Subcortical damage and white matter disconnection associated with non-fluent speech

Abstract

Sir, In a recent paper published in Brain , Dronkers and colleagues (2007) re-examined the brain damage in two historic patients of P. Paul Broca, Leborgne and Lelong, who had lost the ability to speak following brain damage. The observation of these cases lead Broca to suggest that the left inferior frontal lobe (later coined Broca's area) is the crucial lesion location associated with acquired motor speech impairment. Utilizing high resolution MRI, Dronkers and colleagues observed that the brain damage in both of Broca's cases extend further subcortically than Broca could have observed, therefore, suggesting that the critical lesion location for motor speech production is not restricted to the inferior frontal gyrus. In particular, the authors demonstrated that the superior longitudinal fasciculus was damaged in both cases, arguing that this lesion may also have affected Broca's patients’ speech production. This timely examination by Dronkers et al. combines a historical perspective and …