Covert hepatic encephalopathy: does the mini-mental state examination help?

The Mini-Mental State Examination (MMSE) has been utilized for the diagnosis of hepatic encephalopathy (HE). However, its threshold of abnormality has not been formally tested in patients with cirrhosis and its diagnostic/prognostic validity remains unknown. The aim of this study was to assess it in a large group of well-characterized outpatients with cirrhosis and no overt HE.

One-hundred-and-ninety-one patients underwent clinical assessment, MMSE, electroencephalography (EEG) and paper-and-pencil psychometry (PHES); 117 were followed up for 8 ± 5 months in relation to the occurrence of HE-related hospitalizations.

On the day of study, 81 patients (42%) had abnormal EEG and 67 (35%) abnormal PHES; 103 (60%) had a history of HE. Average MMSE was 26.6 ± 3.5; 22 (19%) patients had abnormal MMSE based on the standard threshold of 24. Patients with abnormal EEG/PHES/history of HE had worse MMSE performance than their counterparts with normal tests/negative history (25.7 ± 4.2 vs. 27.3 ± 2.7; P < 0.01; 25.5 ± 3.2 vs. 27.9 ± 1.8, P < 0.0001; 26.3 ± 3.7 vs. 27.4 ± 2.6, P < 0.05, respectively). Based on the above results, MMSE thresholds of 26 and 27 were tested against abnormalities in clinical/EEG/PHES indices and significant associations were observed. An MMSE threshold of 26 was also a predictor of HE-related hospitalization (Cox-Mantel: P = 0.001); patients with MMSE <26 were significantly older than those with MMSE ≥26 but comparable in terms of liver dysfunction and ammonia levels. When MMSE items were considered separately, those which correlated most significantly with standard HE indices where spatial orientation and writing.

In conclusion, an MMSE <26 identifies older patients with cirrhosis who are more prone to manifest HE signs.