Essential Tremor and Essential Tremor Plus Are Essentially Similar Electrophysiologically

作者：Roopa Rajan, Reghu Anandapadmanabhan, Aayushi Vishnoi, Anna Latorre, Nivethida Thirugnanasambandam, Alish Dipani, Deblina Biswas, Divya M. Radhakrishnan, Achal Kumar Srivastava, Kailash P. Bhatia · 发表于：Movement Disorders Clinical Practice · 年份：2023 · DOI：10.1002/mdc3.13941 · 被引用次数：17 · 研究领域：Neurological disorders and treatments、Glycogen Storage Diseases and Myoclonus、Transcranial Magnetic Stimulation Studies

BACKGROUND: The merits of classifying the heterogeneous group of essential tremors into essential tremor (ET) and essential tremor plus (ETP) are debated. OBJECTIVES: We studied the electrophysiological and spiral characteristics of tremor in ET and ETP. METHODS: 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-axial accelerometry-surface electromyography (EMG)-peak frequency, total power, peak power, full width half maximum, tremor stability index and EMG-coherence. We analyzed hand-drawn spirals to derive mean deviation, tremor variability, inter-, and intra-loop widths. We compared these variables among the groups. RESULTS: We recruited 72 participants (81.9% male) with mean age 47.7 ± 16.1 years and Fahn-Tolosa-Marin Tremor Rating Scale total score 31.1 ± 14.1. Patients with ET were younger (P = 0.014) and had less severe tremor (P = 0.020) compared to ETP and DT. In ETP group, 48.6% had subtle dystonia. Peak frequency was greater in ETP (7.3 ± 0.3 Hz) compared to DT (6.1 ± 0.4 Hz; P = 0.024). 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. CONCLUSION: Electrophysiological evaluation revealed postural tremor of frequency 6 to 7 Hz in ET, ETP, and DT with subtle differences more severe tremor in ETP and DT, and higher frequen...