Isolated Neck Extensor Myopathy Associated with Sarcopenia.

A 64-year-old woman with low body weight presented for treatment because of a 1-month history of progressively worsening headdrop. A physical examination revealed isolated weakness in the neck extensor muscles. Short T1 inversion recovery sequences revealed localized high signal intensity in the bilateral splenius capitis muscles, and needle electromyography revealed myopathic changes. Isolated neck extensor myopathy (INEM) secondary to sarcopenia was diagnosed. Steroid therapy was administered, which resulted in a significant improvement in the dropped head syndrome. This case highlights the importance of evaluating sarcopenia in patients who present with dropped head, and considering steroid treatment for INEM associated with inflammatory findings.