Ultrasonographic Findings of Carpal Tunnel Syndrome in Patients with Paraplegia

Objective: To assess the diagnostic value of ultrasonography for the median nerve, the state of life style activities and the pain degree of upper extremities in paraplegics with carpal tunnel syndrome (CTS). Method: Eighteen wheelchair ambulators with spinal cord injury who had neurological level below T2 were studied. Patients with peripheral or central neuropathies were excluded. Patients were assigned to either the electrodiagnostic CTS (group CTS, 7) or electrodiagnostically negative (group nonCTS, 11), and healthy volunteers (15) were classified as control group. The cross sectional area of the median nerve (MN-CSA) at carpal pisiform level was ultrasonographically measured. The degree of painful restriction to execute ADL by hands (TR-ADL), the pain grade (visual analog scale, VAS) of upper extremities and revised version of Korean spinal cord independence measure (KSCIM-R) for functional level were measured and analyzed. Results: Nine hands (14.3%) of 7 patients out of 34 hands had CTS in electrodiagnostic study. There were significant difference among groups in TR-ADL hours (CTS group; 5.0 vs non-CTS group; 10.2, p<0.05), VAS (4.1 vs 2.0, respectively, p<0.05), and no statistical difference in KSCIM-R (68.4 vs 52.1, p>0.05), MN-CSA (12.3 mm(2) vs 7.9 mm(2) vs control group; 8.0 mm(2), p< 0.05). Using the ROC curve, the cut-off value of MN-CSA produced 8.5 mm(2) providing a diagnostic sensitivity of 77.8% and specificity of 59.6%. Conclusion: The ultrasonographic measurement of the median nerve may be a useful non-invasive screening test for the diagnosis of CTS in paraplegic patients with wrist pain.