Anatomical Variability of Parameters of the Third and Fourth Ventricle in Relation to the Shape of the Skull
Authors: Zhuravlova Iuliia 
Published: April 2020

The study objective: to identify the variability of the parameters of the third and fourth ventricles depending on the shape of the skull.

Methods

A collection of 220 computed tomography (CT) scans of the head were used for the study (103 males (46,8%) and 117 females (53,2%)). The mean age of participants was 48.6 years.

The subjects were separated into three groups ‐ brachycranial, mesocranial, and dolichocranial ‐ based on the cranial index (CI= skull width/skull length*100).

The parameters of the third and fourth ventricles were identified as the next step of the study. The height of the third ventricle was measured as a greatest vertical distance between its floor and the roof in its antero‐posterior extent. The length (antero‐posterior diameter) of the ventricle was measured from lamina terminalis to the posterior commissure. The transverse diameter was measured between two thalami below the level of interthalamic connexus.

The height of the fourth ventricle was assessed between the point of entry on the level of the lower opening of the cerebral aqueduct and the point of the upper end of the central medullary canal. The antero‐posterior diameter was measured in the widest portion of the ventricle between the posterior surface of the pons and cerebellum, on the level between the superior and inferior medullary vela. The transverse diameter was assessed on the level of the middle cerebellar peduncles. The data were analyzed with use of the SPSS package 24.0.

Results

The comparison of the morphometric parameters of the third ventricle in all three craniotype groups have shown the prevalence of the anteroposterior diameter (length) of the third ventricle in the dolichocranial individuals (2.31 ± 0.22 cm). The other two groups had lesser numbers of this diameter, with 2.28 ± 0.39 cm in the mesocranial and 2.17 ± 0.37 cm in brachycranial groups.

The height of the third ventricle was also the greatest in the dolichocranial individuals (2.27 ± 0.23 cm), smaller in the mesocranial group (2.11 ± 0.34 cm), and the least ‐ in the brachycranial group (2.06 ± 0.34 cm).

The width of the third ventricle was greater in brachycranial individuals (0.55 ± 0.21 cm), a little smaller in mesocranial individuals (0.53 ± 0.25), and the least numbers were identified in the dolichocranial group (0.49 ± 0.20 cm).

The largest anteroposterior diameter of the fourth ventricle was detected in the dolichocranial individuals – 1.11 ± 0.22 cm, for the mesocranial individuals it was 1.08 ± 0.27 cm, and the brachycranial individuals had the smallest anteroposterior diameter 1.07 ± 0.21 cm.

The largest width of the fourth ventricle belonged to the brachycranial individuals – 1.32 ± 0.19 cm, and the smallest transverse diameter was indicated in dolichocranial individuals – 1.28 ± 0.18 cm. The height of the fourth ventricle was the biggest in the dolichocranial individuals – 2.92 ± 0.28 cm, and the least was identified in the brachycranial individuals – 2.80 ± 0.31 cm.

Conclusions

We have identified that significant statistic difference of the morphometric parameters of the third and fourth ventricles of the brain exists between the groups of dolichocranial, mesocranial and dolichocranial individuals.