Stuttering is one of the most common developmental disorders pediatricians see in preschool-aged children, and recent information is suggesting it is more prevalent than previously thought. Stuttering in a child can generate significant parental concerns and, for the affected child, cause immediate frustration and anxiety and ultimately impact quality of life.
Reviewed by Anthony Giampolo, MD, MBA, DAAPM, ABPN
Stuttering is one of the most common developmental disorders pediatricians see in preschool-aged children, and recent information is suggesting it is more prevalent than previously thought.1 Stuttering in a child can generate significant parental concerns and. for the affected child, cause immediate frustration and anxiety and ultimately impact quality of life. Effective intervention for developmental stuttering is available, although many affected children may recover naturally.1-3 The rate of recovery is low during the first year after onset (6%-9%),2-4 but the majority of stuttering children (~79%) recover within 4 years.2,3
Investigators are hoping ongoing research will lead to future methods for identifying children destined for persistent stuttering, but at present there is no way to reliably predict whether or not a child who is stuttering will recover.
The following review highlights recent developments in understanding about the epidemiology of childhood stuttering, its natural history, and prognostic factors. Staying abreast with emerging information in the field should enable pediatricians in their efforts to identify patients with the disorder, counsel parents, and make appropriate referrals to a speech-language pathologist for further evaluation and care.
Stuttering, also referred to as stammering, is a speech disorder involving involuntary disfluency in verbal expression. It can be present in people of all ages and is classified as developmental, neurogenic, or psychogenic. Developmental stuttering is the most common form of stuttering, and particularly among children. It manifest with repetitions of sounds, syllables, or words and with speech blocks or prolonged interruptions between sounds and words. Secondary physical behaviors, such as eye blinking, jaw jerking, and head movements, may be present. These are learned approaches to minimize the severity of stuttering, and can exacerbate anxiety and feelings of embarrassment for the stutterer.
Other forms of stuttering are neurogenic and psychogenic stuttering. Neurogenic stuttering is an acquired disorder that follows from damage to the central nervous system. It usually is seen in adults and especially in the geriatric population, but it can occur in people of any age because its underlying causes include medications, traumatic head injury, tumors, and infectious diseases. Psychogenic stuttering occurs after some psychological or emotional trauma, and it is rare in children. The remainder of this article focuses on developmental stuttering.
The pathophysiology of developmental stuttering is yet to be fully elucidated. Genetics has been implicated as a major etiologic factor, and researchers seem close to identifying candidate genes and describing the biological basis by which they act.1 However, the fact that multiple genes may be involved along with other constitutional and environmental factors makes the understanding of associations more difficult.
The lifetime incidence of stuttering is widely cited as 5%,1 but recent data indicate the rate is higher.1,4,5 In a community-based prospective study, Reilly and colleagues reported 8.5% of children began stuttering by age 3 years,5 and the cumulative incidence in the sample was 11.2% by age 4.4 According to recent reports, the average age of onset of stuttering is about 33 months, which is 6 to 24 months younger than reported in previous research.1 The discrepancies in these statistics can be explained by methodological differences between investigations, including in the populations studied and the ascertainment of stuttering.
There are also varying estimates on the age range for onset risk, but in a study that included children aged up to 6 years,3 95% of the risk for stuttering onset was reached by age 4. Onset can be gradual but is usually more sudden.1
Stuttering is more common in boys than in girls, but recent studies of childhood stuttering report male-to-female ratios ranging only between 1.3 and 2.2, and the gender predilection seems less marked at younger ages.1 The fact that males clearly predominate over females by at least fourfold in populations of adult stutterers indicates that girls more frequently recover from childhood stuttering than do boys.
Any influence of race, ethnicity, culture, bilingualism, and socioeconomic status on the incidence/prevalence of stuttering is still unclear.1 Regardless of whether these demographic factors are a risk factor for stuttering onset, they have potential importance on the course of a child who develops stuttering because they play a role in the families’ reactions and their access to information, counseling, and treatment.
Aside from male gender, certain factors appear to be associated with an elevated risk for stuttering persistence.6 Possible risk factors include having a family member (parent, sibling, or other) who is a persistent stutterer, onset of stuttering after age 3.5 years, and the presence of other speech and language errors (Table 1). Duration of the problem is also indicative of the chance for recovery. Most children outgrow the problem within 12 to 24 months of onset. Stuttering that continues for longer than 6 months is less likely to resolve on its own and the chance for natural recovery decreases even more if the stuttering is present beyond 12 months.
Recognizing developmental stuttering and determining its severity along with its impact on the child and family guide appropriate intervention. The first consideration is differentiating stuttering from normal disfluency.
When children are first beginning to talk and through about age 7 years, they can exhibit normal speech disfluencies.6 In children aged to about 3 years, these disfluencies are characterized by repetition of sounds, syllables, and words, particularly at the start of sentences and with a frequency of perhaps once in every 10 sentences. Normal disfluencies in older children are more likely to be represented by repetition of entire words or short phrases rather than of sounds or syllables. In addition, these children may begin using fillers such as “uh” or “um” in the middle of sentences or stopping midsentence and switching topics. However, there appears to be no tension or struggle in children with normal disfluencies. Generally, they are not aware of them, nor do they seem frustrated by their speech or exhibit secondary behaviors that are seen in true stutterers.
Children with mild stuttering show the same speech patterns as those with normal disfluencies in terms of repeating sounds, syllables, or words, but the repetitions may be more frequent and occur more regularly. Children with mild stuttering also may prolong sounds in addition to repeating sounds, and their disfluencies are not effortless or unnoticed by them. Children who stutter exhibit physical reactions that may include blinking or closing their eyes, looking to the side, and tensing of the mouth. Awareness of their difficulty talking may prompt stuttering children to ask their parents why they are having trouble.
Severe stuttering tends to occur in older children but may develop as early as age 18 months. It can appear either as a progression from mild stuttering or with a more abrupt onset. It is characterized by more frequent and more prolonged disfluencies. These children may also introduce fillers before a word on which they expect to stutter, and in addition to displaying physical behaviors of mild stutterers, their voice pitch may rise when they are stuttering. Children with severe stuttering may begin to avoid speaking or become tense and anxious in situations where they may be expected to speak.
Although developmental stuttering may resolve on its own, the likelihood that it will persist increases with lengthening time since onset. Furthermore, the chances that children might begin to experience adverse social consequences and negative attitudes toward communication may also increase as they continue to stutter.
Decisions about referral to a speech-language pathologist and intervention should be individualized, taking into account the severity of the stuttering along with each family’s circumstances in terms of the experiences of the child and the level of parental concern (Table 2).6 Children showing signs of severe stuttering should be referred immediately to a speech-language pathologist for evaluation.
At the other end of the spectrum are the children with normal disfluencies. Their concerned parents should be reassured that the speech disfluencies are developmentally appropriate, and the parents may be advised to avoid drawing attention to the child’s disfluencies. Specifically, parents should try not to show concern, comment on the disfluencies, or attempt to correct them. Parents who are not comforted by this counseling may benefit from referral to a speech-language pathologist who can conduct an evaluation and establish that the child is not stuttering.
Prompt referral to a speech-language pathologist also may be justified for children with mild stuttering if the parents have a high level of concern.6 Otherwise, they should be instructed in measures that will create a comfortable speaking environment for the child and minimize any feelings of frustration, anxiety, and embarrassment.
Parents should be patient and attentive listeners, avoiding any display of signs of worry or annoyance, and should model a manner of relaxed speaking, trying themselves to speak slowly and use short simple sentences. Minimizing their use of direct questions also can be helpful. Children who verbalize concerns about their difficulties can be reassured by being told not to worry, that the parent is not bothered or concerned, and that everyone can have problems when learning to talk. It is also recommended that parents should plan specific times for talking one-on-one with their child in a quiet, relaxed environment, letting the child choose the activity and topic of conversation.
The Stuttering Foundation recommends that the family be referred to a speech-language pathologist if after 6 to 8 weeks of using these approaches the child is still stuttering or if the parents are having difficulty applying the advice.6
Sheena Reilly, PhD, and colleagues suggest that referral for speech-language pathology management may be deferred for 6 months if the child is not distressed and the family is not worried or anxious (personal communication). They note the following information is useful for the speech pathologist when a referral is made:
There is a lack of evidence-based consensus about therapy for developmental stuttering, but typically speech-language therapy is used.7 Modalities include controlled fluency techniques, fluency-shaping mechanisms, the Lidcombe approach, and stuttering modification. The choice of technique may vary depending on the child’s age.
The Lidcombe Program is the only intervention for developmental stuttering in preschool children with efficacy supported by results of randomized controlled trials.8-10 It is a home-centered approach carried out under the supervision of a speech-language pathologist in which parents provide an environment conducive to relaxed speaking, praise the child for fluent speech, and occasionally correct stuttering. To monitor improvement, parents record stuttering severity daily using a simple scale. A maintenance treatment phase begins when the child reaches a target of no stuttering or almost no stuttering, and it usually lasts 1 year.
There is no randomized clinical evidence for use of the Lidcombe Program in children aged older than 6 years, and so initiation of treatment before that age is considered essential. Waiting at least 1 year after stuttering onset allows a chance for natural recovery and does not affect responsiveness to the Lidcombe Program.11,12 According to the results of a recent study, waiting 1 year also does not appear to cause any developmental harm to children4 (see “Watchful waiting or initiation of treatment?”). However, treatment should not be delayed if the child shows signs of chronic distress related to stuttering because the distress could be the precursor of lifelong psychological problems known to be associated with stuttering.13
There are reports of pharmacotherapy for stuttering using a variety of psychotropic medications. A systematic review of medication treatment in children and adolescents found a lack of quality evidence in this area.14 The researchers identified only a single study that met criteria for strong evidence quality. The study evaluated clonidine, which had no treatment benefit.
There are no published studies demonstrating the efficacy of fluency-enhancing devices in children, and there is concern that their use in a young child may interfere with development of normal neurologic pathways through speech therapy.15
Many groups of researchers are exploring a variety of domains in order to identify predictors of stuttering recovery. For example, some investigators are looking at features of functional neuroanatomy and interactions of major brain areas for markers, and research in this field may also suggest neural targets for developing novel therapies for children who stutter.16
Christine Weber-Fox, PhD, and colleagues at Purdue University, West Lafayette, Indiana, are investigating motor, language, and emotional factors as predictors for persistent stuttering that can be applied to preschool children. Their hope is to develop a set of standardized clinical tests for assessing risk. At present, their research is a work in progress, but a recently accepted manuscript from the group describes speech articulation and nonword repetition abilities as having potential predictive value.17
Investigators in the longitudinal Early Language in Victoria study also are hoping to identify predictors of stuttering recovery, and they are collecting data on stuttering severity, the frequency of repetitions, rapidity of onset, and whether stuttering is episodic or continuous. These factors could not be analyzed in their report of follow-up to age 4 because so few children had recovered,4 but they are being looked at as the cohort progresses.
Pediatricians have an important role in identifying the type and cause of stuttering in a child and in counseling the family about appropriate care. Natural recovery is well documented in children with developmental stuttering, but decisions on referral and initiation of therapy need to be individualized.
All parents may be counseled about measures they should practice that minimize stress for children with developmental stuttering and help them outgrow their disfluency. In addition, parents can be reassured that with appropriate intervention, their child’s chance for recovery is good.
When referring families to a speech-language pathologist, physicians should verify that the individual has in-state licensure and specific training and experience working with stuttering children. A wealth of information about stuttering, including help with identifying qualified therapists, is available for physicians and families and can be found at numerous sources online (Table 3).
1. Yairi E, Ambrose N. Epidemiology of stuttering: 21st century advances. J Fluency Disord. 2013;38(2):66-87.
2. Yairi E, Ambrose NG, Niermann R. The early months of stuttering: a developmental study. J Speech Hear Res. 1993;36(3):521-528.
3. Yairi E, Ambrose N. Early childhood stuttering. Austin, TX: Pro Ed; 2005.
4. Reilly S, Onslow M, Packman A, et al. Natural history of stuttering to 4 years of age: a prospective community-based study. Pediatrics. 2013;132(3):460-467.
5. Reilly S, Onslow M, Packman A, et al. Predicting stuttering onset by the age of 3 years: a prospective, community cohort study. Pediatrics. 2009;123(1):270-277.
6. Guitar B, Conture EG. The child who stutters: to the pediatrician. 5th edition. Publication no. 0023. Memphis, TN: Stuttering Foundation of America; 2013. Available at:www.stutteringhelp.org/sites/default/files/PedBook.pdf
. Accessed July 31, 2014.
7. Prasse JE, Kikano GE. Stuttering: an overview. Am Fam Physician. 2008;77(9):1271-1276.
8. Jones M, Onslow M, Packman A, et al. Randomised controlled trial of the Lidcombe programme of early stuttering intervention. BMJ. 2005;331(7518):659.
9. Lattermann C, Euler HA, Neumann K. A randomized control trial to investigate the impact of the Lidcombe Program on early stuttering in German-speaking preschoolers. J Fluency Disord. 2008;33(1):52-65.
10. Arnott S, Onslow M, O’Brian S, Packman A, Jones M, Block S. Group Lidcombe Program treatment of early stuttering: a randomized controlled trial. J Speech Lang Hear Res. May 13, 2014. Epub ahead of print.
11. Kingston M, Huber A, Onslow M, Jones M, Packman A. Predicting treatment time with the Lidcombe Program: replication and meta-analysis. Int J Lang Commun Disord. 2003;38(2):165-177.
12. Jones M, Onslow M, Harrison E, Packman A. Treating stuttering in young children: predicting treatment time in the Lidcombe Program. J Speech Lang Hear Res. 2000;43(6):1440-1450.
13. Iverach L, Menzies R, O’Brian S, Packman A, Onslow M. Anxiety and stuttering: continuing to explore a complex relationship. Am J Speech Lang Pathol. 2011;20(3):221-232.
14. Boyd A, Dworzynski K, Howell P. Pharmacological agents for developmental stuttering in children and adolescents: a systematic review. J Clin Psychopharmacol. 2011;31(6):740-744.
15. National Stuttering Association. Childhood stuttering: Information for pediatricians and family physicians. Available at: www.westutter.org/assets/Pediatrician-brochure.pdf. Published May 2009. Accessed July 31, 2014.
16. Chang SE. Research updates in neuroimaging studies of children who stutter. Semin Speech Lang. 2014;35(2):67-79.
17. Spencer C, Weber-Fox C. Preschool speech articulation and nonword repetition abilities may help predict eventual recovery or persistence of stuttering. J Fluency Disord. June 16, 2014. Epub ahead of print.
1. Reilly S, Onslow M, Packman A, et al. Natural history of stuttering to 4 years of age: a prospective community-based study. Pediatrics. 2013;132(3):460-467.
2. Stuttering Foundation. Parents, don’t be misled-early intervention pays off [press release]. Available at: www.stutteringhelp.org/content/dont-be-misled. Published September 10, 2013. Accessed July 31, 2014.
3. Stuttering Foundation. A blunder from down under: Stuttering Foundation warns parents not to be misled by headlines surrounding Australian study on preschoolers’ stuttering [press release]. Available at: www.stutteringhelp.org/content/blunder-down-under. Published August 26, 2013. Accessed July 21, 2014.
4. Bernstein Ratner N. But wait, there’s more (not to like about Reilly et al. study). Available at: www.stutteringhelp.org/wait-theres-more-not-about-reilly-et-al-study. Accessed July 31, 2014.
Ms Krader has 30 years of experience as a medical writer. She has worked as both a hospital pharmacist and a clinical researcher/writer for the pharmaceutical industry and is presently a freelance writer in Deerfield, Illinois. She has nothing to disclose in regard to affiliations with or financial interests in any organizations that may have an interest in any part of this article.