title: Changes in metabolites after treatment with memantine in fibromyalgia. A double-blind randomized controlled trial with magnetic resonance spectroscopy with a 6-month follow-up.
abstract: OBJECTIVE
  To evaluate the efficacy of memantine on metabolite levels in different areas of the brain and to determine whether changes in metabolite levels correlate with clinical variables in Fibromyalgia (FM) patients.
  
  
  METHODS
  Doubled-blind parallel randomized controlled trial. Twenty-five patients diagnosed with FM were enrolled in the study. Patients were administered questionnaires on pain, anxiety, depression, quality of life, and cognitive impairment, and single-voxel MRS of the brain was performed. All assessments were performed at baseline and after 6 months of treatment with memantine or placebo.
  
  
  RESULTS
  Patients treated with memantine exhibited a significant increase in the glutamate (P = 0.010), glutamate/creatine ratio (P = 0.013), combined glutamate + glutamine (P = 0.016) and total N-acetyl-aspartate (NAA+NAAG) (P = 0.034) in the posterior cingulate cortex compared with those on placebo. Furthermore, the memantine group exhibited increases in creatine (P = 0.013) and choline (Cho) (P = 0.025) in the right posterior insula and also a correlation between choline and the Fibromyalgia Impact Questionnaire (FIQ) in the posterior insula (P = 0.050) was observed.
  
  
  CONCLUSIONS
  Memantine treatment resulted in an increase in cerebral metabolism in FM patients, suggesting its utility for the treatment of the illness.
authors.affiliation: Magnetic Resonance Unit, Department of Radiology, Clinica Quiron, Zaragoza, Spain.
authors.forename: Nicolás
authors.initials: N
authors.lastname: Fayed
authors.forename: Bárbara
authors.initials: B
authors.lastname: Olivan-Blázquez
authors.forename: Paola
authors.initials: P
authors.lastname: Herrera-Mercadal
authors.forename: Marta
authors.initials: M
authors.lastname: Puebla-Guedea
authors.forename: Mari-Cruz
authors.initials: MC
authors.lastname: Pérez-Yus
authors.forename: Eva
authors.initials: E
authors.lastname: Andrés
authors.forename: Yolanda
authors.initials: Y
authors.lastname: López del Hoyo
authors.forename: Rosa
authors.initials: R
authors.lastname: Magallon
authors.forename: Laura
authors.initials: L
authors.lastname: Viguera
authors.forename: Javier
authors.initials: J
authors.lastname: Garcia-Campayo
mesh_terms: D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D003401:Creatine; D015259:Dopamine Agents / Q000494:pharmacology / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D005356:Fibromyalgia / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D005500:Follow-Up Studies; D018698:Glutamic Acid; D005973:Glutamine; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008559:Memantine / Q000494:pharmacology / Q000627:therapeutic use*; D008609:Mental Status Schedule; D008875:Middle Aged; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
chemical_list: D015259:Dopamine Agents; D005973:Glutamine; D001224:Aspartic Acid; D018698:Glutamic Acid; C000179:N-acetylaspartate; D003401:Creatine; D008559:Memantine
keywords: Chronic pain; Fibromyalgia; Magnetic Resonance Spectroscopy; Memantine; Randomized controlled trial