title: Cerebral diffusion tensor MR tractography in tuberous sclerosis complex: correlation with neurologic severity and tract-based spatial statistical analysis.
abstract: OBJECTIVE
  The neurologic significance of residual cerebral white matter tracts, identified on diffusion tensor tractography, has not been well studied in tuberous sclerosis complex. We aimed to correlate the quantity of reconstructed white matter tracts with the degree of neurologic impairment of subjects with the use of DTI and determined differences in white matter integrity between patients with tuberous sclerosis complex and controls with the use of voxelwise analysis.
  
  
  METHODS
  In this case-control study, 16 patients with tuberous sclerosis complex and 12 control subjects underwent DTI. Major white matter tracts, comprising bilateral PF and CF, were reconstructed and assessed for quantity, represented by NOP and NOF. A neurologic severity score, based on the presence of developmental disability, seizure, autism, and other neuropsychiatric disorders, was calculated for each subject. We then correlated this score with white matter quantity. Voxelwise tract-based spatial statistics was used to determine differences in FA, axial, and radial diffusivity values between the tuberous sclerosis complex group and the control subjects.
  
  
  RESULTS
  NOP and NOF of CF, bilateral PF, and MWT in the tuberous sclerosis complex group were all significantly lower than those in the control subjects (P < .05). The neurologic severity score was moderately negatively correlated with NOF and NOP regarding CF (r = -.70; r = -.75), bilateral PF (r = -.66; r = -.68), and MWT (r = -.71; r = -.74). Tract-based spatial statistics revealed that patients with tuberous sclerosis complex showed a widespread reduction (P < .05) in FA and axial diffusivity in most cerebral white matter regions.
  
  
  CONCLUSIONS
  Patients with tuberous sclerosis complex with reduced residual white matter were neurologically more severely affected. Tract-based spatial statistics revealed decreased FA and axial diffusivity of the cerebral white matter in the tuberous sclerosis complex group, suggesting reduced axonal integrity.
authors.affiliation: Department of Medical Imaging and Intervention Chang Gung Memorial Hospital and Chang Gung University, Keelung, Linkou, Taiwan, Republic of China.
authors.forename: A M
authors.initials: AM
authors.lastname: Wong
authors.forename: H-S
authors.initials: HS
authors.lastname: Wang
authors.forename: E S
authors.initials: ES
authors.lastname: Schwartz
authors.forename: C-H
authors.initials: CH
authors.lastname: Toh
authors.forename: R A
authors.initials: RA
authors.lastname: Zimmerman
authors.forename: P-L
authors.initials: PL
authors.lastname: Liu
authors.forename: Y-M
authors.initials: YM
authors.lastname: Wu
authors.forename: S-H
authors.initials: SH
authors.lastname: Ng
authors.forename: J-J
authors.initials: JJ
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D002648:Child; D002675:Child, Preschool; D003627:Data Interpretation, Statistical; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D009422:Nervous System Diseases / Q000209:etiology / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013223:Statistics as Topic; D014402:Tuberous Sclerosis / Q000150:complications / Q000473:pathology*; D055815:Young Adult