{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,4]],"date-time":"2026-10-04T03:13:14Z","timestamp":1791083594946,"version":"4.1.0"},"reference-count":30,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[2023,12,14]],"date-time":"2023-12-14T00:00:00Z","timestamp":1702512000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":["movementdisorders.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Movement Disord Clin Pract"],"published-print":{"date-parts":[[2024,2]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Background<\/jats:title><jats:p>The merits of classifying the heterogeneous group of essential tremors into essential tremor (ET) and essential tremor plus (ETP) are debated.<\/jats:p><\/jats:sec><jats:sec><jats:title>Objectives<\/jats:title><jats:p>We studied the electrophysiological and spiral characteristics of tremor in ET and ETP.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>We reviewed standardized videos from a tremor database and clinically classified patients into ET, ETP, or dystonic tremor (DT). The following variables were derived from combined tri\u2010axial accelerometry\u2013surface electromyography (EMG)\u2014peak frequency, total power, peak power, full width half maximum, tremor stability index and EMG\u2010coherence. We analyzed hand\u2010drawn spirals to derive mean deviation, tremor variability, inter\u2010, and intra\u2010loop widths. We compared these variables among the groups.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>We recruited 72 participants (81.9% male) with mean age 47.7\u2009\u00b1\u200916.1\u2009years and Fahn\u2010Tolosa\u2010Marin Tremor Rating Scale total score 31.1\u2009\u00b1\u200914.1. Patients with ET were younger (<jats:italic>P<\/jats:italic>\u2009=\u20090.014) and had less severe tremor (<jats:italic>P<\/jats:italic>\u2009=\u20090.020) compared to ETP and DT. In ETP group, 48.6% had subtle dystonia. Peak frequency was greater in ETP (7.3\u2009\u00b1\u20090.3\u2009Hz) compared to DT (6.1\u2009\u00b1\u20090.4\u2009Hz; <jats:italic>P<\/jats:italic>\u2009=\u20090.024). Peak power was greater in ETP and DT for postural tremor. Rest tremor was recordable on accelerometry in 26.7% of ET. Other variables were similar among the groups.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>Electrophysiological evaluation revealed postural tremor of frequency 6 to 7\u2009Hz in ET, ETP, and DT with subtle differences more severe tremor in ETP and DT, and higher frequency in ETP compared to DT. Our findings suggest a similar tremor oscillator in these conditions, supporting the view that these entities are part of a spectrum of tremor disorders, rather than distinct etiological entities.<\/jats:p><\/jats:sec>","DOI":"10.1002\/mdc3.13941","type":"journal-article","created":{"date-parts":[[2023,11,27]],"date-time":"2023-11-27T17:38:05Z","timestamp":1701106685000},"page":"136-142","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Essential Tremor and Essential Tremor Plus Are Essentially Similar Electrophysiologically"],"prefix":"10.1002","volume":"11","author":[{"given":"Roopa","family":"Rajan","sequence":"first","affiliation":[{"name":"All India Institute of Medical Sciences (AIIMS)  New Delhi 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