The goal of this interventional study is to evaluate the effectiveness of treatment using stereotactic radiosurgery in the treatment of essential tremor in adult patients

The study will include patients diagnosed with essential tremor who have insufficient tremor control despite the use of available pharmacotherapy methods. The study will include patients who have been disqualified from the Deeply Brain Stimulation procedure or who do not consent to its performance. Additional conditions for the examination are age over 50 and the duration of the disease over 5 years.

After qualifying and giving written informed consent, the patient will be randomly assigned to one of two study arms:

1. control arm: patients irradiated with the CyberKnife with a dose of 130 Gy
2. test arm: patients irradiated with the CyberKnife with a dose of 80 Gy

The primary aim of the study is to determine the effectiveness of radiosurgery in patients with essential tremor. Secondary objectives will be to determine the impact of treatment on the quality of life of, as well as to assess the safety and possible complications of radiosurgery.

Inclusion Criteria:

• Essential tremor diagnosed, Parkinson's disease and other causes of tremor excluded.
• Insufficient tremor control despite the use of available pharmacotherapy methods.
• Disqualification from the Deeply Brain Stimualtion procedure/lack of consent to perform it on the side qualified for Stereotactic Radiosurgery
• Consent to participate in a clinical trial.

Exclusion Criteria:

• Age under 50
• Pregnancy
• Duration of the disease less than 5 years
• Dementia, psychosis or other condition that prevents giving informed consent to participate in the study
• Poor general condition, serious comorbidities
• Structural changes in the basal ganglia or major atrophic changes
• Previous radiotherapy to the brain covering the potential treatment area
• Medical contraindications to magnetic resonance imaging