title: Re-establishment of cerebral metabolism after carotid endarterectomy.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the metabolic changes that occur in the human brain in patients with a symptomatic carotid artery stenosis.
  
  
  METHODS
  N-acetyl-aspartate (NAA), choline, creatine and lactate were measured both before, and 4 days after, carotid endarterectomy, by magnetic resonance spectroscopic imaging (MRSI). Eight controls and 16 patients were examined. MRI and MRSI studies were performed on a Philips Gyroscan S15 whole body system operating at 1.5 Tesla. 1H spectra were selected from regions in the centrum semi-ovale outside areas showing white matter hyper intensities on MRI.
  
  
  RESULTS
  All patients showed a decrease of the NAA/choline and NAA/creatine ratio in the symptomatic hemisphere compared to the contralateral hemisphere and also compared to the controls. Lactate was present in some patients (5/16). After endarterectomy, the NAA/choline and NAA/creatine ratios increased significantly compared to the ratios preoperative. Lactate was absent or more than 50% reduced after the operation. MRSI showed metabolic changes in areas of the brain that did not show any abnormalities on MRI.
  
  
  CONCLUSIONS
  There are marked changes in brain metabolism in the symptomatic hemisphere of patients with a severe carotid artery stenosis. These metabolic changes normalise four days after endarterectomy.
authors.affiliation: Department of Vascular Surgery, University Hospital Utrecht, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Balm
authors.forename: J
authors.initials: J
authors.lastname: van der Grond
authors.forename: W P
authors.initials: WP
authors.lastname: Mali
authors.forename: B C
authors.initials: BC
authors.lastname: Eikelboom
mesh_terms: D000368:Aged; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged
chemical_list: D007773:Lactates; D001224:Aspartic Acid; D019344:Lactic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline