Focal lesion in Dronkers’ area associated with developmental apraxia of speech

Excerpt

In 1996 Dronkers made an association between the superior precentral gyrus of the insula (SPGI) and apraxia of speech (AOS) by comparing MRI and CT images of left hemisphere stroke patients with AOS versus left hemisphere stroke patients without AOS [1]. She reported that in 25 out of 25 individuals studied, AOS was associated with lesions of SPGI. AOS is usually defined as a disorder in programming the speech musculature to produce correct sounds in the correct order with the correct timing [2]. AOS is usually an acquired disorder that follows lesion of the language-dominant hemisphere [3], but there is a developmental form known as childhood apraxia of speech that can be congenital or acquired [4]. Developmental apraxia of speech (DAS) refers to the onset of the praxical disorder during the early years of childhood. The natural course of DAS and AOS in adults differs substantially because of the fundamental difference in the developmental stage at which the apraxia expresses itself [4]. …