The thalamus in cirrhotic patients with and without hepatic encephalopathy: a volumetric MRI study

The thalamus is a major relay and filter station in the central neural system. Some previous studies have suggested that the thalamus maybe implicated in the pathogenesis of hepatic encephalopathy. The aim of our study was to investigate changing thalamic volumes in cirrhotic patients with and without hepatic encephalopathy.

Neuropsychological tests and structural MR scanning were performed on 24 cirrhotic patients, 23 cirrhotic patients with minimal hepatic encephalopathy, 24 cirrhotic patients during their first episode of overt hepatic encephalopathy, and 33 healthy controls. Voxel-based morphometry analysis was performed to detect gray matter morphological changes. The thalamus and whole brain volume were extrapolated. A receiver operating characteristic curve analysis of thalamic volumes was used to discriminate patients with minimal hepatic encephalopathy from those with hepatic cirrhosis.

Thalamic volume increased in a stepwise manner in patients with progressively worse stages of hepatic encephalopathy compared to healthy subjects. Additionally, a comparison of gray matter morphometry between patients with Child-Pugh grades A, B, or C and controls revealed a progression in thalamic volumes in parallel with the degree of liver failure. Moreover, thalamic volume was significantly correlated with the number connection test A time and digit-symbol test score in cirrhotic patients with minimal hepatic encephalopathy (r=0.659, P=0.001; r=-0.577, P=0.004; respectively). The area under the receiver operating characteristic curve was 0.827 (P=0.001).

A significantly increased thalamic volume may be provide an objective imaging measure for predicting seizures due to minimal hepatic encephalopathy in cirrhotic patients.