title: Probabilistic fiber tracking of the language and motor white matter pathways of the supplementary motor area (SMA) in patients with brain tumors.
abstract: OBJECTIVE
  Accurate localization of anatomically and functionally separate SMA tracts is important to improve planning prior to neurosurgery. Using fMRI and probabilistic DTI techniques, we assessed the connectivity between the frontal language area (Broca's area) and the rostral pre-SMA (language SMA) and caudal SMA proper (motor SMA).
  
  
  METHODS
  Twenty brain tumor patients completed motor and language fMRI paradigms and DTI. Peaks of functional activity in the language SMA, motor SMA and Broca's area were used to define seed regions for probabilistic tractography.
  
  
  RESULTS
  fMRI and probabilistic tractography identified separate and unique pathways connecting the SMA to Broca's area - the language SMA pathway and the motor SMA pathway. For all subjects, the language SMA pathway had a larger number of voxels (P<0.0001) and higher connectivity (P<0.0001) to Broca's area than did the motor SMA pathway. In each patient, the number of voxels was greater in the language and motor SMA pathways than in background pathways (P<0.0001). No differences were found between patients with ipsilateral and those with contralateral tumors for either the language SMA pathway (degree of connectivity: P<0.36; number of voxels: 0.35) or the motor SMA pathway (degree of connectivity, P<0.28; number of voxels, P<0.74).
  
  
  CONCLUSIONS
  Probabilistic tractography can identify unique white matter tracts that connect language SMA and motor SMA to Broca's area. The language SMA is more significantly connected to Broca's area than is the motor subdivision of the SMA proper.
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275, York avenue, New York, 10065 NY, USA.
authors.forename: Mehrnaz
authors.initials: M
authors.lastname: Jenabi
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275, York avenue, New York, 10065 NY, USA; Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275, York avenue, New York, 10065 NY, USA.
authors.forename: Kyung K
authors.initials: KK
authors.lastname: Peck
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275, York avenue, New York, 10065 NY, USA; Brain Tumor Center, Memorial Sloan-Kettering Cancer Center, 1275, York avenue, New York, 10065 NY, USA; Department of Radiology, Weill Medical College of Cornell University, New York, 10065 NY, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Young
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275, York avenue, New York, 10065 NY, USA.
authors.forename: Nicole
authors.initials: N
authors.lastname: Brennan
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275, York avenue, New York, 10065 NY, USA; Brain Tumor Center, Memorial Sloan-Kettering Cancer Center, 1275, York avenue, New York, 10065 NY, USA; Department of Radiology, Weill Medical College of Cornell University, New York, 10065 NY, USA. Electronic address: holodnya@mskcc.org.
authors.forename: Andrei I
authors.initials: AI
authors.lastname: Holodny
mesh_terms: D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000473:pathology* / Q000503:physiopathology; D065711:Broca Area / Q000473:pathology* / Q000503:physiopathology; D063132:Connectome / Q000379:methods; D003627:Data Interpretation, Statistical; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007802:Language; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000473:pathology* / Q000503:physiopathology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D066127:White Matter / Q000473:pathology* / Q000503:physiopathology
keywords: Brain tumor; DTI; FMRI; Probabilistic fiber tracking; SMA