Morphometric analysis of posterior fossa and craniovertebral junction in subtypes of Chiari malformation

Abstract

Objectives: Chiari malformations (CMs) are a group of disorders defined by anatomic anomalies of the cerebellum, brainstem, and craniovertebral junction (CVJ). In this study, we aimed to investigate morphometry of posterior fossa and CVJ in subtypes of CM and in control group, and to bring up a matter a correlation with demographic data and subtypes of CM. Patients and Methods: The study group included patients managed for CM between 2012 and 2016 and control group. Radiological evaluation was studied by special programs and formulas. Intracranial volumes and morphometric datas of posterior fossa and CVJ were recorded retrospectively. Results: Of the 141 patients, 91 had CM and 50 were control group participants. Mean age was 34.75. Patients were classified as CM-0 (n:10), CM-1 (n:45), CM-1.5 (n:21), CM-2 (n:15). There were statistically significance between Chiari subtypes by syringomyelia (SM) presence (p (<) 0.01), SM localization (p (<) 0.01), posterior fossa volume (PFV) (p (<) 0.01), length of clivus (LoC) and length of subocciput (LoSO) (p (<) 0.01 for both), angle between clivus and subocciput (C-SO angle) (p (<) 0.01), and clivo-dental angle (C-D angle) (p (<) 0.01). Conclusion: On morphometric comparison of CM subtypes we concluded that etiological differences lead to morphological differences. CM-2 has remarkable differences from both other subtypes and the control group.