title: Thalamic metabolic alterations with cognitive dysfunction in idiopathic trigeminal neuralgia: a multivoxel spectroscopy study.
abstract: BACKGROUND
  Although abnormalities in metabolite compositions in the thalamus are well described in patients with idiopathic trigeminal neuralgia (ITN), differences in distinct thalamic subregions have not been measured with proton magnetic resonance spectroscopy ((1)H-MRS), and whether there are correlations between thalamic metabolites and cognitive function still remain unknown.
  
  
  METHODS
  Multivoxel MRS was recorded to investigate the metabolic alterations in the thalamic subregions of patients with ITN. The regions of interest were localized in the anterior thalamus (A-Th), intralaminar portion of the thalamus (IL-Th), posterior lateral thalamus (PL-Th), posterior medial thalamus (PM-Th), and medial and lateral pulvinar of the thalamus (PuM-Th and PuL-Th). The N-acetylaspartate to creatine (NAA/Cr) and choline to creatine (Cho/Cr) ratios were measured in the ITN and control groups. Scores of the visual analogue scale (VAS) and the Montreal Cognitive Assessment (MoCA) were analyzed to correlate with the neuroradiological findings.
  
  
  RESULTS
  The NAA/Cr ratio in the affected side of PM-Th and PL-Th in ITN patients was statistically lower than that in the corresponding regions of the thalamus in controls. The NAA/Cr ratio in the affected PM-Th was negatively associated with VAS and disease duration. Furthermore, decreases of NAA/Cr and Cho/Cr were detected in the affected side of IL-Th, and lower Cho/Cr was positively correlated with MoCA values in the ITN group.
  
  
  CONCLUSIONS
  Our result of low level of NAA/Cr in the affected PM-Th probably serves as a marker of the pain-rating index, and decreased Cho/Cr in IL-Th may be an indicator of cognitive disorder in patients with ITN.
authors.affiliation: Department of Medical Imaging, First Affiliated Hospital of Xi'an Jiaotong University, No. 277, West Yanta Road, Xi'an, Shaanxi, 710061, People's Republic of China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wang
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.forename: Faxiu
authors.initials: F
authors.lastname: Bao
authors.forename: Shaohui
authors.initials: S
authors.lastname: Ma
authors.forename: Chenguang
authors.initials: C
authors.lastname: Guo
authors.forename: Chenwang
authors.initials: C
authors.lastname: Jin
authors.forename: Ming
authors.initials: M
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D016022:Case-Control Studies; D002794:Choline / Q000378:metabolism; D003072:Cognition Disorders / Q000150:complications* / Q000378:metabolism*; D003401:Creatine / Q000378:metabolism; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D013788:Thalamus / Q000378:metabolism*; D014277:Trigeminal Neuralgia / Q000378:metabolism* / Q000523:psychology*
chemical_list: D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline