Asimetrías en el patrón surcal del opérculo frontoparietal

Abstract

The objective of this study was to evaluate the interhemispheric variation (asymmetries) in the sulcal pattern of the frontoparietal operculum. The study of perisilvian areas anatomical variability is important for clinical and surgical neurology, since it allows to study language areas accurately contributing towards a reference frame for medical practice, aiming to achieve the least invasive procedures possible. The used sample consisted of 80 T1 brain magnetic resonance images (MRI) of healthy individuals of both sexes, aged 19-56 years. The following variables were observed in the fronto-parietal operculum of each hemisphere: number of sulci in the frontal and parietal portions of the lateral sulcus; presence of accessory sulci (triangular and diagonal sulcus); continuous or discontinuous pattern of the inferior frontal sulcus and inferior precentral sulcus; and the shape of the termination of the lateral sulcus. The sulcal anatomy of the frontoparietal operculum showed great variation both between individuals and between hemispheres. In the frontal operculum, the presence of accessory sulci were asymmetrical in most individuals, although a consistent trend towards one of the two hemispheres was not observed, and no significant differences were found in relation to sex. The same was observed in the discontinuous pattern of the inferior frontal sulcus and inferior precentral sulcus. In the parietal operculum, whose asymmetries in the accessory sulcal pattern were not studied before, a greater number of accessory sulci were found in the left hemisphere, although the difference between both hemispheres was not significant and no differences were found based on sex. The shape of the lateral sulcus termination was predominantly symmetrical. Given the important prevalence of asymmetries in the sulcal pattern of the sample and the lack of tendency towards a hemisphere, it is possible to propose a fluctuating asymmetry pattern. The accessory sulci were present with a high prevalence in the sample, which should be taken into account when distinguishing between normal variants and pathological findings in neuroimaging.