Phonological Buffer and Selective Deficits of Grammar, with Distinct Time Onsets, in a Patient with a Focal Degenerative Disorder

Abstract

We report a patient with a focal degenerative disorder and very circumscribed neuropsychological deficits, the evolution of which we were able to study over a lengthy period. For years, he presented with only a speech production impediment that clinical observations and experimental studies enabled us to identify as a phonological buffer disorder. Subsequently, he developed agrammatism that appeared to be largely due to his inability to produce pronouns and auxiliary verbs. Remarkably, throughout our studies, even when he was virtually rendered mute, his ability to name objects on demand in writing remained intact. We discuss his case from clinical and theoretical perspectives.

We are grateful to Dr L. A. Wilson and to Professor R. Wise for permission to study and publish the case of this patient. We thank the MRI Unit of the National Hospital for Neurology and Neurosurgery, Queen Square, London, for the imaging studies. We thank Dr Rosaleen A. McCarthy for helpful comments during the preparation of the manuscript. We also thank Mr John Valentine for statistical advice. We are particularly grateful to our patient, RPR, for his utmost co-operation at all times throughout the lengthy period we studied him. Finally, we thank the control subjects for their willingness to participate in our investigations.