Bilateral carpal tunnel syndrome in two children: common manifestation of an uncommon disease.

Carpal tunnel syndrome (CTS) is a rare entity in children and usually has a different clinical presentation than in adults. The majority of these cases are related to a genetic condition. The most common aetiology is a lysosomal storage disease such as mucopolysaccharidoses or mucolipidoses (ML). Two siblings with bilateral median nerve neuropathy, wrist contractures and skeletal deformity on a background of mild facial coarsening and normal cognition are presented. There was a family history of similar complaints in first cousins. Nerve conduction studies were suggestive of bilateral median neuropathy with conduction block at the wrists. Biochemical investigation showed high levels of plasma lysosomal enzymes. Both patients underwent bilateral flexor retinaculum release. The findings at surgery were severe compression of the median nerve by the thickened flexor retinaculum. The histopathology of the thickened tissue showed a fibrosed and vascularised flexor retinaculum. On electron microscopy, macrophages with membrano-vacuolated inclusion zebra bodies were seen. Both patients had an uneventful recovery with symptomatic improvement. CTS is rarely seen in children except in association with genetic disorders. There is usually a delay in the diagnosis as attention is paid to the contractures rather than to the median nerve compression. The presence of CTS is typically seen in ML types II and III. Surgical intervention helps in improving the quality of life and hand function of these patients.