Paraspinal, shoulder, and leg muscles are all affected in people with McArdle disease and increasingly with age

Takeaway

Using muscle MRI studies assessing muscle fat replacement, this multi-centric observational study identified that patients with glycogen storage disease type V (GSDV) have significant involvement of the paraspinal muscles and to a smaller extent lower limb muscles, and not just shoulder-girdle muscles.

GSDV, known as McArdle disease, is a rare inherited muscle glycogenosis that presents with episodic symptoms such as exercise intolerance, myalgia, early fatigue, and muscle contractures, which are all alleviated by rest. Chronic muscle symptoms of fixed muscle weakness affecting the shoulder-girdle muscles have been described in patients over 40 years old.
The findings emphasize the clinical relevance of also assessing paraspinal function and symptoms in patients with McArdle disease, with possible consequences for rehabilitation strategies.