Thalamic single-unit and local field potential activity in Tourette syndrome

Area of Science:

• Neuroscience
• Neurosurgery
• Movement Disorders

Background:

• Tourette syndrome (TS) is a neurological disorder characterized by involuntary movements and vocalizations called tics.
• Deep brain stimulation (DBS) of the ventralis oralis (VO) complex in the thalamus is an effective treatment for severe TS.
• Understanding the neurophysiological characteristics of the VO complex is crucial for optimizing DBS therapy.

Purpose of the Study:

• To neurophysiologically characterize the ventralis oralis (VO) complex in patients with Tourette syndrome (TS).
• To investigate the neuronal activity patterns within the VO complex during DBS surgery for TS.
• To correlate single-unit activity with local field potential (LFP) oscillations in the target region.

Main Methods:

• Single-unit recordings were performed during DBS electrode implantation surgery in seven TS patients.
• Local field potentials (LFPs) were recorded a few days after surgery.
• Analysis included characterizing neuronal bursting patterns and LFP spectral properties (oscillatory activity).

Main Results:

• Single-unit recordings identified a localized pattern of bursting neuronal activity in the VO complex.
• LFP analysis revealed prominent low-frequency (2-7 Hz) and alpha-band (8-13 Hz) oscillations in the VO of TS patients.
• Beta activity was notably absent in the VO of TS patients, and LFP frequency correlated with single-unit interburst frequency.

Conclusions:

• The VO complex in TS patients exhibits distinct oscillatory bursting activity.
• These findings provide neurophysiological insights into the VO complex as a target for DBS in Tourette syndrome.
• The observed oscillatory patterns may inform the development of more targeted and effective DBS strategies for tic disorders.