Clinical and ultrasonographic evaluation of dysphagia in patients with LAMA2-CMD

Background: LAMA2-CMD is a rare autosomal recessive disease characterized by hypotonia, muscle weakness, and the inability to achieve independent gait. It imposes a considerable disease burden, including difficulty in weight gain and dysphagia. Objective: However, this disease burden has not been thoroughly assessed in the medical literature, and this study aims to address this gap. Methods: Patients with genetically confirmed LAMA2-CMD were cross-sectionally evaluated. Clinical assessments included analysis of dysphagia, NdSss scale, weight measurement, and the necessity of gastrostomy. Patients received ultrasound evaluations of tongue muscles, and the muscle abnormalities were classified using the modified Heckmatt scale. The ultrasound M mode assessed the hyoid elevation movement during swallowing. Qualitative analysis of ultrasound findings and correlations with clinical presentations were conducted. Results: 20 patients with LAMA2-CMD were evaluated, ranging from 3-27 years old (mean 7.7). 8/20 patients (40%) weighted below the 3rd percentile. All patients experienced some degree of dysphagia, with a maximum score of 7 on the NdSss scale. 17/20 patients (85%) reported taking over 30 minutes to finish a meal. 4/20 patients (20%) had gastrostomy tubes. The geniohyoid muscle was the most affected among the three tongue muscles evaluated. 14/ 20 patients had markedly hyperechoic muscle. The genioglossus muscle was the second most affected, with 9/20 patients having markedly hyperechoic muscle. None of the patients had normal geniohyoid or genioglossus muscles. Lastly, the least affected muscle was the digastric, with 7/20 patients having markedly hyperechoic muscle. 16/20 patients required an increased number of hyoid elevation movements and had low amplitude movements during swallowing. A correlation was observed between the patient‘s age and the severity of ultrasound abnormalities. The genioglossus and geniohyoid muscles appeared more preserved in patients under 5 years old than older patients (p=0.005 and p=0.017, respectively). Similarly, there was a correlation between extremely low weight (p<3) and markedly hyperechoic genioglossus muscle (p=0.0176). Conclusion: Patients with LAMA2-CMD experience greater difficulty in weight gain and exhibit some degree of dysphagia. Assessing tongue muscles via ultrasound is a valuable tool for comprehending functional abnormalities in these patients, aiding in clinical management, and potentially serving as a marker for disease progression