Ultrasonographic evaluation of the median nerve at the level of the carpal tunnel outlet and mid forearm in patients with type II Mucopolysaccharidosis.

Abstract

The ultrasonographic (US) evaluation of the median nerve at the level of the carpal tunnel outlet (CTO) and mid forearm in pediatric patients with mucopolysaccharidosis type II (MPS II) and comparison with healthy subjects. Fifteen children with MPS II and 44 healthy children were included in the study and they were divided into three age groups. The cross-sectional area, the appearance of the nerve, and the ratio of the cross-sectional areas were evaluated by US. At the level of the CTO the mean area of the nerve was increased in all MPS II groups compared with the correspondent healthy age groups and the differences were statistically significant (p<0.01). At the level of the mid forearm the differences were statistically significant only for the first age group. Other US findings at the level of the CTO in the MPS II groups were represented by hypoechogenicity (86.67 % on the right and 93.33% on the left), thickened fascicles (80% bilaterally), irregular contour (53.33% bilaterally) and the presence of the Doppler signal including the nerve (26.67 % on the right and 33.33 % on the left). The CTO/mid forearm cross-sectional area ratio was higher in all MPS II age groups and the differences were statistically significant (p<0.001). In patients with MPS II there are significant US changes in the size and aspect of the median nerve.