title: Linking Essential Tremor to the Cerebellum: Physiological Evidence.
abstract: Essential tremor (ET), clinically characterized by postural and kinetic tremors, predominantly in the upper extremities, originates from pathological activity in the dynamic oscillatory network comprising the majority of nodes in the central motor network. Evidence indicates dysfunction in the thalamus, the olivocerebellar loops, and intermittent cortical engagement. Pathology of the cerebellum, a structure with architecture intrinsically predisposed to oscillatory activity, has also been implicated in ET as shown by clinical, neuroimaging, and pathological studies. Despite electrophysiological studies assessing cerebellar impairment in ET being scarce, their impact is tangible, as summarized in this review. The electromyography-magnetoencephalography combination provided the first direct evidence of pathological alteration in cortico-subcortical communication, with a significant emphasis on the cerebellum. Furthermore, complex electromyography studies showed disruptions in the timing of agonist and antagonist muscle activation, a process generally attributed to the cerebellum. Evidence pointing to cerebellar engagement in ET has also been found in electrooculography measurements, cerebellar repetitive transcranial magnetic stimulation studies, and, indirectly, in complex analyses of the activity of the ventral intermediate thalamic nucleus (an area primarily receiving inputs from the cerebellum), which is also used in the advanced treatment of ET. In summary, further progress in therapy will require comprehensive electrophysiological and physiological analyses to elucidate the precise mechanisms leading to disease symptoms. The cerebellum, as a major node of this dynamic oscillatory network, requires further study to aid this endeavor.
authors.affiliation: First Department of Neurology, Faculty of Medicine, Masaryk University and St. Anne's Teaching Hospital, Pekařská 53, 656 91, Brno, Czech Republic.|Central European Institute of Technology, CEITEC MU, Behavioral and Social Neuroscience Research Group, Masaryk University, Brno, Czech Republic.
authors.forename: Pavel
authors.identifier: 0000-0001-5656-5164
authors.initials: P
authors.lastname: Filip
authors.affiliation: Department of Psychiatry, Université de Montréal, Montréal, Québec, Canada.|Functional Neuroimaging Unit, Research Center of the Geriatric Institute Affiliated with the Université de Montréal, Montréal, Québec, Canada.
authors.forename: Ovidiu V
authors.initials: OV
authors.lastname: Lungu
authors.affiliation: FNRS-ULB, Hôpital Erasme, Brussels, Belgium.
authors.forename: Mario-Ubaldo
authors.initials: MU
authors.lastname: Manto
authors.affiliation: First Department of Neurology, Faculty of Medicine, Masaryk University and St. Anne's Teaching Hospital, Pekařská 53, 656 91, Brno, Czech Republic. bares@muni.cz.|Central European Institute of Technology, CEITEC MU, Behavioral and Social Neuroscience Research Group, Masaryk University, Brno, Czech Republic. bares@muni.cz.|Department of Neurology, School of Medicine, University of Minnesota, Minneapolis, MN, USA. bares@muni.cz.
authors.forename: Martin
authors.initials: M
authors.lastname: Bareš
mesh_terms: D000818:Animals; D002531:Cerebellum / Q000503:physiopathology*; D020329:Essential Tremor / Q000503:physiopathology*; D006801:Humans
keywords: Cerebellum; Dynamic oscillatory network; Electrophysiology; Essential tremor