title: Correlation of findings in advanced MRI techniques with global severity scales in patients with Parkinson disease.
abstract: OBJECTIVE
  This work is aimed at determining whether magnetic resonance spectroscopy (MRS) and diffusion tensor imaging (DTI) may correlate with disease severity in a series of Parkinson disease (PD) patients.
  
  
  METHODS
  We recruited a consecutive sample of 39 PD patients in several stages of the disease according to Hoehn and Yahr scale. There were 22 men, and the mean age was 74.5 years (SD 7.5). Disease severity was measured with the Unified Parkinson Disease Rating Scale (UPDRS). All of them underwent ¹H MRS in basal ganglia and the anterior cingulate area, as well as DTI in bilateral substantia nigra. Correlation was made between radiological findings and UPDRS.
  
  
  RESULTS
  We found significant negative correlation between UPDRS scores and the Glx (glutamate+glutamine) levels in the right (r = -0.35; P = .03) and the left (r = -0.44; P = .006) lentiform nucleus; as well as with glutamate (r = -0.43; P = .008), the Glx/Cr ratio in the right (r = -0.41; P = .01), and in the left lentiform nucleus (r = -0.36; P = .02). We also found positive correlation between UPDRS scores and DTI in right rostral substantia nigra (r = 0.36; P = .02). Glx was increased in lentiform nucleus and fractional anisotropy was reduced in the rostral SN of subjects with PD in early stages.
  
  
  CONCLUSIONS
  The results are consistent with the view that more than half the dopaminergic neurons in the nigrostriatal projection are lost before the onset of PD.
authors.affiliation: Neurology Department, Hospital Miguel Servet, Zaragoza, Spain. pmodrego@salud.aragon.es
authors.forename: Pedro J
authors.initials: PJ
authors.lastname: Modrego
authors.forename: Nicolás
authors.initials: N
authors.lastname: Fayed
authors.forename: Jorge
authors.initials: J
authors.lastname: Artal
authors.forename: Salvador
authors.initials: S
authors.lastname: Olmos
mesh_terms: D000368:Aged; D001921:Brain / Q000378:metabolism*; D002794:Choline / Q000378:metabolism; D003342:Corpus Striatum / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D056324:Diffusion Tensor Imaging; D004151:Dipeptides / Q000378:metabolism; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D010300:Parkinson Disease / Q000175:diagnosis* / Q000378:metabolism; D012720:Severity of Illness Index; D013378:Substantia Nigra / Q000378:metabolism
chemical_list: D004151:Dipeptides; D005973:Glutamine; C027172:isospaglumic acid; D018698:Glutamic Acid; D003401:Creatine; D002794:Choline