“Hot Tongue and Mouth” on 18F-FDG PET/CT Due to Buccolingual Masticatory Syndrome, Caused by Metoclopramide Antiemetic Treatment

We present a case of a 66-year-old man, where 18F-FDG PET/CT revealed intense FDG uptake in the tongue, lips, cheeks, and chewing musculature and distinct activation of the somatosensory and motor cortex corresponding to the mouth and tongue. The patient suffered from buccolingual masticatory syndrome, characterized by tardive dyskinesia, meaning uncontrollable, repetitive movements of the tongue, lips, cheeks, and masticatory musculature. In this case, the buccolingual masticatory syndrome was caused by metoclopramide antiemetic treatment. "Hot tongue" was previously described on 18F-FDG PET/CT in patients with tardive dyskinesia due to antipsychotic treatment, but the distinct activation of the lower facial motor cortex makes the present case stand out.