Patient case (clinical description): A 60-year-old man comes to the clinic complaining of hand tremor that started few months ago.  It is most bothering when he wants to drink from a glass or pour from a bottle. He does not smoke, but drinks occasionally. He recently started consuming more alcohol as his tremor subsides somewhat when he drinks small amounts of alcohol.  Family history is significant for similar problems in his mother.  Vital signs are normal and the patient has no other medical conditions.  Neurologic examination shows bilateral tremor in the upper extremities. The diagnosis of essential tremor is confirmed.

Patient's own account: I'm only a 60 years old man but I already suffer from shaky hands. It started a few months ago, and it really bothers me when I want to pour myself a glass or even while drinking. I don't smoke, but I drink alcohol from time to time. To be honest, I've been drinking a little more lately since it helps me with the shaking. My mom had the same issue when she was my age. The doctor took my vitals, and they were normal. I don't have any other medical issues. I underwent neurological exams and it showed that I’m shaky from both sides. The doctor diagnosed me with essential tremor.

Clinical trial: Evaluation of Directional Recording and Stimulation Using spiderSTN

Eligibility criteria:
Inclusion Criteria:

        Patient foreseen to undergo DBS for Parkinson's disease or Essential Tremor according to
        routine criteria of the center.

        For Parkinson Disease:

          -  Person is between 18 and 75 years of age

          -  Established diagnosis of idiopathic Parkinson's disease with progression of symptoms
             for a minimum of 2 years.

          -  Person has a history of at least 30% improvement on the UPDRS therapy in L-dopa
             (levodopa), except in the case of tremor dominant patient

          -  Weak control of symptoms by dopaminergic therapy (off phenomenon, fluctuations on /
             off, dyskinesia on)

        For Essential Tremor:

          -  Person is between 18 and 80 years of age

          -  Established diagnosis of Essential Tremor for a minimum of 2 years

          -  Functional disability due to tremor was not adequately controlled by medication for at
             least 3 months prior to implant.

        Person has given his/her written consent

        Exclusion Criteria:

          -  Person suffering from an active major psychiatric disorder

          -  Mattis Dementia Rating Scale score <130 or otherwise not capable of discernment

          -  Presence of major co-morbidity or medical condition that may affect participation to
             the study

          -  Presence of an electrical or electromagnetic implant (e.g., cochlear implant,
             pacemaker)

          -  Person with a previous surgery for the treatment of Parkinson's disease or Essential
             Tremor

          -  Person with a previous brain ablation procedure

          -  Person who suffers from epilepsy

          -  Person who is pregnant: a pregnancy test will be performed in patients of childbearing
             age

          -  Person with coagulopathies

          -  Abuse of drugs or alcohol
No condition on gender to be admitted to the trial.
No healthy subjects accepted to join the trial.
Subject must be at least 18 Years old.
Subject must be at most 80 Years

Eligibility (NLI label): Entailment