Respiratory involvement and neuromotor function in a cohort of Patients With Facioscapulohumeral Dystrophy Type 1: A Retrospective Study

<bold>Background:</bold> Range of respiratory involvement in Facioscapulohumeral Dystrophy (FSHD) is variable, with a proportion of patients that have a mild restrictive ventilatory pattern that ranges from 10% to 39%. <bold>Objectives:</bold> To evaluate the change in respiratory function with respect to decline in motor function in FSHD1 patients. <bold>Methods:</bold> Ambulatory patients with genetically confirmed FSHD1 aged ≥ 18 years underwent yearly neuromuscular (10 Meter Walk Test and 6 Minutes Walking Test) and respiratory (Forced Vital Capacity, Peak Cough Expiratory Flow and polysomnography) assessments at baseline and over time. <bold>Results:</bold> Fifty FSHD1 patients (mean age 41.26 years ± 14.85, male/female ratio of 1.78) were considered and followed for a mean follow-up time of 46.06 months ± 29.18. During the follow-up period, both FVC and PCEF assessments changed significantly over-time (an estimation of –1.60%/years ± 0.30; p < 0.0001 for the FVC % in seated position; -1.26%/years ± 0.31; p = 0.00002 for the FVC % supine position; and -11.70 L/min/years ± 0.31; p = 0.00002 for the PCEF). No significant variations emerged regarding polysomnography assessments and motor evaluations. The decline in respiratory parameters was not associated with neuromotor or general clinical worsening. <bold>Conclusions:</bold> Our data confirm that respiratory decline in FSHD1 is slowly progressive and generally not correlated with a decline in motor function in ambulatory patients. Longer follow-up and monitoring across the spectrum of the disease is ongoing to better define the relationship between respiratory involvement and neuromotor abilities.