Craniometric Analysis of Skullbase With Magnetic Resonance Imaging in Patients With Chiari Malformation.

Basilar invagination, Platibasi, increased tentorium angle, and posterior fossa hypoplasia are the anomalies associated with Chiari malformation. When Chiari is symptomatic; tonsillary ectopenia appears to be a definitive criterion for diagnosis and treatment, the detection of additional anomaly may alter the surgical outcome. The aim of this study is to investigate the relationship between tonsillar ectopia and other anomalies.The authors retrospectively reviewed 31 cases which had Chiari Malformation at our Hospital. There were 8 men (25.8%) and 23 female (74.2%). Average age of the samples is 37.93 ± 12.93 years. Seventeen patients (54.8%) had tonsillar ectopia 0 to 5 mm, 14 patients had tonsillar ectopia over 5 mm. Seven patients had syrinx (22.6%), 2 patients had mild hydrocephalus (6.5%). Six patients had surgery for the treatment. The mean length of the clivus was 39.3 mm, supraoksiput length was 40.4 mm, cerebellar hemisphere length was 61.08 mm, Mc Rae line was 33.14 mm, Twinning Line was 79.4mm, and Tentorium-Twinning line angle was 40.35°. There was no significant difference between Tonsillar ectopia, syrinks, and hydrocephalus. Basilar invagination had relationship between platibasi (6 patients had platibasi according to 2 mm criteria, 2 patients had platibasi according to 5 mm criteria (P < 0.05). Patients with syrinx had relationship between Chamberlain line (P < 0.05).In the authors' study, although there was no statistically significant difference between the tonsillary ectopia and the criteria of these anomalies, the relationship between basilar invagination and platibasi was significant.