Sexual dimorphism and hemispheric asymmetry in the morphology of the sylvian fissure: a magnetic resonance imaging based study

The Sylvian Fissure, the first sulcus to appear during the embryological period, is considered a conventional passageway by neurosurgeons for surgeries related to insular and temporal horn tumours and aneurysm clipping. This study aimed to report the morphological types of the sylvian fissure, explore their distribution patterns among sexes and age groups, and assess the symmetry of morphology between the right and left cerebral hemispheres. A prospective cross-sectional study was performed with 520 participants who visited the Department of Radiology for brain MRI.

The participants were recruited after ethical approval was obtained from the Institutional Review Committee and after written informed consent was obtained from participants. MRI scans were assessed during the reporting of the MRI, and the categorization was performed by a senior radiologist. Statistical methods such as Pearson’s chi-square test, Bowker’s test, and Cohen’s kappa coefficient were used to assess the association and symmetry of the Sylvian fissure morphology.

The type II Sylvian fissure was found to be the most prevalent among both males and females and in both right and left hemispheres. It was also the most common in all age groups except for the > 50 years group, where type I was the most common. The assessment of symmetry reported κ = 0.879 (SE = 0.021, p