REVIEW  NEW INSIGHTS IN STRUCTURAL AND FUNCTIONAL ANATOMY OF THE HUMAN ASSOCIATIVE PATHWAYS FOR OPERATIVE NEUROSURGERY 

Journal of Neurosurgical Sciences 2021 December;65(6):548-59

DOI: 10.23736/S0390-5616.21.05423-0

Copyright © 2021 EDIZIONI MINERVA MEDICA

language: English

The third branch of the superior longitudinal system

Maud J. LANDERS ^{1, 2}, Wouter de BAENE ², Geert J. RUTTEN ^{1, 2}, Emmanuel MANDONNET ^{3, 4, 5} ✉

¹ Department of Neurosurgery, Elisabeth-TweeSteden Hospital, Tilburg, the Netherlands; ² Department of Cognitive Neuropsychology, University of Tilburg, Tilburg, the Netherlands; ³ University of Paris, Paris, France; ⁴ Frontlab, Institut du Cerveau (ICM), CNRS UMR 7225, INSERM U1127, Paris, France; ⁵ Service of Neurosurgery, Lariboisière Hospital, Paris, France

One of the major associative fiber pathways in the brain is the superior longitudinal system. This review discusses the current knowledge gained from studies on the third branch of the superior longitudinal system (SLS) regarding its anatomy, functional role in healthy individuals, results from lesion-symptom mapping studies and intraoperative electrostimulation studies. The results of these studies clearly indicate that the third branch of the SLS is a distinct pathway, as seen both from a functional and anatomical perspective. The third branch of the SLS should be distinguished from the long segment of the arcuate fasciculus, that courses along its trajectory but seems implicated in different functions. Moreover, these studies also provide substantial evidence that the right and left third branch of the SLS have different functional roles. Finally, a hypothesis for an integrated anatomo-functional model is proposed, that describes three subcomponents of the third branch of the superior longitudinal system.

KEY WORDS: Brain; Anatomy; Physiology