Investigation of the improvement rate regarding the herniation of cerebellar tonsils following shunting procedures in patients with chiari malformation and associated hydrocephalus

Abstract

Introduction and Aim: Chiari malformation is a congenital anomaly formed as the result of the herniation of posterior fossa structures through the foramen magnum toward the spinal canal. In this study, we aimed to present the improvement rate regarding the herniation in cerebellar tonsils following shunting procedures in patients with Chiari malformation and associated hydrocephalus.Method: We measured in mm the improvement rate regarding the herniation in cerebellar tonsils in postoperative cervical MRI images obtained following ventriculoperitoneal shunting procedures for hydrocephalus in adult patients with symptoms of Chiari malformation such as balance disorder, dizziness, numbness and loss of muscular strength at the hands who were diagnosed with Chiari malformation and hydrocephalus following cranial and cervical magnetic resonance imaging (MRI).Results: A total of fifteen adult patients in whom the cerebellar tonsillar herniation was over 5 mm and accompanied by hydrocephalus were included in our study. The measure of herniation in the patients involved in the study was between 1.11 cm and 8 mm. The amount of improvement in herniation following the shunting procedure was between 7.76 mm and 2.2 mm.Conclusion: In patients with Chiari malformation associated with hydrocephalus, cerebellar tonsillar herniation can regress to 5 mm, which is considered as physiological, and the symptoms related to Chiari malformation can disappear. When Chiari malformation is associated with hydrocephalus, the tonsillar herniation may improve, and symptoms may disappear following the ventriculoperitoneal shunting procedure for hydrocephalus without necessitating posterior decompression for Chiari-related herniation.