Are Chiari Malformation and Basilar Invagination Associated with Jugular Foramen Stenosis?

Objective: We compared the diameter of the jugular foramen (JF) between normal individuals and those with a diagnosis of craniovertebral junction abnormalities, such as Chiari malformation type I (CMI) and/or basilar invagination (BI).

Methods: This cross-sectional analytical study measured the diameter of the right and left JF on magnetic resonance imaging scans of patients divided into 4 groups: 68 with combined CMI and BI (CMI+BI), 42 with isolated BI, 45 with isolated CMI, and 102 control cases. The t test determined sex differences, and univariate analysis of variance with Tukey's post hoc test assessed JF differences between groups.

Anatomical Implications of Chiari I and Basilar Invagination (Type B) in the IV Ventricle and Cisterna Magna.

Objective: To analyze the anatomical changes of the IV ventricle and cisterna magna in the Chiari malformation I (CMI) and basilar invagination (type B).

Methods: This is a controlled study with 161 exams of magnetic resonance imaging (MRI) of adults grouped into control (n = 37), basilar invagination (BI; n = 31), Chiari malformation I (CMI; n = 37), and CMI+BI (n = 56). The MRIs were analyzed using the visualization software Osirix (Pixmeo, Bernex, Geneva, version 3.