title: Differences in Regional Glucose Metabolism of the Brain Measured with F-18-FDG-PET in Patients with Essential Tremor According to Their Response to Beta-Blockers.
abstract: OBJECTIVE
  In this study, there was an investigation as to whether there is a functional difference in essential tremor (ET), according to responses to beta-blockers, by evaluating regional changes in cerebral glucose metabolism.
  
  
  METHODS
  Seventeen male patients with ET were recruited and categorized into two groups: 8 that responded to medical therapy (group A); and 9 that did not respond to medical therapy (group B). Eleven age-sex matched healthy control male subjects were also included in this study. All subjects underwent F-18 fluorodeoxyglucose (FDG)-PET, and evaluated for their severity of tremor symptoms, which were measured as a score on the Fahn-Tolosa-Marin tremor rating scale (FTM). The FDG-PET images were analyzed using a statistical parametric mapping program.
  
  
  RESULTS
  The mean FTM score 6 months after the initiation of propranolol therapy was significantly lower in group A (18.13 > 8.13), compared with group B (14.67 = 14.67). The glucose metabolism in group A in the left basal ganglia was seen to be decreased, compared with group B. The ET showed a more significantly decreased glucose metabolism in both the fronto-temporo-occipital lobes, precuneus of right parietal lobe, and both cerebellums compared with the healthy controls.
  
  
  CONCLUSIONS
  Essential tremor is caused by electrophysiological disturbances within the cortical-cerebellar networks and degenerative process of the cerebellum. Furthermore, ET may have different pathophysiologies in terms of the origin of disease according to the response to first-line therapy.
authors.affiliation: Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea.
authors.forename: In-Uk
authors.initials: IU
authors.lastname: Song
authors.affiliation: Department of Neurology, Veterans Hospital, Seoul Medical Center, Seoul 05368, Korea.
authors.forename: Sang-Won
authors.initials: SW
authors.lastname: Ha
authors.affiliation: Department of Neurology, Veterans Hospital, Seoul Medical Center, Seoul 05368, Korea.
authors.forename: Young-Soon
authors.initials: YS
authors.lastname: Yang
authors.affiliation: Department of Radiology, College of Medicine, The Catholic University of Korea, Incheon 21431, Korea.
authors.forename: Yong-An
authors.initials: YA
authors.lastname: Chung
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000494:pharmacology* / Q000627:therapeutic use; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000378:metabolism; D001931:Brain Mapping; D020329:Essential Tremor / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000188:drug therapy; D019788:Fluorodeoxyglucose F18 / Q000737:chemistry*; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011433:Propranolol / Q000494:pharmacology / Q000627:therapeutic use; D011859:Radiography; D019275:Radiopharmaceuticals / Q000737:chemistry*
chemical_list: D000319:Adrenergic beta-Antagonists; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D011433:Propranolol; D005947:Glucose
keywords: Beta-blockers; Essential tremor; FDG-PET