Cortical and fibre tract interrelations in conduction aphasia

Abstract

Background: The syndrome of conduction aphasia is an umbrella term to label clinically heterogeneous language disorders that all include a deficit of repetition due to impaired immediate memory or, in some patients, impaired speech production. The present article reviews the currently available literature on conduction aphasia. It covers aspects of the history of conduction aphasia as a fascicular disconnection syndrome and the objections to this view and discusses the proposed subtypes of this syndrome and the underlying cortical and white matter lesions.Aims: The primary objectives of this article are to critically review the influence of historical concepts on recent approaches to optimise existing theoretical synergies. In addition, the article seeks to advance our understanding of the first steps of verbal auditory processing in individuals with normal and impaired language skills.Main Contribution: We present first indications for an involvement of the left hemisphere in both short- and long-term integration of auditory information derived by examining patients with (conduction) aphasia.Conclusions: Conduction aphasia may result from left hemisphere cortical lesions or from a disconnection of critical bundles of axons (fibre tract). The exact course of the fibre tract connections and the cortical regions involved in conduction aphasia remains controversial.