Temporal acoustic measures distinguish primary progressive apraxia of speech from primary progressive aphasia

Abstract

The purpose of this study was to determine if acoustic measures of duration and syllable rate during word and sentence repetition, and a measure of within-word lexical stress, distinguish speakers with primary progressive apraxia of speech (PPAOS) from nonapraxic speakers with the agrammatic or logopenic variants of primary progressive aphasia (PPA), and control speakers. Results revealed that the PPAOS group had longer durations and reduced rate of syllable production for most words and sentences, and the measure of lexical stress. Sensitivity and specificity indices for the PPAOS versus the other groups were highest for longer multisyllabic words and sentences. For the PPAOS group, correlations between acoustic measures and perceptual ratings of AOS were moderately high to high. Several temporal measures used in this study may aid differential diagnosis and help quantify features of PPAOS that are distinct from those associated with PPA in which AOS is not present.

Clinical and imaging progression over 10 years in a patient with primary progressive apraxia of speech and autopsy-confirmed corticobasal degeneration

“…The AOS remained the only prominent symptom for the first five years, with speech worsening during that time, leading to depression and anxiety, and ultimately leaving his job. His speech rate was below average(Duffy, et al, 2017) at his first visit and continued to slow over time, as has been previously observed in a patient with progressive AOS(Code, Ball, Tree, & Dawe, 2013). While there have been no direct comparisons, most of his AOS speech characteristics were not obviously different from those that have been described for stroke-induced or nondegenerative AOS(Duffy and Josephs, 2012; McNeil, Robin, & Schmidt, 2009).…”

“…Non-verbal oral apraxia (NVOA) was rated based on eight items, each on a 0–4 scale. In order to assess speech rate, we measured the average rate of syllable production from three consecutive repetitions of the multisyllabic word “catastrophe” using an acoustic protocol previously described(Duffy et al, 2017). The word catastrophe was selected as we have shown that it is a sensitive and specific stimulus to differentiate PPAOS from primary progressive aphasia(Duffy, et al, 2017).…”

Prosodic and phonetic subtypes of primary progressive apraxia of speech

“…Several speech and language measures were administered, as previously reported (Duffy et al, 2017; Duffy et al, 2015; Josephs et al, 2014; Josephs et al, 2013; Josephs et al., 2012). Judgments of speech included: (1) a 0–4 rating of AOS severity (1 = mild; 4 = severe), as an index of AOS severity regardless of its specific features, (2) a 1–10 rating (10 = normal) of motor speech disorder severity [MSD severity, adapted from (Yorkston, Strand, Miller, & Hillel, 1993)], which indexed the degree to which speech is understandable (i.e.…”

“…An earlier version of the ASRS-3 was used in previous studies of progressive AOS (Duffy et al, 2017; Duffy et al., 2015; Josephs et al, 2013; Josephs et al, 2012). The total ASRS-3 score can range from 0 to 52 (where 0 = no abnormal speech characteristics ); it captures the severity of AOS but does not capture the specific quality of the AOS.…”

Linguistic Aspects of Primary Progressive Aphasia

“…However, only 21% of speech errors in naPPA could be attributed to a motor speech planning disorder because they were distortions that are not part of the English speech sound system. In another study, the duration of syllable production was lengthened and the stress of initial versus subsequent syllable was disordered in patients with AoS compared with controls and other PPA patient groups (Duffy et al 2017). Two classes of speech sound errors have been identified—one consisting of speech sound errors, distortions, and substitutions and the other consisting of syllabically segmented prosodic speech patterns.…”