[On stuttering-like hesitation resulting from infarct in the midbrain and the mesial thalami]

We described a patient who developed stuttering after an infarct both in the midbrain and the medial part of bilateral thalami. Previously, speech disturbance resulting from these lesions has been named palilalia. However, we differentiated such a speech disturbance from both stuttering and palialia, because it had high frequency of repetition and monotonous rhythm, and because repetition was observed more frequently in the head of words than in the middle or the end of words. We proposed to call this speech abnormality stuttering-like hesitation in order to differentiate it from ordinary stuttering or palilalia. As the causative lesion for stuttering-like hesitation, we proposed the lesion in the neuronal circuit including the supplementary motor area and its afferent pathways, in addition to the lesion in the extrapyramidal system.