McNeil, Malcolm R.

Objectives The aim was for the appointed committee of the Academy of Neurological Communication Disorders and Sciences to conduct a systematic review of published intervention studies of acquired apraxia of speech (AOS), updating the previous committee's review article from 2006. Method A systematic search of 11 databases identified 215 articles, with 26 meeting inclusion criteria of (a) stating intention to measure effects of treatment on AOS and (b) data representing treatment effects for at least 1 individual stated to have AOS. Results All studies involved within-participant experimental designs, with sample sizes of 1 to 44 (median = 1). Confidence in diagnosis was rated high to reasonable in 18 of 26 studies. Most studies (24/26) reported on articulatory–kinematic approaches; 2 applied rhythm/rate control methods. Six studies had sufficient experimental control for Class III rating according to the Clinical Practice Guidelines Process Manual (American Academy of Neurology, 2011), with 15 others satisfying all criteria for Class III except use of independent or objective outcome measurement. Conclusions The most important global clinical conclusion from this review is that the weight of evidence supports a strong effect for both articulatory–kinematic and rate/rhythm approaches to AOS treatment. The quantity of work, experimental rigor, and reporting of diagnostic criteria continue to improve and strengthen confidence in the corpus of research.

The exact nature of ipsilateral auditory pathway suppression under dichotic stimulation remains controversial. To help resolve this controversy, the distinctive feature confusions (blend vs nonblend errors) made on a dichotic listening CV test by two hemispherectomees were analyzed. Results support ipsilateral auditory pathway suppression under dichotic CV stimulation. Ipsilateral auditory pathway suppression is discussed in terms of stimulus specificity, subject, and task difference.