1. ¹Department of Orthopedic Surgery, University of Minnesota School of Medicine, Minneapolis, MN, USA
2. ²Department of Pediatric Clinical Neuroscience, University of Minnesota School of Medicine, Minneapolis, MN, USA
3. ³Department of Pediatric Blood and Marrow Transplantation, University of Minnesota School of Medicine, Minneapolis, MN, USA

Correspondence: Dr PJ Orchard, Department of Pediatric Blood and Marrow Transplantation, University of Minnesota School of Medicine, MMC 366, 420 Delaware St. SE, Minneapolis, MN 55455, USA. E-mail: orcha001@umn.edu

⁴Current address: 3350 Main Street, Sadowsky Cancer Center for Children, Springfield, MA 01107, USA.

⁵Current address: Room M504.15, The Children's Mercy Hospital, 2401 Gillham Road, Kansas City, MO 64108, USA.

Deceased.

Received 8 November 2006; Accepted 18 December 2006; Published online 5 February 2007.

Abstract

Children with Hurler syndrome (mucopolysaccharidosis type IH (MPSIH)) have skeletal, joint and soft tissue abnormalities that may persist or progress after hematopoietic stem cell transplantation (HSCT). We report our single center experience with development of carpal tunnel syndrome (CTS) in 43 children with MPSIH after HSCT. Twenty-three children (59%) developed CTS following HSCT; 19 of the 39 children with enzyme activity in the normal or heterozygous range developed CTS (49%), whereas all four children with low heterozygous or absent enzyme activity developed CTS after HSCT. Fourteen of 19 related donor marrow recipients, eight of 19 of those receiving an unrelated donor graft and one of five unrelated cord blood recipients developed CTS. The mean age at surgical release was 4.8 years. With each year increase in age at HSCT, there was a 55% increased risk. Age and enzyme activity after HSCT were significant factors in the development of CTS. Transplantation by 2 years of age reduced the risk of developing CTS by 46%; higher enzyme activity led to a 78% reduction in the risk of developing CTS. However, children transplanted for MPSIH remain at risk for the development of CTS, and should be monitored on an ongoing basis by nerve conduction velocity testing.