Medial cerebral sulci variability for surgical corridors and MRI interpretation: a PRISMA-ScR scoping review of cadaveric evidence

Background: Medial sulci are key intraoperative landmarks and radiologic boundaries that determine safe interhemispheric approaches and accurate MRI interpretation - cingulate, paracingulate, calcarine, parieto-occipital, callosal, Rostral, supra-rostral and subparietal sulci – are the principal surgical corridors and radiologic boundaries on the medial surface. These structures serve as essential neuroanatomical landmarks and surgical corridors in microneurosurgical procedures, yet they exhibit considerable morphological variability. This scoping review consolidates cadaveric morphology and morphometry to define reliable vs variable medial sulcal features that guide surgical corridors and radiologic localization. Methods: Methods followed JBI and PRISMA‑ScR; protocol preregistered (OSF: https://osf.io/9c5av); databases searched (PubMed/MEDLINE, Embase, Scopus, Google Scholar); dual independent screening and data charting; details in Supplement. A comprehensive literature search identified 4,440 records, of which 60 duplicates were removed. Screening of titles and abstracts excluded 3911 records, leaving 469 for full-text review. After applying eligibility criteria, eight cadaveric studies were included. Data were extracted on sample characteristics, morphological classification, and quantitative morphometry for the medial sulci. Findings were synthesized narratively and tabulated by sulcus type. Results: Across 422 hemispheres, the cingulate sulcus was consistent, while the paracingulate sulcus was variable; we map sulcal configurations to interhemispheric approach planning and MRI identification cues. The cingulate sulcus was consistently present in all examined specimens, whereas the paracingulate sulcus displayed marked variability. The calcarine sulcus demonstrated relatively stable morphometry, with mean anterior and posterior segment lengths ranging from 2.3 to 3.5 cm, yet exhibited variable bifurcation patterns and lunate sulcus connections. The parieto-occipital sulcus was a reliable boundary between the cuneus and precuneus, with mean lengths around 4.0 cm. The subparietal sulcus was described less frequently, highlighting a gap in detailed morphometric literature. Conclusion: Cadaveric evidence confirms both consistent and highly variable features in the medial cerebral sulci. Recommendations specify stable landmarks vs variable patterns for intraoperative navigation and radiologic localization to reduce misidentification risk. The paucity of detailed morphometric descriptions for certain sulci, especially the subparietal, callosal, rostral and supra-rostral sulcus, underscores the need for further targeted anatomical research.