title: Transcranial Doppler ultrasonographic evaluation of cerebral circulation during passive tilting in patients with Parkinson's disease.
abstract: OBJECTIVE
  To assess the effects of the tilt test on cerebral blood flow velocity (CBFV), blood pressure, and heart rate in patients with Parkinson's disease (PD) without symptomatic orthostatic dysautonomia.
  
  
  METHODS
  Thirty patients with idiopathic PD and 15 healthy controls were included. Mean middle cerebral artery blood flow velocity (CBFV) was recorded with transcranial Doppler sonography, while systolic (SBP), diastolic (DBP), and mean (MBP) blood pressure and heart rate were measured in the supine position and after passive tilting.
  
  
  RESULTS
  There was no difference in resting SBP, DBP, or MBP between patients and controls. CBFV was lower at rest in patients than in controls and dropped significantly and similarly after tilting in both groups. SBP decreased in patients during the first 5 minutes of tilting (p < 0.05), whereas it increased progressively after the first minute in controls. In patients, DBP decreased slightly and MBP dropped during the first 2 minutes, then increased. Baseline heart rate was higher in patients than in controls (p < 0.05) and increased in both groups during tilting.
  
  
  CONCLUSIONS
  Our results suggest that cardiovascular responses to tilting are delayed in PD patients and that subclinical autonomic dysfunction may be present even in the absence of symptomatic orthostatic dysautonomia.
authors.affiliation: Department of Neurology, Akdeniz University Faculty of Medicine, Arapsuyu 07059, Antalya, Turkey.
authors.forename: Ebru
authors.initials: E
authors.lastname: Mihci
authors.forename: Babür
authors.initials: B
authors.lastname: Dora
authors.forename: Sevin
authors.initials: S
authors.lastname: Balkan
mesh_terms: D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D019540:Area Under Curve; D001783:Blood Flow Velocity; D001794:Blood Pressure; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D012107:Research Design; D012720:Severity of Illness Index; D016683:Supine Position; D018667:Tilt-Table Test; D017585:Ultrasonography, Doppler, Transcranial