A Critical Update of the Classification of Chiari and Chiari-like Malformations

Chiari malformations are a group of craniovertebral junction anomalies characterized by the herniation cerebellar tonsils below foramen magnum, often accompanied brainstem descent. The existing classification systems for have expanded from original four categories to nine, leading debates about need more descriptive and etiopathogenic terminology. This review aims examine various approaches employed proposes simplified scheme differentiate between different types tonsillar herniations. Furthermore, it explores most appropriate terminology acquired other secondary Chiari-like malformations. Recent advances in magnetic resonance imaging (MRI) revealed higher prevalence incidence malformation Type 1 (CM1) identified similar herniations individuals unrelated classic phenotypes described Chiari. As we reassess classifications, becomes crucial establish that accurately reflects diverse presentations underlying causes these conditions. paper contributes ongoing discussion offering insights into evolving understanding proposing system enhance diagnosis management.