Thalamic Deep Brain Stimulation in Essential Tremor Plus Is as Effective as in Essential Tremor.

Josef Kessler,Veerle Visser-Vandewalle,Jochen Wirths,Tabea Thies,Michael T Barbe,Gereon R Fink,Till A Dembek,Stefanie T Jost,Jan N Petry-Schmelzer,Hannah Jergas,Haidar S Dafsari,Julia K Steffen

doi:10.3390/brainsci10120970

Josef Kessler, Veerle Visser-Vandewalle + Show 10 more

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https://doi.org/10.3390/brainsci10120970

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Abstract

The new essential tremor (ET) classification defined ET-plus (ET-p) as an ET subgroup with additional neurological signs besides action tremor. While deep brain stimulation (DBS) is effective in ET, there are no studies specifically addressing DBS effects in ET-p. 44 patients with medication-refractory ET and thalamic/subthalamic DBS implanted at our center were postoperatively classified into ET and ET-p according to preoperative documentation. Tremor suppression with DBS (stimulation ON vs. preoperative baseline and vs. stimulation OFF), measured via the Fahn–Tolosa–Marin tremor rating scale (TRS), stimulation parameters, and the location of active contacts were compared between patients classified as ET and ET-p. TRS scores at baseline were higher in ET-p. ET-p patients showed comparable tremor reduction as patients with ET, albeit higher stimulation parameters were needed in ET-p. Active electrode contacts were located more dorsally in ET-p of uncertain reason. Our data show that DBS is similarly effective in ET-p compared to ET. TRS scores were higher in ET-p preoperatively, and higher stimulation parameters were needed for tremor reduction compared to ET. The latter may be related to a more dorsal location of active electrode contacts in the ET-p group of this cohort. Prospective studies are warranted to investigate DBS in ET-p further.

Highlights

Essential tremor (ET) is characterized by bilateral upper limb action tremor but may include other neurological symptoms
Previous studies on deep brain stimulation (DBS) in essential tremor (ET) did not differentiate between ET and ET-p. Since in those studies, where patients were not systematically grouped in ET with and without plus signs, DBS response varies [6,7], this study aimed to investigate the effect of DBS in the ET-p group
ventral intermediate nucleus (VIM)/posterior subthalamic area (PSA) DBS between February 2009 and May 2019 at our center were retrospectively reclassified as either ET or ET-p

Summary

Introduction

Essential tremor (ET) is characterized by bilateral upper limb action tremor but may include other neurological symptoms. In 2017, the Movement Disorder Society (MDS) published a tremor classification with new diagnostic criteria [1]. In this classification, ET with additional neurological signs, such as ataxia, rest tremor, or cognitive impairment, was defined as ET plus (ET-p). Deep brain stimulation (DBS) of the thalamic ventral intermediate nucleus (VIM) and the posterior subthalamic area (PSA) is an effective treatment for medication-refractory ET.

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