title: Two different days of transcranial Doppler examinations should be performed for detection of right-to-left shunt in acute stroke patients.
abstract: BACKGROUND
  We investigated how many contrast-transcranial Doppler (c-TCD) examinations should be performed on different days in patients with acute stroke.
  
  
  METHODS
  Consecutive acute stroke patients within 24 hours of onset were enrolled. Presence of RLS was examined using c-TCD examinations on days 1, 7, and 14. Each c-TCD examination used one test without Valsalva maneuver (VM) and three tests with VM. Patients were diagnosed with RLS when TCD detected ≥1 microembolic signal on ≥1 c-TCD examination on any of the days 1, 7, or 14.
  
  
  RESULTS
  One hundred seventy patients (105 men [62%]; median age, 74 [IQR, 66-81] years) were enrolled. RLS was diagnosed in 45 patients (26%). RLS was identified on day 1 in 30 patients (18%), on day 7 in 28 patients (16%), and on day 14 in 23 patients (14%; P = .143). Detection rate of RLS by combining day 1 and 7 examinations was significantly higher than that of day 1 alone (25% vs. 18%, P < .001). However, the rate did not increase when results of day 14 were added (25% vs. 26%, P = .250).
  
  
  CONCLUSIONS
  c-TCD examinations should be performed on at least two different days to assess the prevalence of RLS.
authors.affiliation: Department of Stroke Medicine, Kawasaki Medical School, Kurashiki-City, Okayama, Japan. aojyun@med.kawasaki-m.ac.jp
authors.forename: Junya
authors.initials: J
authors.lastname: Aoki
authors.forename: Kazumi
authors.initials: K
authors.lastname: Kimura
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Iguchi
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Sakai
authors.forename: Yuki
authors.initials: Y
authors.lastname: Sakamoto
authors.forename: Yuka
authors.initials: Y
authors.lastname: Terasawa
authors.forename: Kensaku
authors.initials: K
authors.lastname: Shibazaki
authors.forename: Kazuto
authors.initials: K
authors.lastname: Kobayashi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D005260:Female; D006344:Heart Septal Defects, Atrial / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007564:Japan / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D011379:Prognosis; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D020521:Stroke / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D013382:Subtraction Technique; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*