Stuttering severity, psychosocial impact and lexical diversity as predictors of outcome for treatment of stuttering

Genetic factors and therapy outcomes in persistent developmental stuttering

PURPOSE

We investigated whether outcomes of therapy for persistent developmental stuttering differ in individuals who carry a mutation in one of the known genes associated with stuttering compared to individuals without such mutations.

METHOD

We studied outcomes of an intensive fluency shaping-based therapy program in individuals with persistent developmental stuttering. We evaluated a cohort of 51 stuttering individuals with who carried a mutation in either the GNPTAB, GNPTG, NAGPA, or AP4E1 gene. We compared therapy outcomes in these individuals with outcomes in 51 individuals matched for age, gender, and ethnicity, who stutter and underwent the same therapy program, and did not carry a mutation in any of these genes. Fluency pre- and post-therapy was evaluated using blinded observer-based quantitative stuttering dysfluency measures (Dysfluent Words Score, DWS), and by subjects' self-reported measures of struggle, avoidance and expectancy behavior associated with speaking (Perceptions of Stuttering Inventory, PSI). The difference between pre- and post-therapy fluency scores was taken as the measure of near-term therapy efficacy.

RESULTS

Comparison of fluency measures showed a strong effect of therapy overall. Mutation carriers achieved significantly less resolution in PSI following therapy, with PSI scores showing significantly less improvement in individuals who carry a mutation (p = 0.0157, RR = 1.75, OR = 2.92) while the group difference in DWS between carriers and non-carriers was statistically not significant in the present study, the trend observed in the results warrants further research focused on this important issue.

CONCLUSIONS

These results suggest stuttering is more resistant to therapy in individuals who carry a mutation in one of the genes known to be associated with stuttering.

Acquired Stuttering in Veterans of the Wars in Iraq and Afghanistan: The Role of Traumatic Brain Injury, Post-Traumatic Stress Disorder, and Medications

Introduction

Determine the association between acquired stuttering (AS), traumatic brain injury (TBI), and post-traumatic stress disorder (PTSD) in a cohort of 309,675 U.S. Iraq and Afghanistan veterans. The secondary aim was to determine the association between AS and medication patterns for veterans in the sample.

Materials and Methods

Retrospective study using data from the Veterans Health Administration National Repository for veterans deployed in support of combat operations in Iraq and Afghanistan and who received Veterans Health Administration care in 2010 and 2011. We identified stuttering using ICD-9 codes to establish the association between AS, TBI, and PTSD, controlling for demographic characteristics and other comorbidities. Multivariable logistic regression was used to determine the association between comorbid conditions and potentially problematic medications associated with stuttering.

Results

Two hundred thirty-five veterans (0.08%) were diagnosed with AS in the cohort. There was the greater likelihood of an AS diagnosis for veterans with concomitant TBI and PTSD when compared with veterans without these diagnoses. Over 66% of those with stuttering were prescribed at least one medication that affected speech fluency (antidepressants, anxiolytics, and antiepileptic drugs) compared with 35% of those without AS.

Conclusion

Veterans with a comorbid diagnosis of TBI and PTSD were more likely to be diagnosed with AS AOR: 9.77 (95% CI = 6.93-13.78, p < 0.05) and more likely to have been prescribed medications known to affect speech production OR: 3.68 (95% CI = 2.81-4.82, p < 0.05). Clinicians treating veterans with these complex comorbid conditions should consider the impact of medications on speech fluency.

Factors Contributing to Preschoolers' Communicative Participation Outcomes: Findings From a Population-Based Longitudinal Cohort Study in Ontario, Canada

PURPOSE

The aim of this study was to identify predictors of communicative participation outcomes for a large cohort of preschoolers with speech and language impairments.

METHOD

A secondary analysis of longitudinal program evaluation data from Ontario, Canada's Preschool Speech and Language Program was done. Data available for 46,872 children 18-67 months of age (M = 41.76 months, SD = 11.92; 68% boys, 32% girls) were previously used to predict children's communicative participation skill development in 5 levels of function. Demographic and intervention-based variables were added to the models to identify new predictors of growth.

RESULTS

Three demographic and 3 intervention-based variables were statistically significant predictors of children's communicative participation outcomes. Clinically significant predictors included participation in an early learning environment, receipt of speech-language interventions, and the amount of time spent in intervention. These variables impacted predicted outcomes differently, depending on a child's level of communicative function.

CONCLUSIONS

This population-based study of preschoolers with speech and language impairments identified predictors of growth in communicative participation skills-an outcome important and meaningful to families but not often explored. A broad picture emerged of factors that may influence the development of communicative participation skills and may be used to predict outcomes for preschoolers. Given the large sample size, these robust findings may be used to predict outcomes outside the Preschool Speech and Language Program as well.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.6024422.

Immediate effect of delayed auditory feedback on stuttering-like disfluencies

ABSTRACT Objective: to describe the immediate effects of delayed auditory feedback on stuttering-like disfluencies in people who stutter. Methods: a cross-sectional and experimental study. The effect of delayed auditory feedback was analyzed in thirty individuals, from eight to 46 years old, diagnosed with persistent developmental stuttering. Participants should present at least 3% of stuttering-like disfluencies and mild stuttering according to the Stuttering Severity Instrument. The following procedures were used: audiological evaluation, fluency evaluation in two listening situations - with Non-altered and delayed auditory feedback - and the Stuttering Severity Instrument. The Fono Tools software was used to cause the delay effect. Data analysis was performed using pertinent statistical tests. Results: there was no decrease in most stuttering-like disfluencies. There was a statistically significant reduction in word repetition and flow of syllables per minute. Conclusion: the delay in auditory feedback caused, as an immediate effect, the reduction of word repetition and speech rate, in syllables per minute.

Preliminary Evidence That Growth in Productive Language Differentiates Childhood Stuttering Persistence and Recovery

Purpose

Childhood stuttering is common but is often outgrown. Children whose stuttering persists experience significant life impacts, calling for a better understanding of what factors may underlie eventual recovery. In previous research, language ability has been shown to differentiate children who stutter (CWS) from children who do not stutter, yet there is an active debate in the field regarding what, if any, language measures may mark eventual recovery versus persistence. In this study, we examined whether growth in productive language performance may better predict the probability of recovery compared to static profiles taken from a single time point.

Method

Productive syntax and vocabulary diversity growth rates were calculated for 50 CWS using random coefficient models. Logistic regression models were then used to determine whether growth rates uniquely predict likelihood of recovery, as well as if these rates were predictive over and above currently identified correlates of stuttering onset and recovery.

Results

Different linguistic profiles emerged between children who went on to recover versus those who persisted. Children who had steeper productive syntactic growth, but not vocabulary diversity growth, were more likely to recover by study end. Moreover, this effect held after controlling for initial language ability at study onset as well as demographic covariates.

Conclusions

Results are discussed in terms of how growth estimates can be incorporated in recommendations for fostering productive language skills among CWS. The need for additional research on language in early stuttering and recovery is suggested.

Gagueira desenvolvimental persistente familial: disfluências e prevalência

Resumo: OBJETIVO: caracterizar e comparar a frequência das disfluências da fala de adultos com gagueira desenvolvimental persistente familial do sexo masculino e feminino, a severidade do distúrbio e determinar a prevalência familial e a razão entre gêneros da gagueira nos familiares dos probandos. MÉTODOS: participaram 30 adultos com gagueira (18 a 53 anos), divididos em dois grupos, sendo 20 do sexo masculino e 10 do sexo feminino. Os procedimentos realizados foram: história clínica e familial, avaliação da fluência e Instrumento de Severidade da Gagueira. RESULTADOS: as porcentagens de disfluências típicas da gagueira (p=0,352), de outras disfluências (p=0,947) e do total das disfluências (p=0,522) foram semelhantes entre os grupos masculino e feminino. A média de disfluências típicas da gagueira foi 5,23% e de outras disfluências 5,50%. O subtipo leve foi manifestado pela maioria dos participantes (83,3%). Os familiares do gênero masculino apresentaram maior risco de apresentar gagueira (p<0,001). Do total de 1002 familiares, 85 apresentaram gagueira. No total de familiares afetados (n=85), 53 eram do sexo masculino e 32 do feminino. CONCLUSÃO: não houve diferenças entre os grupos masculino e feminino nas medidas analisadas. Quanto à frequência das disfluências, aproximadamente metade do total das disfluências foi caracterizada como disfluências típicas da gagueira. O subtipo de gagueira desenvolvimental persistente familial foi caracterizado principalmente por um distúrbio classificado quanto à severidade como leve. O risco dos familiares dos probandos afetados foi de 8,5%. A gagueira afetou mais pessoas do gênero masculino em relação ao feminino, numa proporção de 3,72:1.

Non-verbal sensorimotor timing deficits in children and adolescents who stutter

There is growing evidence that motor and speech disorders co-occur during development. In the present study, we investigated whether stuttering, a developmental speech disorder, is associated with a predictive timing deficit in childhood and adolescence. By testing sensorimotor synchronization abilities, we aimed to assess whether predictive timing is dysfunctional in young participants who stutter (8-16 years). Twenty German children and adolescents who stutter and 43 non-stuttering participants matched for age and musical training were tested on their ability to synchronize their finger taps with periodic tone sequences and with a musical beat. Forty percent of children and 90% of adolescents who stutter displayed poor synchronization with both metronome and musical stimuli, falling below 2.5% of the estimated population based on the performance of the group without the disorder. Synchronization deficits were characterized by either lower synchronization accuracy or lower consistency or both. Lower accuracy resulted in an over-anticipation of the pacing event in participants who stutter. Moreover, individual profiles revealed that lower consistency was typical of participants that were severely stuttering. These findings support the idea that malfunctioning predictive timing during auditory-motor coupling plays a role in stuttering in children and adolescents.

Health-related quality of life of preschool children who stutter

PURPOSE

The purpose of this study is to compare the health-related quality of life (HrQoL) of preschool children who stutter (CWS) and a reference population of children who do not stutter, and to evaluate the association between stuttering severity and HrQoL.

METHODS

Baseline data were used from 197 children participating in a multicenter Randomized Clinical Trial in the Netherlands. Information on stuttering severity and time since onset (TSO) of stuttering was obtained from the baseline evaluation by speech- and language therapists. Stuttering severity was measured using the SSI-3. HrQoL was assessed using proxy versions of two Child Health Questionnaires (ITQOL-97 and CHQ-PF28), the Health Utility Index 3 (HUI3) and the EuroQoL EQ-VAS (EQ-VAS).

RESULTS

While the outcomes on the EQ-VAS and the HUI3 showed that the HrQoL of CWS is slightly poorer than that of the Dutch reference population, results on the different dimensions of the CHQ-instruments did not reveal any difference in scores between stuttering children and reference groups. Within the group of CWS, two ITQOL-97 and four CHQ-PF28 scales showed statistically different scores for children in different SSI stuttering severity or TSO categories. However, the effect sizes showed that these differences were so small that they could be considered negligible.

CONCLUSION

The results of this study do not reveal a diminished HrQoL for preschool CWS. Future research should include a larger cohort of children with severe stuttering, study the longitudinal course of HrQoL and incorporate additional parameters such as the characteristics of the child and his environment.

EDUCATIONAL OBJECTIVES

The reader will be able to: (a) summarize the current evidence base on HrQoL in people who stutter; (b) describe the HrQoL of preschool CWS on different HrQoL measures; (c) describe the relationship between stuttering severity and HrQoL in preschool CWS.

Birth weight and stuttering: Evidence from three birth cohorts

PURPOSE

Previous studies have produced conflicting results with regard to the association between birth weight and developmental stuttering. This study sought to determine whether birth weight was associated with childhood and/or adolescent stuttering in three British birth cohort samples.

METHODS

Logistic regression analyses were carried out on data from the Millenium Cohort Study (MCS), British Cohort Study (BCS70) and National Child Development Study (NCDS), whose initial cohorts comprised over 56,000 individuals. The outcome variables were parent-reported stuttering in childhood or in adolescence; the predictors, based on prior research, were birth weight, sex, multiple birth status, vocabulary score and mother's level of education. Birth weight was analysed both as a categorical variable (low birth weight, <2500g; normal range; high birth weight, ≥4000g) and as a continuous variable. Separate analyses were carried out to determine the impact of birth weight and the other predictors on stuttering during childhood (age 3, 5 and 7 and MCS, BCS70 and NCDS, respectively) or at age 16, when developmental stuttering is likely to be persistent.

RESULTS

None of the multivariate analyses revealed an association between birth weight and parent-reported stuttering. Sex was a significant predictor of stuttering in all the analyses, with males 1.6-3.6 times more likely than females to stutter.

CONCLUSION

Our results suggest that birth weight is not a clinically useful predictor of childhood or persistent stuttering.

Risk factors and stuttering: evaluating the evidence for clinicians

This paper summarizes and discusses some of the key issues raised in the other four manuscripts in this special edition of Journal of Fluency Disorders. All the four pieces examine risk factors in developmental stuttering from different perspectives and all provide stand-alone contributions to knowledge on the subject. Thus, rather than review, the focus of the present paper is to highlight those matters, which, from a clinical perspective might be seen as either (a) of the greatest contention, (b) of particular relevance to clinicians, or (c) requiring greater emphasis in future research, on the basis of the conclusions from the authors involved.

EDUCATIONAL OBJECTIVES

This paper provides an overview of points of particular clinical interest arising from the four contributions to this special edition. Readers will be able to (a) understand arguments for and against whole word repetitions being included as moments of stuttering in the SSI-3 assessment, (b) understand arguments relating to psychological components in early onset stuttering, (c) understand some of the complexities in interpreting data pertaining to recovery from stuttering, (d) understand where future efforts in research into risk of stuttering should be placed.