A case of unilateral gustatory disturbance produced by the contralateral midbrain lesion

We reported a case of unilateral gustatory disturbance produced by a lesion in the contralateral midbrain. A 37-year-old man first noticed dysesthesia in the left side of his face. Later, the patient developed dysesthesia of the left part of the lip, muscular weakness on the left lower extremity and gustatory disturbance on the left side. MR scan disclosed a lesion in the tegmentum of the right midbrain, which showed low intensity on a T1-weighted image and high intensity on a T2-weighted image. This lesion could be due to multiple sclerosis. This case suggests that the unilateral gustatory information ascends via the contralateral pathway at the midbrain level. It is suggested that the central gustatory pathways above the ipsilateral pontine taste are ascend via the contralateral projections to the thalamic taste area (parvicellular portion of the ventral posteromedial thalamic nucleus, VPMpc).