Analysis Of The Posterior Fossa In Adults With The Chiari 0 Malformation

Objective:To investigate the cause with Chiari 0 malformation and elucidate the clinical significances of the measurements by using the MRI technique to the linear measurement index of the posterior fossa in adult patients with Chiari 0 malformation, as well as Chiari decompression in the treatment of the disease is likely to provide a theoretical basis for the clinical application of effective treatment.Methods:We were collected 23 patients with Chiari 0 malformation(CM 0) from January2011 to September 2015, and 23 patients with Chiari?malformation with syringomyelia(CM?-S), and 23 adults with normal MRI studies of the brain matched with CM 0patients in age and gender were used as controls. Multiple measurements were made on MRcentral sagittal plane studies,including the linear parameters and the angular parameter. Finally, the difference of measurement index of each group was compared by the method of variance analysis.A retrospective analysis of 23 cases underwent curative effect of Chiari decompression for the treatment of Chiari type 0 patients, according to the symptoms and signs of improvement and postoperative MRI changes, postoperative patients were divided into is improved significantly, and the stability and deterioration, analysis of clinical curative effect after operation.Results:1. In the CM 0 and CM?-S groups, the clivus length, the diameter of foramen magnum, the posterior cranial depth, the brainstem length were smaller than the normal group; but the length of cerebellar hemisphere was longer in the normal group(P<0.05).2. the clivus angle, the posterior occipital angle, the angle of tentorium cerebelli and occipital in the normal group were smaller than the CM 0 and CM?-S groups,but the posterior cranial angle and basis cranical angle were greater(P<0.05).3. After 1 weeks in 23 patients with symptoms improved in 19 cases, 4 cases showed no significant changes in symptoms, without the disease gets worse. 21 cases of patients with MRI after 1 weeks showed syringomyelia were reduced, and significantly reduced in 17 cases, 2 cases had no obvious change. Long term efficacy: postoperative follow-up 0.5-2 years, 19 cases were followed up, the outpatient review of MRI showed no significant changes in the spinal cord after surgery a week, no disease progression.Conclusions:The posterior cranial fossa structures is dysplasia in patients with CM 0 and CM?-S groups; the greater clivus angle, posterior cranical angle, basis cranical angle maybe relieve the cerebellar tonsillar ectopia; so the abnormal CSF flow at the foramen magnum especially at the medullary cistern may be the main factor in the emergence of CM 0. Through the Chiari decompression of Chiari 0 type syringomyelia patients may be effective, sometimes it can be properly applied to the expansion of the dural repair, fourth Ventricle exploration and other ways to achieve the purpose of full decompression.