title: Congenital mirror movement: a study of functional MRI and transcranial magnetic stimulation.
abstract: Two male patients (a child and an adult) with congenital mirror movement were studied using functional MRI (fMRI) and transcranial magnetic stimulation (TMS). Bilateral primary sensorimotor cortices were activated during unilateral hand gripping on fMRI when the child patient was 8 years old andthe adult was 37 years old. Bilateral motor evoked potentials were induced from the hand and forearm muscles after TMS of each hemisphere. Bilateral motor responses were also induced from the arm muscles in the adult patient. Bilateral motor responses had short and similar latencies. Contralateral motor responses to TMS were smaller than ipsilateral ones in the hand muscles, while contralateral responses were larger than ipsilateral ones in the arm muscles. Contralateral hand motor responses reduced in amplitude or disappeared with increasing age while in the child patient, mirror movements decreased gradually. Our results suggest that bilateral activation of the primary sensorimotor cortices during intended unilateral hand movement and bilateral motor responses to TMS account, at least in part, for the pathophysiology of congenital mirror movement. Reduction of contralateral hand motor responses may be related to the decrease in mirror movements during development.
authors.affiliation: Division of Child Neurology, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, Yonago, Japan. maegaki@grape.med.tottori-u.ac.jp
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Maegaki
authors.forename: Ayumi
authors.initials: A
authors.lastname: Seki
authors.forename: Ichiro
authors.initials: I
authors.lastname: Suzaki
authors.forename: Shuji
authors.initials: S
authors.lastname: Sugihara
authors.forename: Toshihide
authors.initials: T
authors.lastname: Ogawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Amisaki
authors.forename: Chisako
authors.initials: C
authors.lastname: Fukuda
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Koeda
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology* / Q000503:physiopathology; D002675:Child, Preschool; D055590:Electromagnetic Phenomena / Q000295:instrumentation*; D019054:Evoked Potentials, Motor / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009069:Movement Disorders / Q000151:congenital / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy*; D013003:Somatosensory Cortex / Q000503:physiopathology