Brain white matter fiber tracts involved in post-transjugular intrahepatic portosystemic shunt hepatic myelopathy
We aimed to detect alterations in diffusion characteristics of brain white matter in hepatic myelopathy (HM) patients. Liver cirrhosis patients with (n=25) and without (n=18) HM after transjugular intrahepatic portosystemic shunt and 26 healthy controls were enrolled in this study. All participants were scanned with diffusion tensor imaging on a 3T Siemens scanner. Tract-based spatial statistics analysis was used to detect abnormalities of intracranial white matter tracts. Correlations between clinical characteristics and diffusion metrics were also calculated. HM patients showed widespread decreased fractional anisotropy values in association fibers, callosal fibers, thalamic fibers, and limbic system fibers (P<0.01, family-wise error-corrected) compared with healthy controls. In addition, HM patients showed lower fractional anisotropy values in the corpus callosum, corona radiata, external capsule, and superior longitudinal fasciculus compared with cirrhosis patients without myelopathy (P<0.01, family-wise error-corrected). Furthermore, limb muscle strength grading was correlated with the diffusion characteristics of the corpus callosum and superior longitudinal fasciculus in HM patients (P<0.05). HM patients suffer from more distinct changes of white matter fiber tracts than cirrhosis patients without myelopathy. In addition, alterations of the corpus callosum and superior longitudinal fasciculus may be associated with the major motor disturbance in HM. Our finding may shed light on the underlying neuropathological mechanism of HM.