Mapping Functional Networks of Brain Activity Using EEG in Patients With Essential Tremor or Parkinson Disease Before and After MR-guided Focused Ultrasound Thalamotomy for Tremor
Mapping Functional Networks of Brain Activity Using EEG in Patients With Essential Tremor or Parkinson Disease Before and After MR-guided Focused Ultrasound Thalamotomy for Tremor
A cornerstone in PD and ET research is the investigation of neurophysiological changes as
 potential bio-markers that could help in tracking disease progression and response to
 therapy. Electroencephalography (EEG) could provide a non-invasive and relatively inexpensive
 tool for identification of such bio-markers. In this study the investigators will use
 high-density electroencephalographic (EEG) recordings, in order to develop a platform of
 sensitive and reliable bio-markers for disease progression and response to MR-guided Focused
 ultrasound thalamotomy (FUS-T) intervention for tremor.
Parkinson's disease (PD) is a common neurodegenerative disease the neurochemical hallmark of
 which is dopamine deficiency in nigrostriatal pathways, and characterized clinically by a
 movement disorder consisting of rest tremor, bradykinesia, rigidity, impairment of postural
 reflexes and gait difficulties. The disease may leads to severe neurological dysfunction
 within several years.

 Essential tremor (ET) is a neurological disorder characterized by the presence of action
 tremor in different body parts mainly in the hands, head, larynx (voice box), tongue, and
 chin. The lower body is rarely affected.

 INSIGHTEC uses MR guided Focused Ultrasound to perform a "non-invasive" thalamotomy to
 relieve medication refractory tremor in patients with ET or tremor-dominant PD. The effect of
 MRgFUS is based on tissue destruction targeted to the Vim nucleus of the thalamus which
 enables a highly accurate and controlled thermal effect.

 Ultrasound energy is delivered across the skull, without an incision or craniotomy, heating
 the targeted tissue above the protein denaturation threshold at temperatures near 60°C. Prior
 to the delivery of high temperatures, destructive sonication delivery of lower energy focused
 ultrasound allows for proper anatomic localization, as well as physiologic evaluation of
 symptom relief and/or any unwanted side effects. This process allows for adjustments before
 making a permanent lesion. Treatment effects are immediate and the several hour treatment is
 generally well tolerated with mild sedatives.

 The FUS-T procedure was shown as an efficacious procedure for tremor in both ET patients and
 PD patients; Elminda developed an algorithm of Brain network activation (BNA) Mapping
 Functional Networks of Brain Activity Using EEG.

 Studying brain morphology and function with Neuroimaging and electrophysiological measures is
 critical for our understanding of the pathology and pathophysiology of PD and ET.

 The BNA network can shed a lite on the brain connectivity changes that occur as a result
 treatment in neurological patients, in this case patients with either PD or ET tremor going
 through FUS-T.

 BNA can help understanding the effects of FUS-T on the brain physiology and perhaps to
 identify biomarkers that may serve as tools for chosing the best candidates for this
 treatemnt and optimal treatment parameters.
Inclusion Criteria:

 -  Patients with essential Tremor and unilateral tremor-dominant Idiopathic Parkinson's
 Disease -undergoing ExAblate 4000 Transcranial MR guided focused ultrasound (TcMRgFUS)
 thalamotomy).

 Exclusion Criteria:

 -  In the investigator's opinion, any unstable or clinically significant condition that
 would impair the participants' ability to comply with study requirements.

 -  Patients with significant psychiatric symptoms or history

 -  Treatment with neuroleptics.

 -  Currently with lice or open wounds on scalp.

 -  Significant sensory deficits, e.g., deafness or blindness

 -  Current drug abuse or alcoholism.

 -  Pregnancy or not using a reliable method of birth control