External validation of current prediction systems of improvement after decompression surgery in Chiari malformation type I patients: can we do better?

OBJECTIVEThe Chiari Severity Index (CSI) and points-based algorithm of Thakar et al. are two prognostic tools that have been developed to predict the likelihood of improvement after suboccipital decompression in adult patients with Chiari malformation type I (CM-I). This study aimed to externally validate and critically evaluate these algorithms in the interest of guiding the development of improved prediction systems.METHODSA consecutive cohort of CM-I patients undergoing suboccipital decompression between September 2006 and September 2018 were included. The CSI and Thakar point score were computed for all patients, and associations with improvement were analyzed. The ability of both prediction systems to predict improvement as measured by different Chicago Chiari Outcome Scale (CCOS) cutoffs was assessed using receiver operating curve analysis. Post hoc correlations between the algorithms and different CCOS subcomponents were also assessed.RESULTSThe surgical cohort was composed of 149 adult CM-I patients, of whom 39 (26%) had a syrinx. Most patients experienced improvement after surgery (80% CCOS ≥ 13; 96% CCOS ≥ 11). The proportion of patients improving decreased with increasing CSI, but the results were not statistically significant (p = 0.246). No statistically significant difference in the mean Thakar point score was identified between improved and nonimproved patients using both CCOS cutoffs (p = 0.246 for a cutoff of 13 and p = 0.480 for a cutoff of 11). The CSI had a poor ability in identifying improved patients at a CCOS cutoff of 13 (area under the curve [AUC] 0.582) and 11 (AUC 0.646). The Thakar point score similarly had poor discrimination at a cutoff of 13 (AUC 0.467) and 11 (AUC 0.646). Neither algorithm had significant correlation with any of the CCOS subcomponents except for CSI and nonpain symptom improvement (coefficient = −0.273, p = 0.001).CONCLUSIONSPreviously published algorithms failed to provide prediction value with regard to clinically meaningful improvement following suboccipital decompression in adult CM-I patients. Future models and practical scoring systems are still required to improve the decision-making process.

Download Full-text

Multidimensional, patient-reported outcome after posterior fossa decompression in 79 patients with Chiari malformation type I

Surgical Neurology International ◽

10.25259/sni_377_2019 ◽

2019 ◽

Vol 10 ◽

pp. 242 ◽

Cited By ~ 1

Author(s):

Jan De Vlieger ◽

Joost Dejaegher ◽

Frank Van Calenbergh

Keyword(s):

Patient Satisfaction ◽

Chiari Malformation ◽

Pediatric Patients ◽

Patient Reported Outcome ◽

Symptom Improvement ◽

Posterior Fossa Decompression ◽

Type I ◽

Chiari Malformation Type I ◽

Important Improvement ◽

Patient Reported

Background: We studied patient-reported outcome among patients who underwent posterior fossa decompression (PFD) for Chiari malformation type I (CM-I). Methods: We interviewed patients who underwent PFD for CM-I from 1995 to 2016. Results: A total of 79 patients were interviewed. The median age at surgery was 30 years (range 5–72 years) with 27 pediatric patients. Forty-six patients had syringomyelia (36 adults and 10 pediatric patients). Fifty-four patients (68%) reported at least some improvement, 46 (58%) important improvement, 13 (16%) worsening, and 12 stabilization (15%). Any improvement as well as important improvement were significantly more often reported in the nonsyringomyelia group (85% vs. 57%, P = 0.01 and 76% vs. 46%, P = 0.01, respectively). Of the 47 patients reporting preoperative neck pain, 31 (66%) reported at least some improvement after surgery and 9 (19%) worsening after surgery. Of the 59 patients experiencing headaches before surgery, 45 (76%) reported at least some improvement after surgery and 4 (7%) worsening. Quality of life was mostly affected by pain and discomfort in all groups. Sixty-two patients (78%) were satisfied or very satisfied with the results of surgery and 8 (11%) were unsatisfied or very unsatisfied. Up to 71 patients (90%) would consent to surgery again. Conclusion: In CM-I patients, PFD offers symptom improvement in about two-thirds of patients with high patient satisfaction. Symptom improvement is significantly higher in patients without associated syringomyelia, but patient satisfaction is similar. Symptom worsening is more frequent in the adult than in the pediatric population, with similar rates of postoperative improvement and patient satisfaction.

Download Full-text

Defining the role of the condylar–C2 sagittal vertical alignment in Chiari malformation type I

Journal of Neurosurgery Pediatrics ◽

10.3171/2020.4.peds20113 ◽

2020 ◽

Vol 26 (4) ◽

pp. 439-444

Author(s):

Vijay M. Ravindra ◽

Rajiv R. Iyer ◽

Al-Wala Awad ◽

Robert J. Bollo ◽

Huirong Zhu ◽

...

Keyword(s):

Chiari Malformation ◽

Primary Outcome ◽

Group Versus ◽

Secondary Outcome ◽

Rank Test ◽

Upper Cervical Spine ◽

Type I ◽

Occipitocervical Fusion ◽

Chiari Malformation Type I ◽

Significant Difference

OBJECTIVEThe authors’ objective was to better understand the anatomical load-bearing relationship between the atlantooccipital joint and the upper cervical spine and its influence on the clinical behavior of patients with Chiari malformation type I (CM-I) and craniocervical pathology.METHODSIn a single-center prospective study of patients younger than 18 years with CM-I from 2015 through 2017 (mean age 9.91 years), the authors measured the occipital condyle–C2 sagittal vertebral alignment (C–C2SVA; defined as the position of a plumb line from the midpoint of the occiput (C0)–C1 joint relative to the posterior aspect of the C2–3 disc space), the pB–C2 (a line perpendicular to a line from the basion to the posteroinferior aspect of the C2 body on sagittal MRI), and the CXA (clivoaxial angle). Control data from 30 patients without CM-I (mean age 8.97 years) were used for comparison. The primary outcome was the need for anterior odontoid resection and/or occipitocervical fusion with or without odontoid reduction. The secondary outcome was the need for two or more Chiari-related operations.RESULTSOf the 60 consecutive patients with CM-I identified, 7 underwent anterior odontoid resection or occipitocervical fusion and 10 underwent ≥ 2 decompressive procedures. The mean C–C2SVA was greater in the overall CM-I group versus controls (3.68 vs 0.13 mm, p < 0.0001), as was the pB–C2 (7.7 vs 6.4 mm, p = 0.0092); the CXA was smaller (136° vs 148°, p < 0.0001). A C–C2SVA ≥ 5 mm was found in 35% of CM-I children and 3.3% of controls (p = 0.0006). The sensitivities and specificities for requiring ventral decompression/occipitocervical fusion were 100% and 74%, respectively, for C–C2SVA ≥ 5 mm; 71% and 94%, respectively, for CXA < 125°; and 71% and 75%, respectively, for pB–C2 ≥ 9 mm. The sensitivities and specificities for the need for ≥ 2 decompressive procedures were 60% and 70%, respectively, for C–C2SVA ≥ 5 mm; 50% and 94%, respectively, for CXA < 125°; and 60% and 76%, respectively, for pB–C2 ≥ 9 mm. The log-rank test demonstrated significant differences between C–C2SVA groups (p = 0.0007) for the primary outcome. A kappa value of 0.73 for C–C2SVA between raters indicated substantial agreement.CONCLUSIONSA novel screening measurement for craniocervical bony relationships, the C–C2SVA, is described. A significant difference in C–C2SVA between CM-I patients and controls was found. A C–C2SVA ≥ 5 mm is highly predictive of the need for occipitocervical fusion/ventral decompression in patients with CM-I. Further validation of this screening measurement is needed.

Download Full-text

Effect of symptomatic pseudomeningocele on improvement in pain, disability, and quality of life following suboccipital decompression for adult Chiari malformation Type I

Journal of Neurosurgery ◽

10.3171/2013.8.jns122106 ◽

2013 ◽

Vol 119 (5) ◽

pp. 1159-1165 ◽

Cited By ~ 14

Author(s):

Scott L. Parker ◽

Saniya S. Godil ◽

Scott L. Zuckerman ◽

Stephen K. Mendenhall ◽

Noel B. Tulipan ◽

...

Keyword(s):

Quality Of Life ◽

Chiari Malformation ◽

Type I ◽

Complication Rates ◽

Chiari Malformation Type I ◽

Long Term Outcome ◽

Pain Disability ◽

Patient Reported ◽

Suboccipital Decompression

Object Suboccipital decompression is a common procedure for patients with Chiari malformation Type I (CMI). Published studies have reported complication rates ranging from 3% to 40%, with pseudomeningocele being one of the most common complications. To date, there are no studies assessing the effect of this complication on long-term outcome. Therefore, the authors set out to assess the effect of symptomatic pseudomeningocele on patient outcomes following suboccipital decompression for CM-I. Methods The study comprised 50 adult patients with CM-I who underwent suboccipital craniectomy and C-1 laminectomy with or without duraplasty. Clinical presentation, radiological studies, operative variables, and complications were assessed for each case. Baseline and 1-year postoperative patient-reported outcomes were assessed to determine improvement in pain, disability, and quality of life. The extent of improvement was compared for patients with and without development of a postoperative symptomatic pseudomeningocele. Results A symptomatic pseudomeningocele developed postoperatively in 9 patients (18%). There was no difference with regard to clinical, radiological, or operative variables for patients with or without a postoperative pseudomeningocele. Patients without a pseudomeningocele had significant improvement in all 9 patient-reported outcome measures assessed. On the other hand, patients with pseudomeningocele only had significant improvement in headache (as measured on the Numeric Rating Scale) and headache-related disability (as measured on the Headache Disability Index) but no improvement in quality of life. Twenty-nine (71%) of 41 patients without a pseudomeningocele reported improvement in health status postoperatively compared with only 3 (33%) of 9 patients with a postoperative pseudomeningocele (p = 0.05). Conclusions Surgical management of CM-I in adults provides significant and sustained improvement in pain, disability, general health, and quality of life. Development of a postoperative symptomatic pseudomeningocele has lingering effects at 1 year, and it significantly diminishes the overall benefit of suboccipital decompression for CM-related symptoms. Further research is needed to accurately predict which patients may benefit from decompression alone without duraplasty.

Download Full-text

Time to Resolution of Symptoms After Suboccipital Decompression with Duraplasty in Children with Chiari Malformation Type I

World Neurosurgery ◽

10.1016/j.wneu.2018.06.073 ◽

2018 ◽

Vol 117 ◽

pp. e544-e551 ◽

Cited By ~ 5

Author(s):

Eveline Teresa Hidalgo ◽

Yosef Dastagirzada ◽

Cordelia Orillac ◽

Svetlana Kvint ◽

Emily North ◽

...

Keyword(s):

Chiari Malformation ◽

Type I ◽

Chiari Malformation Type I ◽

Suboccipital Decompression

Download Full-text

Odontoid process inclination in normal adults and in an adult population with Chiari malformation Type I

Journal of Neurosurgery Spine ◽

10.3171/2015.3.spine14926 ◽

2015 ◽

Vol 23 (6) ◽

pp. 701-706 ◽

Cited By ~ 17

Author(s):

David A. Besachio ◽

Ziyad Khaleel ◽

Lubdha M. Shah

Keyword(s):

Chiari Malformation ◽

Pediatric Population ◽

Adult Population ◽

Odontoid Process ◽

Normative Values ◽

Control Group ◽

Type I ◽

Chiari Malformation Type I ◽

Significant Difference ◽

The Mean

OBJECT Posterior odontoid process inclination has been demonstrated as a factor associated with Chiari malformation Type I (CM-I) in the pediatric population; however, no studies to date have examined this measurement in the adult CM-I population. The purpose of this study was to evaluate craniocervical junction (CCJ) measurements in adult CM-I versus a control group. METHODS The odontoid retroflexion, odontoid retroversion, odontoid height, posterior basion to C-2 line measured to the dural margin (pB-C2 line), posterior basion to C-2 line measured to the dorsal odontoid cortical margin (pB-C2* line), and clivus-canal angle measurements were retrospectively analyzed in adult patients with CM-I using MRI. These measurements were compared with normative values established from CT scans of the cervical spine in adults without CM-I. RESULTS A statistically significant difference was found between 55 adults with CM-I and 150 sex-matched controls (125 used for analysis) in the mean clivus-canal angle and the mean pB-C2 line. CONCLUSIONS These data suggest that there are sex-specific differences with respect to measurements at the CCJ between men and women, with women showing a more posteriorly inclined odontoid process. There were also differences between the CM-I and control groups: a more acute clivus-canal angle was associated with CM-I in the adult population. These CCJ findings could have an influence on presurgical planning.

Download Full-text

Suboccipital decompression for Chiari malformation–associated scoliosis: risk factors and time course of deformity progression

Journal of Neurosurgery Pediatrics ◽

10.3171/ped/2008/1/6/456 ◽

2008 ◽

Vol 1 (6) ◽

pp. 456-460 ◽

Cited By ~ 35

Author(s):

Frank J. Attenello ◽

Matthew J. McGirt ◽

April Atiba ◽

Muraya Gathinji ◽

Ghazala Datoo ◽

...

Keyword(s):

Cobb Angle ◽

Spinal Deformity ◽

Chiari Malformation ◽

Time Course ◽

Thoracolumbar Junction ◽

Type I ◽

Chiari Malformation Type I ◽

Severe Scoliosis ◽

Suboccipital Decompression ◽

Deformity Progression

Object Chiari malformation Type I (CM-I) is often associated with scoliosis. It remains unclear which subgroups of patients are most likely to experience progression of spinal deformity after cervicomedullary decompression. The authors' goal was to determine the time frame of curvature progression and assess which patient subgroups are at greatest risk for progression of spinal deformity after surgery. Methods The authors retrospectively reviewed the records of all pediatric patients with significant scoliosis in whom suboccipital decompression was performed to treat for CM-I during a 10-year period at a single academic institution. Clinical, radiological, and operative variables were assessed as independent factors for failure (worsening of scoliosis) by using a univariate regression analysis. Results Twenty-one children (mean age 9 ± 3 years; 4 male) underwent hindbrain decompression for CM-I–associated scoliosis and were followed for a mean of 39 months. All patients harbored a syrinx. Eight patients (38%) experienced improvement in scoliosis curvature, whereas 10 (48%) suffered a progression. Thoracolumbar junction scoliosis (p = 0.04) and failure of the syrinx to improve (p = 0.05) were associated with 5- and 4-fold respective increases in the likelihood of deformity progression. Each increasing degree of preoperative Cobb angle was associated with an 11% increase in the likelihood of scoliotic curve progression (p < 0.05). Conclusions Over one third of patients with CM-I–associated scoliosis will improve after cervicomedullary decompression alone. Cervicomedullary decompression is a good first-line option, particularly in children with concordant posterior fossa symptoms. Patients presenting with more severe scoliosis (increasing Cobb angle) or scoliosis that crosses the thoracolumbar junction may benefit from earlier orthopedic involvement and should be monitored regularly for curvature progression after cervicomedullary decompression. In cases in which there is a failure of the syrinx to show improvement after suboccipital decompression, the patients are also more likely to develop curvature progression.

Download Full-text

The impact of depression on surgical outcome in Chiari malformation type I: an assessment based on the Chicago Chiari Outcome Scale

Journal of Neurosurgery Spine ◽

10.3171/2020.2.spine2069 ◽

2020 ◽

Vol 33 (3) ◽

pp. 273-280

Author(s):

James Feghali ◽

Yuxi Chen ◽

Yangyiran Xie ◽

Christopher Chen ◽

Judy Huang

Keyword(s):

Surgical Outcome ◽

Chiari Malformation ◽

Type I ◽

Univariable Analysis ◽

Chiari Malformation Type I ◽

Depressed Patients ◽

Significant Difference ◽

Pain Symptoms ◽

The Impact

OBJECTIVEThe effect of depression on outcomes in Chiari malformation type I (CM-1) is unclear. The authors sought to determine whether depression affects outcome in a surgical cohort of CM-1 patients by using a validated outcome assessment tool, the Chicago Chiari Outcome Scale (CCOS).METHODSThe authors performed a retrospective analysis of a prospectively maintained database of 149 adult CM-1 patients undergoing suboccipital decompression with duraplasty and cranioplasty. Baseline presentation characteristics and composite as well as subcomponent CCOS scores at last follow-up were compared between depressed and nondepressed patients. Outcome comparisons included both a univariable analysis and a logistic regression model adjusting for several covariates.RESULTSThe prevalence of depression in the study cohort was 28% (41/149). Baseline demographic and imaging characteristics were similar between the 2 patient groups. Dizziness (p = 0.019) and imbalance (p = 0.015) were significantly more common among depressed patients, but clinical symptoms and severity were otherwise comparable. On univariable analysis, depressed patients were significantly less likely to experience improvement in pain symptoms (OR 0.14, 95% CI 0.03–0.61, p = 0.003) and functionality (OR 0.17, 95% CI 0.03–0.99, p = 0.049). No significant difference was identified in complications, nonpain symptom improvement, or overall composite CCOS improvement. Similar results were obtained on multivariable analysis controlling for several covariates.CONCLUSIONSDepression is independently associated with poor surgical outcome in adult CM-1 patients, namely when evaluating improvement in pain symptoms and functionality. Optimizing the management of depression preoperatively and ensuring follow-up for psychiatric comorbidity in the postoperative period may possibly lead to improved outcomes.

Download Full-text

Resolution of syndromic craniosynostosis-associated Chiari malformation Type I without suboccipital decompression after posterior cranial vault release

Journal of Neurosurgery Pediatrics ◽

10.3171/2011.11.peds11268 ◽

2012 ◽

Vol 9 (2) ◽

pp. 111-115 ◽

Cited By ~ 17

Author(s):

Michael R. Levitt ◽

Toba N. Niazi ◽

Richard A. Hopper ◽

Richard G. Ellenbogen ◽

Jeffrey G. Ojemann

Keyword(s):

Chiari Malformation ◽

Watchful Waiting ◽

Cranial Vault ◽

Type I ◽

Crouzon Syndrome ◽

Csf Flow ◽

Chiari Malformation Type I ◽

Syndromic Craniosynostosis ◽

Suboccipital Decompression

Chiari malformation Type I (CM-I) is associated with syndromic and nonsyndromic craniosynostosis in pediatric patients, and the surgical management of CM-I in such cases is controversial. Previous guidelines have recommended simultaneous cranial vault expansion and suboccipital decompression. However, spontaneous resolution of CM-I has been observed, and the combined procedure carries additional surgical risks. The authors report the case of a 6-month-old boy with Crouzon syndrome, CM-I, and a cervical syrinx who underwent posterior cranial vault release without suboccipital decompression. Imaging at the 3-month follow-up visit demonstrated complete resolution of the CM-I, improvement in CSF flow, and reduction in the size of the syrinx. This case suggests that up-front suboccipital decompression may not be necessary in patients with craniosynostosis and CM-I. A strategy of initial cranial vault release, followed by watchful waiting and radiographic surveillance, is proposed.

Download Full-text

Intraoperative ultrasonography as a guide to patient selection for duraplasty after suboccipital decompression in children with Chiari malformation Type I

Journal of Neurosurgery Pediatrics ◽

10.3171/ped/2008/2/7/052 ◽

2008 ◽

Vol 2 (1) ◽

pp. 52-57 ◽

Cited By ~ 69

Author(s):

Matthew J. McGirt ◽

Frank J. Attenello ◽

Ghazala Datoo ◽

Muraya Gathinji ◽

April Atiba ◽

...

Keyword(s):

Chiari Malformation ◽

Intraoperative Ultrasonography ◽

Type I ◽

Tonsillar Herniation ◽

Chiari Malformation Type I ◽

Lower Cranial Nerve ◽

Cerebrospinal Fluid Flow ◽

Subarachnoid Spaces ◽

Suboccipital Decompression ◽

Symptom Recurrence

Object Indications for duraplasty in treatment of Chiari malformation Type I (CM-I) remain unclear. In the present study, the authors evaluate their surgical experience to determine whether intraoperative ultrasonography is effective in the selection of patients with CM-I who can be adequately treated with craniectomy alone without duraplasty. Methods The authors reviewed the records of 256 children who underwent first-time hindbrain decompression for CM-I. Craniectomy alone (without duraplasty) was performed when intraoperative ultrasonography suggested adequate decompression of the subarachnoid spaces ventral and dorsal to the tonsils after suboccipital craniectomy alone. Duraplasty was performed if intraoperative ultrasonography demonstrated persistent dural compression of the tonsils following craniectomy. Symptom recurrence as a function of time was compared between cases of duraplasty versus suboccipital decompression alone stratified by extent of tonsillar herniation. Results Duraplasty was performed in 140 patients (55%), and suboccipital decompression alone was performed in 116 patients (45%). Patients underwent follow-up for 29 ± 15 months. Symptoms included headache in 192 patients (75%) and lower cranial nerve and brainstem dysfunction in 68 (27%). In 38 patients (15%) there was tonsillar herniation rostral to the C-1 lamina, in 195 (76%) it extended between the C-1 and C-2 lamina, and in 23 patients (9%) there was herniation caudal to the lower border of the C-2 lamina. In children with tonsillar herniation caudal to C-1, ultrasonography-guided suboccipital decompression alone was associated with a 2-fold increase in the risk of symptom recurrence compared with those who also underwent duraplasty (p = 0.01). In children with tonsillar herniation rostral to C-1, outcome was equivalent between suboccipital decompression alone and duraplasty (p = 0.41). Conclusions In the setting of moderate-to-severe tonsillar CM-I, intraoperative ultrasonography demonstrating decompression of the subarachnoid spaces ventral and dorsal to the tonsils may not effectively select patients in whom bone decompression alone is sufficient. Duraplasty may be warranted in cases of tonsillar herniation that extends below the C-1 lamina regardless of intraoperative ultrasonography findings. More objective cerebrospinal fluid flow or volumetric measures may be needed intraoperatively to guide duraplasty in patients with more pronounced tonsillar herniation.

Download Full-text