Open AccessImpairment of a parieto‐premotor network specialized for handwriting in writer's cramp
Author(s) -
Gallea Cecile,
Horovitz Silvina G.,
'Ali NajeeUllah Muslimah,
Hallett Mark
Publication year - 2016
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.23315
Subject(s) - handwriting , psychology , physical medicine and rehabilitation , neuroscience , premotor cortex , supplementary motor area , task (project management) , motor program , motor skill , dystonia , functional magnetic resonance imaging , medicine , anatomy , computer science , artificial intelligence , dorsum , management , economics
Abstract Handwriting with the dominant hand is a highly skilled task singularly acquired in humans. This skill is the isolated deficit in patients with writer's cramp (WC), a form of dystonia with maladaptive plasticity, acquired through intensive and repetitive motor practice. When a skill is highly trained, a motor program is created in the brain to execute the same movement kinematics regardless of the effector used for the task. The task‐ and effector‐specific symptoms in WC suggest that a problem particularly occurs in the brain when the writing motor program is carried out by the dominant hand. In this MRI study involving 12 WC patients (with symptoms only affecting the right dominant hand during writing) and 15 age matched unaffected controls we showed that: (1) the writing program recruited the same network regardless of the effector used to write in both groups; (2) dominant handwriting recruited a segregated parieto‐premotor network only in the control group; (3) local structural alteration of the premotor area, the motor component of this network, predicted functional connectivity deficits during dominant handwriting and symptom duration in the patient group. Dysfunctions and structural abnormalities of a segregated parieto‐premotor network in WC patients suggest that network specialization in focal brain areas is crucial for well‐learned motor skill. Hum Brain Mapp 37:4363–4375, 2016 . © 2016 Wiley Periodicals, Inc.