Variation of the major sulci of the occipital lobe - A morphological study

Background: The occipital lobe of cerebrum is intimately related with visual function. The detailed anatomy of this lobe is essential for the surgeons and radiologists. The aim of the present study was to identify the variation of different sulci of the occipital lobe and find the relations between them. So, this study was done to evaluate the different parameters of these sulci by studying cerebral hemispheres morphologically. Methods: Total 106 formalin fixed cadaveric brains were studied. The locations and the length (cm) of the calcarine, lunate and parieto-occipital sulcus were studied in detail. Microsoft excel software was utilized to analyze the data. Results: The calcarine sulcus in 59.43% had terminated by dividing into two rami. In only 31.13% cases calcarine sulcus met lunate sulcus after reaching the superolateral surface of the hemisphere. Lunate sulcus was of myriad shapes. Though in 49.05% of cases it was convex, in majority of brains it was “f” or “S” shaped. Different hemispheres of the same brain revealed significant variation. Conclusion: The study revealed wide variability of the sulci of the occipital lobe. For proper planning of neurosurgical procedures and radiological representation of visual functional areas, detailed knowledge on the variation of these sulci are essential. So, parameters of occipital sulci can permit safer access to deep structures and reduce operative complications.