title: Handwriting performance in the absence of visual control in writer's cramp patients: initial observations.
abstract: BACKGROUND
  The present study was aimed at investigating the writing parameters of writer's cramp patients and control subjects during handwriting of a test sentence in the absence of visual control.
  
  
  METHODS
  Eight right-handed patients with writer's cramp and eight healthy volunteers as age-matched control subjects participated in the study. The experimental task consisted in writing a test sentence repeatedly for fifty times on a pressure-sensitive digital board. The subject did not have visual control on his handwriting. The writing performance was stored on a PC and analyzed off-line.
  
  
  RESULTS
  During handwriting all patients developed a typical dystonic limb posture and reported an increase in muscular tension along the experimental session. The patients were significantly slower than the controls, with lower mean vertical pressure of the pen tip on the paper and they could not reach the endmost letter of the sentence in the given time window. No other handwriting parameter differences were found between the two groups.
  
  
  CONCLUSIONS
  Our findings indicate that during writing in the absence of visual feedback writer's cramp patients are slower and could not reach the endmost letter of the test sentence, but their level of automatization is not impaired and writer's cramp handwriting parameters are similar to those of the controls except for even lower vertical pressure of the pen tip on the paper, which is probably due to a changed strategy in such experimental conditions.
authors.affiliation: Neurological Clinic, University Freiburg, Breisacherstrasse 64, 79106 Freiburg, Germany. vihren@clbme.bas.bg
authors.forename: Vihren
authors.initials: V
authors.lastname: Chakarov
authors.forename: Sibylla
authors.initials: S
authors.lastname: Hummel
authors.forename: Florian
authors.initials: F
authors.lastname: Losch
authors.forename: Jürgen
authors.initials: J
authors.lastname: Schulte-Mönting
authors.forename: Rumyana
authors.initials: R
authors.lastname: Kristeva
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D020821:Dystonic Disorders / Q000503:physiopathology* / Q000523:psychology*; D030141:Feedback, Psychological; D005260:Female; D005403:Fixation, Ocular; D006236:Handwriting; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D011312:Pressure; D013997:Time Factors; D014785:Vision, Ocular