Morphological and morphometric study of insular cortex in human cadaveric brains
Introduction and Aim: The insular cortex is hidden 5th lobe of brain with variable gross anatomical patterns. Insula is situated in operculoinsular compartment of sylvian cistern.
Materials and Methods: 58 human formalin fixed cerebral hemispheres were studied for the gyri and sulci variations of insular cortex and their lengths were recorded using digital vernier caliper. This study was done in department of Anatomy, Gandhi medical college Bhopal.
Result: The morphological normal and variable pattern, discontinuous sulci and joined gyri were observed. Out of the (85/406) 21% variable pattern we observed (44/406) 10.3% Bifid, (31/406) 7.63%, Hypoplastic Gyri and (10/406) 2.46%Trifid. The Bifid pattern was most commonly seen in Anterior Short Gyrus18 /44 (41%). The Hypoplastic pattern was most commonly seen in Middle Short Gyri 18/31 (58%). There was presence of Transverse Gyri in 13/58 (22.41%) and Accessory gyri in 39/58 (65.51%) cerebral hemispheres. Transverse gyrus & Accessory gyrus both were absent in 19/58 (32.76%) cerebral hemispheres in insular cortex. Total number of gyri in every insula and Mean lengths of gyri were Anterior short=24.54mm, Middle short=25.04, Posterior short=34.08mm, Anterior long=36.87mm, Posterior long=37.1mm measured. The Mean lengths of all insular sulci were Central Insular=35.3mm, Superior Periinsular=52.48mm, Anterior Periinsular=24.5mm, Inferior Periinsular=26.4mm, Posterior Periinsular=12.81mm measured.
Conclusion: Variation in morphological pattern of gyri are Bifid, Trifid and Hypoplastic. The Transverse and Accessory gyri were present in anterior lobule, but not observed in each insula. There was variation in number of gyri because of presence of transverse and accessory gyrus. Total number of gyri are more in anterior lobule so it is larger than Posterior lobule. The gyri of anterior lobule are shorter than gyri of Posterior lobule. Such morphological features and variations are important for surgeries.
Keywords: Morphology, Morphometric, Insular cortex gyri and sulci.