Sella Volume and Posterior Fossa Morphometric Measurements in Chiari Type 1

To retrospectively evaluate the relationships between morphometric measurements in craniovertebral junction, and the possible genetic basis of the disease in Chiari 1 malformation patients undergoing surgical treatment.

We included patients who underwent surgical treatment for Chiari 1 malformation with unknown etiology between 2013-2018 in the Neuosurgery Clinic of Eskişehir Osmangazi University. Morphometric and volumetric measurements of the posterior fossa from cranial and cervical radiological imagings of patients with Chiari 1 malformation were performed by a single experienced observer. The results were independently reviewed by two experienced observers who supervised the process and verified the calculations.

It was observed that basal angle was greater in the group of patients with Chiari 1 malformation (125.29° ± 9.522° Vs. 112.33° ± 9.09°), and a significant difference was observed (p=0.000). In patient group, it was also found that the basion-dens distance (3.51 mm ± 1.695mm Vs. 5.27 ± 1.695 mm) (p=0.000), and cerebellar hemispher height were shorter (58.47 ± 5.143 mm Vs. 52.05 ± 5,008 mm) (p=0.000). Tentorium angle was greater in the patient group (97.95° ± 11.321° vs. 87.79° ± 9.891°) (p=0.034). In patient group, dens height was found to be longer (13.9 ± 2.46 mm vs. 14.79 ± 1.631mm) (p=0.041). Sella volume was found to be smaller (41.4 mm3 Vs. 53.3 mm3) in the patient group compared to the control group (p=0.034), and foramen magnum plane was larger (64.6° vs. 31.1°) (p=0.000).

It is concluded that many parameters including BA, FMP, BDD, CHH, TA, DH, and cellar volume are abnormal, suggesting the need for focussing to the hormonal metabolism - related synchondral changes.