Anatomical Variations in the Pseudosylvian Fissure Morphology of Brachy-, Dolicho-, and Mesaticephalic Dogs

The purpose of the study is the following: (1) to anatomically characterize the right and the left pseudosylvian fissure (Psf) morphology; (2) to determine Psf variations between both hemispheres and between the three considered groups; and (3) to understand how these variations may influence brain surgery for dogs. Also we sought to determine whether there are any potential differences between brachy- (B), dolicho- (D), and mesaticephalic (M) dogs. The present study considered 138 brain hemispheres (N=138) from 69 adult dog cadavers and used bregma craniometric point (b- the junction of coronal and sagittal cranial vault sutures) to characterize the Psf location on the superolateral brain surface. For statistical analysis, P values <0.05 were considered significant. The Psf was easily identified in all specimens at both hemispheres. Statistically significant differences for Psf width were registered between the groups, presenting M as the narrowest Psf regions. Fissure body length can be sorted in ascending order as D<M<B in both hemispheres, with the left Psf bigger than the right for all considered skulls. The greatest difference was registered in the B group with the left Psf 25.0% bigger than the right. Bregma has proved to be useful to appoint Psf location as more superior or inferior in the encephalic lateral surface, exhibiting in all groups the left Psf a superior position. For the groups the most inferior location was registered in M and the most superior in D. Understanding the Psf morphology and anatomical variations may provide important information to ensure safer intracranial procedures. Anat Rec, 298:1255-1260, 2015. (c) 2015 Wiley Periodicals, Inc.