title: Failure to Identify the Left Arcuate Fasciculus at Diffusion Tractography Is a Specific Marker of Language Dysfunction in Pediatric Patients with Polymicrogyria.
abstract: BACKGROUND
  Polymicrogyric cortex demonstrates interindividual variation with regard to both extent of dyslamination and functional capacity. Given the relationship between laminar structure and white matter fibers, we sought to define the relationship between polymicrogyria (PMG), intrahemispheric association pathways, and network function.
  
  
  METHODS
  Each arcuate fasciculus (AF) was categorized as present or absent. Language was characterized by a pediatric neurologist. The presence of dysplastic cortex in the expected anatomic locations of Broca's (BA) and Wernicke's areas (WA) was evaluated by two pediatric neuroradiologists blinded to DTI and language data.
  
  
  RESULTS
  16 PMG patients and 16 age/gender-matched controls were included. All normative controls had an identifiable left AF. 6/7 PMG patients with dysplastic cortex within BA and/or WA had no left AF; PMG patients without involvement of these regions had a lower frequency of absence of the left AF (p < 0.006). All patients without a left AF had some degree of language impairment. PMG patients without a left AF had a significantly greater frequency of language impairment compared to those PMG patients with a left AF (p < 0.003).
  
  
  CONCLUSIONS
  In patients with PMG (1) the presence of dysplastic cortex within WA and/or BA is associated with absence of the left AF and (2) absence of the left AF is associated with language impairment.
authors.affiliation: Department of Radiology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Paldino
authors.affiliation: Department of Radiology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Kara
authors.initials: K
authors.lastname: Hedges
authors.affiliation: Developmental Medicine Center, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Nadine
authors.initials: N
authors.lastname: Gaab
authors.affiliation: Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA.
authors.forename: Albert M
authors.initials: AM
authors.lastname: Galaburda
authors.affiliation: Departments of Radiology and Newborn Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.
authors.forename: P Ellen
authors.initials: PE
authors.lastname: Grant
mesh_terms: D000293:Adolescent; D001921:Brain / Q000473:pathology / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D056324:Diffusion Tensor Imaging; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007802:Language; D008297:Male; D009415:Nerve Net / Q000503:physiopathology*; D009434:Neural Pathways / Q000503:physiopathology*; D065706:Polymicrogyria / Q000473:pathology / Q000503:physiopathology*