Background and aims: Minimal hepatic encephalopathy is the mildest form of the spectrum of hepatic encephalopathy (HE) that impairs health-related quality of life. We assessed (1) the usefulness of psychometric hepatic encephalopathy score and critical flicker frequency for the diagnosis of minimal hepatic encephalopathy, and (2) prognostic significance of minimal hepatic encephalopathy.
Methods: One hundred patients with liver cirrhosis without overt HE were subjected to psychometric hepatic encephalopathy score and critical flicker frequency evaluation. Eighty-three age- and sex-matched healthy volunteers served as controls. Minimal hepatic encephalopathy was diagnosed when the psychometric hepatic encephalopathy score was <or=-5. An age-adjusted Z score <-2 on the critical flicker frequency was considered abnormal.
Results: Forty-eight (48%) patients had minimal hepatic encephalopathy as indicated by altered psychometric hepatic encephalopathy score. Critical flicker frequency was altered in 21 patients; 17 also showed impaired psychometric hepatic encephalopathy score thus providing additional information in only 4 patients. Forty-six of 48 patients with minimal hepatic encephalopathy and 48 of 52 patients without minimal hepatic encephalopathy completed the follow-up. Eighteen (39.1%) patients died among those who had minimal hepatic encephalopathy compared to 11 (22.9%) patients who did not have minimal hepatic encephalopathy. Among the several variables analyzed in this study, univariate analyses showed that age, serum bilirubin level, Child-Turcotte-Pugh score and psychometric hepatic encephalopathy score were associated with a poor prognosis. The multivariate analysis identified two variables as significant independent prognostic factors; psychometric hepatic encephalopathy score <or=-6 [hazard ratio 2.419 (95% CI, 1.014-5.769)] and Child-Turcotte-Pugh score >or=8 [hazard ratio 2.466 (95% CI, 1.010-6.023)] predicted poor survival.
Conclusions: Psychometric hepatic encephalopathy score is a useful tool for the diagnosis of minimal hepatic encephalopathy in an outpatient setting. Both psychometric hepatic encephalopathy score and Child-Turcotte-Pugh score have prognostic value on survival.