Correlation between proton magnetic resonance spectroscopic lactate measurements and vascular reactivity in chronic occlusive cerebrovascular disease: a comparison with positron emission tomography

The purpose of this study is to investigate the correlation between lactate levels and cerebral vascular reactivity (VR) in regions outside an area of chronic cerebral infarction. Multivoxel proton magnetic resonance spectros copy (H-1-MRS) and positron emission tomography (PET) were performed in 11 patients who suffered chronic cerebral infarction. Of these 11 patients, 4 were examined before and after bypass surgery. Two regions-of-interests (RO Is) were placed outside the area of chronic infarction. One ROI was placed within a control region on the contralateral side. A lactate peak area was obtained in all ROIs. An N-acetyl aspartate (NAA) peak area was obtained in the ROI within the control region. The ratio of the lactate peak area and NAA peak area (Lct/NAA) was calculated for normalization of the lactate lev el, and was found to be 0.13 +/- 0.10 (range, 0 to 0.43). The VR was record ed at 13.3 +/- 20.7% (range, - 44.3 to 68.9%), utilizing PET and administer ing acetazolamide. A significant negative correlation was observed between the Lct/NAA ratio and VR (r = - 0.709, p < 0.0001). These results suggest t hat lactate levels and VR are closely related in regions outside areas of c hronic cerebral infarction. (C) 2000 Elsevier Science Inc. All rights reser ved.