title: The pathophysiology of essential tremor and Parkinson's tremor.
abstract: We review recent evidence about the pathophysiology of essential tremor and tremor in Parkinson's disease. We believe that a network perspective is necessary to understand this common neurological symptom, and that knowledge of cerebral network dysfunction in tremor disorders will help to develop new therapies. Both essential tremor and Parkinson's tremor are associated with increased activity in the cerebellothalamocortical circuit. However, different pathophysiological mechanisms lead to tremulous activity within this circuit. In Parkinson's disease, evidence suggests that dopaminergic dysfunction of the pallidum triggers increased activity in the cerebellothalamocortical circuit. In essential tremor, GABAergic dysfunction of the cerebellar dentate nucleus and brain stem, possibly caused by neurodegeneration in these regions, may lead to tremulous activity within the cerebellothalamocortical circuit. In both disorders, network parameters such as the strength and directionality of interregional coupling are crucially altered. Exciting new research uses these network parameters to develop network-based therapies, such as closed-loop deep brain stimulation and transcranial magnetic or direct current stimulation.
authors.affiliation: Donders Institute for Brain, Cognition and Behaviour, Centre for Cognitive Neuroimaging, Radboud University Nijmegen, Nijmegen, The Netherlands. r.helmich@neuro.umcn.nl
authors.forename: Rick C
authors.initials: RC
authors.lastname: Helmich
authors.forename: Ivan
authors.initials: I
authors.lastname: Toni
authors.forename: Günther
authors.initials: G
authors.lastname: Deuschl
authors.forename: Bastiaan R
authors.initials: BR
authors.lastname: Bloem
mesh_terms: D000818:Animals; D004599:Electric Stimulation Therapy / Q000379:methods; D020329:Essential Tremor / Q000150:complications / Q000503:physiopathology* / Q000628:therapy; D006801:Humans; D009069:Movement Disorders / Q000503:physiopathology; D009415:Nerve Net / Q000503:physiopathology; D010300:Parkinson Disease / Q000150:complications / Q000503:physiopathology* / Q000628:therapy; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D005680:gamma-Aminobutyric Acid
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