Introduction
Target selection remains one of the most critical determinants of outcome in tremor surgery. While the ventral intermediate nucleus (VIM) of the thalamus has long been the standard target, increasing attention has been directed toward the pallidothalamic tract (PTT) due to its network-level effects.
Key Concepts
VIM Targeting
VIM is widely used in both DBS and lesioning procedures. It provides reliable tremor suppression, particularly for distal tremor, but may show limitations in proximal or intention tremor and can be associated with recurrence.
PTT Targeting
PTT focuses on fiber pathways rather than a discrete nucleus. This approach enables broader modulation of tremor circuits and may provide advantages in selected or refractory cases.
Practical Considerations
- VIM remains first-line in most essential tremor cases
- PTT is useful in complex or recurrent tremor
- Tractography enhances targeting accuracy
- Balance and ataxia risks must be considered
Conclusion
VIM and PTT are complementary targets. Increasing emphasis on network-based targeting is likely to refine patient-specific strategies in tremor surgery.