Bilateral Ageusia Caused by a Unilateral Midbrain and Thalamic Infarction

BACKGROUND Based upon scarce clinical data in humans and experimental findings in animal studies, it has been postulated that the ascending gustatory projection from the nucleus tractus solitarii courses ipsilaterally through the pons and midbrain to the ipsilateral ventral posteromedial nucleus. Thus, it has been assumed that ischemic lesions affecting the secondary projection gustatory fibers would cause ipsilateral taste disorders. DESCRIPTION OF CASE We report a case of bilateral ageusia following an acute right midbrain and thalamic infarction affecting the ipsilateral central trigeminal tract and ventral posteromedial nucleus in a right-handed man. CONCLUSION The present case indicates that, in contrast to animal data, some secondary projection gustatory fibers may cross in humans and consequently unilateral right-sided posterior circulation ischemic lesions can cause bilateral gustatory deficits.