title: Evaluation of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes with magnetic resonance imaging and proton magnetic resonance spectroscopy.
abstract: OBJECTIVE
  To study the characteristics of spectra on proton magnetic resonance spectroscopy (1H-MRS) and its value in patients with mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS).
  
  
  METHODS
  Seven clinically diagnosed patients with MELAS underwent magnetic resonance imaging (MRI) and 1H-MRS examinations. The 1H-MRS techniques, characteristics of the spectra, and its correlation with the laboratory tests were analyzed.
  
  
  RESULTS
  Cerebral abnormalities were revealed in all 7 patients on conventional MR images, and most abnormal signals were observed in bilateral occipital, parietal, and temporal lobes. We found 4 cases with basal ganglia involvement, 2 cases with mild frontal lobe lesions, and 1 case with involvement of lateral cerebral peduncles and thalami. Additionally, 1 patient was involved with left insular lobe. Spectra from prominent lesions in brain parenchyma showed lactate doublet peak in 6 patients, 3 of whom were also noted lactate peak in ventricular cerebrospinal fluid (CSF).
  
  
  CONCLUSIONS
  1H-MRS may provide more direct information about the metabolism changes, which aids to affirm the diagnosis, and may replace the conventional invasive method of quantifying lactate in CSF.
authors.affiliation: Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730. ffeng@pumch.cn
authors.forename: Feng
authors.initials: F
authors.lastname: Feng
authors.forename: Hui
authors.initials: H
authors.lastname: You
authors.forename: Jing
authors.initials: J
authors.lastname: Gao
authors.forename: Xiao-Zhen
authors.initials: XZ
authors.lastname: Li
authors.forename: Chun-Ling
authors.initials: CL
authors.lastname: Meng
authors.forename: Hong-Yi
authors.initials: HY
authors.lastname: Sun
authors.forename: Zheng-Yu
authors.initials: ZY
authors.lastname: Jin
authors.forename: Yu-Pu
authors.initials: YP
authors.lastname: Guo
mesh_terms: D000293:Adolescent; D000328:Adult; D001479:Basal Ganglia / Q000473:pathology / Q000503:physiopathology; D002540:Cerebral Cortex / Q000473:pathology* / Q000503:physiopathology; D002648:Child; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism; D017241:MELAS Syndrome / Q000175:diagnosis* / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D010296:Parietal Lobe / Q000473:pathology / Q000503:physiopathology
chemical_list: D019344:Lactic Acid