title: Left frontal glioma induces functional connectivity changes in syntax-related networks.
abstract: BACKGROUND
  A glioma leads to a global loss of functional connectivity among multiple regions. However, the relationships between performance/activation changes and functional connectivity remain unclear. Our previous studies (Brain 137:1193-1212; Brain Lang 110:71-80) have shown that a glioma in the left lateral premotor cortex or the opercular/triangular parts of the left inferior frontal gyrus causes agrammatic comprehension accompanied by abnormal activations in 14 syntax-related regions. We have also confirmed that a glioma in the other left frontal regions does not affect task performances and activation patterns.
  
  
  RESULTS
  By a partial correlation method for the time-series functional magnetic resonance imaging data, we analyzed the functional connectivity in 21 patients with a left frontal glioma. We observed that almost all of the functional connectivity exhibited chaotic changes in the agrammatic patients. In contrast, some functional connectivity was preserved in an orderly manner in the patients who showed normal performances and activation patterns. More specifically, these latter patients showed normal connectivity between the left fronto-parietal regions, as well as normal connectivity between the left triangular and orbital parts of the left inferior frontal gyrus.
  
  
  CONCLUSIONS
  Our results indicate that these pathways are most crucial among the syntax-related networks. Both data from the activation patterns and functional connectivity, which are different in temporal domains, should thus be combined to assess any behavioral deficits associated with brain abnormalities.
authors.affiliation: Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902 Japan ; Division of Neurology, Department of Internal Medicine, Showa University Northern Yokohama Hospital, 35-1 Chigasaki-chuo, Tsuzuki-ku, Yokohama, Kanagawa, 224-8503 Japan ; CREST, Japan Science and Technology Agency, 7 Gobancho, Chiyoda-ku, Tokyo, 102-0076 Japan.
authors.forename: Ryuta
authors.initials: R
authors.lastname: Kinno
authors.affiliation: Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902 Japan ; CREST, Japan Science and Technology Agency, 7 Gobancho, Chiyoda-ku, Tokyo, 102-0076 Japan.
authors.forename: Shinri
authors.initials: S
authors.lastname: Ohta
authors.affiliation: CREST, Japan Science and Technology Agency, 7 Gobancho, Chiyoda-ku, Tokyo, 102-0076 Japan ; Department of Neurosurgery, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666 Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Muragaki
authors.affiliation: CREST, Japan Science and Technology Agency, 7 Gobancho, Chiyoda-ku, Tokyo, 102-0076 Japan ; Department of Neurosurgery, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666 Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Maruyama
authors.affiliation: Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902 Japan ; CREST, Japan Science and Technology Agency, 7 Gobancho, Chiyoda-ku, Tokyo, 102-0076 Japan.
authors.forename: Kuniyoshi L
authors.initials: KL
authors.lastname: Sakai
keywords: Agrammatic comprehension; Frontal regions; Functional MRI; Functional connectivity; Glioma; Neural network