Shannon C. Mauszycki

Task specificity in adductor spasmodic dysphonia versus muscle tension dysphonia

Objectives: Adductor spasmodic dysphonia (ADSD) has been characterized as a “task specific” laryngeal dystonia, meaning that the severity of dysphonia varies depending on the demands of the vocal task. Voice produced in connected speech as compared with sustained vowels is said to provoke more frequent and severe laryngeal spasms. This study examined the diagnostic value of “task specificity” as a marker of ADSD and its potential to differentiate ADSD from muscle tension dysphonia (MTD), a functional voice disorder that can often masquerade as ADSD.

The effects of rate control treatment on consonant production accuracy in mild apraxia of speech

Background: A primary feature of acquired apraxia of speech (AOS) is a slow speech rate associated with lengthened sound segments and intersegment durations (McNeil, Robin, & Schmidt, 1997). This disturbance in speech production timing has been the focus of a limited number of treatment studies designed to manipulate rate and/or rhythm of speech production with speakers with mild AOS. Aims: The purpose of this investigation was to study the effects of rate control treatment on sound production accuracy and utterance durations of multisyllabic words, phrases, and sentences in a speaker with mild AOS and aphasia. Methods & Procedures: An individual with mild AOS and aphasia was trained to produce multisyllabic words and phrases using a combination of metronomic rate control and hand tapping. The speaker was trained to produce one syllable per beat of the metronome in conjunction with hand tapping. Feedback was only provided for accuracy of hand tapping and/or syllable production to the beat of the metronome. No feedback was given regarding the accuracy of sound production. Initially, the speakers rate of production was reduced, but was then systematically increased. A multiple baseline design was used to examine the acquisition, response generalisation, and maintenance effects of treatment. Outcomes & Results: Findings revealed an increase in sound production accuracy for trained four‐syllable words and some improvement in sound production accuracy for treated phrases and untrained four‐syllable words. There was only a slight reduction in total utterance duration for treated items versus untreated items. There was a gradual decline in total utterance duration over time on untrained stimulus generalisation items with no consistent improvement on sound production accuracy. Conclusions: Treatment resulted in an improvement in sound production accuracy in an individual with AOS and aphasia. Positive changes were observed for treated four‐syllable words, phrases, and untrained four‐syllable words, although treatment did not directly target sound production accuracy (i.e., feedback was not given regarding accuracy of productions). The study represents an initial investigation of the effects of rate control treatment specifically increasing rate of production in a speaker with mild AOS and aphasia. This type of treatment appears to have promise in terms of improving sound production accuracy and warrants further investigation.

Treatment for acquired apraxia of speech: A systematic review of intervention research between 2004 and 2012

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 committees 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.

Toward Improved Differential Diagnosis of Adductor Spasmodic Dysphonia and Muscle Tension Dysphonia

Objective: Adductor spasmodic dysphonia (ADSD) is characterized by a strained-strangled voice quality, whose diagnosis relies exclusively on auditory-perceptual features. However, muscle tension dysphonia (MTD) – a functional voice disorder – can mimic ADSD thereby contributing to diagnostic confusion. Unlike MTD, ADSD has been described as ‘task-specific’, implying that certain vocal tasks such as sentences loaded with predominantly voiced consonants will provoke greater sign expression. This investigation examined the diagnostic value of variable sign expression based upon phonetic loading as a means to disambiguate ADSD and MTD. Patients and Methods: Five listeners, who were blinded to the purpose of the study, used a 10-cm visual analog scale to rate the dysphonia severity of two sentences (one all-voiced and one containing primarily voiceless consonants) produced by participants with ADSD (n = 29) or MTD (n = 33). Results: A mixed-design ANOVA, with Group (ADSD vs. MTD) as the between-subjects variable and Sentence Type (all-voiced vs. voiceless) as the within-subjects variable, confirmed a significant Group-by-Sentence Type interaction effect (p = 0.0002). In ADSD, ratings of dysphonia severity for the all-voiced sentence were significantly more severe than for the voiceless sentence (p < 0.0001), whereas in MTD no significant difference was observed (p = 0.9981). The ROC curve confirmed that differences in dysphonia severity between voiced and voiceless sentences represented a highly specific (88–100%), but only 48% sensitive diagnostic marker. Conclusions: Phonetic loading influences sign expression in ADSD, and assists in discriminating ADSD from MTD.

Sound Production Treatment: Application with severe apraxia of speech

Background: Acquired apraxia of speech (AOS) has been shown to be responsive to behavioural intervention. Although numerous treatments for AOS have been developed, most have received limited study. Specifically, the AOS treatment evidence base is compromised by a lack of replication of treatment effects. Sound Production Treatment (SPT; Wambaugh, Kalinyak-Fliszar, West, & Doyle, 1998) has undergone more systematic examination than other AOS treatments and has been documented to result in predictable improvements in consonant production. However, SPT has not been studied with persons with severe AOS and perseverative speech behaviours. Aims: The purpose of this investigation was to examine the acquisition, response generalisation, and maintenance effects of SPT with a speaker with severe AOS, significant nonfluent aphasia, and verbal perseverations. Methods & Procedures: A single-participant, multiple baseline design across behaviours was employed to examine the effects of treatment on production of six consonants in monosyllabic words. Treatment was applied sequentially to two sets of items, with three consonants targeted in each set. A third phase of treatment entailed training of all target sounds. Follow-up probing was conducted at 10 and 15 weeks post-treatment. Outcomes & Results: Improved productions were observed for all trained items and response generalisation to untrained exemplars of trained items was positive. Across-sound generalisation was not evident. Maintenance effects were strong at 10 weeks post-treatment, but diminished considerably for most of the sounds by 15 weeks. Conclusions: Results for this speaker with severe AOS and verbal perseverations were similar to those previously reported for SPT. The decrease in performance from 10 weeks to 15 weeks indicated that changes in behaviour had not been sufficiently instantiated. Furthermore, these findings suggested that maintenance probing may need to be conducted over a considerably longer period of time than has previously been reported in the literature.

Individual variability on discourse measures over repeated sampling times in persons with aphasia

Background: Although persons with aphasia typically have difficulty with the production of language at the level of discourse, there is a paucity of reliable measurement systems to quantify the characteristics of spoken language. Nicholas and Brookshire (1993) developed one of the few standardised, rule-based systems to quantify the informativeness of spoken language samples. While the authors reported temporal stability for all measures, they also noted variability at the individual level. Because individual data were not reported, it is difficult to determine the nature and extent of that variability. Aims: The aim of the current investigation was to further explore Nicholas and Brookshires (1993) quantitative linguistic analyses, and to examine individual variability over time in persons with aphasia. Methods & Procedures: Five fluent and six nonfluent persons with aphasia produced language samples over repeated sampling times in response to the 10 stimulus items used by Nicholas and Brookshire (1993). Measurements of mean number of words, mean correct information units (CIUs), percent CIUs, words per minute, and CIUs per minute were calculated, and results from the sessions were compared. To examine factors related to individual variability, correlations between linguistic measures, months post onset of aphasia, and scores on standardised assessment tools were explored. Outcomes & Results: Visual inspection of the data and descriptive statistics suggested that participants were more variable in their repeated productions than previously described by Nicholas and Brookshire (1993). Repeated measures ANOVAs revealed non-significant effects at the group level. There was no pattern of variability uniquely associated with aphasia fluency type. Range of mean number of CIUs was positively and significantly correlated with all test measures; however, the other range correlations were non-significant. Conclusions: The current results suggest greater variability over repeated sampling times in the spoken language of persons with aphasia than previously reported by Nicholas and Brookshire (1993). Clinicians and researchers should consider this variability, and establish stable baselines prior to the initiation of treatment to document meaningful change over time.

Variability in apraxia of speech: Perceptual analysis of monosyllabic word productions across repeated sampling times

Background: Variability in speech sound errors has been regarded as a primary characteristic of apraxia of speech (AOS). Early research deemed errors extremely unpredictable, resulting in a number of different error types on repeated productions of the same stimuli. However, recent research has suggested that errors may not be variable, but there are limited data regarding variability over time (i.e., beyond a single sampling occasion). Furthermore, the influence of conditions of stimulus presentation (i.e., blocked vs random) on sound errors remains unclear. Aims: The purpose of this investigation was to examine variability of sound errors in 11 individuals with AOS and aphasia. Of particular interest were the effects of repeated sampling and method of speech elicitation on the variability of error types as evaluated with narrow phonetic transcription. Methods & Procedures: A total of 28 monosyllabic words served as experimental stimuli. There were four exemplars for each of the seven initial target phonemes (i.e., /h, f, m, d, s, r, n/). Stimuli were elicited on three sampling occasions over a 7-day period with each sampling occasion separated by 2 days. At each sampling time productions were elicited under two conditions: blocked presentation (blocked by sound) and randomised presentation. Speech productions were analysed perceptually utilising narrow phonetic transcription. Outcomes & Results: Findings revealed a similar overall mean percentage of errors for the group in both conditions of stimulus presentation across the three sampling times. The target phoneme with the least number of errors was /h/. The target phoneme with the greatest number of errors was /s/. The predominant error type across target phonemes was distortions. However, the predominant error type varied across target phonemes and appeared to be influenced by number of errors. Conclusions: Repeated sampling or method of speech elicitation did not influence errors, with a similar overall mean percentage of errors for the group in both conditions of stimulus presentation across the three sampling times. Distortions were found to be the predominant error type for the majority of target sounds. A comparison of the number of error types produced by the group in each condition across the three sampling times found no obvious pattern of responding by the group in either condition for individual phonemes. That is, condition of elicitation did not appear to influence the variability of error type for any given sound.

Semantic feature analysis: Application to confrontation naming of actions in aphasia

Background: Despite advances in the development and testing of therapies for verb retrieval impairments in aphasia, generalisation effects of treatment remain a challenge. Semantic Feature Analysis (SFA) is a word retrieval treatment that has been reported to result in generalised responding to untrained object names with persons with aphasia. The theorised therapeutic mechanisms of SFA appeared to be appropriate for facilitating retrieval of trained and untrained action names. Aims: This investigation was designed to extend pilot research in which SFA was applied to verb retrieval. The primary purpose of the current study was to examine the acquisition and response generalisation effects of SFA applied to action naming with four persons with chronic aphasia. Additional purposes were to examine changes in production of content in discourse and to explore the correspondence of accuracy of naming during treatment to probe performance. Methods & Procedures: SFA was modified slightly to be appropriate for application to action naming as opposed to object naming; several feature categories were changed, but all other procedures were retained. Treatment was applied sequentially to two sets of action names in the context of multiple baseline designs across behaviours and participants. Accuracy of naming of trained and untrained actions in probes was measured repeatedly throughout all phases of the design. Production of correct information units (CIUs) in discourse was measured prior to and following treatment. The relationship of probe-naming performance to naming performance during treatment sessions was examined using correlational analyses. Outcomes & Results: Increased accuracy of naming of trained action names was associated with treatment for three of the four participants. The remaining participant did not demonstrate improvement in naming on probes, despite some gains during treatment. Generalisation to untrained action names did not occur for any of the participants. Increases in CIU production were observed for only one of the participants. For the participants with positive naming outcomes, probe performance correlated well with naming performance during treatment. For the participant who demonstrated some improvements in treatment, but did not show gains in naming on probes, weak correlations were obtained. Conclusions: SFA appears to have potential for promoting improved action naming in aphasia. However, more research is warranted to explore treatment modifications to promote generalisation. Correlational analyses indicated that gains in naming during treatment may not always be reflected in probe performance and thus, require verification through probing in non-treatment conditions.

Sound Production Treatment: Effects of Blocked and Random Practice

PURPOSE This investigation was designed to further the development of a treatment for acquired apraxia of speech (AOS), Sound Production Treatment (SPT), by examining the effects of blocked and random practice. METHOD A multiple-baseline design across participants and behaviors was used with 6 speakers with chronic AOS and aphasia. Accuracy of production of target sounds in treated and untreated words produced in probe sessions served as the primary dependent variable. Stimulus generalization was also measured to phrase production and sentence completion. Participants received SPT applied with blocked presentation of treatment words (SPT-blocked) and SPT applied with random presentation of treatment words (SPT-random). RESULTS Increases in accuracy of articulation of target sounds in treated words were observed for all participants for both conditions of treatment. SPT-random appeared to be associated with better maintenance for 2 participants. Generalization to untreated words was positive for all participants for SPT-random and SPT-blocked. Stimulus generalization effects varied across participants and measurement conditions; patterns of generalization did not appear to be associated with treatment condition. CONCLUSIONS There may be an advantage for SPT-random for some speakers with AOS. Findings from the nonspeech motor learning literature may not translate directly to the treatment of AOS.

Effects of age, gender, and education on semantic fluency for living and artifact categories

Background: Evidence exists that many individuals with neurological damage exhibit a “category effect”, typically naming more artifact than living items. However, there is a paucity of research exploring the existence of a category effect with neurologically intact individuals. The investigations performed to date have focused on a limited number of categories, and most authors have not controlled for possible age, gender, and/or education‐related effects among groups. Aims: The purpose of this study was to explore the effects of age, gender, and education on semantic fluency for four living and four artifact categories. Methods & Procedures: A total of 60 individuals recruited from four groups participated in the study: younger males, younger females, older males, and older females. Each group of 15 individuals was matched for years of education. Participants were asked to name as many items as possible in four living categories: birds, four‐footed animals, fruits, and vegetables as well as four artifact categories: tools, kitchen utensils, furniture, and clothing. Outcomes & Results: There was no significant difference between living and artifact domains. With regard to specific categories, females named significantly more fruit and furniture items, while males named more tools. Younger females with fewer than 16 years of education named the most fruits, and participants with at least 16 years of education had an advantage for clothing. Older males and younger females named more four‐footed animals than did their gender‐matched peers. Conclusions: In contrast to previous reports, this investigation failed to identify naming differences between living and artifact domains, which might partly be related to dissimilar task demands (i.e., semantic fluency versus confrontation naming). However, several gender‐based differences observed for specific categories were consistent with previous research. Moreover, the use of a broader range of categories exposed additional differences in naming performance.