Speech and motor speech disorders and intelligibility in adolescents with Down syndrome.
Erin M Wilson, Leonard Abbeduto, Stephen M Camarata and 1 others
PMID 31221010WHAT IT FOUND
Reduced intelligibility in adolescents with Down syndrome was not associated with age, intelligence, language, or speech motor delay.
It was associated with dysarthria or apraxia, especially both together.
Key findings
01In the original sample of 50 adolescents with Down syndrome, 56% had reduced intelligibility, meaning fewer than 85% of words were intelligible in conversational speech.
02Reduced intelligibility was not significantly associated with demographic, intelligence, or language variables, or with Speech Motor Delay.
03For the 10 participants with concurrent childhood dysarthria and childhood apraxia of speech, 80% had reduced intelligibility and 20% had High intelligibility, and that difference was statistically significant.
STILL TO COME
How it was doneWhat they foundWhat it means for SLPs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
The primary analyses included 45 adolescents, and several motor speech groups were very small, with 1 participant in the no motor speech disorder group, 5 with childhood apraxia of speech, 10 with both dysarthria and apraxia, 12 with speech motor delay, and 17 with dysarthria. They did not adjust for multiple statistical tests because power was low, so some significant comparisons may not replicate. The sample was limited to American-English speaking adolescents aged 10 to 20 years, so the findings may not apply to younger children, adults, or speakers of other languages. Only one participant had no motor speech disorder, so intelligibility in that group could not be compared with the motor speech groups. Dysarthria subtype analyses combined participants with dysarthria and those with both dysarthria and apraxia, and most had mixed dysarthria, so subtype-specific intelligibility could not be tested. The study did not test treatment, and the authors state that clinical implications are premature pending replication and extension. The paper says cross-validation is needed and that other assessment modalities were not used, so the findings need replication.
Declared interests
The authors report no declarations of interest. The article is listed as supported by NIH and non-PHS U.S. government research support.
The easy way to misread this
Do not read the significant dysarthria and apraxia finding as proof that treatment for those classifications will improve intelligibility. This study analysed assessment data, had small groups, and the authors say clinical implications are premature.