Age-related changes in the vestibulothalamic pathway: Association with balance ability and subjective visual vertical...

The thalamus regulates various sensory information to each related brain area. The vestibular nucleus transmits information of motor control to the thalamus regulating coordination function. The vestibulothalamic tract (VTT) is a neural pathway between the vestibular nucleus and thalamus that processes vestibular information for postural balance and spatial perception. Therefore, this study analyzed ipsilateral VTT to compare the neural pathway and the differences in vestibular and balance functions according to aging.

Eleven elderly and 12 young healthy adults were recruited. This study measured subjective visual vertical (SVV) for vestibular function and body sway during one-leg standing. The ipsilateral VTT were reconstructed to investigate changes of neural pathway between two groups using diffusion tensor imaging.

Track volume of left and right VTTs was significantly more in the young healthy adults. In eyes-open (EO) condition during one-leg standing, the body sway demonstrated significant differences between two groups. In the eyes-closed (EC) condition, the degree of hip sway was decreased in the young healthy adults. In the EO condition, the body sway except for antero-posterior direction was significantly correlated with VTT. Meanwhile, in the EC condition, hip sway and all values of body sway were negatively correlated with VTT. In addition, the VTT revealed a negative correlation with SVV.

The tract volume of VTT and static balance decreased according to aging. The changes of VTT also affected verticality perception and static balance. Therefore, the study could be helpful in providing the data for patients with thalamus or vestibular injury.