scholarly journals Clinical significance of changes in pB–C2 distance in patients with Chiari Type I malformations following posterior fossa decompression: a single-institution experience

2016 ◽  
Vol 17 (3) ◽  
pp. 336-342 ◽  
Author(s):  
Phillip A. Bonney ◽  
Adrian J. Maurer ◽  
Ahmed A. Cheema ◽  
Quyen Duong ◽  
Chad A. Glenn ◽  
...  

OBJECT The coexistence of Chiari malformation Type I (CM-I) and ventral brainstem compression (VBSC) has been well documented, but the change in VBSC after posterior fossa decompression (PFD) has undergone little investigation. In this study the authors evaluated VBSC in patients with CM-I and determined the change in VBSC after PFD, correlating changes in VBSC with clinical status and the need for further intervention. METHODS Patients who underwent PFD for CM-I by the senior author from November 2005 to January 2013 with complete radiological records were included in the analysis. The following data were obtained: objective measure of VBSC (pB–C2 distance); relationship of odontoid to Chamberlain’s, McGregor’s, McRae’s, and Wackenheim’s lines; clival length; foramen magnum diameter; and basal angle. Statistical analyses were performed using paired t-tests and a mixed-effects ANOVA model. RESULTS Thirty-one patients were included in the analysis. The mean age of the cohort was 10.0 years. There was a small but statistically significant increase in pB–C2 postoperatively (0.5 mm, p < 0.0001, mixed-effects ANOVA). Eleven patients had postoperative pB–C2 values greater than 9 mm. The mean distance from the odontoid tip to Wackenheim’s line did not change after PFD, signifying postoperative occipitocervical stability. No patients underwent transoral odontoidectomy or occipitocervical fusion. No patients experienced clinical deterioration after PFD. CONCLUSIONS The increase in pB–C2 in patients undergoing PFD may occur as a result of releasing the posterior vector on the ventral dura, allowing it to relax posteriorly. This increase appears to be well-tolerated, and a postoperative pB–C2 measurement of more than 9 mm in light of stable craniocervical metrics and a nonworsened clinical examination does not warrant further intervention.

2007 ◽  
Vol 6 (3) ◽  
pp. 216-221 ◽  
Author(s):  
Atsushi Ono ◽  
Futoshi Suetsuna ◽  
Kazumasa Ueyama ◽  
Toru Yokoyama ◽  
Shuichi Aburakawa ◽  
...  

Object The clinical characteristics of pediatric scoliosis associated with syringomyelia have been reported in previous studies, but scoliosis associated with syringomyelia in adults is rarely treated, and there is a paucity of detailed studies. In the present study of adult syringomyelia associated with Chiari malformation Type I, the authors investigated the relationships among the syrinx, scoliosis, and neurological data. Methods The population was composed of 27 patients (≥ 20 years of age) who underwent foramen magnum decompression for the treatment of syringomyelia. The patients were divided into two groups: those with scoliosis of 10° or more (Group A) and those without scoliosis (Group B). The authors assessed the length of the syrinx, duration of morbidity, and clinical status before and after surgery based on the Japanese Orthopaedic Association (JOA) Scale. There were 15 cases in Group A and 12 in Group B. The mean length of the syrinx was 12.8 vertebral bodies (VBs) in Group A and 7.2 VBs in Group B. The mean duration of morbidity was 14.2 years in Group A and 6.8 years in Group B. The mean preoperative JOA score was 10.1 in Group A and 14.4 in Group B, whereas the mean postoperative JOA scores were 11.9 and 15.8, respectively. There were significant differences between Groups A and B in length of the syrinx, duration of morbidity, and pre- and postoperative JOA scores. Conclusions In patients with syringomyelia and scoliosis the syringes spanned a greater number of VBs, the duration of morbidity was greater, neurological dysfunction was more severe, and surgical results were poorer. Scoliosis could be a predicting factor of the prognosis in patients with syringomyelia and Chiari malformation Type I.


2018 ◽  
Vol 27 (1) ◽  
pp. 71-73
Author(s):  
Lindolfo Carlos Heringer ◽  
Matheus Fernandes De Oliveira ◽  
Ulysses Oliveira De Sousa ◽  
Wanderley Cerqueira De Lima ◽  
Ricardo Vieira Botelho

Introduction. The association between hydrocephalus and Chiari malformation (CM) has not been described frequently. Ventricular dilation affects 7% to 10% of patients with CM, but the ideal choice of surgical treatment is controversial. Wereport a case of a patient with Chiari malformation and hydrocephalus with improvement in clinical symptoms and ventricular dilatation. Case Description. A 19-year-old male complaining of frontal headache when coughing, laughing and during valsalva maneuvers, associated with dizziness for 2 months. Magnetic resonance (MR) showed hydrocephalus and small posterior fossa with overcrowding of contents, characterizing Chiari malformation type I, with cerebellar tonsils protruding through magnum foramen. Patient underwent surgery with posterior fossa decompression in a semi-sitting position and removal of the arc C1.After 3 months of follow-up, headache disappeared becoming asymptomatic. Control MR showed improvement of hydrocephalus with restoration of the cisterna magna and CSF flow. Discussion. Hydrocephalus has been related to CM for a long time. In our case, we performed treatment with intradural and intra-arachnoidal approach with bilateral tonsillectomy without placing ventricular shunt. The cisterna magna was “recreated”. There was improvement of hydrocephalus with decreased Evans ratio index and symptoms disappearance. Although there is no other studies addressing such matter, in this case, the improvement suggests that the CSF compression at the foramen magnum was the cause of associated hydrocephalus with Chiari malformation. 


2015 ◽  
Vol 123 (1) ◽  
pp. 226-231 ◽  
Author(s):  
Brandon W. Smith ◽  
Jennifer Strahle ◽  
Erick Kazarian ◽  
Karin M. Muraszko ◽  
Hugh J. L. Garton ◽  
...  

OBJECT It is unclear if there is a relationship between Chiari malformation Type I (CM-I) and body mass index (BMI). The aim of this study was to identify the relationship between BMI and cerebellar tonsil position in a random sample of people. METHODS Cerebellar tonsil position in 2400 subjects from a cohort of patients undergoing MRI was measured. Three hundred patients were randomly selected from each of 8 age groups (from 0 to 80 years). A subject was then excluded if he or she had a posterior fossa mass or previous posterior fossa decompression or if height and weight information within 1 year of MRI was not recorded in the electronic medical record. RESULTS There were 1310 subjects (54.6%) with BMI records from within 1 year of the measured scan. Of these subjects, 534 (40.8%) were male and 776 (59.2%) were female. The average BMI of the group was 26.4 kg/m2, and the average tonsil position was 0.87 mm above the level of the foramen magnum. There were 46 subjects (3.5%) with a tonsil position ≥ 5 mm below the level of the foramen magnum. In the group as a whole, there was no correlation (R2 = 0.004) between BMI and cerebellar tonsil position. CONCLUSIONS In this examination of 1310 subjects undergoing MRI for any reason, there was no relationship between BMI and the level of the cerebellar tonsils or the diagnosis of CM-I on imaging.


2011 ◽  
Vol 8 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Joshua J. Chern ◽  
Amber J. Gordon ◽  
Martin M. Mortazavi ◽  
R. Shane Tubbs ◽  
W. Jerry Oakes

Object In 1998 the authors identified 5 patients with syringomyelia and no evidence of Chiari malformation Type I (CM-I). Magnetic resonance imaging of the entire neuraxis ruled out other causes of a syrinx. Ultimately, abnormal CSF flow at the foramen magnum was the suspected cause. The label “Chiari 0” was used to categorize these unique cases with no tonsillar ectopia. All of the patients underwent posterior fossa decompression and duraplasty identical to the technique used to treat patients with CM-I. Significant syrinx and symptom resolution occurred in these patients. Herein, the authors report on a follow-up study of patients with CM-0 who were derived from over 400 operative cases of pediatric CM-I decompression. Methods The authors present their 12-year experience with this group of patients. Results Fifteen patients (3.7%) were identified. At surgery, many were found to have physical barriers to CSF flow near the foramen magnum. In most of them, the syringomyelia was greatly diminished postoperatively. Conclusions The authors stress that this subgroup represents a very small cohort among patients with Chiari malformations. They emphasize that careful patient selection is critical when diagnosing CM-0. Without an obvious CM-I, other etiologies of a spinal syrinx must be conclusively ruled out. Only then can one reasonably expect to ameliorate the clinical course of these patients via posterior fossa decompression.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jian Shen ◽  
Jie Shen ◽  
Kaiyuan Huang ◽  
Yixin Wu ◽  
Jianwei Pan ◽  
...  

This study aimed to summarize the clinical features, diagnosis, and treatment of Chiari malformation type I- (CM-1-) associated syringobulbia. We performed a literature review of CM-1-associated syringobulbia in PubMed, Ovid MEDLINE, and Web of Science databases. Our concerns were the clinical features, radiologic presentations, treatment therapies, and prognoses of CM-1-associated syringobulbia. This review identified 23 articles with 53 cases. Symptoms included headache, neck pain, cranial nerve palsy, limb weakness/dysesthesia, Horner syndrome, ataxia, and respiratory disorders. The most frequently involved area was the medulla. Most of the patients also had syringomyelia. Surgical procedures performed included posterior fossa decompression, foramen magnum decompression, cervical laminectomy, duraplasty, and syringobulbic cavity shunt. Most patients experienced symptom alleviation or resolution postoperatively. A syringobulbic cavity shunt provided good results in refractory cases. Physicians should be aware of the possibility of syringobulbia in CM-1 patients, especially those with symptoms of sudden-onset brain-stem involvement. The diagnosis relies on the disorder’s specific symptomatology and magnetic resonance imaging. Our review suggests that the initial therapy should be posterior fossa decomposition with or without duraplasty. In refractory cases, additional syringobulbic cavity shunt is the preferred option.


2020 ◽  
Vol 26 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Jennifer M. Strahle ◽  
Rukayat Taiwo ◽  
Christine Averill ◽  
James Torner ◽  
Jordan I. Gewirtz ◽  
...  

OBJECTIVEIn patients with Chiari malformation type I (CM-I) and a syrinx who also have scoliosis, clinical and radiological predictors of curve regression after posterior fossa decompression are not well known. Prior reports indicate that age younger than 10 years and a curve magnitude < 35° are favorable predictors of curve regression following surgery. The aim of this study was to determine baseline radiological factors, including craniocervical junction alignment, that might predict curve stability or improvement after posterior fossa decompression.METHODSA large multicenter retrospective and prospective registry of pediatric patients with CM-I (tonsils ≥ 5 mm below the foramen magnum) and a syrinx (≥ 3 mm in width) was reviewed for clinical and radiological characteristics of CM-I, syrinx, and scoliosis (coronal curve ≥ 10°) in patients who underwent posterior fossa decompression and who also had follow-up imaging.RESULTSOf 825 patients with CM-I and a syrinx, 251 (30.4%) were noted to have scoliosis present at the time of diagnosis. Forty-one (16.3%) of these patients underwent posterior fossa decompression and had follow-up imaging to assess for scoliosis. Twenty-three patients (56%) were female, the mean age at time of CM-I decompression was 10.0 years, and the mean follow-up duration was 1.3 years. Nine patients (22%) had stable curves, 16 (39%) showed improvement (> 5°), and 16 (39%) displayed curve progression (> 5°) during the follow-up period. Younger age at the time of decompression was associated with improvement in curve magnitude; for those with curves of ≤ 35°, 17% of patients younger than 10 years of age had curve progression compared with 64% of those 10 years of age or older (p = 0.008). There was no difference by age for those with curves > 35°. Tonsil position, baseline syrinx dimensions, and change in syrinx size were not associated with the change in curve magnitude. There was no difference in progression after surgery in patients who were also treated with a brace compared to those who were not treated with a brace for scoliosis.CONCLUSIONSIn this cohort of patients with CM-I, a syrinx, and scoliosis, younger age at the time of decompression was associated with improvement in curve magnitude following surgery, especially in patients younger than 10 years of age with curves of ≤ 35°. Baseline tonsil position, syrinx dimensions, frontooccipital horn ratio, and craniocervical junction morphology were not associated with changes in curve magnitude after surgery.


2011 ◽  
Vol 21 (6) ◽  
pp. 1143-1150 ◽  
Author(s):  
Tao Wu ◽  
Zezhang Zhu ◽  
Jian Jiang ◽  
Xin Zheng ◽  
Xu Sun ◽  
...  

OBJECTIVE Posterior vault distraction osteogenesis (PVDO) is an effective tool to increase intracranial volume and expand the posterior cranial fossa. During PVDO, the authors extended osteotomy posterior to the foramen magnum to fully expand the posterior cranial fossa. The aim of this study was to investigate the efficacy of complete PVDO in posterior fossa expansion and treatment of Chiari malformation type I (CM-I) in patients with craniosynostosis. METHODS Patients with craniosynostosis who had undergone complete PVDO between January 2012 and May 2020 were reviewed retrospectively. A coronal osteotomy extending to the foramen magnum was performed and the foramen magnum was decompressed by removing its posterior rim with a 1-mm Kerrison rongeur. Four distractor devices were placed and the vector of distraction was controlled from the posterior to the inferior-posterior direction, depending on the deformity. Changes in the intracranial volume, posterior cranial fossa area, and cerebellar tonsillar descent were measured after complete PVDO by using CT and MRI. RESULTS A total of 11 patients with craniosynostosis and concurrent CM-I were included in the study. The mean age was 34.6 ± 24.0 months (continuous variables are expressed as the mean ± SD throughout). One patient had sleep apnea, which was consistent with CM-I, and another patient had a headache, which was nonspecific. The intracranial volume increased from 1179.6 ± 180.2 cm3 to 1440.6 ± 251.5 cm3 (p = 0.003; 24.5% increase compared to the preoperative volume). The posterior skull base area increased from 44.9 ± 19.3 cm2 to 72.7 ± 18.1 cm2 (p = 0.004). Cerebellar tonsillar descent decreased in all 11 patients after complete PVDO (preoperative: 10.8 ± 3.7 mm, postoperative: 2.7 ± 3.0 mm; p = 0.003). Among the 11 patients, 5 showed complete resolution of cerebellar tonsillar herniation. CONCLUSIONS Complete PVDO can more efficiently expand the posterior cranial fossa, unlike conventional methods. Moreover, it helps to relieve cerebellar tonsillar herniation. Complete PVDO is a powerful tool to increase the intracranial and posterior fossa volumes in patients with craniosynostosis and concurrent CM-I.


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