All right, thank you so much. Our next talk will be Dr. Chang Park. Is Dr. Park here? Oh, great. Wonderful. Dr. Park will be talking about a prospective trial of magnetic resonance-guided focused ultrasound thalamotomy for essential tremor. To your follow-up. Thank you. I'm Chang Park from South Korea. I will present to you a follow-up result of a magnetic resonance-guided focused ultrasound thalamotomy for essential tremor. The essential tremor is not a life-threatening disease, but it causes personal, social, and economic problems. So the patient requires active treatment. So most of them take medication first. But the response to medication is not so good. So the following surgical treatment will be treated to a patient with a medically-reflectory tremor. That is a radiofrequency aberration, anti-brain stimulation, and gamma-wave thalamotomy, and recently, magnetic resonance-guided focused ultrasound, called MRG-PUS. But the RF and DBS needed to general anesthesia and in-house vulnerable device and gamma-wave thalamotomy. The problem is that the effect appeared to be delayed, so MRG-PUS, which can reduce this inconvenience, has emerged as a new treatment option for essential tremor. The safety and efficacy of MRG-PUS has been already reported in the, through the previous one-year follow-up study, but the durability of the procedure has not yet been evaluated. So this, the reported result at two years follow-up for MRG-PUS thalamotomy for essential tremor. A total of 76 patients were near the study from August 2030 to September 2014. The important inclusion criteria is that those with higher skull density ratio than 0.45 were included in the study. The patient had the following demographics and ultrasound therapy was performed as following, and the CRST was used for clinical evaluation of the patient. In result, each patient showed in the following symptom change after the surgery, that most of the patient were maintained with the improvement of the symptom after the surgery. The total of nine patient dropped out during the study. The main value of the CRST score for each period was shown in the following graph. The decreased score after the surgery were maintained until to the second years. There was a clinical course of the nine patient who did not complete the study to two years. There was no severe side effect, but the three patient were treated with alternative treatment such as DBS because of no improvement of the symptom with MRG-PUS. It is a statistical analysis of whether improvement of the symptom according to the change of the time has a significant, so in result, in all scores, the improvement of the symptom remained significant for post-operative period. It is a distribution of the patient according to the trauma severity after the MRG-PUS. Before the surgery, most of the patient were distributed three or four point, but after the surgery, most of the patient were distributed low scores, and it is maintained until the second years. There is a change in the trauma score from the baseline to two years. More than half of patient showed that the improvement of the symptom by the more 50%. There is a adverse effect at treatment time continued to one month. And in the current study, one year later, one paresthesia and one T-sergia were resolved. But the important point to note in the current study is that there were no new complications or adverse event which relate to MRG-PUS from one year to two years after MRG-PUS. The effect of DBS are long-lasting. It has reported in main study, but in some studies, it's shown that the DBS effect decreased over the time. So development of tolerance to stimulation or misdiagnosis or disease prognation were being cited to causes. According to another study, the RF thalamotomy significantly suppressed the essential trauma in 86% of the patient in the long-term follow-up. However, trauma record in the 24% of the patient up to five years positively. And in gamma-F thalamotomy, this effect also diminished over the time. So this result which showed that the benefit of various treatment for essential trauma can decrease over time. So it is highlight the need for long-term evaluation of the effect of MRG-PUS. So further work is required to optimize patient selection, improve clinical result, and avoid adverse effect. And determining which patient are most correct to show an optimal response to treatment and who is less likely to respond or show adverse effect is important. And in addition, characterizing the topography and the size of region that cause adverse effect is a priority. In conclusion, the present study showed that the reduction in trauma and disability in the patient with essential trauma of the MRG-PUS thalamotomy is durable to two years after treatment. And no new delayed complication which relate to MRG-PUS thalamotomy occurred from one year to two years. And some previous adverse effects were further resolved. This study was published in the Analyzer's Library on this year. So this paper will give you more information. Thank you for your attention. Thank you very much. Any questions from the audience? Tell us a little bit about the gait disturbance in the 10 patients that had some walking problems. No. The 10 patients that had problems walking, was it a long-term problem for them then? Did it improve? No, no. There was no worse complication and they have mild complication. Okay, thank you very much. Thank you. Okay.

Dr. Chang Park

MRG-PUS thalamotomy

essential tremor

long-term evaluation

treatment effectiveness