title: Synchronized brain network underlying postural tremor in Wilson's disease.
abstract: Common neurological manifestation of Wilson's disease (WD) is a postural tremor of the upper extremities. Recently, the primary sensorimotor cortex (S1/M1) has been shown to be involved in WD postural tremor generation. However, neuropathological changes in WD are mostly observed in subcortical structures. We therefore aimed to investigate whether S1/M1 may be functionally interconnected with other brain areas. In five WD patients, we used magnetoencephalography and surface electromyography (EMG) to record simultaneously cerebral neuronal activity and muscular activity during sustained posture of the right forearm. As demonstrated previously, the strongest coupling to tremor EMG was observed in the contralateral S1/M1. This area was taken as reference in order to identify and localize cerebro-cerebral coherence at tremor frequency and its first harmonic. The analysis revealed significant coherence within an oscillatory network including S1/M1, higher cortical motor areas (premotor cortex, PM; supplementary motor area, SMA), posterior parietal cortex (PPC) and thalamus contralateral as well as the cerebellum ipsilateral to the tremor forearm. Flow of information was mainly of bidirectional nature. Taken together, our results indicate that WD postural tremor is generated within a synchronized cerebello-thalamo-cortical network, comprising S1/M1, higher cortical motor areas (SMA, PM), and PPC.
authors.affiliation: Department of Neurology, Heinrich Heine University, Düsseldorf, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Südmeyer
authors.forename: Bettina
authors.initials: B
authors.lastname: Pollok
authors.forename: Harald
authors.initials: H
authors.lastname: Hefter
authors.forename: Joachim
authors.initials: J
authors.lastname: Gross
authors.forename: Markus
authors.initials: M
authors.lastname: Butz
authors.forename: Lars
authors.initials: L
authors.lastname: Wojtecki
authors.forename: Lars
authors.initials: L
authors.lastname: Timmermann
authors.forename: Alfons
authors.initials: A
authors.lastname: Schnitzler
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D001931:Brain Mapping; D004569:Electroencephalography / Q000379:methods; D004576:Electromyography / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology / Q000528:radiation effects; D006527:Hepatolenticular Degeneration / Q000150:complications*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology; D009415:Nerve Net / Q000503:physiopathology*; D011187:Posture; D014202:Tremor / Q000209:etiology*