Children who stutter at 3 years of age: A community-based study

Multiple-Community-Based Epidemiological Study of Stuttering among 3-Year-Old Children in Japan

INTRODUCTION

Many epidemiological studies of the disorder of stuttering have been conducted during the 20th century, continuing during the current one. Unfortunately, only a few were carried out in Japan. This study aimed at assessing (1) the incidence and prevalence of stuttering in 3-year-old children in multiple Japanese communities and (2) factors associated with the onset of stuttering among these children.

METHODS

A questionnaire aimed at screening for the presence of stuttering was employed for 2,055 children aged 3 years, who underwent a standard nationwide health checkup. Positive responses were confirmed in several ways: (1) direct interviews and assessment of the child's speech, (2) confirmatory questionnaire, or (3) telephone interviews by licensed Speech Language Hearing Therapists.

RESULTS

Approximately 6.5% of the children were found to exhibit stuttering at the time of their health checkup. This figure rose to 8.9% after including individuals who previously, but not currently, were reported to have exhibited stuttering. Among the putative risk factors, higher stuttering odds (odds ratio, OR = 3.27) were detected in those with a family history of stuttering, those whose guardians had concerns about their child's development (OR = 1.75), and those with diagnosed diseases or disabilities (OR = 2.13).

DISCUSSION/CONCLUSIONS

It was concluded that, in Japan, both the risk of stuttering incidence (8.9%) in children up to, and including, the age of 3 years, as well as its prevalence (6.5%) in this population, was similar to those reported by recent studies in other countries. Additionally, our findings also confirmed that an increased risk for stuttering at age 3 is associated with a family history of stuttering.

Linguistic aspects of stuttering: research updates on the language-fluency interface

PURPOSE

Although commonly defined as a speech disorder, stuttering interacts with the language production system in important ways. Our purpose is to summarize research findings on linguistic variables that influence stuttering assessment and treatment.

METHOD AND RESULTS

Numerous topics are summarized. First, we review research that has examined linguistic features that increase stuttering frequency and influence where it occurs. Second, we tackle the question of whether or not persons who stutter exhibit subtle language differences or deficits. Next, we explore language factors that appear to influence recovery from early stuttering in children. The final topic discusses the unique challenges inherent in differentially diagnosing stuttering in bilingual children. Clinical implications for each topic are discussed.

DISCUSSION

The article concludes with a discussion of the unique differences in the integration of language and speech demands by people who stutter, when compared to people who are typically fluent, and their clinical ramifications.

Performance of Bimanual Finger Coordination Tasks in Speakers Who Stutter

Stuttering is a neurodevelopmental speech disorder characterized by the symptoms of speech repetition, prolongation, and blocking. Stuttering-related dysfluency can be transiently alleviated by providing an external timing signal such as a metronome or the voice of another person. Therefore, the existence of a core motor timing deficit in stuttering has been speculated. If this is the case, then motoric behaviors other than speech should be disrupted in stuttering. This study examined motoric performance on four complex bimanual tasks in 37 adults who stutter and 31 fluent controls. Two tasks utilized bimanual rotation to examine motor dexterity, and two tasks used the bimanual mirror and parallel tapping movements to examine timing control ability. Video-based analyses were conducted to determine performance accuracy and speed. The results showed that individuals who stutter performed worse than fluent speakers on tapping tasks but not on bimanual rotation tasks. These results suggest stuttering is associated with timing control for general motor behavior.

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.

Developmental Stuttering Screening Instrument: development and content validation

ABSTRACT Purpose: to develop a screening instrument to identify the risk of developmental stuttering in preschoolers. Methods: the procedures were divided into two stages: The first one (theoretical), consisted of the literature review and the construction of the items that make up the instrument; the second stage (content validation), consisted of the analysis of the instrument by a judging committee formed by 10 speech-language-hearing therapists who work in the field of fluency. The data analysis was based on the calculation of the item content validity index (I-CVI) and the total number of answers (T-CVI). Also, an item reliability analysis was conducted with Cronbach’s alpha. Results: the Developmental Stuttering Screening Instrument (DSSI) encompassed 24 items distributed into four key categories. The I-CVI and T-CVI revealed a high agreement between the judges. The Cronbach’s alpha coefficients indicated a high internal consistency between the judges’ answers in 19 of the 24 items. The qualitative analysis pointed to the need for new adjustments. All the analyses contributed to the construction of the second version of the instrument. Conclusion: the proposed instrument showed content-based validity evidence that made it possible, up to the present moment, to adjust it to its construct. It is suggested that the validation process continue, employing new accuracy measures.

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.

Speech-Induced Suppression for Delayed Auditory Feedback in Adults Who Do and Do Not Stutter

Speech-induced suppression is the normal, relative amplitude reduction of the auditory evoked potential for self-, compared to externally-generated, auditory stimulation. It remains controversial as to whether adults who stutter exhibit expected auditory modulation during speech; some studies have reported a significant difference between stuttering and fluent groups in speech-induced suppression during speech movement planning, while others have not. We compared auditory evoked potentials (N1 component) for auditory feedback arising from one’s own voice (Speaking condition) with passive listening to a recording of one’s own voice (Listening condition) in 24 normally-fluent speakers and 16 adults who stutter under various delayed auditory feedback (DAF) time conditions (100 ms, 200 ms, 500 ms, and 1,000 ms). We presented the participant’s own voice with a delay, immediately after presenting it without a delay. Our working hypothesis was that the shorter the delay time, the more likely the delayed sound is perceived as self-generated. Therefore, shorter delay time conditions are proposed to result in relatively enhanced suppression of the auditory system. Results showed that in fluent speakers, the shorter the delay time, the more the auditory evoked potential in the Speaking condition tended to be suppressed. In the Listening condition, there was a larger evoked potential with shorter delay times. As a result, speech-induced suppression was only significant at the short delay time conditions of 100 and 200 ms. Adults who stutter did not show the opposing changes in the Speaking and Listening conditions seen in the fluent group. Although the evoked potential in the Listening condition tended to decrease as the delay time increased, that in the Speaking condition did not show a distinct trend, and there was a significant suppression only at 200 ms delay. For the 200 ms delay condition, speakers with more severe stuttering showed significantly greater speech-induced suppression than those with less severe stuttering. This preliminary study suggests our methods for investigating evoked potentials by presenting own voice with a delay may provide a clue as to the nature of auditory modulation in stuttering.