Longitudinal upper limb muscle MRI in dysferlinopathy: examining the relationship between semi quantitative MRI and physiotherapy outcome measures

Methods:

The Clinical Outcome Study for Dysferlinopathy is a multi-centre natural history study in dysferlinopathy patients. 203 patients (11 to 86 years old) were enrolled. Patients underwent physiotherapy, medical and MRI assessments. 74 patients underwent upper limb muscle MRI at baseline and 61 patients had upper limb muscle MRI at year 3. Muscles were scored on axial T1-weighted sequences with the semi quantitative Mercuri visual scale modified by Fisher. Physiotherapy assessments included muscle strength and functional ability evaluations. Change between baseline and year 3 muscle MRI was assessed using Wilcoxon“s Signed Rank Tests and statistical significance was set at p < 0.05.

Results:

The subscapularis (80.8%), latissimus dorsi (82.6%), infraspinatus (73.8%) and supraspinatus (72.8%) were the most affected scapular muscles at baseline. The biceps brachii (57.1%) and the anterior muscles (53.8%) were the most affected muscles from the arm and forearm at baseline. Cranial muscles and cervical did not show longitudinal changes apart for tongue and cervical paraspinal muscles. Only the brachialis, triceps, and the posterior muscles from the forearm did not show longitudinal changes.

Conclusion:

The subscapularis muscle and the latissimus were the most affected muscles at baseline. Only the tongue and cervical muscles showed changes at year 3 but nearly all scapular and arm muscles showed longitudinal changes.