title: Assessment of disease severity in parkinsonism with fluorine-18-fluorodeoxyglucose and PET.
abstract: Fluorine-18-fluorodeoxyglucose (FDG) and PET have been used to identify an abnormal regional metabolic covariance pattern in Parkinson's disease (PD). To examine the potential use of this covariance pattern as a metabolic imaging marker for PD, we describe the Topographic Profile Rating (TPR), which is a method for calculating subject scores for this pattern in individual PD patients. We then assess the relationship between these metabolic measures and objective independent disease severity ratings.
  
  
  METHODS
  Two independent groups of PD patients were studied with FDG-PET. Group A consisted of 23 patients (mean age 60.2 +/- 12.2; mean Hoehn and Yahr stages 2.4 +/- 1.3) and Group B had 14 patients (mean age 49.0 +/- 12.1; mean Hoehn and Yahr stage 3.2 +/- 1.2). The regional cerebral metabolic rates for glucose (rCMRGlc) in all patients in each group were measured. TPR was used to calculate subject scores for the disease-related covariance pattern on a patient-by-patient basis.
  
  
  RESULTS
  In both PD patient groups, subject scores correlated with Hoehn and Yahr disease severity ratings (Group A: r = 0.59, p < 0.004; Group B: 0.57, p < 0.04), quantitative ratings for bradykinesia (Group A: r = 0.63, p < 0.002; Group B: r = 0.61, p < 0.03), rigidity (Group A: r = 0.59, p < 0.004; Group B: r = 0.59, p < 0.04), but not with tremor.
  
  
  CONCLUSIONS
  These findings indicate that regional metabolic covariance patterns are robust imaging markers of disease severity. FDG-PET may be useful clinically in assessing parkinsonian disability and disease progression.
authors.affiliation: Department of Neurology, North Shore University Hospital/Cornell University Medical College, Manhasset, NY 11030.
authors.forename: D
authors.initials: D
authors.lastname: Eidelberg
authors.forename: J R
authors.initials: JR
authors.lastname: Moeller
authors.forename: T
authors.initials: T
authors.lastname: Ishikawa
authors.forename: V
authors.initials: V
authors.lastname: Dhawan
authors.forename: P
authors.initials: P
authors.lastname: Spetsieris
authors.forename: T
authors.initials: T
authors.lastname: Chaly
authors.forename: W
authors.initials: W
authors.lastname: Robeson
authors.forename: J R
authors.initials: JR
authors.lastname: Dahl
authors.forename: D
authors.initials: D
authors.lastname: Margouleff
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging; D003847:Deoxyglucose / Q000031:analogs & derivatives*; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging*; D012720:Severity of Illness Index; D014055:Tomography, Emission-Computed
chemical_list: D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose