Objective: To evaluate the relationship of the respiration patterns and the abdominal muscle activities during various speech productions in the adults with athetoid cerebral palsy (CP).

Method: Subjects were 7 athetoid CPs and 7 healthy controls. Respirography and abdominal muscle activities were recorded by use of the pneumobelt and the surface EMG during their performances of six kinds of non-speech and speech tasks.

Results: The followings were observed in the athetoid CP.

1) Respiratory phase was irregular and variable in the intensity and period of revolution. The frequency of the respiratory phase was not different from the control in usual respiration, but higher in deep breathing. The time to persist one vowel phonation was shorter.

2) Inappropriate and frequent inspirations were occurred during speech task and the number of syllables was fewer and irregular for one speech breath.

3) The abdominal muscle activities were abrupt, irregular, inconsistent with the respiratory phase during all kinds of non-speech and speech tasks.

Conclusion: These findings suggest that the abnormal respiration patterns and abdominal muscle activities contribute to the abnormal speech production of athetoid CP and their incoordination is similar to athetoid movement of the extremities. We should consider the athetoid speech production as well as the dysarthria in the athetoid CP.