Is there an anatomical basis for the production of speech automatisms?

Abstract

The CT scans of fifty-nine right-handed patients who had suffered a single left middle cerebral artery infarction including more than 2% of forebrain volume were analysed for correlations between lesion configuration and the presence of speech automatisms. No remarkable effects were found concerning lesion size and configuration of the cortical lesion. All eighteen patients with speech automatisms shared a common lesion in the deep fronto-parietal white matter. This finding was assumed to indicate that the pathology underlying the production of speech automatisms involves structures in the depth of the area of supply of the middle cerebral artery. However, the pathogenesis of speech automatisms seems to be multifactorial. Parameters of lesion anatomy could account for only a fraction of the variance included in automatism production. Age at infarction was demonstrated to have a significant effect upon the production of speech automatisms.