Neuroimaging abnormalities with hypoglossal nerve palsies.

Seven patients with acute or chronic unilateral hypoglossal nerve lesions were evaluated by magnetic resonance imaging and computed tomography. In the patients with acute to subacute paralysis of the tongue, the base of the ipsilateral side of the tongue appeared expanded with increased signal intensity on T2-weighted images. This appearance suggested an infiltrative mass lesion within the tongue. These radiographic findings are due to the pathophysiological process of nerve injury and muscle denervation.