Electroencephalography in patients with cirrhosis

Background & Aims: Electroencephalography has not been completely quantified in patients with cirrhosis. We investigated the electroencephalogram (EEG) dynamics in patients with cirrhosis. Methods: We performed closed-eye EEGs on 175 patients with cirrhosis (age, 55 ± 11 years; 24% Child-Pugh class A, 48% class B, and 285 class C), conducted clinical and psychometric assessments for hepatic encephalopathy (HE), and followed the patients for 1 year. EEG characteristics were assessed in the frequency domain, in the frontal (F3-F4) and parietal (P3-P4) derivations. Intrahemispheric (frontoparietal, right, and left) and interhemispheric (F3-F4 and P3-P4) coherence were computed. The EEGs of 50 healthy volunteers (age, 56 ± 17 years) served as controls. Results: Compared with controls, the EEGs of patients with cirrhosis had a reduced frequency in the posterior derivations (P3/P4 mean dominant frequency, 9.1 ± 1.8 and 8.9 ± 1.7 Hz vs 10.4 ± 1.3 and 10.2 ± 1.3 Hz, respectively; P < .01) and an increase in interhemispheric parietal relative coherence within the theta band (22.3% ± 5.5% vs 18.9% ± 3.5%; P < .01). These features were more prominent in patients with Child class C and in patients with a history of overt HE; they correlated with hyperammonemia and hyponatremia. The decrease in EEG frequency, along with the increase in interhemispheric theta coherence in the posterior derivations, was inversely associated with survival and the occurrence of overt HE during the follow-up period. Conclusions: In patients with cirrhosis, alterations in the EEG were significantly associated with the severity of liver disease and HE; the EEG might be used in determining prognosis.