Abstract
Objective. The aim of this study was to determine the posterior cranial fossa volume, cerebellar volume, and herniated tonsillar volume in patients with chiari type I malformation and control subjects using stereological methods. Material and Methods. These volumes were estimated retrospectively using the Cavalieri principle as a point-counting technique. We used magnetic resonance images taken from 25 control subjects and 30 patients with chiari type I malformation. Results. The posterior cranial fossa volume in patients with chiari type I malformation was significantly smaller than the volume in the control subjects (P < 0.05). In the chiari type I malformation group, the cerebellar volume was smaller than the control group, but this difference was not statistically significant (P > 0.05). In the chiari type I malformation group, the ratio of cerebellar volume to posterior cranial fossa volume was higher than in the control group. We also found a positive correlation between the posterior cranial fossa volume and cerebellar volume for each of the groups (r = 0.865, P < 0.001). The mean (±SD) herniated tonsillar volume and length were 0.89 ± 0.50 cm3 and 9.63 ± 3.37 mm in the chiari type I malformation group, respectively. Conclusion. This study has shown that posterior cranial fossa and cerebellum volumes can be measured by stereological methods, and the ratio of these measurements can contribute to the evaluation of chiari type I malformation cases.
Highlights
The chiari malformations generally describe increasing degrees of hindbrain herniation through the foramen magnum
While there were no significant differences for age and cerebellar volume (CV) to posterior cranial fossa volume (PCFV) ratio (P < 0.05), a significant difference was found for PCFV and CV between genders (P > 0.05; Table 2)
This study has shown that there are statically significant differences in the posterior cranial fossa volumes between Chiari type I malformation (CMI) patients and control subjects
Summary
The chiari malformations generally describe increasing degrees of hindbrain herniation through the foramen magnum. Chiari type I malformation (CMI) is defined as a herniation of the cerebellar tonsils of at least 5 mm or more through the foramen magnum. Syringomyelia is associated with this condition in 50–75% of cases [1, 2]. The etiology of CMI is unclear and may be multifactorial. It is believed to be congenital, even though those who have it do not usually have symptoms until early childhood or adolescence [3, 4]. Some conditions under which the herniation of the cerebellar tonsils occurs include hydrocephalus and intracranial mass. A generally decreased volume of the posterior cranial fossa is thought to be one of the predisposing factors in some cases [5, 6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
