Validation of the Zigzag Tracking Task Test for the Evaluation of Handwriting Difficulties in Writer's Cramp
Validation of the Zigzag Tracking Task Test for the Evaluation of Handwriting Difficulties in Writer's Cramp
Writer's cramp (WC) is a task specific dystonia that occurs from the moment patient starts
 writing. It leads to partial or complete inability to use the hand only during the
 handwriting gesture. It is characterized by the appearance of cramps or spasms of certain
 muscles of the hand and/or forearm.

 Clinical scales currently use for the assessment of WC fail to accurately reflect changes in
 the characteristics of handwriting in response to treatments (Botulinum Neurotoxin injections
 and / or retraining therapy).

 The Zigzag Tracking Task (ZZTT), easy to use in current practice provides useful information
 in terms of speed and precision of handwriting gesture. This timed handwriting test is to
 follow with a pen a zigzag path beset with obstacles to avoid. It permits to evaluate the
 time in seconds required to carry out the zigzag path and count the number of errors (output
 path and contacts with obstacles). The investigators propose to validate the ZZTT for the
 assessment of the handwriting gesture of WC.
Inclusion Criteria:

 -  scholarship in French language, at least until 16 years old

 -  writer's cramp (diagnostic confirmed by a neurologist specialized in movement
 disorders)

 -  prescription of botulinum neurotoxin injection

 -  prescription de novo or absence of injection in the last 3 months

 -  informed consent

 -  medical insurance coverage

 Exclusion Criteria:

 -  writing tremor

 -  -other neurological disease with effect on handwriting

 -  pain or traumatism of the upper limb, with effect on handwriting

 -  non-corrected visual disturbances

 -  patient living outside the region where the study will be held (Ile-de-France)

 -  participation in another research with a potential impact on evaluation criteria

 -  pregnant or breast feeding patient

 -  patient under judiciary protection