The Western Aphasia Battery-revised Part 1 (Kertesz, 2007 ) served as the primary measure of global language ability; the Writing Output subtest from Part 2 of the Western Aphasia Battery served as a speech-independent measure of language expression. A 22-item version of Part V of DeRenzi and Vignolo’s Token Test (DeRenzi and Vignolo, 1962 (link)) served as a challenging measure of verbal comprehension ability (Wertz et al., 1971 ), and the 15-item Boston Naming Test (Lansing et al., 1999 (link)) as a sensitive measure of confrontation-naming ability. Action (verb) Fluency (Woods et al., 2005 (link)) and Letter (FAS) Fluency (Loonstra et al., 2001 (link)) tasks served as indices of rapid-word retrieval ability for those categories. A score >2 standard deviations (SD) below the mean on all language tests with published or derived mean and standard deviation was considered abnormal.
Judgements about motor speech abilities were based on all spoken language tasks of the Western Aphasia Battery plus additional speech tasks that included vowel prolongation, speech alternating motion rates (e.g. rapid repetition of ‘puhpuhpuh…’), speech sequential motion rates (e.g. rapid repetition of ‘puhtuhkuh’), word and sentence repetition tasks and a conversational speech sample. Sixteen speech characteristics (Box 1 ), consistent with current criteria for AOS diagnosis (Duffy, 2005 ; Wambaugh et al., 2006 ; McNeil et al., 2009 ), or observations of characteristics of AOS associated with neurodegenerative disease (Duffy, 2006 ), and selected to cast a wide net for capturing features of the disorder, were rated on an AOS rating scale, which provided a description of AOS characteristics and their prominence. Ratings were based on the following scale: 0 = not present; 1 = detectable but not frequent; 2 = frequent but not pervasive; 3 = nearly always evident but not marked in severity; 4 = nearly always evident and marked in severity. Normal cut-off values for the summed ratings were based on the performance of 14 subjects with PPA for whom there was no clinical evidence of AOS. A global AOS severity rating (0–4) was also made.
The same speech tasks were also judged for the presence or absence of dysarthria, which was rated on a 0–4 severity scale. An eight-item measure of non-verbal oral praxis, with responses to each item rated on a 0–4 scale (with a score of 4 representing best/normal performance), served as a quantitative index of non-verbal oral apraxia. A global judgement about the presence or absence of non-verbal oral apraxia was also made.
Quantitative scores and video recordings of crucial aspects of the test protocol were reviewed for all subjects by two authors (J.R.D. and E.A.S.) who made independent judgements about the presence or absence of aphasia, AOS, dysarthria and non-verbal oral apraxia, and the severity of each disorder. Independent agreement about the presence or absence of aphasia and presence or absence of AOS and non-verbal oral apraxia was achieved for 11/12 subjects. Discussion regarding the presence or absence of AOS was required for consensus for Subject 8, whose AOS was very mild and the least severe among the 12 subjects. Independent agreement regarding the presence or absence of dysarthria was 100%. Both judges agreed after discussion that the evidence for spastic dysarthria was equivocal for Subjects 1 and 3, and that evidence of a hypokinetic component for Subject 7 was equivocal.
Judgements about motor speech abilities were based on all spoken language tasks of the Western Aphasia Battery plus additional speech tasks that included vowel prolongation, speech alternating motion rates (e.g. rapid repetition of ‘puhpuhpuh…’), speech sequential motion rates (e.g. rapid repetition of ‘puhtuhkuh’), word and sentence repetition tasks and a conversational speech sample. Sixteen speech characteristics (
The same speech tasks were also judged for the presence or absence of dysarthria, which was rated on a 0–4 severity scale. An eight-item measure of non-verbal oral praxis, with responses to each item rated on a 0–4 scale (with a score of 4 representing best/normal performance), served as a quantitative index of non-verbal oral apraxia. A global judgement about the presence or absence of non-verbal oral apraxia was also made.
Quantitative scores and video recordings of crucial aspects of the test protocol were reviewed for all subjects by two authors (J.R.D. and E.A.S.) who made independent judgements about the presence or absence of aphasia, AOS, dysarthria and non-verbal oral apraxia, and the severity of each disorder. Independent agreement about the presence or absence of aphasia and presence or absence of AOS and non-verbal oral apraxia was achieved for 11/12 subjects. Discussion regarding the presence or absence of AOS was required for consensus for Subject 8, whose AOS was very mild and the least severe among the 12 subjects. Independent agreement regarding the presence or absence of dysarthria was 100%. Both judges agreed after discussion that the evidence for spastic dysarthria was equivocal for Subjects 1 and 3, and that evidence of a hypokinetic component for Subject 7 was equivocal.
