Prevalence and prognostic value of quantified electroencephalogram (EEG) alterations in cirrhotic patients

The electroencephalogram (EEG) is frequently altered in cirrhotic patients. We, therefore, performed a study to ascertain the features and the prognosis of cirrhotic patients without current overt hepatic encephalopathy (OHE) who have EEG alterations.

A series of 296 consecutive cirrhotic patients who had undergone quantified-EEG was studied. The median follow-up was 442 days, 128 patients had bouts of OHE and 78 patients died from liver-related causes. Another group of 124 cirrhotic patients with a median follow-up of 223 days was examined to validate the prognostic model.

EEG alterations were detected in 38% of the patients. The prevalence of EEG alterations was associated with the severity of cirrhosis (class B: odds ratio (OR) = 2.3, 95% confidence interval (CI) = 1.2-4.7; class C: OR = 3.5, 95% CI = 1.6-7.7), but not with the aetiology (alcoholic vs. non-alcoholic: OR = 0.9; 95% CI = 0.5-1.5). The EEG predicted the occurrence of OHE (chi2 = 26; P < 0.001) and mortality (chi2 = 34; P < 0.001), also adjusting for Child-Pugh class by a multivariate analysis. In the patients with a Child-Pugh score of > or = 8, the EEG discriminated between those patients with a higher 1-year risk of OHE (hazard ratio (HR) = 3.3, 95% CI = 1.8-6.1) and death (HR = 3.1, 95% CI = 1.7-5.6).

In conclusion, quantified-EEG had a prognostic value for the occurrence of bouts of OHE and mortality in cirrhotic patients.