title: Diagnostic impact of cerebral transit time in the identification of microangiopathy in dementia: A transcranial ultrasound study.
abstract: OBJECTIVE
  The diagnosis and quantification of microangiopathy in dementia is difficult. The assessment of small-vessel disease requires expensive and sophisticated nuclear medicine techniques. This study was performed to identify microangiopathy related to the integrity of cerebral microcirculation by sonographic measurements (arteriovenous cerebral transit time [cTT]).
  
  
  METHODS
  We performed transcranial color-coded duplex sonography in 40 patients with vascular dementia, 20 patients with Alzheimer's disease or Lewy body disease, and 25 age-matched controls. The clinical diagnosis was established by history of dementia and neuroimaging findings. Cognitive impairment was assessed by the Mini-Mental State Examination and Alzheimer's Disease Assessment Scale. cTT is defined as the time required by an ultrasound contrast agent to pass from a cerebral artery to a vein. This was measured by recording the power-Doppler intensity curves in the P2 segment of the posterior cerebral artery and the vein of Galen. Previous studies have shown a prolongation of cTT in patients with cerebral microangiopathy.
  
  
  RESULTS
  cTT was substantially prolonged in patients with vascular dementia (5.8 seconds; 25th percentile 4.5; 75th percentile 7.5; U test, P<0.001) compared with controls (3.1 seconds; 2.3; 3.4) but not in patients with degenerative dementia (3.7 seconds; 3.7; 4.2). In patients with vascular dementia, cTT was significantly correlated with cognitive impairment.
  
  
  CONCLUSIONS
  cTT may be useful tool to disclose small-vessel disease in demented patients. Examination is noninvasive and quickly performed. It may be also useful in follow-up examinations in patients undergoing therapy.
authors.affiliation: Department of Neurology, Bayerische Julius-Maximilians-Universität, Würzburg, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Puls
authors.forename: K
authors.initials: K
authors.lastname: Hauck
authors.forename: K
authors.initials: K
authors.lastname: Demuth
authors.forename: A
authors.initials: A
authors.lastname: Horowski
authors.forename: M
authors.initials: M
authors.lastname: Schliesser
authors.forename: P
authors.initials: P
authors.lastname: Dörfler
authors.forename: P
authors.initials: P
authors.lastname: Scheel
authors.forename: K V
authors.initials: KV
authors.lastname: Toyka
authors.forename: K
authors.initials: K
authors.lastname: Reiners
authors.forename: M
authors.initials: M
authors.lastname: Schöning
authors.forename: G
authors.initials: G
authors.lastname: Becker
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D002550:Cerebral Veins / Q000000981:diagnostic imaging; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003072:Cognition Disorders / Q000175:diagnosis; D003287:Contrast Media; D015140:Dementia, Vascular / Q000000981:diagnostic imaging*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020961:Lewy Body Disease / Q000000981:diagnostic imaging*; D008297:Male; D008609:Mental Status Schedule; D008833:Microcirculation / Q000502:physiology; D008875:Middle Aged; D011134:Polysaccharides; D020769:Posterior Cerebral Artery / Q000000981:diagnostic imaging; D013997:Time Factors; D018615:Ultrasonography, Doppler, Color; D018616:Ultrasonography, Doppler, Duplex; D017585:Ultrasonography, Doppler, Transcranial
chemical_list: D003287:Contrast Media; D011134:Polysaccharides; C059891:SHU 508