title: Comparison of carbon dioxide responsiveness of cerebellar blood flow between affected and unaffected sides with crossed cerebellar diaschisis.
abstract: OBJECTIVE
  Concerning vasoreactivity of cerebellar blood flow (CeBF) in patients affected with crossed cerebellar diaschisis (CCD), several controversies have been reported. One is reduced asymmetry of CeBF after acetazolamide administration in 99mTc hexamethylpropyleneamine oxime single-photon emission-computed tomography, and the other is persistent asymmetry with alternation in PaCO2 using the 133Xe clearance method. The purpose of this study is to examine whether CeBF vasoreactivity in the side affected with CCD is the same as that in the unaffected side.
  
  
  METHODS
  We analyzed CeBF during hypocapnia, normocapnia, and hypercapnia performed in 27 patients with cerebrovascular disease (age range, 38 to 73 years; mean age, 62.0 +/- 8.5 years) affected by CCD. CeBF was measured using H2(15)O and positron emission tomography.
  
  
  RESULTS
  The CeBF ratio of CCD-affected side to CCD-unaffected side was consistent during the perturbation of PaCO2. This ratio was 0.82 +/- 0.08 for PaCO2 elevation and 0.83 +/- 0.07 for PaCO2 lowering. Both were not significantly different from unity.
  
  
  CONCLUSIONS
  The percent change of CeBF per millimeter of mercury PaCO2 change was uniform across affected and unaffected sides with CCD. These findings are consistent with our recent findings observed in activated cerebral tissue during photic stimulation.
authors.affiliation: Department of Radiology and Nuclear Medicine, Research Institute for Brain and Blood Vessels, Akita, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ishii
authors.forename: I
authors.initials: I
authors.lastname: Kanno
authors.forename: K
authors.initials: K
authors.lastname: Uemura
authors.forename: J
authors.initials: J
authors.lastname: Hatazawa
authors.forename: T
authors.initials: T
authors.lastname: Okudera
authors.forename: A
authors.initials: A
authors.lastname: Inugami
authors.forename: T
authors.initials: T
authors.lastname: Ogawa
authors.forename: H
authors.initials: H
authors.lastname: Fujita
authors.forename: E
authors.initials: E
authors.lastname: Shimosegawa
mesh_terms: D000328:Adult; D000368:Aged; D002245:Carbon Dioxide / Q000378:metabolism*; D002526:Cerebellar Diseases / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology*; D002531:Cerebellum / Q000098:blood supply*; D002561:Cerebrovascular Disorders / Q000378:metabolism / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D012039:Regional Blood Flow; D014661:Vasoconstriction
chemical_list: D002245:Carbon Dioxide