Background and objective Oculopharyngeal muscular dystrophy (OPMD) is a genetic disorder caused by an abnormal expansion of GCN triplets within the PABPN1 gene. Previous descriptions have focused on lower limb muscles in small cohorts of patients with OPMD, but larger imaging studies have not been performed. Previous imaging studies have been too small to be able to correlate imaging findings to genetic and clinical data.
Methods We present cross-sectional, T1-weighted muscle MRI and CT-scan data from 168 patients with genetically confirmed OPMD. We have analysed the pattern of muscle involvement in the disease using hierarchical analysis and presented it as heatmaps. Results of the scans were correlated with genetic and clinical data.
Results Fatty replacement was identified in 96.7% of all symptomatic patients. The tongue, the adductor magnus and the soleus were the most commonly affected muscles. Muscle pathology on MRI correlated positively with disease duration and functional impairment.
Conclusions We have described a pattern that can be considered characteristic of OPMD. An early combination of fat replacement in the tongue, adductor magnus and soleus can be helpful for differential diagnosis. The findings suggest the natural history of the disease from a radiological point of view. The information generated by this study is of high diagnostic value and important for clinical trial development.
- muscle MRI
- muscular dystrophy
- oculopharyngeal muscular dystrophy
- outcome measures
- registro español de enfermedades neuromusculares (NMD-ES)
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Contributors AA-J, AA-M, JD-M: Study design, acquisition and analysis of data, manuscript drafting, study coordination. CN-P, MTG, MJR, LG-Q: acquisition and analysis of data, article drafting. HMJMK, CGCH, BGMV-E, MO, LG, EV, CP, CM, MG, CD-G, JV, TFMF, A-SVE, TG-S, JP, RG-F, NM, JJV, SK, GT, MM, ER, MTG, JAB, JD-J, IIZ, RYC, PL, ALP-N, AR-F, AM, CM-B, VS, GG, MAM, GM, RF-T, AL-M, EC-V, LQ, RR-G, II: acquisition of data, drafting the paper.
Funding This study was partially funded by a grant from Fondo de Investigaciones Sanitarias (FISS) PI15/01822 (J.D-M) and by a grant FONDECYT 1151383 from the Comisión Nacional de Investigación Científica y Tecnológica of Chile (CONICYT) to JAB.
Competing interests None declared.
Patient consent for publication Obtained.
Ethics approval Ethics committee of Sant Pau Hospital.
Provenance and peer review Not commissioned; externally peer reviewed.
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