Estimates of the prevalence of speech and motor speech disorders in persons with complex neurodevelopmental disorders

Figures & data

Figure 1. Four classification dichotomies in Speech Sound Disorders (SSD).

Figure 2. The Speech Disorders Classification System (SDCS).

Table 1. Information for participants with one of eight types of Complex Neurodevelopmental Disorders (ordered alphabetically).^a.

		Assessment			Demographic				Cognitive-Language
		Original Sample	SDCS Classified		Age (yrs)		Sex (%)		Cognition^b		Language^c
Group	Abbreviation	n	n	%	M	SD	% Female	% Male	M	SD	M	SD
16p11.2 deletion and duplication syndrome	16p	111	108	97.3	14.7	12.4	50.9	49.1	*	*	*	*
22q11.2 deletion syndrome	22q	18	17	94.4	10.2	3.3	35.3	64.7	77.8	11.5	77.4	11.8
Autism Spectrum Disorder	ASD	42	42	100	6	1.2	21.4	78.6	104.3	15.7	98.9	17.3
Down syndrome	DS	50	45	90	14.2	2.3	44.4	55.6	42.8	6.4	42.6	4.4
Fragile X syndrome	FXS	30	28	93.3	16	3.2	0	100	38.3	5.4	48.6	4.1
Galactosemia	GAL	31	31	100	8.8	2.9	35.5	64.5	86.7	16.4	79.6	15.3
Idiopathic Intellectual Disability	IID	26	23	88.5	36.4	7	52.2	47.8	*	*	*	*
Severe Traumatic Brain Injury	TBI	54	52	96.3	7.3	2.9	42.3	57.7	*	*	*	*
Totals		362	346	95.6	13.3	10.3	39	61	70	11	69.4	10.6

^a Cell values for demographic and cognitive-language variables are for the 346 participants that were eligible to be classified using Speech Disorders Classification System (SDCS) measures. Standardized cognitive and language data were not currently available for participants in three of the eight groups.

^b Standard scores for IQ Composite: (Kaufman & Kaufman, 2004). IQ Scores: (Thorndike, Hagen, & Sattler, 1986). * = no data.

^c Standard scores for Oral Composite: (Carrow-Woolfolk, 1995). Standard scores for Core Language: (Semel, Wiig, & Secord, 2003). * = no data.

Figure 3. Sample outputs from the Speech Disorders Classification System Summary (SDCSS).

Table 2. Reliability estimates for phonetic transcription, prosody-voice coding, and acoustic analyses.

	Agreement Types
Data	Interjudge	Intrajudge	No. of Tokens Analyzed	Variable	Percentage of Agreement
Phonetic Transcription	X			Consonants
			2535 utterances	Broad	93.3
			7239 words	Narrow	77.2
				Vowels
				Broad	85.5
				Narrow	75
		X		Consonants
			2535 utterances	Broad	95.6
			7287 words	Narrow	84.8
				Vowels
				Broad	89.8
				Narrow	81.5
Prosody-Voice Coding	X		801 utterances	Appropriate-	87.3
				Inappropriate
		X		Appropriate-	91.3
				Inappropriate
Acoustic Analyses	X			Phoneme Duration
			651	Consonants	81.9
			2754	Vowels	81.9
		X		Phoneme Duration
			710	Consonants	84.1
			2760	Vowels	84.7
	X			Vowel Frequency
			2616	F0	97.4
			450	F1	90
			442	F2	90.3
		X		Vowel Frequency
			2632	F0	97.5
			470	F1	90.1
			460	F2	94.8
	X			Pause Variables
			558	Pause –	88.1
				Non-Pause
			487	Appropriate –	71.9
				Not Appropriate
			60	Type 1 – Type 2	82.7
		X		Pause Variability
			558	Pause –	86.2
				Non-Pause
			475	Appropriate –	69.7
				Not Appropriate
			59	Type 1 – Type 2	81.8

Figure 4. Speech Disorders Classification System Summary (SDCSS) findings for participants in eight Complex Neurodevelopmental Disorders.

Figure 5. Percentage of participants in eight Complex Neurodevelopmental Disorders classified into one of three speech classifications.

Figure 6. Percentage of participants in eight Complex Neurodevelopmental Disorders classified into one of five motor speech classifications.

Table 3. Percentage of participants with Childhood Dysarthria (CD) and Childhood Dysarthria & Childhood Apraxia of Speech (CD & CAS) with scores ≤ 10th percentile on subtypes of CD.^a.

Complex Neurodevelopmental Disorder					Percentage of Participants with CD Subtype Score ≤ 10^th Percentile
Type^b	n	No. of Participants with Dysarthria			Ataxia			Spastic			Hyperkinetic			Hypokinetic			Flaccid
		CD	CD & CAS	Total	CD	CD & CAS	Total	CD	CD & CAS	Total	CD	CD & CAS	Total	CD	CD & CAS	Total	CD	CD & CAS	Total
DS	45	17	10	27	82.4	70.0	77.8	29.4	30.0	29.6	41.2	50.0	44.4	17.6	30.0	22.2	29.4	20.0	25.9
GAL	31	5	4	9	20.0	25.0	22.2	40.0	50.0	44.4	60.0	50.0	55.6	20.0	25.0	22.2	0.0	75.0	33.3
FXS	28	9	0	9	55.6	0.0	55.6	44.4	0.0	44.4	22.2	0.0	22.2	66.7	0.0	66.7	44.4	0.0	44.4
22q	17	5	2	7	20.0	50.0	28.6	20.0	50.0	28.6	60.0	50.0	57.1	60.0	0.0	42.9	60.0	50.0	57.1
Severe TBI	52	4	1	5	25.0	100.0	40.0	50.0	100.0	60.0	25.0	100.0	40.0	25.0	0.0	20.0	75.0	0.0	60.0
IID	23	4	0	4	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	100.0	0.0	100.0	50.0	0.0	50.0
16p	108	2	0	2	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	50.0	0.0	50.0	100.0	0.0	100.0
Total	304	46	17	63
Group-Averaged %					29.0	35.0	32.0	26.3	32.9	29.6	29.8	35.7	31.3	48.5	7.9	46.3	51.3	20.7	53.0

^a Bolded cells are those in which at least half (50%) of the participants with CD or CD & CAS had subscale scores ≤ 10^th percentile.

^b DS = Down syndrome; GAL = Galactosemia; FXS = fragile X syndrome; 22q = 22q11.2 deletion syndrome; Severe TBI = Severe Traumatic Brain Injury;

IID = Idiopathic Intellectual Disorder; 16p = 16p11.2 deletion and duplication syndrome. None of the 42 participants with Autism Spectrum Disorder were classified as CD or CD & CAS.

Table

Eight Complex Neurodevelopmental Disorders	Abbreviation in Text	n Available Data	n Eligible for Classification	Brief Description of Participants	Sources of the Speech Samples
16p11.2 Deletion and Duplication Syndrome	16p	111	108	Audio recordings of the Autism Diagnostic Observations Schedule (ADOS; Lord, Rutter, DiLavore, & Risi, 1999) administrations from children and adults with 16p11.2 variants obtained from the Simons – Variation in Individuals Project (Simons VIP Consortium, 2012) were collected and analyzed. Participation in the Simons VIP requires the canonical deletion or duplication (~600 kb, chr16: 29,557,497–30,107,356; hg18), or a smaller CNV at the locus. Exclusion criteria include any other pathogenic CNVs or other neurogenetic or neurological diagnoses unrelated to 16p11.2 (e.g., tuberous sclerosis). Participant ages ranged from 3;2 to 62;0 (yrs;mos), with approximately equal numbers of males (56) and females (55). The overall percentage of 16p11.2 variants included 54.1% deletions and 45.9% duplications. A total of 23 of the 111 (20.7%) participants with 16p11.2 deletions and duplications met criteria for verbal participants with Autism Spectrum Disorder.	Simons Foundation. (2015). The Simons VIP Consortium (2012).
22q11.2 Deletion Syndrome	22q	18	17	Inclusionary criteria included: (a) diagnosis of 22q11.2 deletion syndrome by Fluorescence In Situ Hybridization (FISH) testing or microarray, (b) 6–18 years of age, (c) English as the participant’s primary language, and (d) no history of permanent bilateral hearing loss.	Baylis and Shriberg (2018)
Autism Spectrum Disorder	ASD	42	42	Inclusionary criteria included: (a) a previous diagnosis of autism, PDD-NOS, ASD, or Asperger syndrome from a qualified clinician; (b) full scale IQ ≥ 70; (c) mean length of utterance of at least 3.0, based on transcription of a 3–5 min conversational sample; (d) > 70% of words intelligible in the language sample; and (e) normal hearing and vision (or corrected with glasses) on standard screening. Exclusionary criteria included known craniofacial or neurological impairment or bilingual background.	Shriberg, Paul, Black, and van Santen (2011)
Down syndrome	DS	50	45	Three samples of participants: (1) 29 participants, 10–18 years of age with a confirmed diagnosis of Trisomy 21 and no diagnosis of autism spectrum disorders; (2) 17 participants, 8–18 years of age, with a confirmed diagnosis of Trisomy 21 and no diagnosis of autism spectrum disorders; (3) 4 male participants, ages 13–20 years, with a confirmed diagnosis of Trisomy 21.	Wilson, Abbeduto, Camarata, and Shriberg (2019a; 2019b); Camarata, Yoder, and Camarata (2006); Davis, Camarata, and Camarata (2016)
fragile X syndrome	FXS	30	28	Males ranging in age from 11–22 yrs. Inclusionary criteria: (a) DNA or cytogenetic confirmation of the syndrome; (b) speech as the primary means of communication; (c) no more than a mild hearing loss per Chapman, Schwartz, and Kay-Raining Bird (1991) criterion; (d) ability to complete all tests; (e) nonverbal IQs <70; (f) passed screening and follow-up psychologist assessment for ASD.	Abbeduto, Murphy, Cawthon, Richmond, Weissman, Karadottir, and O‘Brien (2003); Abbeduto, Murphy, Kover, Giles, Karadottir, Amman, Bruno, Kim, Schroeder, Anderson, and Nollin (2008); Keller-Bell and Abbeduto (2007)
Galactosemia	GAL	31	31	Inclusionary criteria: (a) a diagnosis of classic (full expression) galactosemia; (b) prior or persistent Speech Delay, as documented by a history of treatment for Speech Delay; (c) 4–17 years of age; (d) residence in the United States; (e) English as the only or first language; and (f) no history of significant hearing loss or craniofacial disorder affecting speech.	Shriberg, Potter, and Strand (2011)
Idiopathic Intellectual Disability	IID	26	23	Audiotape speech samples from adults with IID living in the Madison, WI, area. Participants were non-institutionalized, and worked at settings ranging from work activity centers to independent jobs in the community. As reported in Shriberg and Widder (1990), audiotape samples from a parent study (Reynolds & Baker, 1988) were assessed for use and tapes were removed that (a) had unacceptable signal quality or excessive background noise; (b) were from persons who were nonambulatory; (c) were from persons who sounded frankly dysarthric (six tapes), using screening criteria in Darley, Aronson, and Brown (1975); (d) were from persons for whom records were not available on age, gender, race, or level of mental retardation; (e) were from persons outside the ages of 20 to 50 years (excepting one 53-year-old); and/or (f) were from persons outside the range of mild to moderate levels of retardation, that is, excluding borderline and severe or profound involvement as determined by AAMD classification (Grossman, 1977) available in agency records.	Shriberg and Widder (1990)
Severe Traumatic Brain Injury	TBI	54	52	Subsample of 56 children who sustained severe pediatric traumatic brain injury (TBI) between age 1 month and 11 years. Inclusionary criteria: (a) severe TBI, defined as a Glasgow Coma Scale score ≤ 8 and a positive CT scan; (b) age at injury < 11 years; (c) injury not known or suspected to have resulted from abuse; and (d) monolingual English home environment and no previously diagnosed neurodevelopmental, speech, or language deficits according to parent report.	Campbell and Dollaghan (1995); Campbell, Dollaghan, Janosky, Rusiewicz, Small, Dick, Vick, and Adelson (2013); Campbell, Dollaghan, and Shriberg (2019)
	Total:	362	346

Table

SDCS Classifications andDysarthria Subtypes	Abbreviation	Age (yrs;mos) at Assessment	Description	References^a
Five Speech Classifications
Normal(ized) Speech Acquisition	NSA	3–80	Does not meet criteria for any of the four Speech Disorder classifications	2, 3, 4
Speech Errors	SE	6–8;11	Age-inappropriate speech sound distortions	3, 4
Persistent Speech Errors	PSE	9–80	Age-inappropriate speech sound distortions that persist past 9 years of age	4, 5
Speech Delay	SD	3–8;11	Age-inappropriate speech sound deletions and/or substitutions	3, 4
Persistent Speech Delay	PSD	9–80	Age-inappropriate speech sound deletions and/or substitutions that persist past 9 years of age	3, 4, 5
Five Motor Speech Classifications
No Motor Speech Disorder	No MSD	3–80	Does not meet criteria for any of the four Motor Speech Disorders classifications	2, 6, 8
Speech Motor Delay	SMD	3–80	Meets PSI criterion for SMD	2, 6, 8
Childhood Dysarthria	CD	3–80	Meets DI and DSI criteria for CD	2, 6, 8
Childhood Apraxia of Speech	CAS	3–80	Meets PM criterion for CAS	6, 7, 8
Childhood Dysarthria &  Childhood Apraxia of Speech	CD & CAS	3–80	Meets SDCS criteria for CD & CAS	2, 6, 8
Five Dysarthria Subtypes
Ataxic		3–80	Cerebellar disorder	1, 2
Spastic		3–80	Upper motor neuron disorder	1, 2
Hyperkinetic		3–80	Basal ganglia disorder; increased movement	1, 2
Hypokinetic		3–80	Basal ganglia disorder; decreased movement	1, 2
Flaccid		3–80	Lower motor neuron disorder	1, 2

Notes: PSI = Precision-Stability Index; DI = Dysarthria Index; DSI = Dysarthria Subtype Index; PM = Pause Marker.

^a 1. Duffy (2013); 2. Mabie and Shriberg (2017); 3. Shriberg (1993); 4. Shriberg, Austin, Lewis, McSweeny, and Wilson (1997); 5. Shriberg et al. (2010a); 6. Shriberg and Mabie (2017); 7. Shriberg et al. (2017a); 8. Tilkens et al. (2017).

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