Congenital Bilateral Thenar Amyotrophy due to Carpal Tunnel Narrowing

Abstract

Bilateral thenar musculature atrophy due to carpal tunnel syndrome is rarely documented in children. It is usually the result either of carpal bone malformation or of hereditary metabolic disorders. We report a case of a 5-year-old female patient presenting with thenar atrophy due to severe median neuropathy at the carpal tunnel of both hands. Using high-resolution ultrasonography, we detected a significant carpal tunnel deformation due to a narrowing at its inlet. Additional tests did not reveal structural alterations of carpal bones nor metabolic disorders. Surgery, which had been initially ruled out, was performed when the patient was 15 years old in view of progressive worsening (complex regional autonomic syndrome). Surgery improved symptoms and confirmed the above morphological findings. We present a case of both acute bilateral median neuropathy at carpus and bilateral symmetric deformation of carpal tunnel due to a narrowing of the entrance in a healthy young girl without other causative pathology. To our knowledge, such a case has not been described before.