title: Middle longitudinal fasciculus delineation within language pathways: a diffusion tensor imaging study in human.
abstract: BACKGROUND
  The existence in the human brain of the middle longitudinal fasciculus (MdLF), initially described in the macaque monkey, is supported by diffusion tensor imaging studies. In the present work, we aim (1) to confirm that this fascicle is found constantly in control subjects with the use of DTI techniques and (2) to delineate the MdLF from the other fiber bundles that constitute the language pathways.
  
  
  METHODS
  Tractography was realized in four right-handed healthy volunteers for the arcuate fascicle, uncinate fascicle, inferior fronto-occipital fascicle, inferior longitudinal fascicle and the middle longitudinal fascicle. The fiber tracts were characterized for their size, mean fractional anisotropy (FA), for their length, number of streamlines, and lateralization indices were calculated.
  
  
  RESULTS
  The MdLF is found constantly and it is clearly delineated from the other fascicles that constitute the language pathways, especially the ventral pathway. It runs within the superior temporal gyrus white matter from the temporal pole, then it extends caudally in the upper part of the sagittal stratum and the posterior part of the corona radiata, to reach the inferior parietal lobule (angular gyrus). We found a leftward asymmetry for all fiber tracts when considering the mean FA.
  
  
  CONCLUSIONS
  Using DTI methods, we confirm that the MdLF connects the angular gyrus and the superior temporal gyrus. On the basis of these findings, the role of the MdLF is discussed.
  
  
  CONCLUSIONS
  The middle longitudinal fasciculus, connects the angular gyrus and the superior temporal gyrus and its course can be systematically differenciated from those of other fascicles composing both ventral and dorsal routes (IFOF, IFL, AF and UF).
authors.affiliation: Department of Neuroradiology, University Hospital Center, Gui de Chauliac Hospital, Montpellier, France. nicolasdechampfleur@orange.fr
authors.forename: Nicolas
authors.initials: N
authors.lastname: Menjot de Champfleur
authors.forename: Igor
authors.initials: I
authors.lastname: Lima Maldonado
authors.forename: Sylvie
authors.initials: S
authors.lastname: Moritz-Gasser
authors.forename: Paolo
authors.initials: P
authors.lastname: Machi
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Le Bars
authors.forename: Alain
authors.initials: A
authors.lastname: Bonafé
authors.forename: Hugues
authors.initials: H
authors.lastname: Duffau
mesh_terms: D000328:Adult; D001933:Brain Stem / Q000033:anatomy & histology*; D003391:Cranial Nerves / Q000033:anatomy & histology*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007802:Language; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000648:ultrastructure*; D009434:Neural Pathways / Q000033:anatomy & histology; D055815:Young Adult