Ho, ho, ho! Gather around, my curious elves, for a tale from the medical workshop, a story not of toys and reindeer, but of a condition known as rhabdomyolysis. This tale, my dear friends, is a journey through the snowy peaks of muscle mysteries, where doctors, much like toy makers, seek to uncover the hidden secrets of unprovoked rhabdomyolysis, a condition where muscles, much like overworked elves, become tired and break down, releasing a substance called creatine kinase (CK) into the bloodstream.

In our story, set between the years 2012 and 2022, a group of medical elves embarked on an expedition to explore the role of electrodiagnostic (EDX) testing, a magical tool not unlike our toy-making machines, in identifying underlying myopathies, or muscle disorders, in patients with this curious condition. They delved into their EDX database, a vast library of knowledge, to find 66 patients who had been struck by this unexplained muscle malady.

As they sifted through the data, much like sorting through letters to Santa, they discovered that 32 of these patients had myopathic electromyography (EMG) results, indicating a muscle disorder. Muscle biopsies, akin to checking the list twice, and genetic testing, a bit like using Santa’s magical globe, were performed on 41 and 37 patients, respectively.

The medical elves found that a definitive diagnosis was achieved in 15 patients, with the help of abnormal muscle biopsy results or genetic testing, revealing a mix of seven metabolic and eight nonmetabolic myopathies, including five muscular dystrophies and three ryanodine receptor 1 (RYR1)-myopathies. It was like finding the exact toy a child wished for, hidden deep within Santa’s sack.

Interestingly, patients with myopathic EMG, much like those on the nice list, were more likely to have baseline weakness and elevated CK levels. They were also more likely to have nonmetabolic myopathies. However, the story teaches us that nonmyopathic EMG, akin to finding coal in your stocking, did not exclude the possibility of a myopathy, and genetic testing emerged as the shining star atop the Christmas tree, guiding the way to identifying an underlying myopathy.

In the end, my dear elves, the moral of our Christmas tale is that genetic testing should likely be the first-tier diagnostic testing following unprovoked rhabdomyolysis, much like checking the list before loading the sleigh. And so, with their newfound knowledge, the medical elves continued their work, armed with the magic of science, to bring health and joy to all. Merry Christmas, and may all your diagnoses be bright!