Vim stereotactic radiosurgical thalamotomy for drug-resistant idiopathic Holmes tremor: a case report

The Relevance of Intraoperative Clinical and Accelerometric Measurements for Thalamotomy Outcome

Thalamotomy alleviates medication-refractory tremors in patients with movement disorders such as Parkinson's Disease (PD), Essential tremor (ET), and Holmes tremor (HT). However, limited data are available on tremor intensity during different thalamotomy stages. Also, the predictive value of the intraoperative tremor status for treatment outcomes remains unclear. Therefore, we aimed to quantify tremor status during thalamotomy and postoperatively. Data were gathered between January 2020 and June 2023 during consecutive unilateral thalamotomy procedures in patients with PD (n = 13), ET (n = 8), and HT (n = 3). MDS-UPDRS scores and tri-axial accelerometry data were obtained during rest, postural, and intention tremor tests. Measurements were performed intraoperatively (1) before lesioning-probe insertion, (2) directly after lesioning-probe insertion, (3) during coagulation, (4) directly after coagulation, and (5) 4-6 months post-surgery. Accelerometric data were recorded continuously during the coagulation process. Outcome measures included MDS-UPDRS tremor scores and accelerometric parameters (peak frequency, tremor amplitude, and area under the curve of power (AUCP)). Tremor intensity was assessed for the insertion effect (1-2), during coagulation (3), post-coagulation effect (1-4), and postoperative effect (1-5). Following insertion and coagulation, tremor intensity improved significantly compared to baseline (p < 0.001). The insertion effect clearly correlated with the postoperative effect (ρ = 0.863, p < 0.001). Both tremor amplitude and AUCP declined gradually during coagulation. Peak frequency did not change significantly intraoperatively. In conclusion, the study data show that both the intraoperative insertion effect and the post-coagulation effect are good predictors for thalamotomy outcomes.

Case report: Radiofrequency thalamotomy as palliative care for Holmes tremor in a patient with terminal cancer and cardiac pacemaker

Background:

Herein, we present a case report of a patient with Holmes tremor due to thalamic infarction with end-stage pancreatic cancer who underwent successful computed tomography (CT)-guided ventralis intermedius nucleus (Vim) thalamotomy as palliative care.

Case Description:

A 78-year-old man with gradually worsening involuntary movements on the left side of his body 2 years after a right thalamic infarction was referred to our institute. He had a history of chronic atrial fibrillation for which he was implanted with a cardiac pacemaker not compatible with magnetic resonance imaging. He also received adjuvant therapy for pancreatic cancer. As the involuntary movements interfered with his daily life, the patient elected for neurosurgical treatment despite having terminal cancer. Although the prognosis for pancreatic cancer was considered to be more than 6 months at the time of surgery, we performed CT-guided Vim thalamotomy under local anesthesia without pulse generator implantation considering the patient’s general condition. The involuntary movements of the left side of the body reduced following surgery, thus improving his quality of life (QOL). However, 6 months after thalamotomy, the patient died of pancreatic cancer.

Conclusion:

Thalamotomy significantly reduced the involuntary movements immediately after the procedure. Therefore, thalamotomy can be performed under local anesthesia without the use of any device and may contribute to the improvement of QOL in terminal patients.