Journal Article

261 Quantifying deterioration of motor abilities in ambulant boys with Duchenne muscular dystrophy as a result of COVID-19 lockdowns

Cohen Anthony Jesse Edward, Ambegaonkar Gautam, Ross, Daniel S, Morse, Christopher, De Goede Christian

2023

Overview

ObjectivesDuchenne muscular dystrophy (DMD) is an X-linked disorder caused by mutations in the dystrophin gene, coding for dystrophin. There is a gradual decline in motor abilities, usually presenting before age five.1 DMD boys receive multiple supplementary services to their care including hydrotherapy, physiotherapy and school support. On the 23rd March, the UK government announced a national lockdown, leading to closure of schools and other in-person services, followed by further lockdowns. This provided a unique natural study opportunity into the use of habitual physical activity and regular therapies and their benefits in DMD patient ambulation. Parents have anecdotally reported declines in their child’s motor abilities beyond the expected rate. We sought to quantify this.MethodsThe North Star Ambulatory Assessment (NSAA) score was used to quantify mobility, ideally being performed 6-monthly. A lower age cut-off of 7 years was used and patients non-ambulant prior to 23rd March 2020 were excluded. 42/48 non-wheelchair-dependent patients were selected from Cambridge University Hospital’s (CUH) cohort and age-matched to historical patients using the North Star Network (NSN) database. Matching of a 2:1 historical-to-CUH was attempted, based on steroid regimen, age, NSAA trajectory,2 clinical trial participation and DMD genotype. CUH mean and individual NSAA scores were plotted over time. 19 CUH patients had sufficient data points to plot.ResultsCUH NSAA combined mean scores pre- versus post-March 2020 showed a 23% decrease (Graph 1, n=17). Individual patient NSAA scores from CUH (Graph 2, n=19) showed an average 9.43% decrease 2018–2019 and an average 10.8% decrease 2019–2020 (only second half of 2020 scores used). CUH and NSN data had incomplete entries with insufficient data points to extract meaningful matched results or calculate trends pre-2018.DiscussionResults show a general decline in CUH patient ambulation but insufficient matched data meant no decisive trend could be extrapolated looking at the impact of lockdown. Obtaining matched NSAA scores with historical patients was not possible due to gaps in data and post-lockdown data was insufficient in quantity. Decline of DMD ambulation occurs over a period of years and it is likely a one-year timeframe is insufficient to spot meaningful declines.2, 3 With clinical service restoration, patient data collection over longer periods will be possible. To increase study power, we aim to coordinate a national study observing trends before, during and after lockdowns. Emphasising NSAA form completion within CUH and the NSN is key to enabling future research.ReferencesGene Expression in Muscle, Rowland, 1985.Muntoni, et al. Categorising trajectories and individual item changes of the North Star Ambulatory Assessment in patients with Duchenne muscular dystrophy, 2019.Brogna, et al. Long-term natural history data in Duchenne muscular dystrophy ambulant patients with mutations amenable to skip exons 44, 45, 51 and 53, 2019.Abstract 261 Figure 1Line graph depicting mean CUH NSAA scores pre- and post-March 2020 (n=17). Line of best fit in red showing a 23% decrease in mean NSAA scores achieved pre- and post-March 2020[Image Omitted. See PDF.]

• Publisher: BMJ Publishing Group LTD
• Subject: Ambulatory assessment / Coding / COVID-19 / Data collection / Duchenne's muscular dystrophy / Dystrophin / Dystrophy / Exons / Gene expression / Genotypes / Motor ability / Muscular dystrophy / Mutation / Patients / Pediatrics / Physical activity / School Support / Schools / Trends