Coprolalia denotes the involuntary utterance of obscenities. Intent is an important classifier in coprolalic behaviors, and unfortunately it remains unclear how to objectively distinguish coprolalia from common swearing.
Comment:
In Tourette syndrome (TS), the unintended expression of coprolalic behaviors is encountered in about one-fifth of patients. Typical coprolalic behaviors in TS are characterized by the utterance of single short obscenities (e.g., in English, so-called four-letter words) with a different pitch or tone from ongoing speech. There have been only a few reports of patients exhibiting coprolalia in other neurological conditions, such as neurodevelopmental disorders (e.g., Kleine-Levin and fragile X syndrome), neurodegenerative syndromes (e.g., FTD, Alzheimer's disease, and chorea-acanthocytosis), after focal brain lesions, in encephalitis lethargica, or as ictal phenomenon.