title: Essential pitfalls in "essential" tremor.
abstract: Although essential tremor has been considered the most common movement disorder, it has largely remained a diagnosis of exclusion: many tremor and nontremor features must be absent for the clinical diagnosis to stand. The clinical features of "essential tremor" overlap with or may be part of other tremor disorders and, not surprisingly, this prevalent familial disorder has remained without a gene identified, without a consistent natural history, and without an acceptable pathology or pathophysiologic underpinning. The collective evidence suggests that under the rubric of essential tremor there exists multiple unique diseases, some of which represent cerebellar dysfunction, but for which there is no intrinsic "essence" other than a common oscillatory behavior on posture and action. One approach may be to use the term essential tremor only as a transitional node in the deep phenotyping of tremor disorders based on historical, phenomenological, and neurophysiological features to facilitate its etiologic diagnosis or serve for future gene- and biomarker-discovery efforts. This approach deemphasizes essential tremor as a diagnostic entity and facilitates the understanding of the underlying disorders to develop biologically tailored diagnostic and therapeutic strategies. © 2017 International Parkinson and Movement Disorder Society.
authors.affiliation: UC Gardner Neuroscience Institute, Department of Neurology, Gardner Center for Parkinson's Disease and Movement Disorders, University of Cincinnati, Ohio, USA.
authors.forename: Alberto J
authors.initials: AJ
authors.lastname: Espay
authors.affiliation: Morton and Gloria Shulman Movement Disorders Center, Toronto Western Hospital and The Edmond J. Safra Program in PD, Toronto, Ontario, Canada, University of Toronto, Toronto, Ontario, Canada.|Krembil Research Institute, Toronto, Ontario, Canada.
authors.forename: Anthony E
authors.initials: AE
authors.lastname: Lang
authors.affiliation: Department of Neuroscience, Biomedicine and Movement Science, University of Verona, Verona, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Erro
authors.affiliation: UC Gardner Neuroscience Institute, Department of Neurology, Gardner Center for Parkinson's Disease and Movement Disorders, University of Cincinnati, Ohio, USA.
authors.forename: Aristide
authors.initials: A
authors.lastname: Merola
authors.affiliation: Morton and Gloria Shulman Movement Disorders Center, Toronto Western Hospital and The Edmond J. Safra Program in PD, Toronto, Ontario, Canada, University of Toronto, Toronto, Ontario, Canada.|Krembil Research Institute, Toronto, Ontario, Canada.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Fasano
authors.affiliation: Department of Neurology and Psychiatry, "Sapienza" University of Rome, Rome, Italy.|IRCCS Neuromed, Pozzilli, IS, Italy.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Berardelli
authors.affiliation: Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, UK.
authors.forename: Kailash P
authors.initials: KP
authors.lastname: Bhatia
mesh_terms: D020329:Essential Tremor / Q000145:classification* / Q000175:diagnosis*; D006801:Humans
keywords: biomarkers; essential tremor; nomenclature; tremor