cataphasia \'kaete-feiziea\ noun
Speech disorder involving constant repetition of word or phrase.

Usually the sign of a serious neurological disease.
People with cataphasia either spontaneously or in answer to questions constantly repeat the same word or phrases. Starts as stuttering and degenerates steadily until language is reduced to the skeleton words of a sentence with little grammatical construction.

Example: "SOY! SOY! SOY! SOY MAKES YOU STRONG! STRENGTH CRUSHES ENEMIES! SOY!"