Acquired stuttering following right frontal and bilateral pontine lesion: a case study

We report neurological information and experimental data regarding acquired neurogenic stuttering in a 57-year-old male following ischemic lesion to the orbital surface of the right frontal lobe and the pons. The experimental data consist of stuttering frequency measures under various conditions that are well known to enhance fluency in most individuals with developmental stuttering. Specifically, we report data for adaptation, unison reading, delayed auditory feedback (DAF), and frequency altered feedback (FAF). This work is the first published report of such a comprehensive examination of a variety of fluency-enhancing conditions in acquired stuttering. The patient read six 200-word texts under different conditions: Six solo readings (Text 1), five unison readings followed by five solo readings (Text 2), five readings with non-altered auditory feedback (Text 3), five readings with 50 ms delayed auditory feedback (Text 4), five readings with increased FAF (Text 5), and five readings with decreased FAF (Text 6). Results indicate that, unlike the typical situation for developmental stuttering, this individual with acquired neurogenic stuttering did not show increased fluency during an adaptation paradigm or under unison, DAF, and FAF conditions. We discuss possible implications of these findings and emphasize the need for further research on acquired neurogenic stuttering.