Significance of Sufficient Neck Flexion During Magnetic Resonance Imaging in the Diagnosis of Hirayama Disease: Report of Two Cases

It is difficult to distinguish Hirayama disease (HD) from other mimicking disorders in adolescent patients with distal upper limb weakness. The prevailing theory of HD postulates that the lower cervical cord is susceptible to compression during neck flexion because of insufficient growth of the dura relative to the spinal column. Confirmation of a dynamic change in the dorsal epidural space on magnetic resonance imaging (MRI) during neck flexion is essential for diagnosing HD. However, neck flexion MRI has not been routinely performed in juvenile patients with distal upper limb weakness in the absence of suspected HD. We report two cases of HD that were initially confused with other diseases because of insufficient or absent cervical flexion during MRI. Full-flexion MRI showed typical findings of HD in both cases. Our cases suggest that dynamic cervical MRI in the fully flexed position is necessary for evaluating suspected HD.

Successive Acute Calcific Tendinitis at Different Sites

Acute calcific tendinitis (ACT) is a benign painful inflammatory disorder characterized by resorptive process of calcific deposits following the formation of calcium hydroxyapatite crystals in the tendons. It can occur at various sites, especially in the shoulder or hip joint. ACT involving the lateral epicondyle of the humerus and the cervical spine is very rare. Few reports have demonstrated successive ACT at different sites. We report three cases of successive ACT in women, occurring at the subscapularis followed by the lateral epicondyle, flexor carpi ulnaris followed by the supraspinatus, and longus colli followed by the iliopsoas, respectively.