[Carpal tunnel syndrome in children with mucopolysaccharidosis type 1H: diagnosis and therapy in an interdisciplinary centre].

Carpal tunnel syndrome is common in children with mucopolysaccharidosis type 1H (MPS type 1H). Clinical signs of carpal tunnel syndrome are frequently absent in these children and it is often very difficult to perform and interpret neurophysiological investigations. In this article we wish to present our experience and results regarding the diagnosis and postoperative results after decompression of the median nerve.In an interdisciplinary set-up we are currently treating 11 MPS type 1H children following blood stem cell transplantation. 7 patients were operated 12 times (5 bilateral operations) because of a carpal tunnel syndrome (age at the time of operation 83,3 months, (43-143 months), 2 male, 5 female). 6 patients had a follow up after 23,7 months (9-59 months). 6 patients had a histological analysis of the flexor retinaculum. Three patients had a postoperative neurophysiological investigation.Each of the operated patients had at least 1 preoperative clinical sign of a carpal tunnel syndrome. We found at least 1 pathological finding in motor and sensory nerve conduction studies in each patient. 6 of the 7 children operated on were symptom-free at postoperative follow-up. 1 of the 3 patients with a postoperative neurophysiological follow up showed a deterioration of the nerve conduction studies. This patient was free of symptoms postoperatively. Biopsy of the flexor retinaculum confirmed abundant proteoglycan deposition. We had neither postoperative complications nor were revisional operations necessary.The Diagnosis of a carpal tunnel syndrome in children with MPS Typ 1H needs a thorough medical history, the correct interpretation of the clinical symptoms and sophisticated nerve conduction studies. Wether the improvement of the postoperative clinical situation lasts has to be evaluated in a long term investigation especially because in one patient in our group we saw a deterioration of the nerve conduction studies postoperatively.