title: Bilateral grey-matter increase in the putamen in primary blepharospasm.
abstract: BACKGROUND
  Primary blepharospasm is a focal dystonia characterised by excessive involuntary closure of the eyelids. The pathophysiology of primary blepharospasm is unresolved.
  
  
  OBJECTIVE
  To pinpoint grey-matter changes that are associated with primary blepharospasm.
  
  
  METHODS
  16 right-handed patients with primary blepharospasm (mean age 67.4 (SD 4.3) years; 12 women) were compared with 16 healthy volunteers matched for sex and age. High-resolution T1-weighted magnetic resonance imaging of each participant was obtained and analysed by voxel-based morphometry, a method to detect regionally specific differences in grey matter between patients and control group. To evaluate whether the identified grey-matter changes were correlated with the duration of primary blepharospasm or botulinum neurotoxin treatment (BoNT), separate regression analyses were carried out.
  
  
  RESULTS
  In patients with primary blepharospasm, grey-matter increase in the putamina was observed, whereas regression analyses did not indicate a correlation between grey-matter increases and the duration of primary blepharospasm or BoNT. Grey-matter decrease was detected in the left inferior parietal lobule; here regression analyses of grey-matter decrease showed a significant (p = 0.013) correlation of grey-matter decrease with the duration of BoNT.
  
  
  CONCLUSIONS
  The data suggest structural changes in primary blepharospasm and point to a crucial role of the putamen for the pathophysiology of this focal dystonia.
authors.affiliation: Department of Neurology, Technische Universität München, München, Germany. thorleif.etgen@klinikum-traunstein.de
authors.forename: T
authors.initials: T
authors.lastname: Etgen
authors.forename: M
authors.initials: M
authors.lastname: Mühlau
authors.forename: C
authors.initials: C
authors.lastname: Gaser
authors.forename: D
authors.initials: D
authors.lastname: Sander
mesh_terms: D000368:Aged; D001764:Blepharospasm / Q000503:physiopathology*; D016022:Case-Control Studies; D005260:Female; D019788:Fluorodeoxyglucose F18; D007839:Functional Laterality; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011699:Putamen / Q000473:pathology*; D019275:Radiopharmaceuticals
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18