Structural connectivity standard of the human sensory-motor cortex

In the 19th century, Gratiolet created the term plis de passage, which was mapped by the neurosurgeon Jean Regis to describe gyri that were interconnected and anatomically covered by main sulci. Besides, Cunningham characterized the plis de passage, which binds the precentral gyrus, associated to the hand´s primary motor area, and the postcentral gyrus, associated to the hand´s somatosensory area, having become a subject of interest with the advent of imaging tests. This is a descriptive and prospective study which aims to understand the central lobe´s anatomy regarding its morphometry, connectivity patterns, syntopy and presence of fronto-parietal plis de passage, using human cadavers. We analyzed 33 brains with intact cerebral hemispheres looking for the presence of plis de passage in the upper, middle and lower thirds of the right and left hemispheres. In addition, we measured the distance between the plis de passage of the upper and middle third, middle and lower, upper and lower thirds, when present. Results showed that in the upper third, the plis de passage was present in all pieces analyzed from both brain hemispheres. In the middle third, 48% did not have the structure in both hemispheres and there was a predominance in the left hemisphere with 24% and a minority in the right hemisphere, with 6%. Regarding the lower third, 88% had plis de passage in both hemispheres. Another finding was that there is a constancy between the distance values when comparing the right and left sides of the brain. It was also found that there was no significant variation in the values between the distances of the plis de passage measured. Thus, the analysis of the results may be an essential factor for the topographic neuronal diagnosis, for the interventions of patients affected by cerebrovascular diseases and to assist in the interpretation of neuroimaging alongside the neurological patient's clinic.