title: The curse of motor expertise: Use-dependent focal dystonia as a manifestation of maladaptive changes in body representation.
abstract: Focal task-specific dystonia (FTSD) impairs not only motor dexterity, but also somatosensory perception involved in well-trained behavioral tasks. Occupations that carry a risk of developing FTSD include musician, writer, painter, surgeon, and golfer, which are characterized by repetitive and precise motor actions over a prolonged period. Behavioral studies have uncovered various undesirable effects of FTSD on sensorimotor functions, such as a loss of independent movement control, unintended muscular co-activation, awkward limb posture, and impairment of fine discrimination of tactile and proprioceptive sensations. Studies using neuroimaging and noninvasive brain stimulation techniques have related such sensorimotor malfunctions to maladaptive neuroplastic changes in the sensorimotor system, including the primary motor and somatosensory areas, premotor area, cerebellum, and basal ganglia. In this review, we summarize recent empirical findings regarding phenomenological and pathophysiological abnormalities associated with the development of FTSD. We particularly focused on maladaptive alterations of body representations underlying the degradation of fine motor control and somatosensory perception in FTSD patients.
authors.affiliation: Musical Skill and Injury Center (MuSIC), Sophia University, Japan; Integrative Brain Imaging Center (IBIC), National Center of Neurology and Psychiatry, Japan. Electronic address: sfuruya@sophia.ac.jp.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Furuya
authors.affiliation: Musical Skill and Injury Center (MuSIC), Sophia University, Japan; Integrative Brain Imaging Center (IBIC), National Center of Neurology and Psychiatry, Japan. Electronic address: hanakawa@ncnp.go.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Hanakawa
mesh_terms: D000818:Animals; D001828:Body Image; D001921:Brain / Q000503:physiopathology; D020821:Dystonic Disorders / Q000503:physiopathology / Q000523:psychology*; D006801:Humans
keywords: Fine motor control; Movement disorders; Neuroplasticity; Somatotopy; Surround inhibition