Dual Lead Thalamic DBR-DBS Interface for Closed Loop Control of Severe Essential Tremor
This is a feasibility study based on physician-initiated Investigational Device Exemption (IDE) including intraoperative experiments and chronic testing of implanted dual thalamic DBS lead systems. This study will inform protocols for optimal use of implanted next-gen DBS systems for primarily tremor control in refractory essential tremor.If the approach appears to be successful, the pilot data generated will be used to base a future pivotal trial for FDA approval for enhanced tremor control and adaptive DBS (aDBS) functionality of DBS systems.
• Patient gives an informed consent.
• Patient is over 21 years of age.
• Patient is diagnosed with a postural-intention (essential) tremor for at least 3 years, meets diagnostic criteria for ET, has been evaluated and examined by a movement disorders fellowship trained neurologist, and is being treated with traditional VIM DBS therapy.
• Patient has no evidence of non-ET central nervous system disease or injury and has had a significantly disabling, upper extremity tremor despite ongoing VIM DBS therapy for at least three (3) months prior to DBS revision surgery.
• Patient has a postural or kinetic tremor severity score of at least 2 out of 4 in the extremity intended for treatment on the Fahn-Tolosa-Marin Clinical Rating Scale for Tremor (TRS) despite ongoing VIM DBS therapy.
• Patient has a TRS score of 2 or above in any one of the items 16-23 from the Disability subsection of the TRS: speaking, feeding other than liquids, bringing liquids to mouth, hygiene, dressing, writing, working and social activities despite ongoing VIM DBS therapy.
• Patient's tremor is refractory to adequate trials of at least two medications, one of which should be either propranolol or primidone. Proof of this is not required for patients with a current device that is being removed and replaced with a new device. An adequate medication trial is defined as a therapeutic dose of each medication or the development of side effects as the medication dose is titrated.
• Patient is available for appropriate follow-up times for the length of the study.