Sporadic inclusion body myositis presenting with severe camptocormia

Sporadic inclusion body myositis (sIBM) is a slowly progressive idiopathic inflammatory myopathy. The characteristic early quadriceps and finger flexor muscle weakness often leads to the diagnosis of sIBM, especially when all canonical pathological features of sIBM are not present on muscle biopsy. Weakness of the paraspinal muscles, resulting in head drop and/or camptocormia, is a rare clinical finding along the course of sIBM, and even more rare as the presenting feature. We describe two patients with sIBM manifesting with camptocormia as the sole clinical manifestation for several years prior to the diagnosis by muscle biopsy. This observation emphasizes the role of sIBM in the etiology of camptocormia and the need to consider this common myopathy as a cause of weakness, despite the lack of classic quadriceps and finger flexor muscle weakness years after the onset of the paraspinal muscle weakness.