Lateral Medullary Syndrome Following Injury of Lateral Vestibulospinal Tract: Diffusion Tensor Imaging Study.

BACKGROUND

Unilateral lesions of vestibular nucleus can cause lateral medullary syndrome. Little is known about injury of medial and lateral vestibulospinal tract (VST) after dorsolateral medullary infarct. We investigated injury of the lateral VST in patients with typical central vestibular disorder using diffusion tensor tractography (DTT).

METHODS

Seven patients with lateral medullary syndrome and ten control subjects were recruited. For the medial VST, we determined seed region of interest (ROI) as medial vestibular nuclei of pons and target ROI on posteromedial medulla. For the lateral VST, the seed ROI was placed on lateral vestibular nuclei of pons, and the target ROI on posterolateral medulla. Fractional anisotropy (FA), mean diffusivity (MD), and tract volume were measured.

RESULT: Reconstructed lateral VST on both sides had significantly lower FA values in patients than controls (p<0.05). Tract volume of lateral VST in affected side was significantly lower than unaffected side and control group (p<0.05). However, no DTI parameters of the medial VST differed between patients and controls (p>0.05).

CONCLUSION

Injury of the lateral VST was demonstrated in patients with lateral vestibular syndrome following dorsolateral medullary infarct. Analysis of the lateral VST using DTT would be helpful in evaluation of patients with lateral medullary syndrome.