Probabilistic mapping of deep brain stimulation effects in essential tremor

Area of Science:

• Neuroscience
• Neurology
• Neurosurgery

Background:

• Essential tremor (ET) is a common neurological disorder characterized by involuntary shaking.
• Deep brain stimulation (DBS) is an established therapy for managing ET symptoms.
• Optimizing DBS target selection is crucial for maximizing tremor suppression and minimizing side effects.

Purpose of the Study:

• To develop probabilistic stimulation maps (PSMs) for visualizing deep brain stimulation (DBS) effects in essential tremor (ET) patients.
• To assess the spatial relationship between DBS parameters, tremor suppression, and stimulation-induced side effects.
• To evaluate the utility of PSMs in guiding DBS target selection for ET.

Main Methods:

• Utilized monopolar review data from 16 ET patients, encompassing over 600 stimulation settings.
• Employed a spherical model of neural activation to estimate the volume of tissue activated by DBS.
• Performed voxel-wise statistical analysis and nonparametric permutation testing to validate the PSMs.

Main Results:

• Probabilistic stimulation maps revealed that stimulating the zona incerta (ZI) resulted in more pronounced tremor suppression compared to the ventral intermediate nucleus (VIM).
• Paresthesias and dizziness were frequently reported side effects associated with stimulation within the ZI and adjacent thalamic regions.
• The study confirmed the validity of PSMs in representing DBS effects.

Conclusions:

• The zona incerta (ZI) shows promise as an effective target for essential tremor (ET) suppression via DBS.
• Stimulation within or near the ZI is linked to increased side effects, making the optimal target (ZI vs. VIM) a subject for further investigation.
• Probabilistic stimulation maps (PSMs) offer a valuable tool for DBS target selection, evaluation, and clinical programming, potentially improving patient outcomes across various neurological and psychiatric disorders.