title: Direct optic nerve pulvinar connections defined by diffusion MR tractography in humans: implications for photophobia.
abstract: The pathway that underlies exacerbation of migraine headache by light has not been elucidated in the human brain but has recently been reported in a rodent model. We employ diffusion weighted imaging and probabilistic tractography to map connectivity of direct pathways from the optic nerve to the pulvinar implicated with whole-body allodynia during migraine. Nine healthy subjects were recruited to the study and underwent scanning on a 3T magnet. We were able to define well-known image-forming (optic nerve -> lateral geniculate -> visual cortex) as well as a less known nonimage forming visual pathway from the optic chiasm to the pulvinar, and from the pulvinar to several associative cortical brain regions. Such pathway may allow photic signals to converge on a thalamic region we described recently to be selectively activated during migraine headache. Consistent with physiological and anatomical studies in rats, the data provide an anatomical substrate for exacerbation of migraine headache by light in the human.
authors.affiliation: PAIN Group, Brain Imaging Center, McLean Hospital, Harvard Medical School, Belmont, MA 02478, USA.
authors.forename: Nasim
authors.initials: N
authors.lastname: Maleki
authors.forename: Lino
authors.initials: L
authors.lastname: Becerra
authors.forename: Jaymin
authors.initials: J
authors.lastname: Upadhyay
authors.forename: Rami
authors.initials: R
authors.lastname: Burstein
authors.forename: David
authors.initials: D
authors.lastname: Borsook
mesh_terms: D000328:Adult; D001931:Brain Mapping; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D009900:Optic Nerve / Q000502:physiology*; D020795:Photophobia / Q000503:physiopathology; D020649:Pulvinar / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology*