Clinical and MRI analyses of dorsal spinal column function in compressive cervical myelopathy

This study aimed to evaluate whether the somatosensory functions of the upper (UE) and lower extremities (LE) were correlated with the degree of fasciculus cuneatus (FC) and fasciculus gracilis (FG) degeneration based on magnetic resonance imaging in patients with compressive cervical myelopathy (CCM). We prospectively recruited 32 patients with CCM. Median nerve somatosensory evoked potentials (SEPs) and the Semmes–Weinstein monofilament (SWM) test were employed to test UE somatosensory function. Tibial nerve SEPs, the foot SWM test, and Romberg ratio were used to evaluate LE somatosensory function. We imaged FC and FG using three-dimensional anisotropy contrast diffusion magnetic resonance axonography. Diffusion tensor invariant of fractional anisotropy (FA) was used to measure the degree of degeneration in FC and FG. FA values of FC degeneration were significantly correlated with the median nerve SEPs (Spearman’s rank correlation coefficient [rs] = − 0.66) and hand SWM tests (rs = − 0.52). FA values of FG degeneration were correlated with the tibial nerve SEPs (rs = − 0.66), foot SWM tests (rs = − 0.70), and Romberg ratio (rs = − 0.60). Our study demonstrates that in patients with CCM, UE and LE somatosensory examinations are correlated with the degree of degeneration in the FC and FG, respectively.