Sympathetic arousal as a marker of chronicity in childhood stuttering

A Preliminary Study of Speech Rhythm Differences as Markers of Stuttering Persistence in Preschool-Age Children

PURPOSE

The purpose of this study was twofold: (a) to determine whether there are speech rhythm differences between preschool-age children who stutter that were eventually diagnosed as persisting (CWS-Per) or recovered (CWS-Rec) and children who do not stutter (CWNS), using empirical spectral analysis and empirical mode decomposition of the speech amplitude envelope, and (b) to determine whether speech rhythm characteristics close to onset are predictive of later persistence.

METHOD

Fifty children (3-4 years of age) participated in the study. Approximately 2-2.5 years after the experimental testing took place, children were assigned to the following groups: CWS-Per (nine boys, one girl), CWS-Rec (18 boys, two girls), and CWNS (18 boys, two girls). All children produced a narrative based on a text-free storybook. From the audio recordings of these narratives, fluent utterances were selected for each child from which seven envelope-based measures were extracted. Group-based differences on each measure as well as predictive analyses were conducted to identify measures that discriminate CWS-Per versus CWS-Rec.

RESULTS

CWS-Per were found to have a relatively higher degree of power in suprasyllabic oscillations and greater variability in the timing of syllabic rhythms especially for longer utterances. A logistic regression model using two speech rhythm measures was able to discriminate the eventual outcome of recovery versus persistence, with 80% sensitivity and 75% specificity.

CONCLUSION

Findings suggest that envelope-based speech rhythm measures are a promising approach to assess speech rhythm differences in developmental stuttering, and its potential for identification of children at risk of developing persistent stuttering should be investigated further.

A study of respiratory sinus arrhythmia and stuttering persistence

INTRODUCTION

The present study investigated potential differences in respiratory sinus arrhythmia between preschool-age children with persisting stuttering, children who recovered from stuttering, and children who do not stutter.

METHODS

Participants were 10 children with persisting stuttering (persisting group), 20 children who recovered from stuttering (recovered group), and 36 children who do not stutter (non-stuttering group). Participants viewed a neutral video clip to establish a pre-arousal baseline and then viewed two emotionally-arousing video clips (positive and negative, counterbalanced). Age-appropriate speaking tasks followed each of the video clips (post-baseline, post-positive, and post-negative). Respiratory sinus arrhythmia (RSA), an index of parasympathetic nervous system activity, was measured during the video clips and subsequent speaking tasks.

RESULTS

First, the persisting group, recovered group, and non-stuttering group did not significantly differ in baseline RSA. Second, during the emotionally-arousing video clips, there was a significant group x condition interaction, with the recovered group exhibiting significantly lower RSA in the positive than negative condition, and the non-stuttering group exhibiting significantly higher RSA in the positive than negative condition. Third, in the narrative tasks, there was a significant group x condition interaction, with a greater difference in RSA between the post-baseline speaking task and the post-positive and post-negative speaking tasks for the persisting compared to the non-stuttering group. Lastly, a follow-up analysis indicated that the recovered and nonstuttering groups, compared to the persisting group, exhibited significantly greater RSA during the baseline (neutral) condition compared to the post-neutral narrative task.

CONCLUSIONS

Findings provide a physiological perspective of emotion within children who stutter and persist and children who stutter and recover. Future investigations with larger sample sizes and diverse methodologies are necessary to provide novel insights on the specific emotion-related processes that are potentially involved with persistence of stuttering in young children.

Child's perceived stress: A concept analysis

PROBLEM

Child's perceived stress is a term used widely in literature, yet it is poorly defined. Perceived stress in childhood has been linked to negative health outcomes throughout the lifespan. Therefore, the ability of researchers and healthcare providers to conceptualize child's perceived stress and form accurate measures of the concept is of utmost importance.

ELIGIBILITY CRITERIA

Following the eight steps identified by Walker and Avant, a literature review was conducted to identify studies that measured perceived stress in school-age children over the last 10 years.

SAMPLE

Of 914 records identified, 136 were screened, and 16 met inclusion criteria.

RESULTS

Child's perceived stress is best defined as any actual or imagined threat, personal and specific to childhood, which overwhelms the child and leads to changes in emotional, psychological, developmental, and/or physiological domains.

CONCLUSIONS

While the concept of child's perceived stress is understood similarly throughout studies, there is notable variation in the way child's perceived stress is measured. Because of the specificity of perceived stress to childhood, and the wide range of what may be perceived as stressful by the child, the child is the best reporter of child's perceived stress.

IMPLICATIONS

Researchers and clinicians must use child self-report tools to measure the concept of child's perceived stress. Opportunities exist for healthcare workers to intervene, educate, and help children and families recognize and manage child's perceived stress. This concept analysis includes many resources that practitioners may use to help alleviate stress in children.

Definitions, theories, and measurement of stress in children

PROBLEM

Stress in children remains a complex concept to examine due to the inherent subjectivity and lack of specific manifestations, as well as the multiple ways stress can be defined and measured in children. Because stress is multifactorial,is experienced daily by children, and undergirds adolescent health and early mental illness, it is crucial to have a clear understanding of stress and the effects of stress in children from infancy through age twelve years.

ELIGIBILITY CRITERIA

To be included in this review, literature must pertain to and highlight theories, definitions/classifications, and measurements of stress in children from infancy to 12 years of age.

SAMPLE

The most pertinent articles identified through database searches (PubMed, Scopus, PsycINFO, CINAHL, Google Scholar), gray literature sources (e.g., child health websites), and reference lists of identified articles were included in this narrative overview.

RESULTS

The results of this review are organized by themes and include: classifications and definitions of stress, stress-related theories, and tools to measure stress in children.

CONCLUSIONS

Research addressing stressors and stress in children is limited, and there is wide variation in how researchers define and classify stress in children. Existing measures of stress in children younger than 12 address physiological, psychological, and observational components, but may be inconsistent and threaten validity of otherwise well-designed and well-executed studies.

IMPLICATIONS

Improving the understanding and accurate measurement of stress in children enables researchers and clinicians to curtail undesirable health outcomes.

Predicting Persistent Developmental Stuttering Using a Cumulative Risk Approach

PURPOSE

The purpose of this study was to explore how well a cumulative risk approach, based on empirically supported predictive factors, predicts whether a young child who stutters is likely to develop persistent developmental stuttering. In a cumulative risk approach, the number of predictive factors indicating a child is at risk to develop persistent stuttering is evaluated, and a greater number of indicators of risk are hypothesized to confer greater risk of persistent stuttering.

METHOD

We combined extant data on 3- to 5-year-old children who stutter from two longitudinal studies to identify cutoff values for continuous predictive factors (e.g., speech and language skills, age at onset, time since onset, stuttering frequency) and, in combination with binary predictors (e.g., sex, family history of stuttering), used all-subsets regression and receiver operating characteristic curves to compare the predictive validity of different combinations of 10 risk factors. The optimal combination of predictive factors and the odds of a child developing persistent stuttering based on an increasing number of factors were calculated.

RESULTS

Based on 67 children who stutter (i.e., 44 persisting and 23 recovered) with relatively strong speech-language skills, the predictive factor model that yielded the best predictive validity was based on time since onset (≥ 19 months), speech sound skills (≤ 115 standard score), expressive language skills (≤ 106 standard score), and stuttering severity (≥ 17 Stuttering Severity Instrument total score). When the presence of at least two predictive factors was used to confer elevated risk to develop persistent stuttering, the model yielded 93% sensitivity and 65% specificity. As a child presented with a greater number of these four risk factors, the odds for persistent stuttering increased.

CONCLUSIONS

Findings support the use of a cumulative risk approach and the predictive utility of assessing multiple domains when evaluating a child's risk of developing persistent stuttering. Clinical implications and future directions are discussed.

Temperament is Linked to Avoidant Responses to Stuttering Anticipation

PURPOSE

The purpose of the present study was to examine the degree to which certain temperament constructs predict individual differences in three types of behavioral responses to anticipation among children and adults who stutter (CWS and AWS, respectively): avoidance, physical change, and approach.

METHODS

Participants included 64 CWS (9- to 17-years-old) and 54 AWS (18- to 50-years-old) who completed an online survey package including a temperament questionnaire (Early Adolescent Temperament Questionnaire-Revised for the CWS; Adult Temperament Questionnaire for the AWS) and the Stuttering Anticipation Scale. The data were analyzed separately for CWS and AWS using multivariate multiple regressions to assess how each temperament construct predicted avoidance, physical change, and approach responses to anticipation.

RESULTS

CWS who reported higher levels of shyness were more likely to engage in avoidant behavioral responses when they anticipate an upcoming moment of stuttering. AWS who reported higher levels of orienting sensitivity were more likely to engage in avoidant behavioral responses when they anticipate an upcoming moment of stuttering. No temperament constructs predicted physical change or approach responses to anticipation among either age group.

CONCLUSION

Specific aspects of temperament appear to be linked to the degree that CWS and AWS engage in avoidant behavioral responses to stuttering anticipation. These findings support the continued study of how individual differences impact the internal experience and outward manifestation of stuttering behaviors.

Exploring Relationships Among Risk Factors for Persistence in Early Childhood Stuttering

Purpose The purpose of this study is to investigate how epidemiological and clinical factors collectively predict whether a preschooler who is stuttering will persist or recover and to provide guidance on how clinicians can use these factors to evaluate a child's risk for stuttering persistence. Method We collected epidemiological and clinical measures from 52 preschoolers (M = 54.4 months, SD = 6.7 months; 38 boys and 14 girls) diagnosed as stuttering. We then followed these children longitudinally to document whether they eventually recovered or persisted in stuttering. Risk factors found to be significantly associated with stuttering persistence were used to build single and multiple variable predictive statistical models. Finally, we assessed each model's prediction capabilities by recording how accurate a model was in predicting a child's stuttering outcome-persisting or recovered. Results We found that a positive family history of stuttering, poorer performance on a standardized articulation/phonological assessment, higher frequency of stuttering-like disfluencies during spontaneous speech, and lower accuracy on a nonword repetition task were all significantly associated with an increased probability of persistence. The interaction between family history of stuttering and nonword repetition performance was also significant. The full multiple regression model incorporating all these risk factors resulted in the best fitting model with the highest predictive accuracy and lowest error rate. Conclusions For the first time, we show how multiple risk factors collectively predict the probability of stuttering persistence in 3- to 5-year-old preschool children who stutter. Using the full combination of risk factors to assess preschoolers who stutter yielded more accurate predictions of persistence compared to sparser models. A better understanding of the factors that underlie stuttering persistence will yield insight into the underpinnings of chronic stuttering and will help identify etiological targets for novel treatment approaches.

Predictive factors for persistence and recovery of stuttering in children: A systematic review

PURPOSE

The purpose of this study was to systematically review the available literature on various factors that can predict the persistence and recovery of stuttering in children.

METHOD

An electronic search yielded a total of 35 studies, which considered 44 variables that can be potential factors for predicting persistence and recovery.

RESULT

Among 44 factors studied, only four factors- phonological abilities, articulatory rate, change in the pattern of disfluencies, and trend in stuttering severity over one-year post-onset were identified to be replicated predictors of recovery of the stuttering. Several factors, such as differences in the second formant transition between fluent and disfluent speech, articulatory rate measured in phones/sec, etc., were observed to predict the future course of stuttering. However, these factors lack replicated evidence as predictors.

CONCLUSION

There is clear support only for limited factors as reliable predictors. Also, it is observed to be too early to conclude on several replicated factors due to differences in the age group of participants, participant sample size, and the differences in tools used in research that lead to mixed findings as a predictive factor. Hence there is a need for systematic and replicated testing of the factors identified before initiating their use for clinical purposes.

Emotional Reactivity and Regulation in Preschool-Age Children Who Do and Do Not Stutter: Evidence From Autonomic Nervous System Measures

Purpose: This experimental cross-sectional research study examined the emotional reactivity and emotion regulation in preschool-age children who do (CWS) and do not stutter (CWNS) by assessing their psychophysiological response during rest and while viewing pictures from the International Affective Picture System (Lang et al., 2008).

Method: Participants were 18 CWS (16 boys and two girls; mean age 4 years, 5 months) and 18 age- and gender-matched CWNS. Participants' psychophysiological responses were measured during two baselines and two picture viewing conditions. Skin conductance level (SCL) and heart rate were measured to assess emotional reactivity. Respiratory sinus arrhythmia (RSA) was measured to assess emotional regulation. Participants' shyness and executive function were assessed via parent report and considered for their effects on participants' psychophysiological responses.

Results: First, CWNS and CWS did not differ in their initial baseline SCL, heart rate, or RSA, but all participants had higher SCL and lower RSA in the second baseline, subsequent to the first challenge condition, compared to the first baseline. Second, during the challenge conditions, CWS did not differ from CWNS in their SCL, but showed a significantly higher heart rate than CWNS. Third, CWS exhibited a significantly lower RSA during the challenge conditions compared to CWNS. Lastly, the temperamental quality of shyness was associated with preschool-age children's SCL, such that participants who were rated higher in shyness had a higher SCL during the challenge conditions. Participants' executive function had a marginally significant effect on the RSA, such that the participants who had higher executive function composite scores exhibited lower RSA during the challenge conditions.

Conclusions: Our findings suggest that CWS and CWNS did not differ in their emotional reactivity and emotional regulation abilities at rest. During challenge conditions, however, CWS tended to be more emotionally reactive, as indicated by a higher heart rate, and also employed more emotional regulation, indexed by a greater decrease in RSA, compared to CWNS. Preschool-age children's behavior is largely dominated by reactivity, but there is the emergence of regulation, which can help children adjust to various contextual demands. For CWS who are more emotionally reactive, regulatory skills may be particularly critical to their prognosis and treatment.

Clinical Characteristics Associated With Stuttering Persistence: A Meta-Analysis

Purpose The purpose of this meta-analytic study was to identify clinical characteristics, defined as child factors that can be assessed by a speech-language pathologist as part of a routine speech-language evaluation that may differentiate children who persist in stuttering from children who eventually recover from stuttering. Clinical characteristics explored included sex, age at onset, family history of stuttering, stuttering frequency and severity, speech-language skills, and temperament. Method Studies were identified through electronic databases, journals, and reference lists of relevant reports (e.g., research articles). Eligible studies followed young children who stutter (i.e., under 6 years old) for at least 24 months, assessed a potential clinical marker at study entry, and determined talker group classification (i.e., persistent or recovered) at study completion. Sex and family history differences were estimated using risk ratios; all other differences were estimated using Hedges's g. Heterogeneity and methodological differences among studies were evaluated. Results Eleven studies (41 reports) met eligibility criteria. Persistent children were older at stuttering onset and exhibited higher frequencies of stuttering-like disfluencies, lower speech sound accuracy, and lower expressive and receptive language skills than recovered children. Males and children with a family history of stuttering were also more likely to persist. Conclusions Clinical characteristics were identified that are associated with increased risk for stuttering persistence. Future studies have the potential to translate these clinical characteristics into prognostic markers for stuttering persistence risk.

Temperament and early stuttering intervention: Two perspectives

PURPOSE

To discuss clinical applications of research findings about temperament and early stuttering.

METHOD

A "1000-bytes" format (Onslow & Millard, 2012) was used to provide readers with contemporaneous observation of a "conversation" between the authors. The conversation is proceeded by a prologue and followed by concluding statements from each author.

RESULTS

One author contended that comprehensive, multidimensional assessment of temperament domains is essential during clinical management of early stuttering, and the results of that assessment are best incorporated into a multifactorial treatment approach. The other author contested that view, arguing that such an approach is not empirically justifiable at present.

CONCLUSIONS

The authors agree about the salience of research on temperament and early stuttering but have different perspectives about the topic when applied to providing health care for early stuttering.

The recovery rate of early stuttering

PURPOSE

Across studies there is great variability in reported rates of stuttering recovery. This study examined the impact that different definitions of recovery had on calculation of recovery rates and factors associated with recovery within the same sample of children.

METHOD

Speech samples and parents and child reports of their experiences of stuttering were collected from 38 children who stuttered aged 2-5 years of age (Occassion-1) and again at 9-13 years of age (Occassion-2). Four different criteria for recovery that were developed representing variations in criteria reported in previous research were applied to data from these children.

RESULTS

. The majority of the participants (82%) showed very little disfluent speech (<1% syllables stuttered) at Occasion 2. Recovery rate varied greatly depending on the criteria used, ranging from 13.2%-94.7%. Definitions ordered from least to greatest recovery that were (a) parent and clinician report no stuttering and no stuttering observed (13.2 %); (b) ≤1% syllables stuttered; severity rated at ≤1; parent, clinician, and child report recovery (55.3 %); (c) ≤1% syllables stuttered; severity rated at ≤1; parent and clinician report recovery (71.1 %); (d) <3.0 % syllables stuttered (94.7 %). Five participants were considered recovered and two were considered persistent stutters across all criteria. Different factors were associated with recovery from stuttering depending on the criterion used.

CONCLUSION

The concept of recovery from stuttering is complex and estimations of recovery rate are likely to be greatly affected by differences in definitions and measurement across studies. This has a flow-on effect in determining the factors associated with recovery from stuttering.

A parent-report scale of behavioral inhibition: Validation and application to preschool-age children who do and do not stutter

PURPOSE

This two-part (i.e., Study 1, Study 2) study investigated behavioral inhibition (BI) in preschool-age children who do (CWS) and do not (CWNS) stutter. The purpose of Study 1 was to develop the Short Behavioral Inhibition Scale (SBIS), a parent-report scale of BI. The purpose of Study 2 was to determine, based on the SBIS, differences in BI between CWS and CWNS, and associations between BI and CWS's stuttering frequency, stuttering severity, speech-associated attitudes, and stuttering-related consequences/reactions.

METHOD

Participants in Study 1 were 225 CWS and 243 CWNS with the majority of them being included in Study 2. In Study 2, a speech sample was obtained for the calculation of stuttering frequency and severity, and the parents of a subset of CWS completed the Communication Attitude Test for Preschool and Kindergarten Children Who Stutter (Vanryckeghem & Brutten, 2007), and the Test of Childhood Stuttering Disfluency-Related Consequences Rating Scale (Gillam, Logan, & Pearson, 2009).

RESULTS

Study 1 analyses indicated that SBIS is a valid and reliable tool whose items assess a single, relatively homogeneous construct. In Study 2, CWS exhibited greater mean and extreme BI tendencies than CWNS. Also CWS with higher, compared to CWS with lower, BI presented with greater stuttering frequency, more severe stuttering, greater stuttering-related consequences, and more negative communication attitudes (for CWS older than 4 years of age).

CONCLUSION

Findings were taken to suggest that BI is associated with early childhood stuttering and that the SBIS could be included as part of a comprehensive evaluation of stuttering.

Physiological Correlates of Fluent and Stuttered Speech Production in Preschool Children Who Stutter

Purpose The purpose of this study was to compare physiological indices of sympathetic nervous system arousal recorded during fluent and stuttered utterances in a preschool children who stutter (CWS). Method Twenty-two 4- to 5-year-old CWS participated in the experiment. We recorded children's skin conductance response amplitude and frequency, blood pulse volume amplitude, and pulse rate as they completed a picture description task. We then compared indices of phasic sympathetic arousal recorded during stuttered versus fluent utterances. In addition, children's communication attitudes were evaluated with a self-report measure. Results We detected significantly higher sympathetic arousal during stuttered utterances compared to fluent utterances. Specifically, we found larger skin conductance responses occurring at an increased frequency and decreased blood pulse volume amplitudes during stuttered speech. The behavioral measure indicated a negative communication attitude in only one-third of the participants. Conclusion Our findings suggest that preschool CWS may exhibit higher levels of sympathetic arousal during stuttered speech compared to when they are speaking fluently. We discuss the potential impact of increased sympathetic arousal on speech regulatory mechanisms in early childhood stuttering and present questions to guide future research.

Autonomic Nervous System Response to Speech Production in Stuttering and Normally Fluent Preschool-Age Children

Purpose We studied speech-related sympathetic nervous system arousal of preschool-age children who do (CWS) and do not stutter (CWNS) and its association with children's proclivity to experience negative emotions and children's self-reported attitudes toward speaking. Method Electrodermal activity measures were collected from 32 preschool-age children while they engaged in a picture description and a nonword repetition task. Children's proclivity to experience negative emotions was assessed with a parent report questionnaire. Children's communication attitude was assessed with a self-report questionnaire. Results CWS did not differ from CWNS in their sympathetic arousal during a picture description task. However, during a more challenging nonword repetition task, preschool-age CWS had a higher sympathetic arousal level than CWNS. Although CWS were rated by their caregivers as more fearful and prone to sadness, children's tendency to experience stronger and more frequent negative emotions was not associated with their sympathetic arousal during speaking. Lastly, although CWS had a more negative communication attitude than CWNS, it was not associated with their level of sympathetic arousal during speaking. Conclusions Our findings suggest that age-appropriate social communication tasks are not inherently more stressful for preschool-age CWS and are not associated with state-related stress or anxiety that is often reported for adults who stutter. However, speaking tasks that place a higher demand on children's cognitive-linguistic system may be more taxing and challenging to preschool CWS than CWNS, leading to a higher level of arousal.

Sympathetic Nervous System Activity in Preschoolers Who Stutter

BACKGROUND

In our Dynamic Pathways, account, we hypothesized that childhood stuttering reflects an impairment in speech sensorimotor control that is conditioned by cognitive, linguistic, and emotional factors. The purpose of this study was to investigate potential differences in levels of sympathetic arousal during performance of speech and non-speech tasks between children who do and do not stutter.

METHODS

Seventy-two preschool-aged children participated in the study, 47 children who stutter (CWS; 38 boys) and 25 children who do not stutter (CWNS; 18 boys). We recorded skin conductance and blood pulse volume (BPV) signals, indices of sympathetic arousal, during higher/lower load speech tasks (structured sentence production and picture description) and non-speech tasks (jaw wagging and forceful blowing). We included a measure that reflects children's attitudes about their communication skills and a parent-report assessment of temperament.

RESULTS

We found no significant differences between preschool CWS and CWNS in phasic skin conductance response amplitude or frequency, BPV, and pulse rate for any of the experimental tasks. However, compared to CWNS, CWS had, on average, significantly higher skin conductance levels (SCL), indexing slowly changing tonic sympathetic activity, across both speech and non-speech experimental conditions. We found distinctive task-related profiles of sympathetic arousal in both groups of preschool children. Most children produced the highest levels of sympathetic arousal in the physically demanding blowing task rather than in speech, as seen in previous studies of adults. We did not find differences in temperament between the two groups of preschool children nor a relationship among behavioral indices of temperament and communication attitude and physiological measures of sympathetic arousal.

CONCLUSION

We did not find that atypically high, speech-related sympathetic arousal is a significant factor in early childhood stuttering. Rather, CWS had higher, on average, task-related tonic SCLs across speech and non-speech tasks. A relationship among behavioral measures of temperament and physiological measures of sympathetic arousal was not confirmed. Key questions for future experiments are how the typical coupling of sympathetic and speech sensorimotor systems develops over childhood and adolescence and whether task related developmental profiles follow a different course in children who continue to stutter.

What Are Predictors for Persistence in Childhood Stuttering?

Over the past 10 years, we (the Purdue Stuttering Project) have implemented longitudinal studies to examine factors related to persistence and recovery in early childhood stuttering. Stuttering develops essentially as an impairment in speech sensorimotor processes that is strongly influenced by dynamic interactions among motor, language, and emotional domains. Our work has assessed physiological, behavioral, and clinical features of stuttering within the motor, linguistic, and emotional domains. We describe the results of studies in which measures collected when the child was 4 to 5 years old are related to eventual stuttering status. We provide supplemental evidence of the role of known predictive factors (e.g., sex and family history of persistent stuttering). In addition, we present new evidence that early delays in basic speech motor processes (especially in boys), poor performance on a nonword repetition test, stuttering severity at the age of 4 to 5 years, and delayed or atypical functioning in central nervous system language processing networks are predictive of persistent stuttering.