A method for pre-operative single-subject thalamic segmentation based on probabilistic tractography for essential...

Area of Science:

• Neurosurgery
• Neurology
• Medical Imaging

Background:

• Deep brain stimulation (DBS) is a common treatment for medication-refractory essential tremor.
• Current coordinate-based targeting methods for DBS yield variable outcomes due to anatomical differences in the thalamus and the need for patient-specific functional targeting.

Purpose of the Study:

• To compare traditional coordinate-based pre-operative targets with patient-specific thalamic segmentation derived from probabilistic tractography.
• To evaluate the efficacy of a novel targeting methodology for essential tremor DBS.

Main Methods:

• Diffusion MRI data from 32 Human Connectome Project subjects were analyzed using probabilistic tractography.
• Thalamic voxels were coded based on connectivity to six predefined cortical targets.
• Segmentation results were compared to standard 2-mm spherical targets in the ventral intermediate thalamic nucleus.

Main Results:

• The conventional coordinate-based target showed maximal overlap with regions connected to the primary motor cortex (M1) and supplementary motor area/premotor cortex (SMA/PMC).
• Significant intra- and inter-subject variability was observed in the overlap of coordinate-based targets with functional regions (M1 and SMA/PMC).

Conclusions:

• Thalamic segmentation using structural connectivity is a viable technique for enhancing DBS targeting in essential tremor.
• This method may provide reproducible, patient-specific functional targets, potentially improving upon the variability of indirect, coordinate-based approaches.
• Further clinical studies are necessary to validate this patient-specific targeting methodology for essential tremor treatment.