Objective
To evaluate the characteristics of peripheral nervous system involvement in patients with mucopolysaccharidoses (MPS).

Method
Electrophysiologic studies were performed in 26 children with MPS confirmed by semiquantitative MPS study, high resolution electrophoresis and enzyme assay. The age distribution of the patients were 2 to 18 year old (mean 8.2 year old).

Results
Of the 26 children, 21 children (80.8%) showed abnormal electrophysiologic finding. Eighteen children had median entrapment neuropathy at wrist level (carpal tunnel syndrome), 3 children had demyelinating peripheral polyneuropathies dominant in motor nerves.

Conclusion
The most prominent features of the peripheral nervous system involvement in MPS patients were entrapment neuropathy at wrist but concomittent peripheral polyneuropathy. Further studies would be necessary to clarify the characteristics of the peripheral polyneuropathy in MPS.