# Different Types of Connections Between the Thalamus and Vestibular Nucleus in the Human Brain

## TL;DR

This study maps connections between the thalamus and vestibular nucleus in the human brain using DTI tractography.

## Contribution

The novel contribution is identifying distinct connectivity patterns between specific vestibular and thalamic nuclei in humans.

## Key findings

- The lateral vestibular nucleus (LVN) shows high connectivity to ventral posterolateral and ventral posteromedial thalamic nuclei.
- The medial vestibular nucleus (MVN) has the strongest connection to the ventral intermediate thalamic nucleus.
- Vestibulothalamic tracts mainly pass through the midbrain tegmentum, not the tectum.

## Abstract

Background/Objectives: The vestibulothalamic tract (VTT) serves as a crucial pathway transmitting vestibular information from the brainstem nuclei to the thalamus, where integration with other sensory modalities occurs. This study aimed to investigate the structural connectivity between three vestibular nuclei and three thalamic nuclei in the human brain using diffusion tensor imaging (DTI) tractography. Methods: Twelve healthy adults underwent DTI to visualize vestibulothalamic connections using probabilistic tractography. Results: Results revealed distinct patterns of connectivity: the lateral vestibular nucleus (LVN) exhibited the highest reconstruction rates to both the ventral posterolateral (95.8%) and ventral posteromedial (83.3%), while the medial vestibular nucleus (MVN) showed the strongest connection to the ventral intermediate (75.0%). All vestibulothalamic tracts predominantly passed through the tegmentum of the midbrain, with limited or absent contributions from the tectum. Conclusions: These findings indicate differential roles of vestibular nuclei in relaying information to thalamic targets, with the LVN showing preferential projections to sensory relay nuclei and the MVN contributing to motor-related thalamic regions. Such insights may have important implications for the diagnosis and treatment of vestibular disorders, as well as for advancing anatomical research. These findings provide anatomical insights that may help explain symptoms of vestibular and thalamic lesions and guide rehabilitation strategies for balance and gaze control disorders.