Speech disfluencies in children with Down Syndrome

Stuttering in individuals with Down syndrome: a systematic review of earlier research

The main objective of this systematic review was to synthesize the evidence on the occurrence and characteristics of stuttering in individuals with Down syndrome and thus contribute knowledge about stuttering in this population. Group studies reporting outcome measures of stuttering were included. Studies with participants who were preselected based on their fluency status were excluded. We searched the Eric, PsychInfo, Medline, Scopus, and Web of Science Core Collection databases on 3rd January 2022 and conducted supplementary searches of the reference lists of previous reviews and the studies included in the current review, as well as relevant speech and language journals. The included studies were coded in terms of information concerning sample characteristics, measurement approaches, and stuttering-related outcomes. The appraisal tool for cross-sectional studies (AXIS) was used to evaluate study quality. We identified 14 eligible studies, with a total of 1,833 participants (mean = 131.29, standard deviation = 227.85, median = 45.5) between 3 and 58 years of age. The estimated occurrence of stuttering ranged from 2.38 to 56%, which is substantially higher than the estimated prevalence (1%) of stuttering in the general population. The results also showed that stuttering severity most often was judged to be mild-to-moderate and that individuals with Down syndrome displayed secondary behaviors when these were measured. However, little attention has been paid to investigating the potential adverse effects of stuttering for individuals with Down syndrome. We judged the quality of the evidence to be moderate-to-low. The negative evaluation was mostly due to sampling limitations that decreased the representability and generalizability of the results. Based on the high occurrence of stuttering and the potential negative effects of this condition, individuals with Down syndrome who show signs of stuttering should be referred to a speech and language pathologist for an evaluation of their need for stuttering treatment.

There is more to cluttering than meets the eye: The prevalence of cluttering and association with psychological well-being indices in an undergraduate sample

BACKGROUND

Cluttering is a fluency disorder characterized by an abnormally fast or irregular speech delivery rate along with disfluencies that are frequent but are not judged to be stuttering. Data on cluttering prevalence in the general population are scarce, as well as its association with psychological well-being indices, such as anxiety, and depressive symptoms.

AIMS

To estimate cluttering prevalence among undergraduates, as well as its relationship with psychological and well-being indicators.

METHODS & PROCEDURES

To address these issues, a large sample (n = 1582) of undergraduates completed a questionnaire that provided a lay definition of cluttering and were asked to identify themselves as clutterers (SI-Clut), as well as to indicate the presence of several psychological and mental well-being indices.

OUTCOMES & RESULTS

A total of 276 respondents (23%) self-identified as clutterers (now or in the past), with 55.1% of those being male. Only 56 respondents (3.5% of the total sample; about 21% of SI-Clut) reported having received speech therapy for cluttering. Relative to students self-identifying as non-clutterers, self-identification of cluttering was associated with higher levels of psychosomatic symptoms, depressive symptoms and stress, indicating a tendency toward internalizing psychopathology, along with lower self-esteem, and lower subjective happiness.

CONCLUSIONS & IMPLICATIONS

The current findings point to the high prevalence of students self-identifying as clutterers, along with a significant link between cluttering and mental distress. Therefore, it is important to increase public awareness of cluttering, its diagnosis and treatment. From the clinical perspective, the elevated levels of somatic complaints, anxiety and depression may represent internalizing psychopathology, associated with more covert rather than overt symptomatology. Such symptom manifestation calls for special attention from the speech-language pathologists providing cluttering therapy, using designated well-being or mental health screening tools. Although data on standard cluttering treatment are limited, it should be customized to the client's unique difficulties. Speech-language pathologists' understanding of cluttering, which includes both speech characteristics as well as psychological and social aspects of well-being, may assist them in implementing effective treatments.

WHAT THIS PAPER ADDS

What is already known on the subject Cluttering is a fluency disorder characterized by an abnormally fast or irregular speech rate, along with various disfluencies and articulatory imprecision. It may co-occur with other disorders, such as learning disabilities, and attention-deficit/hyperactivity disorder. Data on cluttering prevalence and its association with psychological well-being indices, such as anxiety and depression, are limited. What this paper adds to existing knowledge A total of 276 undergraduates (23%) self-identified as clutterers, of whom 55.1% were males. A total of 56 respondents (3.5% of the total sample, and about 21% of undergraduates self-identified as clutterers) reported having received speech therapy for cluttering. Psychosomatic symptoms, depressive symptoms and stress levels were higher among these students, suggesting a tendency toward internalizing psychopathology, along with a lower sense of self-esteem and subjective happiness. What are the potential or actual clinical implications of this work? The high prevalence of students self-identifying as clutterers, along with the low percentage of respondents who received speech therapy for cluttering, emphasize the need to raise public awareness of the problem, its diagnosis and treatment (Reichel et al., 2010). The association between cluttering and mental distress requires speech-language pathologists to be aware that cluttering may have covert symptomatology, similar to stuttering, which should be addressed in therapy.

The effect of manual movements on stuttering in individuals with down syndrome

PURPOSE

Stuttering may disrupt the speech of individuals with Down syndrome (DS), but standard stuttering therapies may be less adapted to these clients' needs. This study examined if their strength in gesture use can lead to the development of a new stuttering therapy.

METHOD

Eighteen individuals with DS who stutter participated in an experimental task. During this task, they produced sentences in three different conditions: once without the ability to use gestures, once while moving the mouth of a hand puppet synchronous with their speech, and once while making beat gestures along their speech. Stuttering frequency was measured and compared between conditions while controlling for the effect of articulation rate.

RESULTS

The experimental hand puppet and beat condition did not affect the stuttering frequency, but the covariate articulation rate did. An exploratory posthoc analysis showed that the articulation rate decreased during the experimental hand puppet and beat condition. Manual movements in the present task might only induce fluency through articulation rate reduction. However, analyses at individual level show significant interindividual variability.

CONCLUSION

Individual analyses show that effect on stuttering frequency cannot be attributed entirely to articulation rate reduction and that beat gestures might still play a role. However, at this point, there is not enough direct evidence to implement beat gestures in current stuttering therapy.

A lightweight CNN and Transformer hybrid model for mental retardation screening among children from spontaneous speech

Mental retardation (MR) is a group of mental disorders characterized by low intelligence and social adjustment difficulties. Early diagnosis is beneficial for the timely intervention of children with MR to ease the degree of disability. Children with MR always have impaired speech functions compared to normal children, which is significant for clinical diagnosis. On the basis of this, our study proposes a spontaneous speech-based framework (MT-Net) for screening MR, which merges mobile inverted bottleneck convolutional blocks (MBConv) and visual Transformer blocks. MT-Net takes log-mel spectrograms converted from raw interview speech as data source, and utilizes MBConv and visual Transformer to learn low-level and high-level features well. In addition, SpecAugment, a data augmentation strategy, has been used to expand our audio dataset to further enhance the performance of MT-Net. The experimental results show that our proposed MT-Net outperforms Transformer networks (ViT) and convolutional neural networks (ResNet18, MobileNetV2, EfficientNetV2), achieving accuracy of 91.60% after using SpecAugment. Our proposed MT-Net has fewer parameters, low computing consumption and high prediction accuracy, which is expected to be an auxiliary screening tool for MR.

Stuttering Behavior in a National Age Cohort of Norwegian First-Graders With Down Syndrome

PURPOSE

The aims of this study were to investigate the occurrence of stuttering behavior across time and to evaluate the relationship between stuttering behavior and language ability in children with Down syndrome.

METHOD

A national age cohort of Norwegian first graders with Down syndrome (N = 75) participated in the study. Speech samples from a story-retelling task and a picture book dialogue as well as standardized measures of vocabulary, grammar, and nonverbal mental ability were collected at two time points approximately 5 months apart. Stuttering behavior was evaluated through counting stuttering-like disfluencies and stuttering severity ratings. The relationship between stuttering behavior and language ability was investigated through hierarchical regression analysis.

RESULTS

The participants had stuttering severity ratings ranging from no stuttering behavior to severe and displayed all types of stuttering-like disfluencies. There were significant relationships between stuttering behavior and language ability at the first time point, whereas the relationships were not significant at the second time point. The stuttering severity ratings were significantly predicted by language ability across time, whereas the frequency of stuttering-like disfluencies was not.

CONCLUSIONS

The occurrence of stuttering behavior was high across the measures and time points; however, the relationship between stuttering behavior and language ability varied across these variables. Thus, the nature of the relationship does not seem to follow a strict pattern that can be generalized to all children across time.

Defining Expressive Language Benchmarks for Children with Down Syndrome

Establishing expressive language benchmarks (ELBs) for children with Down syndrome (DS), as developed by Tager-Flusberg et al. for children with autism, is critically needed to inform the development of novel treatments, identify individualized treatment targets, and promote accurate monitoring of progress. In the present study, we assessed ELB assignments in three language domains (phonology, vocabulary, and grammar) for 53 young children with DS (CA range: 2.50–7.99 years) using standardized assessments. The participants were classified into one of four ELB levels (preverbal, first words, word combinations, and sentences) in each language domain. Associations with additional measures of language, chronological age, nonverbal cognition, and verbal short-term memory were considered. Analyses of individual ELB profiles indicated substantial variability across the three language domains, with six different patterns of variation across domains emerging. At the same time, the ELB categories were significantly associated with independent language measures and broader developmental domains. Moreover, ELB changes were observed in a small sample of children with DS reassessed 18–24 months after the initial visit. Results from the present study suggest the procedures outlined by Tager-Flusberg et al. for defining ELBs are a potentially useful tool for describing the language abilities of children with DS.

Cluttering in the Speech of Young Men With Fragile X Syndrome

PURPOSE

Cluttering is a fluency disorder that has been noted clinically in individuals with fragile X syndrome (FXS). Yet, cluttering has not been systematically characterized in this population, hindering identification and intervention efforts. This study examined the rates of cluttering in male young adults with FXS using expert clinical opinion, the alignment between expert clinical opinion and objectively quantified features of cluttering from language transcripts, and the association between cluttering and aspects of the FXS phenotype.

METHOD

Thirty-six men with FXS (aged 18-26 years; M = 22, SD = 2.35) contributed language samples and completed measures of nonverbal cognition, autism symptoms, anxiety, and symptoms of attention-deficit/hyperactivity disorder (ADHD). The presence of cluttering was determined by the consensus of two clinical experts in fluency disorders based on characteristics exhibited in the language sample. Cluttering features (speech rate, disfluencies, etc.) were also objectively quantified from the language transcripts.

RESULTS

Clinical experts determined that 50% of participants met the criteria for a cluttering diagnosis. Phrase repetitions were the most salient feature that distinguished individuals who cluttered. Although the presence of cluttering was not associated with autism symptoms or mean length of utterance, cluttering was more likely to occur when nonverbal cognitive ability was higher, ADHD symptoms were elevated, and anxiety symptoms were low.

CONCLUSIONS

Half of the male young adults with FXS exhibited cluttering, which supports FXS as a genetic diagnosis that is highly enriched for risk of cluttering. Cluttering was associated with increased ADHD symptoms and cognitive ability and reduced anxiety symptoms. This study contributes a new description of the clinical presentation of cluttering in men with FXS and may lead to improved understanding of the potential underlying mechanisms of cluttering and eventual refinements to treatment and diagnosis.

Influence of gestures on the intelligibility and comprehensibility of utterances with stuttering events in individuals with Down syndrome

INTRODUCTION

Individuals with Down syndrome (DS) often stutter, which can affect their speech intelligibility. Previous research has shown that manual signs can enhance speech intelligibility and comprehensibility. It remains unclear to what extent spontaneous hand gestures, such as iconic and beat gestures, may enhance intelligibility and/or comprehensibility during utterances with stuttering events.

METHODS

Eleven individuals with DS who stutter provided video-recorded speech samples. From these samples, 60 utterances containing a stuttering event were selected. In half of them, the stuttering events were accompanied by gestures; in the other half, the stuttering events were not accompanied by gestures. The samples were shown to 250 assessors who were blind to the study's goals. Each sample was shown in three visibility conditions: 1) video-with-audio, 2) video-with-audio but with the speaker's mouth covered and 3) audio-only. The assessors rated speech intelligibility on a 7-point Likert scale and transcribed the speech sample. The effect of gesture production, gesture type and the visibility conditions on comprehensibility and intelligibility was examined with a hierarchical multiple linear regression.

RESULTS

When a speaker had used a gesture during a stuttering event, the Likert scale score increased with 0.47 and the accuracy of transcription with 9.07%. There was no difference in effect between the different gesture types. Despite the effect from gesture use, there was no effect of the visibility conditions on the Likert scale or transcription score.

CONCLUSIONS

Gestures positively affect intelligibility and comprehensibility of utterances with stuttering events in individuals with DS by altering the speech production. The possibility of beat gestures as a therapy method should be examined, with caution for the development of maladaptive behaviours.

Speech production accuracy in children with Down syndrome: relationships with hearing, language, and reading ability and change in speech production accuracy over time

BACKGROUND

This study examines speech production accuracy in children with Down syndrome and concurrent relationships with hearing, language and reading ability. It also examines change in speech production accuracy over a 21-month period.

METHODS

A group of 50 children with Down syndrome (aged 5-10 years) completed measures of speech accuracy, non-verbal IQ, reading (single-word reading, letter-sound knowledge and phoneme blending) and language (expressive and receptive vocabulary and receptive grammar). Hearing was assessed by parental report. Speech accuracy was reassessed 21 months later.

RESULTS

Although there was considerable variability in the sample, speech was characterised by high levels of errors. There were no effects of gender, hearing status or non-verbal IQ on speech production accuracy. In contrast, speech production accuracy was significantly related to age and to measures of receptive vocabulary, phoneme blending and word reading. There was no significant improvement in speech production accuracy over time.

CONCLUSIONS

Children with Down syndrome experience difficulties producing accurate sounds in speech. These difficulties are related to age and to vocabulary and reading skills and persist over time, highlighting the need for intensive targeted speech intervention in this group of children.

Non-pharmacological interventions for stuttering in children six years and younger

BACKGROUND

Stuttering, or stammering as it is referred to in some countries, affects a child's ability to speak fluently. It is a common communication disorder, affecting 11% of children by four years of age. Stuttering can be characterized by sound, part word or whole word repetitions, sound prolongations, or blocking of sounds or airflow. Moments of stuttering can also be accompanied by non-verbal behaviours, including visible tension in the speaker's face, eye blinks or head nods. Stuttering can also negatively affect behavioural, social and emotional functioning.

OBJECTIVES

Primary objective To assess the immediate and long-term effects of non-pharmacological interventions for stuttering on speech outcomes, communication attitudes, quality of life and potential adverse effects in children aged six years and younger. Secondary objective To describe the relationship between intervention effects and participant characteristics (i.e. child age, IQ, severity, sex and time since stuttering onset) at pretest.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, PsycINFO, nine other databases and two trial registers on 16 September 2020, and Open Grey on 20 October 2020. There were no limits in regards to language, year of publication or type of publication. We also searched the reference lists of included studies and requested data on unpublished trials from authors of published studies. We handsearched conference proceedings and programmes from relevant conferences.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs that assessed non-pharmacological interventions for stuttering in young children aged six years and younger. Eligible comparators were no intervention, wait list or management as usual.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We identified four eligible RCTs, all of which compared the Lidcombe Program to a wait-list control group. In total, 151 children aged between two and six years participated in the four included studies. In the Lidcombe Program, the parent and their child visit a speech and language therapist (SLT) in a clinic. One study conducted clinic visits by telephone. In each clinic visit, parents were taught how to conduct treatment at home. Two studies took place in Australia, one in New Zealand and one in Germany. Two studies were conducted for nine months, one for 16 weeks and one for 12 weeks. The frequency of clinic visits and practice sessions at home varied within the programme. One study was partially funded by the Rotary Club, Wiesbaden, Germany; and one was funded by the National Health and Medical Research Council of Australia. One study did not report funding sources and another reported that they did not receive any funding for the trial.  All four studies reported the outcome of stuttering frequency. One study also reported on speech efficiency, defined as articulation rate. No studies reported the other predetermined outcomes of this review, namely stuttering severity; communication attitudes; emotional, cognitive or psychosocial domains; or adverse effects.  The Lidcombe Program resulted in a lower stuttering frequency percentage syllables stuttered (% SS) than a wait-list control group at post-test, 12 weeks, 16 weeks and nine months postrandomization (mean difference (MD) -2.16, 95% confidence interval (CI) -3.48 to -0.84, 4 studies, 151 participants; P = 0.001; very low-certainty evidence).  However, as the Lidcombe Program is designed to take one to two years to complete, none of the participants in these studies had finished the complete intervention programme at any of the data collection points. We assessed stuttering frequency to have a high risk of overall bias due to high risk of bias in at least one domain within three of four included studies, and to have some concern of overall bias in the fourth, due to some concern in at least one domain. We found moderate-certainty evidence from one study showing that the Lidcombe Program may increase speech efficiency in young children. Only one study reported outcomes at long-term follow-up. The long-term effect of intervention could not be summarized, as the results for most of the children in the control group were missing. However, a within-group comparison was performed between the mean % SS at randomization and the mean % SS at the time of extended follow-up, and showed a significant reduction in frequency of stuttering.  AUTHORS' CONCLUSIONS: This systematic review indicates that the Lidcombe Program may result in lower stuttering frequency and higher speech efficiency than a wait-list control group in children aged up to six years at post-test. However, these results should be interpreted with caution due to the very low and moderate certainty of the evidence and the high risk of bias identified in the included studies. Thus, there is a need for further studies from independent researchers, to evaluate the immediate and long-term effects of other non-pharmacological interventions for stuttering compared to no intervention or a wait-list control group.

An experiment on measuring awareness of stuttering in individuals with Down syndrome

BACKGROUND

Awareness of stuttering is likely to depend upon the development of the metalinguistic skill to discriminate between fluent speech and stuttering and the ability to identify one's own speech as fluent or stuttered. Presently, little is known about these abilities in individuals with Down syndrome (DS).

PURPOSE

This study investigates whether individuals with DS and typically developing (TD) children who stutter and who do not stutter differ in their ability to discriminate between fluent speech and stuttering. The second purpose of this study is to discover if this ability is correlated with their self-identification ability.

METHOD

An experiment to investigate awareness with tasks for discrimination of stuttering and self-identification was developed. It was administered to 28 individuals (7-19 years) with DS, 17 of them stutter and 11 do not, and 20 TD children (3-10 years), 8 of them stutter and 12 do not. Skills to discriminate stuttering were compared between these groups and correlated with self-identification within these groups. The influence of stuttering severity and developmental/chronological age on their ability to discriminate was also investigated.

RESULTS

The ability to discriminate does not differ significantly between the DS and TD group, but is highly influenced by developmental age. This ability correlates with self-identification but only for the TD individuals who speak fluently.

CONCLUSION

The ability to discriminate matures around the age of 7 and conscious awareness may rely on this ability. Differences between the present findings and earlier studies suggest that differentiation in levels and types of awareness is warranted.

The Association between Difficulties with Speech Fluency and Language Skills in a National Age Cohort of Children with Down Syndrome

The present study (a) addressed difficulties in speech fluency in children with Down syndrome and typically developing children at a similar non-verbal level and (b) examined the association between difficulties with speech fluency and language skills in children with Down syndrome. Data from a cross-sectional parent survey that included questions about children's difficulties with speech fluency, as well as clinical tests from a national age cohort of 43 six-year-olds with Down syndrome and 57 young typically developing children, were collected. Fisher's exact test, Student's t-test, linear regression, and density ellipse scatter plots were used for analysis. There was a significantly higher occurrence of parent-reported difficulties with speech fluency in the children with Down syndrome. Higher language scores were significantly associated with a lower degree of difficulties; this association was strongest for vocabulary and phonological skills. Although difficulties with speech fluency were not reported for all children with Down syndrome, a substantially higher occurrence of such difficulties was reported compared to that for typically developing children. The significant association between difficulties with speech fluency and the level of language functioning suggests that speech fluency and language skills should be taken into consideration when planning treatment for children with Down syndrome.

Effects of Massage Therapy on the Development of Babies Born with Down Syndrome

Objective

To determine the short-term effects of infant massage on the development of Down syndrome babies.

Materials and Methods

The study compared two groups (intervention and control), each with 16 babies with Down syndrome between 4 and 8 months old. The variables developmental age and developmental quotient were measured at two distinct time points, at pretest and after 5 weeks, using the Brunet-Lézine Early Childhood Psychomotor Development revised scale. This scale measures the variables of age and development quotient in a partial way (motor, visual-motor coordination, language, and social development) and in a global way. The experimental group received infant massage, applied by the parents, during these 5 weeks, every day for at least 10 minutes. The massage protocol was based on the methodology created by Vimala McClure. The control group received it after 5 weeks.

Results

All developmental variables were improved in the experimental group but not in the control group. There were significant differences in developmental age between the two groups, and this outcome was better in the experimental group (p < 0.001). The 2-by-2 mixed-model analysis of variance indicates a statistically significant group-by-time interaction for all development quotients, both partial and global (p < 0.001), which was significantly higher in the experimental group than in the control group.

Conclusion

Infant massage therapy improves the development of babies with Down syndrome in the short term.

Cluttering symptoms in school-age children by communicative context: A preliminary investigation

Purpose: The objective of this study was to compare the symptoms of cluttering among school-age children who do and do not clutter in the contexts of monologue, conversation and expository discourse.Method: A matched pairs design was used to compare cluttering symptoms according to the Lowest Common Denominator (LCD) definition of cluttering, a definition representing the core speech and fluency characteristics of cluttering agreed upon among experts. Cluttering symptoms (over-coarticulated words, normal disfluencies, abnormal pauses) in eight school-aged males with cluttering were compared to eight controls matched by sex and grade level in school. Symptoms were compared in the speech contexts of conversation, monologue and expository discourse.Result: Regardless of the speaking context, significantly more over-coarticulated words were found in children with cluttering (CWC) as compared to controls. Significantly more normal disfluencies were produced by CWC during monologue only.Conclusion: Study findings confirm increased over-coarticulation and normal disfluencies in specific speaking contexts in CWC when compared to controls. These findings provide the premise for clinical implications for cluttering assessment and diagnosis. Findings also provide the basis for further investigation of the validity of the LCD's symptom of abnormal pausing for accurate diagnosis of people who clutter.

Auditory-Perceptual Speech Features in Children With Down Syndrome

Speech disorders occur commonly in individuals with Down syndrome (DS), although data regarding the auditory-perceptual speech features are limited. This descriptive study assessed 47 perceptual speech features during connected speech samples in 26 children with DS. The most severely affected speech features were: naturalness, imprecise consonants, hyponasality, speech rate, inappropriate silences, irregular vowels, prolonged intervals, overall loudness level, pitch level, aberrant oropharyngeal resonance, hoarse voice, reduced stress, and prolonged phonemes. These findings suggest that speech disorders in DS are due to distributed impairments involving voice, speech sound production, fluency, resonance, and prosody. These data contribute to the development of a profile of impairments in speakers with DS to guide future research and inform clinical assessment and treatment.