Chiari Malformation Type 1.5-related Syringomyelia

Abstract

The term, Chiari Malformations, has been used to define conditions with ectopia of cerebellar tonsils below the level of the posterior edge of the foramen magnum for several decades. There are 4 traditional types based on the degree of herniation. Since the late 1990s, a group of patients with tonsillar herniation seen in Chiari type I malformation but with the addition of an elongated brainstem and fourth ventricle have been referred as Chiari type 1.5 syndromes. There are only few reports that review their treatment options and give postoperative results for this group of patients. We report a case of 49-year-old woman with Chiari type 1.5 syndrome and reviewed the literature to determine the differences between the treatment options of Chiari type 1-related and 1.5-related syringomyelia. Syringosubarachnoidal shunting must be considered as a complementary treatment option for progressive worsened, symptomatic patients with Chiari 1.5 malformation-related syringomyelia in early stages.