The sulci of the lateral superior parietal lobule: anatomical overview and nomenclatural consideration.

Discrepancies in the terminology describing sulcal structures within the lateral superior parietal lobule prompted our comprehensive investigation to clarify their morphology and nomenclature. We reviewed literature from the 19th century to the present, focusing on the intraparietal sulcus, interparietal sulcus, superior parietal sulcus, transverse parietal sulcus, paroccipital sulcus, and transverse occipital sulcus. Additionally, we analyzed neuroimaging data from 40 healthy young adults and two cadavers. Our investigation revealed that the original term intraparietal sulcus, introduced by Sir Turner, described a complex structure comprising the inferior segment of the postcentral sulcus, a horizontally extending component into the occipital lobe, and the transverse occipital sulcus. We also found that the superior parietal sulcus is often synonymous with transverse parietal sulcus, the sulcus of Brissaud is an eponym that shall describe the paroccipital sulcus's dorsal parietal ramus, and the transverse occipital sulcus is the combination of the occipital rami of the paroccipital sulcus. Additionally, we identified an unnamed transverse segment of the intraparietal sulcus, the intraparietal sulcus-transverse. Based on these observations, we consider that the sulci of the lateral superior parietal lobule primarily include the intraparietal sulcus, with longitudinal and transverse segments, the transverse parietal sulcus of Brissaud, and the paroccipital sulcus of Wilder.