Developmental Courses in Childhood Dysarthria: Longitudinal Analyses of Auditory-Perceptual Parameters

Exploring Motor Speech Disorders in Low and Minimally Verbal Autistic Individuals: An Auditory-Perceptual Analysis

PURPOSE

Motor deficits are widely documented among autistic individuals, and speech characteristics consistent with a motor speech disorder have been reported in prior literature. We conducted an auditory-perceptual analysis of speech production skills in low and minimally verbal autistic individuals as a step toward clarifying the nature of speech production impairments in this population and the potential link between oromotor functioning and language development.

METHOD

Fifty-four low or minimally verbal autistic individuals aged 4-18 years were video-recorded performing nonspeech oromotor tasks and producing phonemes, syllables, and words in imitation. Three trained speech-language pathologists provided auditory perceptual ratings of 11 speech features reflecting speech subsystem performance and overall speech production ability. The presence, attributes, and severity of signs of oromotor dysfunction were analyzed, as were relative performance on nonspeech and speech tasks and correlations between perceptual speech features and language skills.

RESULTS AND CONCLUSIONS

Our findings provide evidence of a motor speech disorder in this population, characterized by perceptual speech features including reduced intelligibility, decreased consonant and vowel precision, and impairments of speech coordination and consistency. Speech deficits were more associated with articulation than with other speech subsystems. Speech production was more impaired than nonspeech oromotor abilities in a subgroup of the sample. Oromotor deficits were significantly associated with expressive and receptive language skills. Findings are interpreted in the context of known characteristics of the pediatric motor speech disorders childhood apraxia of speech and childhood dysarthria. These results, if replicated in future studies, have significant potential to improve the early detection of language impairments, inform the development of speech and language interventions, and aid in the identification of neurobiological mechanisms influencing communication development.

Age Estimation and Gender Attribution in Typically Developing Children and Children With Dysarthria

PURPOSE

The purposes of this study were (a) to investigate adult listeners' perceptions of age and gender in typically developing children and children with dysarthria and (b) to identify predictors of their estimates among auditory-perceptual parameters and an acoustic measure of vocal pitch (F0). We aimed to evaluate the influence of dysarthria on the listeners' impressions of age and gender against the background of typical developmental processes.

METHOD

In a listening experiment, adult listeners completed age and gender estimates of 144 typically developing children (3-9 years of age) and 25 children with dysarthria (5-9 years of age). The Bogenhausen Dysarthria Scales for Childhood Dysarthria (BoDyS-KiD) were applied to record speech samples and to complete auditory-perceptual judgments covering all speech subsystems. Furthermore, each child's mean F0 was determined from samples of four BoDyS-KiD sentences.

RESULTS

Age estimates for the typically developing children showed a regression to the mean, whereas children with dysarthria were systematically underestimated in their age. The estimates of all children were predicted by developmental speech features; for the children with dysarthria, specific dysarthria symptoms had an additional effect. We found a significantly higher accuracy of gender attribution in the typically developing children than in the children with dysarthria. The prediction accuracy of the listeners' gender attribution in the preadolescent children by the included speech characteristics was limited.

CONCLUSIONS

Children with dysarthria are more difficult to estimate for their age and gender than their typically developing peers. Dysarthria thus alters the auditory-perceptual impression of indexical speech features in children, which must be considered another facet of the communication disorder associated with childhood dysarthria.

Vocal Characteristics of Infants at Risk for Speech Motor Involvement: A Scoping Review

PURPOSE

The purpose of this scoping review was to (a) summarize methodological characteristics of studies examining vocal characteristics of infants at high risk for neurological speech motor involvement and (b) report the state of the high-quality evidence on vocal characteristic trends of infants diagnosed or at high risk for cerebral palsy (CP).

METHOD

The PRISMA (Preferred Reporting Items of Systematic Reviews and Meta-Analyses) extension for scoping reviews was followed for reporting our review. Studies measured prelinguistic vocal characteristics of infants under 24 months with birth risk or genetic conditions known to commonly present with speech motor involvement. Fifty-five studies met criteria for Part 1. Eleven studies met criteria for synthesis in Part 2.

RESULTS

A smaller percentage of studies examined infants with or at risk for CP compared to studies examining genetic conditions such as Down syndrome. The median year of publication was 1999, with a median sample size of nine participants. Most studies were conducted in laboratory settings and used human coding of vocalizations produced during caregiver-child interactions. Substantial methodological differences were noted across all studies. A small number of high-quality studies of infants with or at risk for CP revealed high rates of marginal babbling, low rates of canonical babbling, and limited consonant diversity under 24 months. Mixed findings were noted across studies of general birth risk factors.

CONCLUSIONS

There is limited evidence available to support the early detection of speech motor involvement. Large methodological differences currently impact the ability to synthesize findings across studies. There is a critical need to conduct longitudinal research with larger sample sizes and advanced, modern technologies to detect vocal precursors of speech impairment to support the accurate diagnosis and prognosis of speech development in infants with CP and other clinical populations.

Clinical Practice in Childhood Dysarthria: An Online Survey of German-Speaking Speech-Language Pathologists

PURPOSE

This survey study aimed to establish current clinical practices of German-speaking speech-language pathologists (SLPs) regarding their assessment and treatment of communication disorders in children with neurological conditions, with a particular focus on the management of childhood dysarthria.

METHOD

A 23-question cross-sectional online survey was disseminated to practicing SLPs in Germany, Austria, and Switzerland via relevant professional bodies. SLPs were invited to provide information on their current assessment and treatment practices. Demographic data including case load and clinical settings were also gathered to contextualize practices.

RESULTS

One hundred two SLPs responded to the survey, of which 68 valid responses were analyzed. German-speaking SLPs comprehensively assess and treat various aspects of overall communication, language, and swallowing functions in children with neurological conditions. Speech motor aspects did not represent a main intervention focus. In cases where the dysarthric component was targeted, specific approaches for childhood dysarthria were rarely used. Instead, SLPs reported using approaches developed for speech disorders other than dysarthria.

CONCLUSIONS

German-speaking SLPs working with children with neurological conditions use various assessment and treatment methods to support children's communication. However, dysarthria-specific approaches were not an established part of clinical practice. Results of the survey highlight the need for access to relevant developments in German and for evaluation of current curricula for speech-language pathology students and continuing education opportunities for practicing clinicians.

Speech Naturalness in the Assessment of Childhood Dysarthria

PURPOSE

This study investigated perceived speech naturalness estimated by adult listeners in typically developing children and children with dysarthria. We aimed to identify predictors of naturalness among auditory-perceptual parameters and to evaluate the concept of naturalness as a clinical marker of childhood dysarthria.

METHOD

In a listening experiment, naive adult listeners rated speech naturalness of 144 typically developing children (3-9 years old) and 28 children with neurological conditions (5-9 years old) on a visual analog scale. Speech samples were recorded using the materials of the Bogenhausen Dysarthria Scales-Childhood Dysarthria, which also provides for auditory-perceptual judgments covering all speech subsystems.

RESULTS

Children with dysarthria obtained significantly lower naturalness ratings compared to typically developing children. However, there was a substantial age effect observable in the typically developing children; that is, younger typically developing children were also perceived as somewhat unnatural. The ratings of the typically developing children were influenced by the occurrence of developmental speech features; for the children with neurological conditions, specific symptoms of dysarthria had an additional effect. In both groups, the perception of naturalness was predominantly determined by the children's articulation and intelligibility.

CONCLUSIONS

Both symptoms of childhood dysarthria and developmental speech features (e.g., regarding articulation and intelligibility) were associated to some extent with unnatural speech by the listeners. Thus, perceived speech naturalness appears less suitable as a marker of dysarthria in children than in adults.

Review of methods for conducting speech research with minimally verbal individuals with autism spectrum disorder

The purpose of this paper was to review best-practice methods of collecting and analyzing speech production data from minimally verbal autistic speakers. Data on speech production data in minimally verbal individuals are valuable for a variety of purposes, including phenotyping, clinical assessment, and treatment monitoring. Both perceptual ("by ear") and acoustic analyses of speech can reveal subtle improvements as a result of therapy that may not be apparent when correct/incorrect judgments are used. Key considerations for collecting and analyzing speech production data from this population are reviewed. The definition of "minimally verbal" that is chosen will vary depending on the specific hypotheses investigated, as will the stimuli to be collected and the task(s) used to elicit them. Perceptual judgments are ecologically valid but subject to known sources of bias; therefore, training and reliability procedures for perceptual analyses are addressed, including guidelines on how to select vocalizations for inclusion or exclusion. Factors to consider when recording and acoustically analyzing speech are also briefly discussed. In summary, the tasks, stimuli, training methods, analysis type(s), and level of detail that yield the most reliable data to answer the question should be selected. It is possible to obtain rich high-quality data even from speakers with very little speech output. This information is useful not only for research but also for clinical decision-making and progress monitoring.

A Descriptive Study of Speech Breathing in Children With Cerebral Palsy During Two Types of Connected Speech Tasks

PURPOSE

This study examined speech breathing during two connected speech tasks in children with cerebral palsy (CP) and typically developing (TD) peers. Understanding how the respiratory system supports speech production during various speech tasks can help researchers construct appropriate models of speech production and clinicians remediate speech disorders effectively.

METHOD

Four children with CP and four age- and sex-matched TD peers completed two speech tasks, reading and extemporaneous speech. Respiratory kinematic and acoustic data were collected. Dependent variables included utterance length, speech rate, sound pressure level, and lung volume variables.

RESULTS

Based on descriptive results, children with CP and speech motor involvement demonstrated reduced utterance length and speech rate, equivalent intensity levels, and changes in lung volume variables indicative of respiratory physiological impairment as compared to their TD peers. However, children with CP and no speech motor involvement exhibited speech production and speech breathing variables in the more typical range. In relation to task effects, the majority of children (CP and TD) produced shorter utterances, slower speech rates, equivalent intensity levels, higher lung volume initiation, termination, excursion, higher percent vital capacity per syllable, and longer inspiratory duration during extemporaneous speech as compared to reading.

CONCLUSIONS

Two major themes emerged from the data: (a) Children with CP, particularly those with concomitant speech motor involvement, demonstrate different speech production and speech breathing patterns than their TD peers. (b) Speech task impacts speech production and speech breathing variables in both children with CP and their TD peers, but the extemporaneous speech task did not seem to exaggerate group differences.

Intelligibility, Speech Rate, and Communication Efficiency in Children With Neurological Conditions: A Longitudinal Study of Childhood Dysarthria

PURPOSE

This study aimed to describe communication-related parameters (i.e., intelligibility, speech rate, and communication efficiency) and their developmental courses in children with neurological conditions against the background of typical development. In addition, interrelations between the developmental courses of communication-related parameters and auditory-perceptual ratings related to speech subsystems were investigated.

METHOD

Fourteen children with neurological conditions (CNC) and 14 typically developing children (CTD), matched for age and gender (four girls; 5;1-8;4 [years;months] at first examination), were assessed at three points in time over an 18-month period. Speech samples were collected using the Bogenhausener Dysarthrie Skalen-Kindliche Dysarthrien (English: Bogenhausen Dysarthria Scales-Childhood Dysarthria), a German tool for the assessment of childhood dysarthria. To assess intelligibility, naïve listeners transcribed audio samples of sentence repetitions of the children. Speech rate was measured by acoustic analyses, and communication efficiency was determined by multiplying the proportion of correctly transcribed syllables with speech rate. Age normalization was performed following a recently published approach.

RESULTS

On the group level, CNC had conspicuous raw and normalized scores for the three communication-related parameters and were more variable than the CTD group regarding their developmental courses. These differences were more pronounced for intelligibility than for speech rate. A strong relationship between communication-related and speech subsystems-related auditory-perceptual characteristics was apparent only between intelligibility and articulation/resonance.

CONCLUSIONS

For the first time, age-normalized scores for communication-related parameters were reported in children with neurological disorders and put into a developmental context within the framework of a longitudinal study. Age-normalized intelligibility was more vulnerable to large developmental changes than speech rate and was best predicted by changes in articulation and resonance. Overall, this study may contribute to a more comprehensive and valid clinical assessment of childhood dysarthria and to a better understanding of its developmental dynamics.

Childhood Dysarthria: Auditory-Perceptual Profiles Against the Background of Typical Speech Motor Development

PURPOSE

The purpose of this study was to describe childhood dysarthria by means of auditory-perceptual analyses covering all speech subsystems. We aimed to identify the most seriously affected auditory-perceptual dimensions in the observed dysarthria profiles and to detect specific markers of childhood dysarthria against the backdrop of typical speech development. Moreover, the relationship between the speech disorder and other relevant aspects of multiple disability was investigated.

METHOD

Thirty-one children with neurologic conditions were assessed with Bogenhausen Dysarthria Scales for Childhood Dysarthria, a German tool for the auditory-perceptual analysis of dysarthria in children. Nine relevant speech dimensions (scales, e.g., voice quality [VOQ]) and 29 individual symptoms (features, e.g., breathy) were evaluated. Moreover, we documented motor, communicative, and cognitive-linguistic measures (i.e., Gross Motor Function Classification System [GMFCS], Communication Function Classification System [CFCS], Test for Reception of Grammar [TROG-D], and memory span). Recently published data from typically developing children were used for the purpose of age normalization.

RESULTS

Dysarthria severity was moderately correlated with GMFCS and CFCS but not with TROG-D and memory span. At the group level, respiration, articulation, and prosodic modulation were most severely affected, whereas voice function was only mildly affected or even spared in the majority of children. Four features were identified as most relevant markers of childhood dysarthria: conspicuous rhythm/stress pattern, hypernasality, strained-strangled voice, and reduced articulatory precision.

CONCLUSIONS

Childhood dysarthria is part of a complex multiple disability, but speech motor skills may still dissociate from gross-motor and cognitive-linguistic functions. Auditory-perceptual analyses incorporating age norms allow for a comprehensive description and identification of childhood dysarthria.

A Tool for Differential Diagnosis of Childhood Apraxia of Speech and Dysarthria in Children: A Tutorial

PURPOSE

While there has been mounting research centered on the diagnosis of childhood apraxia of speech (CAS), little has focused on differentiating CAS from pediatric dysarthria. Because CAS and dysarthria share overlapping speech symptoms and some children have both motor speech disorders, differential diagnosis can be challenging. There is a need for clinical tools that facilitate assessment of both CAS and dysarthria symptoms in children. The goals of this tutorial are to (a) determine confidence levels of clinicians in differentially diagnosing dysarthria and CAS and (b) provide a systematic procedure for differentiating CAS and pediatric dysarthria in children.

METHOD

Evidence related to differential diagnosis of CAS and dysarthria is reviewed. Next, a web-based survey of 359 pediatric speech-language pathologists is used to determine clinical confidence levels in diagnosing CAS and dysarthria. Finally, a checklist of pediatric auditory-perceptual motor speech features is presented along with a procedure to identify CAS and dysarthria in children with suspected motor speech impairments. Case studies illustrate application of this protocol, and treatment implications for complex cases are discussed.

RESULTS

The majority (60%) of clinician respondents reported low or no confidence in diagnosing dysarthria in children, and 40% reported they tend not to make this diagnosis as a result. Going forward, clinicians can use the feature checklist and protocol in this tutorial to support the differential diagnosis of CAS and dysarthria in clinical practice.

CONCLUSIONS

Incorporating this diagnostic protocol into clinical practice should help increase confidence and accuracy in diagnosing motor speech disorders in children. Future research should test the sensitivity and specificity of this protocol in a large sample of children with varying speech sound disorders. Graduate programs and continuing education trainings should provide opportunities to practice rating speech features for children with dysarthria and CAS.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19709146.

Intelligibility, Articulation Rate, Fluency, and Communicative Efficiency in Typically Developing Children

Purpose This article describes the developmental trajectories of four communication-related parameters (i.e., intelligibility, articulation rate, fluency, and communicative efficiency) in a cross-sectional study of typically developing children between 3 and 9 years. The four target parameters were related to auditory-perceptual parameters of speech function. Method One hundred forty-four typically developing children (ages 3;0-9;11 [years;months]; 72 girls and 72 boys) participated. Speech samples were collected using the materials of the Bogenhausen Dysarthria Scales for Childhood Dysarthria, a German assessment tool for childhood dysarthria, and analyzed following established auditory-perceptual criteria on relevant speech functions. To assess intelligibility, naïve listeners transcribed sentences repeated by the children. Articulation rate and fluency were measured by acoustic analyses; communicative efficiency was determined by multiplying the proportion of correctly transcribed syllables by speech rate. Results Intelligibility showed a steep developmental trajectory, with the majority of children obtaining a proportion of intelligible syllables close to 1.0 at the age of 5 years. Articulation rate demonstrated a flatter trajectory, with high variability still within the older children. Disfluencies, on the contrary, occurred only in the youngest children. By definition, communicative efficiency shared the characteristics of intelligibility and rate curves. A principal component analysis revealed, among other findings, strong connections between intelligibility and articulation, as well as between communicative efficiency, articulation, and rate measures. Conclusions While children speak intelligibly, in terms of the applied assessment, at a comparably young age, other communication-relevant parameters show a slower developmental progress. Knowledge on the typical development of communication-related parameters and on their complex relationships with functional speech variables is crucial for the clinical assessment of childhood dysarthria. Supplemental Material https://doi.org/10.23641/asha.14880285.