Multicentre RCT of Awake Versus Asleep Tractography Based DBS for ET

Rationale: Deep brain stimulation (DBS) of the thalamus is an effective surgical treatment for patients with disabling essential tremor, despite optimal pharmacological treatment. To date, the standard DBS procedure is performed under local anesthesia which is very burdensome for patients. It is now possible to directly visualize the target (motor) area in the thalamus due to advances in modern imaging techniques. DBS surgery could be performed under general anesthesia (asleep).

Objective: The primary objective of the study is to determine whether asleep thalamic DBS surgery provides an equal tremor reduction compared to awake thalamic DBS surgery, measured by the clinically validated Essential Tremor Rating Assessment Scale after six months of DBS.

Secondary outcomes are: disease related daily functioning, adverse effects, operation time, quality of life, patient satisfaction with treatment outcome and patient evaluation of treatment burden.

Study design: The study will be a multicentre prospective randomized open label blinded (PROBE) endpoint trial comparing thalamic DBS under general versus local anesthesia.

Study population: A total of 110 patients with disabling essential tremor despite optimal pharmacological treatment will be randomized.

Intervention (if applicable): Patients will be randomized for asleep DBS or awake DBS. According to the standard DBS procedure, two brain-electrodes are connected to an implanted neurostimulator, which is placed subcutaneously in the subclavicular area

Main study parameter/endpoints: The primary outcome measure is the change in tremor score on the Essential Tremor Rating Assessment Scale after 6 months of thalamic DBS.

The secondary outcome measures are the Amsterdam Linear Disability Score for functional health status, Quality of Life in Essential Tremor Questionnaire, patient satisfaction with the treatment, patient evaluation of treatment burden, operating time, hospitalization time, change of tremor medication, side effects and complications.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Awake DBS at present is very burdensome and by many patients and health care providers considered to be an overly invasive treatment for essential tremor. Through this trial, we aim to investigate whether asleep DBS in essential tremor can become the new treatment standard. This is expected to increase the accessibility for DBS and subsequently would allow more people with essential tremor to be helped, as well as in an earlier stage of their disease than currently; more patients will benefit for a longer time period from DBS. Asleep DBS will have a shorter procedure length. The proposed research project involves treatment options that are standard care in daily practice. The therapies will not be combined with other research products. Both treatments have a low risk of serious complications and a higher risk of minor side effects. Regular follow up will be used. Participation in this study constitutes moderate risk according to NFU criteria for human research.