The effect of deafferentation on cerebral blood flow response to acetazolamide.
OBJECTIVE
Decreased cerebral blood flow (CBF) response after acetazolamide administration may indicate increased cerebral blood volume (CBV) owing to reduced perfusion pressure from major cerebral artery steno-occlusive disease. However, decreased cerebral metabolic rate of oxygen (CMRO(2)) caused by neuronal damage or deafferentation may also decrease the CBF response to acetazolamide, which adds complexity to the assessment of autoregulatory vasodilatation. The purpose of this study was to investigate the relationship between CBF response to acetazolamide and CBV or CMRO(2) in a pure form of deafferentation, crossed cerebellar diaschisis (CCD).


METHODS
We used positron emission tomography to study 17 patients with unilateral supratentorial infarct and contralateral cerebellar hypoperfusion. The CBF response to acetazolamide was assessed by measuring baseline CBF and CBF 10 minutes after an intravenous injection of acetazolamide. Multivariate analysis was used to test the independent predictive value of the CBV and CMRO(2) at baseline with respect to the change of CBF during acetazolamide administration.


RESULTS
Multivariate analysis revealed that in CCD CBV was significantly and independently associated with the percent change of CBF during acetazolamide administration (P <.0001), whereas CMRO(2) was not.


CONCLUSIONS
In deafferentation, changes in CBV may account for variations in CBF response to acetazolamide and decreased CMRO(2) may not affect CBF response to acetazolamide expressed as the percent change.
Yamauchi
Hiroshi
H
Research Institute, Shiga Medical Center, Moriyama, Japan.
Okazawa
Hidehiko
H
Sugimoto
Kanji
K
Kishibe
Yoshihiko
Y
Takahashi
Masaaki
M
D000086:Acetazolamide / Q000008:administration & dosage*; D000368:Aged; D001810:Blood Volume / Q000187:drug effects*; D002257:Carbonic Anhydrase Inhibitors / Q000008:administration & dosage*; D002525:Cerebellar Cortex / Q000098:blood supply / Q000000981:diagnostic imaging; D002540:Cerebral Cortex / Q000098:blood supply / Q000000981:diagnostic imaging; D002544:Cerebral Infarction / Q000175:diagnosis / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010101:Oxygen Consumption / Q000187:drug effects; D011237:Predictive Value of Tests; D011859:Radiography; D012044:Regression Analysis; D013223:Statistics as Topic; D014055:Tomography, Emission-Computed; D014664:Vasodilation / Q000187:drug effects
D002257:Carbonic Anhydrase Inhibitors; D000086:Acetazolamide