Differential diagnostic characteristics between cluttering and stuttering—Part one
Introduction
Speech-language pathologists generally agree that cluttering and stuttering represent two different fluency disorders. Whereas research into stuttering has increased markedly in the past century, studies on cluttering remain scarce. “One of the problems in diagnosing and treating cluttering is that it often occurs in conjunction with other disorders, some of which are speech/language based and others that are not” (Ward, 2006, p. 359). Differentially diagnosing between cluttering and stuttering is difficult because these disorders have similar characteristics and often occur in conjunction with each other. For example, Van Borsel and Tetnowski (2007) reviewed stuttering patterns in clients with mental retardation who showed evidence of disfluency patterns, concluding that not all would be considered stuttering. This paper presents an analysis of the differential diagnostic characteristics of the two disorders, and a proposal for distinguishing between the two in clinical settings.
Stuttering is a disorder characterized by a high frequency of involuntary interruptions of the forward flow of speech, regarded by the person who stutters (PWS) as “stutters”, which are often accompanied by a feeling of loss of control (Curlee and Conture, 2007, Guitar, 2006, Quesal, 2004, Shapiro, 1999, Van Borsel and Tetnowski, 2007, Ward, 2006). These interruptions usually take the form of (1) repetitions of sounds, syllables or one syllable words; (2) prolongations of sounds; (3) blocks of airflow or voicing in speech. The results of an exploratory study on speech motor practice and learning by Namasivayam and Van Lieshout (2008) indicated that PWS and persons who do not stutter may resemble each other on a number of performance variables (such as movement amplitude and duration), but they differ in terms of practice and learning on variables that relate to movement stability and strength of coordination patterns.In the last decades of the previous century research on cluttering has addressed overt as well as covert symptomatology (Daly, 1996, Daly and Burnett, 1999, Myers and Bradley, 1992, St. Louis, 1992, Weiss, 1968). Weiss (1964) described cluttering as a disorder in the fluent flow of communication. According to experts, cluttering is characterized by three main features: (1) a rapid and/or irregular articulatory rate (Daly, 1993, Damsté, 1984, Dinger et al., 2008, St. Louis, 1992, St. Louis et al., 1996, St. Louis et al., 2003, Weiss, 1964); (2) a higher than average frequency of disfluencies, dissimilar to those seen in stuttering [see section on stuttering characteristics above] (Myers and Bradley, 1992, St. Louis, 1992, St. Louis, 1996, St. Louis et al., 2003) and (3) reduced intelligibility due to exaggerated coarticulation (deletion of syllables or sounds in multi-syllabic words) and indistinct articulation (Daly and Burnett, 1999, Damsté, 1984, Dinger et al., 2008, Gutzmann, 1893, Mensink-Ypma, 1990, St. Louis et al., 2003, St. Louis et al., 2007, Van Zaalen and Winkelman, 2009, Voelker, 1935, Ward, 2006, Weiss, 1964).
According to the St. Louis et al. (2003) working definition of cluttering a high and/or irregular articulatory rate is a main characteristic in differential diagnostics between cluttering and stuttering, however, agreement on what defines abnormally fast and abnormally irregular articulatory rate is needed. It is hypothesized that there are persons who clutter that maintain a high articulatory rate in a more demanding speaking situation, and their speech-language system cannot handle that fast speed. Due to speech motor or language planning problems in a high articulatory rate, intelligibility problems or disfluencies occur (Daly, 1992).
Many researchers and clinicians (Bezemer et al., 2006, Ward, 2006) report that persons who clutter experience intelligibility problems due to exaggerated coarticulation (deletion of sounds or syllables in multi-syllabic words) and indistinct articulation (substitution of sounds and/or syllables). Several researchers discuss the fact that although persons who clutter experience intelligibility problems in running speech, they are able to produce correct syllable and word structures in controlled situations (Damsté, 1984, Van Zaalen and Winkelman, 2009, Ward, 2006, Weiss, 1964). The findings of Hennessey, Nang, and Beilby (2008) suggest that contrary to persons who clutter (PWC), PWS were not deficient in the time course of lexical activation and selection, phonological encoding, and phonetic encoding. In order to be able to produce correct syllable or word structures, speech motor control should be appropriate. Riley and Riley (1985) defined speech motor control as the ability to time laryngeal, articulatory and respiratory movements, that lead to fast and accurate syllable production. It is hypothesized that cluttering is a fluency disorder in which speech motor control at word level is disturbed in high speech rate, resulting in errors in word structure.
Relying upon clinical experience, St. Louis, Hinzman, and Hull (1985) and St. Louis et al. (1996) differentiated the fluency disorders of disfluent people and concluded that persons who clutter had a high frequency of normal disfluencies (e.g. revisions, interjections, phrase- and syllable repetitions) and a low frequency of disfluencies typical for stuttering. A higher than average frequency of disfluencies, dissimilar to those seen in stuttering is considered to be a characteristic of cluttering;
Differential diagnostics in cluttering and stuttering has up till now mainly been based on the subjective clinical judgement of the speech-language therapist. Clinical judgement in the assessment of cluttering and stuttering should be based on different aspects of communication and cognition, for instance oral reading, spontaneous speech, retelling a memorized story, and questionnaires (Sick, 2004, St. Louis et al., 2003, St. Louis et al., 2007, Ward, 2006). It would appear important to develop a more objective assessment method for the above mentioned aspects besides the subjective clinical judgement.
The main goal of this two-part article is to set objective norms for differential diagnostic assessment of cluttering and stuttering symptoms, based on the three main characteristics of cluttering indicated/identified by St. Louis et al. (2003): a fast and/or irregular articulatory rate together with errors in syllable, word or sentence structure and or a high frequency of normal disfluencies (not being stuttering). In the first half of the article, objective measures are compared to the subjective clinical judgement made by fluency experts. In other words, which differentiating characteristics can be found in the speech profiles of persons who were diagnosed as people who clutter or stutter? In the second part of the article, results on the Predictive Cluttering Inventory (Daly & Cantrell, 2006) are discussed in relationship to the subjective and objective measurements studied in the first half of the article.
Section snippets
Participants
All persons participating in this study had been referred to centres for stuttering therapy in the centre of the Netherlands (between January 2006 and January 2007) with self-reported fluency problems. Participants were 41 males (mean age 10.2; range 6–39 years) and 13 females (mean age 12.9; range 6–47 years). Controls for disfluent adolescents and adults were 17 males and 8 females (see Table 1.). A control group was included in order to obtain normative values for articulatory rate in
Diagnostic decision making
Pearson's correlation between SLP diagnoses was low (r = .638). Of the 54 male and female disfluent speakers, only 27 (50%) were agreed upon by the SLPs. Of the 54 male and female disfluent speakers, 7 (13%) were diagnosed as PWC by one researcher and PWS by the other researcher; and 20 (37%) were diagnosed as PWC or PWS by one researcher and PWCS by the other researcher. Analyses presented here were carried out only on the 27 subjects that were agreed upon by the judges (PWC: N = 9; PWCS: N = 10;
Discussion
The main goal of this research was to compare the subjective clinical judgements made by experts in fluency disorders to results obtained by objective measurements. Findings indicate that a differential diagnosis based on a subjective clinical judgement of a speech-language pathologist specialized in fluency disorders appeared to correspond with the subjective clinical judgement of another SLP specialized in fluency disorders in only 50% of all disfluent cases. In 37.0% of all disfluent cases a
Participants
In this study 137 Dutch speaking participants ranging in age between 10.6 and 12.11 years, were divided into five groups and examined by eight different SLPs. The groups were based on SLPs diagnosis as described in part one of this article. Age range in all groups was restricted to exclude bias due to developmental issues. Group 1 consisted of cluttering children (N = 17, M = 11.5 years); Group 2 consisted of cluttering-stuttering children (N = 25, M = 11.6 years); Group 3 consisted of stuttering
Checklist
Based on the proposed norm score for cluttering by Daly (in press), only two participants from the cluttering or cluttering–stuttering group were detected by the checklist as having cluttering components (see Table 4.). That is, only 4.44% (2/45) of persons with cluttering symptoms were tested positive on the index test. This sensitivity level is considered to be extremely low. The specificity of the checklist is 94.7% (89/94), meaning, that 94.7% of a group of persons without cluttering indeed
Discussion
The main purpose of this research was to investigate the validity of the PCI in a fluent and disfluent population. PCI/CBK in its original form is not sensitive enough to detect cluttering in persons with cluttering symptoms, but is specific enough to reject people that do not clutter.
The low sensitivity level of the PCI is due to frequent type I errors, that is, a difference was observed when there was none. This may be explained by the fact that a lot of symptoms on the list are common
Yvonne Van Zaalen-op’t Hof, MSc works as a speech-language therapist specialized in stuttering since 1988, in a centre for stuttering therapy in the Netherlands. In 2006, she graduated as a member of the first cohort of ten speech-language scientists in the Netherlands. Yvonne is lecturer at Fontys University of applied sciences Eindhoven (NL). In May 2007, Yvonne became the first coordinator of clinical issues of the International Cluttering Association.
References (52)
- et al.
Characteristics of stuttering-like disfluencies in Dutch-speaking children
Journal of Fluency Disorders
(2007) - et al.
Speeded verbal responding in adults who stutter: Are there deficits in linguistic encoding?
Journal of Fluency Disorders
(2008) - et al.
Investigating speech motor practice and learning in people who stutter
Journal of Fluency Disorders
(2008) - et al.
Influences of rate, length, and complexity on speech disfluency in a single-speech sample in preschool children who stutter
Journal of Fluency Disorders
(2008) - et al.
Studies of cluttering: Disfluency and language measures in young possible clutterers and stutterers
Journal of Fluency Disorders
(1985) - et al.
Efficacy of delayed auditory feedback for treating cluttering: Two case studies
Journal of Fluency Disorders
(1996) - et al.
Fluency disorders in genetic syndromes
Journal of Fluency Disorders
(2007) Cluttering: Central language imbalance
Pediatric Clinics of North America
(1968)Subtyping stuttering I: A review
Journal of Fluency Disorders
(2007)- et al.
Speaking rate and diadochokinetic abilities of children who stutter
Journal of Fluency Disorders
(1994)
Stotteren van theorie naar therapie
Systematic disfluency analysis
Speech rate of non-stuttering Spanish speaking adults
Stuttering and related disorders of fluency (3eED)
Helping the clutterer: Therapy considerations
Cluttering, another fluency syndrome
The source for stuttering and cluttering
Cluttering: Assessment, Treatment planning, and case study illustration
Journal of Fluency Disorders
Cluttering: Traditional views and new perspectives
Cluttering characteristics identified as diagnostically significant by 60 fluency experts
Expressiever en gemakkelijker spreken
Articulation rate in children and adolescents: Hebrew speakers
Stuttering an integrated approach to its nature and treatment
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2021, Journal of Fluency DisordersCitation Excerpt :In a well-known video (Myers & St. Louis, 2007), a featured adult who clutters remarked, “Cluttering is what makes people say ‘What?’.” Differentiating clearly between these two fluency disorders can be puzzling even for professionals (Adams & Cook, 2016; Georgieva, 2001; Van Zaalen, Wijnen, & Dejonckere, 2009), and this is exacerbated by the fact that professional knowledge of cluttering by speech-language pathologists (SLPs) is exceedingly limited (Georgieva, 2001; Myers, 2018a; St. Louis & Hinzman, 1986; St. Louis & Myers, 1997; St. Louis & Rustin, 1992). Initially, cluttering was investigated primarily in Europe; only in recent decades has it gained serious interest in other countries, such as the United States (Daly, 1993; Georgieva, 2010; Myers, 2018b; Preus, 1996; Reichel & Draguns, 2011; St. Louis, 1992; Tarkowski, 1993, 2002; Weiss, 1964; Woźniak, 2008, 2020).
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2021, Journal of Fluency DisordersBilingual children who stutter: Convergence, gaps and directions for research
2020, Journal of Fluency DisordersSpeech disfluencies in children with Down Syndrome
2018, Journal of Communication DisordersCitation Excerpt :It is known that the speech of young children (despite whether they stutter or not) contains more disfluencies than that of older children (Byrd, Logan & Gillam, 2012; Wijnen, 1990, 1991). Van Zaalen-op‘t Hof et al. (2009) suggest to use the 10% criterion as a criterion to identify cluttering in speech samples of (normal) individuals older than 6 years of age. Tumanova et al. (2014), however, reported more disfluencies (OD) in the speech of pre-school age CWS than in those who do not stutter.
Yvonne Van Zaalen-op’t Hof, MSc works as a speech-language therapist specialized in stuttering since 1988, in a centre for stuttering therapy in the Netherlands. In 2006, she graduated as a member of the first cohort of ten speech-language scientists in the Netherlands. Yvonne is lecturer at Fontys University of applied sciences Eindhoven (NL). In May 2007, Yvonne became the first coordinator of clinical issues of the International Cluttering Association.
P.H. Dejonckere, MD, PhD is currently full professor at the University of Utrecht (NL), general coordinator of the Scientific Council at the Institute of Occupational Diseases (Fed. Gov., Brussels), guest professor at the Catholic University of Leuven (B), visiting professor at the Université de Lille II (F) and Chairman of the European Laryngological Research Group.
Frank Wijnen obtained his PhD in psychology in 1990 at the Radboud University, Nijmegen (NL). Currently he is a professor of psycholinguistics in the Linguistics Programme/UIL OTS and the Department of Psychology at Utrecht University. His research revolves around primary language development. In several publications he has explored the connections between language acquisition, developmental dysfluency and stuttering.