[Chiromegaly in syringomyelia--radiologic studies of hand bones]

Chiromegaly, localized hypertrophy of a hand, is known to be a rare but pathognomonic trophic disturbance in syringomyelia. We recently reported that the sympathetic hyperfunction was associated with chiromegaly. This time we carried out radiological studies of hand bones in 4 patients with syringomyelic chiromegaly. In simple roentogenography, enlargement and enhanced shadows of hand bones were recognized in the chiromegalic side. Radiographic measurements showed metacarpophalangeal length and width were increased by 1.7% and 8.8% respectively compared to the normal side, and metacarpal index was decreased significantly in the chiromegalic side. In X-ray photodensitometry (MD/MS method) of the second metacarpal bones, bone density was increased by 10.6% compared to the normal side. These results suggested that bone hypertrophy was associated with chiromegaly in patient with syringomyelia. Trophic disturbance may exert some influence on the bone tissue.