The clinical and electromyographic characteristics of median mononeuropathy in 17 children, 6 girls and 11 boys, aged 5-17 years, are reported from the Departments of Neurology, Children’s Hospital, Boston and the Lahey Clinic, Burlington, MA. EMG showed a lesion at the wrist in 7 children, including 3 with idiopathic carpal tunnel syndrome (CTS), 1 related to skiing. Proximal lesions were identified in 10 (59%), including 8 with trauma. Five had bilateral disease, 3 with CTS. Nontraumatic cases (7) presented with intermittent numbness characteristic of CTS, pain and weakness, and painless weakness and atrophy of the thenar eminence. Mucolipidosis III, scleroderma, cutaneous mucinosis, and osteoid osteoma at the elbow were etiological factors in 4. Symptoms improved in 4 patients. Traumatic cases (10) occurred mainly in boys (8). Five were secondary to an elbow injury and 2 to more distal fractures. A laceration was responsible in 2. Complete recovery occurred in 2 with nerve compression. The results of surgery were variable; of 5 who had surgical decompression for nerve entrapment 3 improved initially. 
COMMENT. Carpal tunnel syndrome is more common in adults than children. A small thenar eminence in a child may be secondary to congenital thenar hypoplasia or congenital constriction bands.