Wearable Sensor for Responsive DBS for ET
Wearable Sensor for Responsive DBS for ET
The purpose of this study is evaluate the effectiveness and safety of a possible new
 treatment for Essential Tremor (ET) using external wearable sensors, which have the
 capability of recording acceleration and Electromyography (EMG). This therapy is called
 Responsive Deep Brain Stimulation (R-DBS). R-DBS systems will communicate with a computer,
 and apply stimulation when the computer detects patterns associated with tremor. This
 detection will suppress pathological activity and improve or alleviate the tremor.

 Currently, DBS is approved for the treatment of ET; however, stimulation is delivered
 continuously even when tremor or other symptoms are absent. Continuous DBS can lead to
 unwanted side effects such as stuttering and gait\balance problems. On the other hand, R-DBS
 will turn on only if activity associated with ET from the external sensors is detected.
The overall purpose of this application is to capture pathological activity related to
 essential tremor using external wearable sensors to responsively initiate or terminate DBS.
 To this end, the researchers propose to use the Nexus-D system, which requires a firm ware
 update to an Activa Implantable Neurostimulator (INS), and it will in a smart way turn DBS
 on/off in patients. The study team will recruit subjects with Activa SC or PC neurostimulator
 implants during 6 post-operative programming visits. The research group is already familiar
 with and is in possession of the Nexus-D system, and the investigators have successfully
 performed responsive DBS in two patients with Tourette syndrome (TS) and in four patients
 with Parkinson's disease in acute settings. The lab is also equipped with wireless wearable
 sensor and amplifier systems, such as a 16-unit wireless EMG+ acceleration+inertia Trigno
 Wireless Bio Acquisition System (Delsys Inc, Natick, MA). The study team aims to combine
 these signal modalities to capture pathological symptoms and generate commands to initiate or
 terminate DBS (also record adverse side effects, if any). The project goal is to characterize
 the clinical efficacy, side effect profile, and battery life of closed-loop DBS in acute
 settings using wearable sensors in essential tremor patients.
Inclusion Criteria:

 -  Provide informed consent

 -  Patient is over 21 years of age

 -  Patient has had a significant disabling, medication-refractory upper extremity tremor
 with no evidence of non-ET central nervous system disease or injury for at least three
 (3) months prior to implantation of Activa SC, PC, or RC device.

 -  Patient receives Vim electrode and Activa SC, PC or RC device implants, and recovers
 fully after surgery.

 -  Patient is available for study participation after their clinical programming
 appointments for six months.

 Exclusion Criteria:

 -  Medication related movement disorders.

 -  Any suspicion of Parkinsonian tremor, including presence of Parkinsonian features such
 as bradykinesia, rigidity, or postural instability.

 -  Severe medical co-morbidity including cardiovascular disorder, lung disorder, kidney
 disease, continuous neurological disease, hematological disease, or frailty that
 impact tolerability of the surgery as judged by the screening physicians.

 -  Patient is undergoing a lead revision surgery.