with a good short-term prognosis.

Comparison of Clinical Efficacy of Epidural Injection With or Without Steroids in the Treatment of Degenerative Disc Disease: Meta-analysis.

BACKGROUND: Selective nerve root block has been widely used to treat degenerative disc disease (DDD), but no detailed research data is provided to compare the efficacy of epidural injection of anesthetics with or without steroids on the DDD treatment. OBJECTIVES: This study aimed to  provide the first comparison of steroids + local anesthetic (LA) or LA alone for the treatment of DDD. STUDY DESIGN: We systematically searched PubMed, Medline, Embase, and Cochrane. A systemic review and meta-analysis were performed to assess the clinical efficacy of both the steroids + LA group and the LA alone group, and subgroup analysis was also adopted. SETTING: A systematic review and meta-analysis using a random effects model on randomized controlled studies (RCTs). METHODS: After reviewing titles, abstracts, risk of bias, and full texts of 15,889 studies that were chosen following removal of duplicates after the initial database search, finally, 19 RCTs were included. Pain rating, functional score, follow-up period, and other-related data were extracted from these included works, and the effect size and statistical significance were calculated by the random effects model. The quality and level of the derived evidence were assessed by means of the  Grading of Recommendations Assessment, Development and Evaluation method. RESULTS: In terms of the Numeric Rating Scale (NRS-11) and Oswestry Disability Index (ODI) at one year, the combination of steroids + LA was obviously superior to LA. Subgroup analysis suggested that the combination of steroids + LA was more effective than LA alone in regard to the ODI in the lumbar group within 2 years. The opioids intake of patients treated by LA alone was less than that of the steroids + LA group within 3 months, and LA alone was more effective in pain score reduction, with more than 50% within 6 months in the interlaminar injection group. However, the combination of steroids + LA was more effective when alleviating the NRS-11 within 18 months in the caudal injection group. LIMITATIONS: Firstly, this analysis was inconsistent in technique, dosage, injection frequency, and follow-up period of epidural injections. Such differences may compromise the reported efficacy. Secondly, adverse reactions arising out of the 2 groups were not examined in that the included RCTs did not provide the data. Thirdly, different injection methods would compromise the outcomes, and no subgroup analysis was performed on different injection methods. Finally, these included articles that were mainly sourced from Manchikanti's team, and thus biased to some extent. CONCLUSIONS: The addition of steroids to anesthetic injectates was associated with a better NRS-11 and ODI compared with LA alone within one year in patients with DDD. Furthermore, the improvement of the ODI was observed within 2 years in patients with lumbar DDD.

SPECT Imaging of Acute Disc Herniation by Targeting Integrin α5ß1 in Rat Models.

Objective: Traditional morphological imaging of intervertebral disc herniation (IVDH) is challenging in early disease diagnosis. Aiming at the early diagnosis of IVD by non-invasive molecular imaging targeting of integrin α5ß1, we performed novel imaging in rats with acute IVDH for the first time. Methods: Animal models were prepared by conducting an established needle puncture procedure through the normal intervertebral disc (IVD). The disc-injured rats underwent SPECT/CT imaging of the 99mTc-3PisoDGR2 peptide at 1 day to 2 months postinjury. The expression change of integrin α5ß1 was determined by anti-integrin α5 and anti-integrin α5ß1 immunohistochemistry (IHC). Magnetic resonance imaging (MRI) was performed for comparison during disease progression. The morphological changes of the disc were determined by safranin-O staining. Results: Rats with acute IVDH showed gradually increased disc uptake of 99mTc-3PisoDGR2 from 1 to 7 days posttreatment, which was a significantly higher level than that of the normal disks in degenerative diseases. IHC results showed the expression of integrin α5ß1 on the surface of annulus fibrosus (AF) cells and nucleus pulposus (NP) cells, which agreed with the uptake data. MRI showed a progressively decreased T2 density and MRI index throughout the investigation. Hematoxylin and eosin (HE) staining and safranin-O staining revealed a disorganized structure of the IVD as well as loss of proteoglycans after puncture. Conclusions: The present study demonstrated a good correlation between integrin α5ß1 expression and acute disc herniation. The SPECT/CT imaging of 99mTc-3PisoDGR2 targeting integrin α5ß1 may diagnose IVDH in an acute phase for early disease management.

Phenotypes and Prognostic Factors of Syringomyelia in Single-Center Patients With Chiari I Malformation: Moniliform Type as a Special Configuration.

OBJECTIVE: The specific association between morphometric characteristics of the syrinx and the prognosis of Chiari malformation type I (CM-I) with syringomyelia following surgical procedure seems to have not been fully elaborated. This study focused on the preoperative clinical and radiologic parameters in CM-I patients with syringomyelia to find out the relationship between the patients' clinical status and the phenotypes of the syrinx with surgical outcome. METHODS: A continuous series of pediatric and adult patients with CM-I and syringomyelia from a prospectively maintained database in a single center were included, and we explored the related factors affecting the prognosis following decompression surgery through retrospective analysis of clinical presentations, imaging characteristics, and the morphological features of syringomyelia, to provide a clinical reference for the treatment of syringomyelia. RESULTS: There were 28 pediatric patients (13.8%), and 174 adults (86.2%) included in our study. The average Chicago Chiari Outcome Scale score was 14.56 ± 1.78. The overall prognosis after surgery was good in our series, among them 152 cases (75.25%) with a favorable prognosis, and syrinx was resolved effectively in 172 cases (85.15%). According to the univariate and multivariate analyses, the preoperative symptom duration, observation time, and with/without moniliform type were independent factors affecting the prognosis in adults. The most obvious difference between moniliform type and nonmoniliform type lies in the preoperative symptom duration, ventral subarachnoid space at the foramen magnum, and with/without straightened cervical physio-curve. CONCLUSION: Timely decompression surgery could achieve a better outcome in CM-I patients with syringomyelia. Moniliform syringomyelia may suggest a relatively better prognosis.

Spinal Obstruction-Related vs. Craniocervical Junction-Related Syringomyelia: A Comparative Study.

Background: No prior reports have focused on spinal cord injury (SCI) characteristics or inflammation after destruction of the blood-spinal cord barrier by syringomyelia. This study aimed to determine the differences in syringomyelia-related central SCI between craniocervical junction (CCJ) syringomyelia and post-traumatic syringomyelia (PTS) before and after decompression. Methods: In all, 106 CCJ, 26 CCJ revision and 15 PTS patients (mean history of symptoms, 71.5 ± 94.3, 88.9 ± 85.5, and 32.3 ± 48.9 months) between 2015 and 2019 were included. The symptom course was analyzed with the American Spinal Injury Association ASIA and Klekamp-Samii scoring systems, and neurological changes were analyzed by the Kaplan-Meier statistics. The mean follow-up was 20.7 ± 6.2, 21.7 ± 8.8, and 34.8 ± 19.4 months. Results: The interval after injury was longer in the PTS group, but the natural history of syringomyelia was shorter (p = 0.0004 and 0.0173, respectively). The initial symptom was usually paraesthesia (p = 0.258), and the other main symptoms were hypoesthesia (p = 0.006) and abnormal muscle strength (p = 0.004), gait (p < 0.0001), and urination (p < 0.0001). SCI associated with PTS was more severe than that associated with the CCJ (p = 0.003). The cavities in the PTS group were primarily located at the thoracolumbar level, while those in the CCJ group were located at the cervical-thoracic segment at the CCJ. The syrinx/cord ratio of the PTS group was more than 75% (p = 0.009), and the intradural adhesions tended to be more severe (p < 0.0001). However, there were no significant differences in long-term clinical efficacy or peripheral blood inflammation markers (PBIMs) except for the red blood cell (RBC) count (p = 0.042). Conclusion: PTS tends to progress faster than CCJ-related syringomyelia. Except for the RBC count, PBIMs showed no value in distinguishing the two forms of syringomyelia. The predictive value of the neutrophil-to-lymphocyte ratio for syringomyelia-related inflammation was negative except in the acute phase.

Neurological deterioration after posterior fossa decompression for adult syringomyelia: Proposal for a summarized treatment algorithm.

Background: Patients with syringomyelia who present with new neurological symptoms after posterior fossa decompression (PFD) are not uncommon. However, systematic reports on different pathologies are few in the literature. Objective: The purpose of this study was to summarize our experience for failed PFD. Methods: Between January 2015 and December 2019, 85 consecutive failed PFD patients were identified. The neurological courses were summarized with Klekamp J (KJ) or mJOA score system for all patients. Long-term results were summarized with Kaplan-Meier method. Results: Twenty-eight consecutive patients underwent FMDD (Foramen magnum and foramen of Magendie dredging) (Group I), extradural PFD and manipulation of tonsil was significantly associated with lower failure rates. Twenty patients underwent craniocervical fixation (Group II), nine underwent local spinal segment decompression (Group III), six underwent CSF diversion procedures, and one were treated for persistent pain by radiofrequency. Neuropathic pain was most significantly improved in Group I while swallowing improved in Group II within 1 year after the surgery. In the long term, late postoperative deterioration-free possibility in Group II was better than in Group I. All patients in Group III improved (P = 0.0088). Six cases of CSF diversion procedures were relieved in a short time. Pain in one patient persisted after PFD, and trial of radiofrequency failed. Conclusion: Not only does the recurrent cerebrospinal fluid flow obstruct the foramen magnum, but also spinal pathologies and craniocervical instabilities may occur. This study provides the largest summarized clinical experience that may assist surgeons with different therapeutic decisions for failed PFD.

Prognostic factors and nomogram prediction of survival probability in primary spinal cord astrocytoma patients.

OBJECTIVE: Knowledge on the management of spinal cord astrocytoma (SCA) remains scarce. Here, the authors constructed and validated a predictive nomogram, often used for individualized prognosis and evaluations, to estimate cancer-specific survival (CSS) and overall survival (OS) for patients with SCA. METHODS: Epidemiological characteristics were compared between low-grade SCA (LGSCA) and high-grade SCA (HGSCA) patients from the Surveillance, Epidemiology, and End Results (SEER) database. Risk factors for CSS and OS were determined using univariate and multivariate analyses and Kaplan-Meier curves. A nomogram was developed to individually predict the 3-, 5-, and 10-year CSS and OS rates. The clinical usefulness of the nomogram was assessed using calibration plots, the concordance index (C-index), and time-dependent receiver operating characteristic curves. RESULTS: A total of 468 LGSCA and 165 HGSCA patients were eligible for inclusion. LGSCA and HGSCA patients demonstrated differences in age, tumor extension, insurance status, adjuvant treatment, and survival. Multivariate analysis demonstrated that in the LGSCA group, tumor extension, surgery type, and adjuvant therapy were individually associated with CSS. The distance of tumor extension and WHO grade were individually associated with CSS in the HGSCA group. The prognostic variables were further demonstrated using the Kaplan-Meier method, which also suggested that adjuvant treatment provided no advantage to HGSCA patients. A nomogram was constructed, and the C-index for CSS was 0.84 by internal validation (95% CI 0.79-0.90). CONCLUSIONS: This research suggests that the distance of tumor extension, type of surgery, and adjuvant therapy are significant risk factors for CSS using multivariate analysis in the LGSCA group. Adjuvant treatment provided no advantages for CSS or OS in patients with HGSCAs. The nomogram may be clinically useful to healthcare providers.

Spinal column shortening versus revision detethering for recurrent adult tethered cord syndrome: a preliminary comparison of perioperative and clinical outcomes.

OBJECTIVE: Recurrent tethered cord syndrome (TCS), believed to result from tension on the distal portion of the spinal cord, causes a constellation of neurological symptoms. Detethering surgery has been the traditional treatment for TCS. However, in cases of recurrent TCS, there is a risk of new neurological deficits developing, and subsequent retethering is difficult to prevent. Spinal column shortening has been proposed as an alternative technique to reduce the tension on the spinal cord without incurring the morbidity of revision surgery on the spinal cord. The authors compared the perioperative outcomes and morbidity of patients who were treated with one or the other procedure. METHODS: The medical records of 16 adult patients with recurrent TCS who were treated between 2005 and 2018 were reviewed. Eight patients underwent spinal column shortening, and 8 patients underwent revision detethering surgery. Patient demographics, clinical outcomes, and perioperative factors were analyzed. The authors include a video to illustrate their technique of spinal column shortening. RESULTS: Within the spinal column shortening group, no patients experienced any complications, and all 8 patients either improved or stabilized with regard to lower-extremity and bowel and bladder function. Within the revision detethering group, 2 patients had worsening of lower-extremity strength, 3 patients had worsening of bowel and bladder function, and 1 patient had improvement in bladder function. Also, 3 patients had wound-related complications. The median estimated blood loss was 731 ml in the shortening group and 163 ml in the revision detethering group. The median operative time was 358 minutes in the shortening group and 226 minutes in the revision detethering group. CONCLUSIONS: Clinical outcomes were comparable between the groups, but none of the spinal column shortening patients experienced worsening, whereas 3 of the revision detethering patients did and also had wound-related complications. Although the operative times and blood loss were higher in the spinal column shortening group, this procedure may be an alternative to revision detethering in extremely scarred or complex wound revision cases.

Quantitative Reduction of Basilar Invagination With Atlantoaxial Dislocation by a Posterior Approach.

OBJECTIVE: This study evaluated the feasibility and efficacy of quantitative reduction and fixation to treat basilar invagination (BI) with atlantoaxial dislocation (AAD). METHODS: Posterior occipitocervical angle (POCA), occiput-C2 angle (Oc-C2A), clivusaxial angle (CAA), and C2-7 angle (C2-7A) were considered for quantitative reduction. Twelve patients with BI complicated with AAD received posterior interarticular release and individualized cage implantation to restore vertical dislocation. The POCA was adjusted using cantilever technology to further reduce the horizontal dislocation and adjust lower cervical vertebral angle. All patients received a radiological follow-up for ≥12 months. Improvements in spinal cord function were evaluated using Japanese Orthopedic Association (JOA) score. RESULTS: All the patients received successful quantitative reduction for BI-AAD, and bony fusion was achieved without spinal cord injury after surgery for 12 months. The JOA score was improved significantly to 15.2 ± 0.9 twelve months after surgery (p < 0.01). Radiological follow-up revealed that individualized cage and POCA play vital roles in quantitative correction: (1) distance of the dens above McRae's line and atlantodens interval were restored to normal level, respectively; (2) changes in Oc-C2 angle (ΔOc-C2A), C2-7 angle (ΔC2-7A), clivus-axial angle (ΔCAA), and POCA (ΔPOCA) were all caused by changes in axis tilt. Based on the changes of radiological parameter we deduced the formula for quantitative reduction by linear regression analysis: -ΔPOCA = ΔOc-C2A = -ΔC2-7A = ΔCAA. CONCLUSION: Quantitative posterior reduction by individualized cage and adjusting ΔPOCA is feasible for treating BI with AAD.

Intradural Pathology Causing Cerebrospinal Fluid Obstruction in Syringomyelia and Effectiveness of Foramen Magnum and Foramen of Magendie Dredging Treatment.

OBJECTIVE: This article discusses the procedure of foramina magnum and Magendie dredging, summarizing the pathologic changes in the intradural region of the craniocervical junction in patients with syringomyelia and the pathophysiologic mechanism of cerebrospinal fluid (CSF) circulation obstruction. METHODS: Clinical data from 50 adult patients with syringomyelia treated at Xuanwu Hospital from July 2018 to January 2019 were collected and retrospectively analyzed. All operations were performed with foramina magnum and Magendie dredging, and all intradural factors that may have induced the obstruction of CSF circulation were recorded. RESULTS: Intradural pathology was found in all patients. The pathologic changes that may have caused obstruction of the CSF circulation include tonsil occupying the foramen magnum and overlying foramen of Magendie in 88% (44/50), intertonsillar arachnoid adhesions in 36% (18/50), tonsil to medulla arachnoid adhesions in 18% (9/50), medialized tonsils in 70% (35/50), vermian branch of posterior inferior cerebellar artery in 22% (11/50), arachnoid veil in 16% (8/50), cisterna magna cyst in 4% (2/50), and tonsil to dura mater arachnoid adhesions in 8% (4/50). Mean duration of follow-up was 13.3 months. The long-term effective rate was 96.0%. Postoperative magnetic resonance imaging revealed that the size of the syringomyelia was reduced or completely resolved in 88% of patients. The mean preoperative Japanese Orthopaedic Association score was 12.9 ± 3.1, which improved to 14.7 ± 3.2 (P < 0.05) at last clinical follow-up. CONCLUSIONS: Intradural pathology that causes CSF circulation obstruction exists in many forms. Relieving the obstruction of the foramen magnum and foramen of Magendie is key to surgical treatment.

Repeat Craniocervical Decompression in Patients with a Persistent or Worsening Syrinx: A Preliminary Report and Early Results.

OBJECTIVE: Foramen magnum decompression (FMD) remains the first-line treatment for Chiari malformation type I associated with syringomyelia, although consistent approaches are not used. However, there are few reports on a persistent or recurrent syrinx or worsening neurologic symptoms after FMD. METHODS: We retrospectively reviewed medical records of patients who attended Xuanwu Hospital between January 2018 and July 2019 with persistent or recurrent syringomyelia after FMD. RESULTS: All 8 patients had syringomyelia preoperatively with a mean disease course of 43 (range, 3-120) months and underwent FMD. The presenting symptoms improved in 1 patient. There was radiologic evidence of decreased syrinx size in 1 patient. Worsening syringomyelia presented at a median of 65 (range, 7-168) months after the primary FMD. Secondary decompression was performed in all patients. A structural, pathological cause for the first FMD failure was identified in all cases at the time of the second decompression. Symptoms were resolved in all patients after repeat decompression surgery. Radiologically, 6 patients had a decrease in syringomyelia size. The level of the upper segment of the syringomyelia was higher in 7 of our revision patients, among which 6 patients had a decrease in syringomyelia size. The median follow-up duration after the secondary decompression was 11.5 (range, 6-22) months. CONCLUSIONS: Adults with persistent syringomyelia after FMD and the higher level of the upper segment of the syringomyelia often have a surgically remediable structural cause. The beneficial effect of a secondary decompression should be considered and guide the decision-making of patients with Chiari malformation type I-related syringomyelia.

Spontaneous Resolution of Syringomyelia with a 16-Year Serial Magnetic Resonance Imaging Follow-Up: A Case Report and Literature Review.

BACKGROUND: The natural course of syringomyelia is unpredictable. Only a few cases of adults with spontaneous resolution of syringomyelia associated with Chiari malformation type I (CM-I) have been reported. The timing of surgical intervention for syringomyelia remains controversial. The present report has documented a case with the longest medical history of syringomyelia reported, the associated imaging findings over 16 years, the mild symptom progression after the spontaneous resolution of syringomyelia, and a review of the relevant reported data. The natural history of our patient provides a unique view regarding the factors that might lead to the development and spontaneous resolution of syringomyelia. CASE DESCRIPTION: We present the case of a 36-year-old woman who had been monitored for 16 years for mild symptomatic CM-I and syringomyelia. After regular follow-up examinations for the initial 10 years, magnetic resonance imaging revealed partial spontaneous resolution of the syringomyelia and unchanged symptoms. However, after 6 additional years of follow-up examinations, her symptoms had mildly progressed, and the size of the syringomyelia had obviously decreased. CONCLUSIONS: The findings from our patient suggest that the natural course of mild symptomatic CM-I in adult patients will be benign and nonprogressive. Patients will commonly present with very few or mild symptoms, despite the presence of a large syrinx. It would be reasonable to observe patients with similar mild symptoms and syringomyelia. Surgery will be indicated by the type, severity, and duration of symptoms at the first clinical visit. Periodic follow-up examinations are also essential after spontaneous resolution because the pathophysiology of syringomyelia is incompletely understood and recurrence possible.