[Auditory speech-evoked cerebral cortex potentials in patients with stuttering syndromes]

The cause of stuttering is unknown. For clinical purposes it proved to be useful to assume a multifactorial genesis with organic psychological and social aspects. A longstanding organic theory focussed on the failure to develop left-hemispheric dominance for speech, whereas others favoured deficits of the speech motor system. Positron emission tomography (PET) studies support organic theories for the development of stuttering. The purpose of this study was to find out whether in stutterers auditory cortical potentials evoked by pure tones, noise and words are different to those of healthy controls.

10 young adults having suffered from stuttering since infancy were examined. The potentials were measured and analysed as previously described.

No correlation of clinical and electrophysiological findings were found. In one case the evoked potentials were normal, in all other patients heterogeneous results were obtained in respect of tone-evoked and both noise- and speech-evoked potentials. Cortical hemispheric differences could be detected.

In agreement with PET findings reported in the literature the data obtained in this study indicate an organic, central nervous cause of stuttering. Obviously both speech motoric components and perception elements are affected. These facts have to be taken into account whenever a psychological cause of stuttering is suspected. Nevertheless, psychosomatic aspects of the disturbances must be considered since they influence the patients' ability to cope with their symptom.