Keiichiro SHINDO, Tetsuya TSUJI, Yoshihisa MASAKADO, Kimitaka HASE, Akio KIMURA, Naoichi CHINO

Department of Rehabilitation Medicine, Keio University School of Medicine

(Received 13 November 2003; accepted 4 April 2004)

Abstract: Objectives: To analyze writing patterns in patients with writer's cramp using a simple pen-type writing pressure gauge. Design: Paired comparisons of writing parameters between patients with writer's cramp and the controls. Setting: Outpatient clinic in the department of rehabilitation medicine of a university hospital in Japan. Subjects: 10 healthy subjects (average age, 32.7 years; 6 males) and 10 patients with writer's cramp (average age, 47.6 years; 9 males). Main outcome measures: Maximum and average writing pressure; the degree of variation in writing pressure, which reflects the writer's skill in writing; and writing time, which is the amount of time required to complete the task. Results: The intra-class correlations were over 0.7 for all parameters in the healthy subjects, indicating satisfactory reproducibility. Writing time and degrees of variation in patients with writer's cramp were significantly longer and larger, respectively, than those in the controls. Conclusions: The electronic pen is an easily used instrument and is useful for reliable analysis of writing patterns. Writing time and degree of variation are recommended as reliable parameters for characterizing patients with writer's cramp.

Key words: focal dystonia, writing pressure, clumsiness