title: Cerebral blood flow velocity and cognition in children before and after adenotonsillectomy.
abstract: OBJECTIVE
  The goal was to determine whether amelioration of sleep-disordered breathing through adenotonsillectomy would reduce middle cerebral artery velocity in parallel with improvements in cognition and behavior.
  
  
  METHODS
  For 19 children (mean age: 6 years) with mild sleep-disordered breathing, and 14 healthy, ethnically similar and age-similar, control subjects, parents repeated the Pediatric Sleep Questionnaire an average of 12 months after adenotonsillectomy. Children with sleep-disordered breathing underwent repeated overnight measurement of mean oxyhemoglobin saturation. Neurobehavioral tests that yielded significant group differences preoperatively were readministered. Middle cerebral artery velocity measurements were repeated with blinding to sleep study and neuropsychological results, and mixed-design analyses of variance were performed.
  
  
  RESULTS
  The median Pediatric Sleep Questionnaire score significantly improved postoperatively, and there was a significant increase in mean overnight oxyhemoglobin saturation. The middle cerebral artery velocity decreased in the sleep-disordered breathing group postoperatively, whereas control subjects showed a slight increase. A preoperative group difference was reduced by the postoperative assessment, which suggests normalization of middle cerebral artery velocity in those with sleep-disordered breathing. The increase in mean overnight oxyhemoglobin saturation postoperatively was associated with a reduction in middle cerebral artery velocity in a subgroup of children. A preoperative group difference in processing speed was reduced postoperatively. Similarly, a trend for a preoperative group difference in visual attention was reduced postoperatively. Executive function remained significantly worse for the children with sleep-disordered breathing, compared with control subjects, although mean postoperative scores were lower than preoperative scores.
  
  
  CONCLUSIONS
  Otherwise-healthy young children with apparently mild sleep-disordered breathing have potentially reversible cerebral hemodynamic and neurobehavioral changes.
authors.affiliation: Developmental Brain-Behaviour Unit, Neurosciences Unit, University College London Institute of Child Health, London, England.
authors.forename: Alexandra M
authors.initials: AM
authors.lastname: Hogan
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Hill
authors.forename: Dawn
authors.initials: D
authors.lastname: Harrison
authors.forename: Fenella J
authors.initials: FJ
authors.lastname: Kirkham
mesh_terms: D000234:Adenoids / Q000601:surgery*; D001783:Blood Flow Velocity; D002648:Child; D002675:Child, Preschool; D003072:Cognition Disorders / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D010092:Oximetry; D010108:Oxyhemoglobins / Q000032:analysis; D011184:Postoperative Period; D012891:Sleep Apnea Syndromes / Q000453:epidemiology* / Q000503:physiopathology*; D011795:Surveys and Questionnaires; D014068:Tonsillectomy; D017585:Ultrasonography, Doppler, Transcranial
chemical_list: D010108:Oxyhemoglobins