title: Multiple sclerosis: cerebral circulation time.
abstract: OBJECTIVE
  To assess cerebral circulation times (CCTs) in patients with multiple sclerosis (MS) and control subjects by using contrast material-enhanced ultrasonography (US) to determine whether vascular abnormalities can be detected in this disease.
  
  
  METHODS
  This study was approved by the local ethics committee, and informed consent was obtained from all subjects. One hundred three patients with MS and 42 control subjects underwent extracranial and transcranial venous echo-color Doppler ultrasonography (US) and contrast-enhanced US. CCT was defined as the difference in arrival time of the US contrast agent bolus between the carotid artery and the internal jugular vein. The presence of chronic cerebrospinal venous insufficiency (CCSVI) was defined according to previously reported criteria for the extracranial and transcranial US techniques. Nonparametric statistics, including the Mann-Whitney U test and the Kruskal-Wallis analysis of variance, were used to compare contrast-enhanced US parameters between groups.
  
  
  RESULTS
  The longest and average CCTs were substantially prolonged in patients with MS compared with those in control subjects (median longest CCT in patients with MS, 6.47 seconds [range, 3.29-29.24 seconds]; that in control subjects, 5.54 seconds [range, 2.57-7.63 seconds]; P < .001; median average CCT in patients with MS, 5.76 seconds [range, 2.64-17.51 seconds]; that in control subjects, 5.01 seconds [range, 2.57-7.06 seconds]; P < .002). No correlation was found between CCTs and clinical parameters. The prevalence of CCSVI was higher in patients with MS than in control subjects (77% vs 28%, P < .0001). CCT was not significantly different between patients with MS who had CCSVI and patients with MS who did not (P = .182).
  
  
  CONCLUSIONS
  These results suggest that contrast-enhanced US with CCT assessment may have a role in the evaluation of cerebral blood flow in patients with MS and that a vascular impairment could be associated with MS. The finding of a prolonged CCT at contrast-enhanced US does not result from outflow impairment. Further studies are required to verify these observations and to clarify if CCT and CCSVI have any physiologic and clinical relevance in MS.
authors.affiliation: Institute of Biostructure and Bioimaging, National Research Council of Italy, Federico II University School of Medicine, Via Pansini 5, Edificio 10, 80131 Naples, Italy. marcello.mancini@libero.it
authors.forename: Marcello
authors.initials: M
authors.lastname: Mancini
authors.forename: Vincenzo Brescia
authors.initials: VB
authors.lastname: Morra
authors.forename: Orlando
authors.initials: O
authors.lastname: Di Donato
authors.forename: Valentina
authors.initials: V
authors.lastname: Maglio
authors.forename: Roberta
authors.initials: R
authors.lastname: Lanzillo
authors.forename: Raffaele
authors.initials: R
authors.lastname: Liuzzi
authors.forename: Elena
authors.initials: E
authors.lastname: Salvatore
authors.forename: Arturo
authors.initials: A
authors.lastname: Brunetti
authors.forename: Vittorio
authors.initials: V
authors.lastname: Iaccarino
authors.forename: Marco
authors.initials: M
authors.lastname: Salvatore
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation / Q000502:physiology*; D016009:Chi-Square Distribution; D003287:Contrast Media; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D010743:Phospholipids; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D013459:Sulfur Hexafluoride; D017585:Ultrasonography, Doppler, Transcranial
chemical_list: D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride