title: Anatomic characterization of prelemniscal radiations by probabilistic tractography: implications in Parkinson's disease.
abstract: To characterize the anatomical connectivity of the prelemniscal radiations (Raprl), a white matter region within the posterior subthalamic area (PSA) that is an effective neurosurgical target for treating motor symptoms of Parkinson's disease (PD). Diffusion-weighted images were acquired from twelve healthy subjects using a 3T scanner. Constrained spherical deconvolution, a method that allows the distinction of crossing fibers within a voxel, was used to compute track-density images with sufficient resolution to accurately delineate distinct PSA regions and probabilistic tractography of Raprl in both hemispheres. Raprl connectivity was reproducible across all subjects and showed fibers traversing through this region towards primary and supplementary motor cortices, the orbitofrontal cortex, ventrolateral thalamus, and the globus pallidus, cerebellum and dorsal brainstem. All brain regions reached by Raprl fibers are part of motor circuits involved in the pathophysiology of PD; while these fiber systems converge at the level of the PSA, they can be spatially segregated. Fibers of distinct and specific motor control networks are identified within Raprl. The description of this anatomical crossroad suggests that, in the future, tractography could allow deep brain stimulation or lesional therapies in white matter targets according to individual patient's symptoms.
authors.affiliation: Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México.
authors.forename: María Guadalupe
authors.initials: MG
authors.lastname: García-Gomar
authors.affiliation: Unit for Stereotactic and Functional Neurosurgery and Radiosurgery, Mexico General Hospital, Mexico City, Mexico.
authors.forename: Julian
authors.initials: J
authors.lastname: Soto-Abraham
authors.affiliation: Unit for Stereotactic and Functional Neurosurgery and Radiosurgery, Mexico General Hospital, Mexico City, Mexico.
authors.forename: Francisco
authors.initials: F
authors.lastname: Velasco-Campos
authors.affiliation: Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México. lconcha@unam.mx.
authors.forename: Luis
authors.identifier: 0000-0002-7842-3869
authors.initials: L
authors.lastname: Concha
mesh_terms: D000328:Adult; D001921:Brain / Q000033:anatomy & histology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000033:anatomy & histology; D010300:Parkinson Disease / Q000473:pathology / Q000503:physiopathology; D020531:Subthalamic Nucleus / Q000033:anatomy & histology*; D066127:White Matter / Q000033:anatomy & histology*
keywords: Constrained spherical deconvolution; Parkinson’s disease; Prelemnsical radiations; Probabilistic tractography; Track-density images