title: Cerebrovascular pulsatility in patients with sleep-disordered breathing.
abstract: OBJECTIVE
  The aim of our study is to determine the association between the pulsatility index (PI), a surrogate of cerebral small vessel disease and sleep-disordered breathing (SDB).
  
  
  METHODS
  We conducted a transcranial Doppler ultrasound (TCD) study of 19 consecutive patients free of stroke and cardiovascular disease, referred for the evaluation of SDB. TCD was performed by a certified technologist. Subsequent polysomnography was performed according to the practice parameters of the American Academy of Sleep Medicine. We evaluated the association between the apnea-hypopnea index (AHI), the oxygen nadir, the blood flow velocities, and the Gosling PI, for the middle cerebral artery. We performed Spearman's rank correlation and nonparametric regression to evaluate the relationship between AHI, oxygen levels, and the PI.
  
  
  RESULTS
  Median age was 48 years (range 37-83), with 52 % male sex (n = 10), and median BMI of 29.9 (range 25-40.4). The median AHI was 16.4 (0.2-69). The median PI was 0.97 (0.72-1.89) cm/s. The PI correlated with the AHI (rho = 0.44; p = 0.004) and with age (rho = 0.57; p = 0.001). Nonparametric regression adjusting for age showed a positive association between the AHI and the PI (standardized estimate = 0.88; p = 0.002). There was no relation between the oxygen nadir and the PI.
  
  
  CONCLUSIONS
  We observed increased PI in patients with SDB during wakefulness. The PI could potentially be an estimate of cerebral small vessel disease in patients with SDB and hence allow evaluating cerebral hemodynamics during wakefulness with a clinically relevant device.
authors: Department of Neurology, Miller School of Medicine, University of Miami, 1120 NW 14th Street, Suite 1350, Miami, FL 33136, USA. aramos@med.miami.edu
authors: Alberto R
authors: AR
authors: Ramos
authors: Digna
authors: D
authors: Cabral
authors: David J
authors: DJ
authors: Lee
authors: Ralph L
authors: RL
authors: Sacco
authors: Tatjana
authors: T
authors: Rundek
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity / Q000502:physiology; D002544:Cerebral Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology; D059345:Cerebral Small Vessel Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D010100:Oxygen / Q000097:blood; D011673:Pulsatile Flow / Q000502:physiology*; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000000981:diagnostic imaging / Q000503:physiopathology*; D013223:Statistics as Topic; D017585:Ultrasonography, Doppler, Transcranial
chemical_list: D010100:Oxygen