Multidimensional Measurements of Dysarthria in Myotonic Dystrophy Type 1.

Twenty-two patients from one centre and no control group: everything is compared against reference values taken from other studies, which did not always use the same speaking task or match the individual, and for some measures existed only split by sex. No statistical testing was done, so the links between severity and loudness, rate and relatives' ratings are descriptive patterns that could be chance or caused by something else. Only two patients had severe dysarthria, and the finding of reduced loudness rested largely on those two. Six of the 22 relatives did not give ratings and the rest varied widely, so patients' and relatives' ratings cannot be reliably compared. Cognition was checked with a single subtest measuring mental flexibility, so the idea that reduced self-awareness explains the mismatch between patients and relatives could not be examined. Both juvenile-onset and adult-onset patients were included, mixing different disease courses and possibly hiding differences between them. During the spontaneous speech task the script counted the therapist's own questions and replies as the patient's syllables, and shorter segments had to be selected to work around this, which reduced the amount of speech analysed.

The authors declare no conflicts of interest and state they have nothing to report on funding, so no commercial sponsor is declared.

Do not read these acoustic measures as a way to diagnose or grade dysarthria in DM1. The study had no control group, ran no statistical tests, and the link between loudness and severity came mostly from two patients with severe dysarthria. The same applies to the mismatch between patients' and relatives' ratings: six relatives' forms were missing and cognition was barely tested.