Objective: The purpose of this study was to determine whether tremor reduces in patients after stereotactic thalamotomy using tractography targeting the dentatorubrothalamic (DRT) tract.

Background: The ventralis intermedius (Vim) nucleus of the thalamus is the primary target for the surgical treatment of tremor in essential tremor, Parkinson’s disease and other neurodegenerations. Tractography may be a useful tool for direct localization of the Vim and DRT tract, which could improve the accuracy of surgical procedures for tremor treatment [1].

Method: We analyzed treatment results in 6 patients, characteristics are presented in the table, DRT tractography is realized by DSI Studio with RK4 method, 100 million seeds (Fig. 1). Tract density (TD) is calculated, it is summarized over each/all slices. The state of TD distribution disorder is evaluated with Shannon entropy. All patients underwent stereotactic thalamotomy with targeting in DRT at the AC-PC level. Tremor was assessed using a Clinical Rating Scale for Tremor (CRST) in preoperative and postoperative period.

Results: For all cases, TD sum and entropy are both decreased in post-operation state for all slices (Fig. 2). The TD sum decreasing shows the suppression of DRT, low entropy is associated with “more-ordered” TD distribution (in turn, shows the poor DRT re-organization). Sum of TD and its entropy over all slices are decreased for all patients, that correlates with CRST decline (Fig. 3). Significant reduction of tremor was observed in all patients. In one case, patient K had a complication in the form of hemiparesis in the early postoperative period, which completely resolved 1 week after surgery.

Conclusion: DRT tractography is an effective method for stereotactic thalamotomy in the treatment of drug refractory tremor. Sum of TD as well as its entropy over all slices is a potential sign to evaluate the suppression/destruction of DRT, but further studies of the TD statistical properties are need.

Patients characteristics and DRT visualisation

Pre- and postoperation TD and entropy

CRST with sum of TD and its entropy

References: 1. Parras O, Domínguez P, Tomás-Biosca A, Guridi J. The role of tractography in the localisation of the Vim nucleus of the thalamus and the dentatorubrothalamic tract for the treatment of tremor. Neurologia (Engl Ed). 2022 Oct;37(8):691-699. doi: 10.1016/j.nrleng.2019.09.008. Epub 2021 Sep 23. PMID: 34563477.

« Back to 2025 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/outcomes-of-invasive-stereotactic-thalamotomy-using-dentatorubrothalamic-tractography-targeting-for-patients-with-drug-refractory-tremor/