Sub-classification of apraxia of speech in patients with cerebrovascular and neurodegenerative diseases.

Some studies have hypothesized that primary progressive apraxia of speech (ppAOS) consists of heterogeneous symptoms that can be sub-classified; however, no study has classified stroke-induced AOS (sAOS) and ppAOS according to common criteria. The purpose of this study was to elucidate the symptoms and relevant brain regions associated with sAOS and ppAOS for sub-classification. Participants included 8 patients with sAOS following lesions in the left precentral gyrus and/or underlying white matter, and 3 patients with ppAOS.