This was a prospective, multicentric and cross-sectional study from December 1st 2018 to July 31st, 2019 in two study populations. On one hand, healthy volunteers and on the other hand cirrhotic patients who did not show clinical signs of hepatic encephalopathy (HE). This study was carried out in 5 hospitals in the cities of Douala and Yaoundé (Douala General Hospital, Gynaeco-Obstetric and Paediatric Hospital Douala, Yaoundé Central Hospital, University Teaching Hospital Yaoundé, Yaoundé General Hospital).

**Group of Healthy Volunteers**

Persons present at the hospital for non-medical reasons were selected as healthy volunteers: Excluded from this group were persons with: a risky alcohol consumption in the last three months ( >30g/day in males and >20g/day in females), chronic liver disease, psychiatric or neurologic disease, renal failure, heart failure, use of psychotic drugs. For each volunteer socio-demographic data (age, gender, level of education) and past medical history were recorded. The volunteers were grouped by age (20-29,30-39,40-49,50-59, >60years), gender and level of education (less than or equal to 5 years, 6-12 years, >12years).

**Group of cirrhotic patients**

The diagnosis of cirrhosis was based on clinical, biological, morphologic and endoscopic evidence of portal hypertension and liver failure or elastography criteria (Fibrosis score 4). For each cirrhotic patient, socio-demographic data (age, gender, level of education), past history (alcohol consumption, smoking, past history of hepatic encephalopathy, gastrointestinal bleeding, spontaneous bacteria peritonitis in the last three months, presence of hepatocellular carcinoma and psychiatric follow up) were recorded. Clinical data included signs of clinical hepatic encephalopathy: mental confusion, asterixis; signs of portal hypertension and chronic liver failure: jaundice, splenomegaly, hepatomegaly, ascites and pedal edema. Para-clinical data included complete blood count, serum albumin, total bilirubin, prothrombin time, international normalized ratio, etiology of cirrhosis, ultrasound evidence of cirrhosis, endoscopic evidence of portal hypertension (esophageal varices, gastric varices). Patients were classified either using Child or MELD (Model for End Stage Liver Disease) score [7].

**Psychometric Tests:**

All healthy volunteers and cirrhotic patients had a series of 5 psychometric tests made up of:

- Number Connection Test-A (NCT-A): It consists in connecting numbers in an arithmetic order (1-25) as quick as possible. Time taken to complete the test and time taken to correct any errors is expressed in seconds.
- Number Connection Test-B (NCT-B): It consists in linking of numbers and letters in an alternative manner (1-A, 2-B, 3-C). Time taken to complete the test and time taken to correct any errors is expressed in seconds.
- Serial Dotting Test (SDT): It consists in making dots at the centre of 10 circles as fast as possible from left to right. Time taken to complete the test and time taken to correct any errors is expressed in seconds.
- Digit Symbol Test (DST): It consists in linking symbols to corresponding numbers as quick as possible. The time required to complete the test is 90 seconds. The result is expressed in points.
- Line Tracing Test (LTT): It consists in drawing a dash between 2 lines 5mm apart without touching the borders as fast as possible. The LTT results is expressed in terms of time taken to complete the test (LTTt seconds) and error score (LTTe), LTT= (1+ LTTe/100) xLTTt.

The tests were performed using a pencil. After an initial demonstration, participants performed the test following recommendations in a calm and lighted place between 8 AM to 3 PM.

The results of cirrhotic patients were compared to those of healthy volunteers with the same age and educational level. Test results of (NCT-A, NCT-B, SDT, LTT) found between the mean ± 1SD were given a score of 0 points. Those between the mean, +1SD and + 2SD were given a score of -1 point, those between the mean +2SD and +3SD were given a score of -2 points, those above the mean+3SD were given a score of -3. Test results with the mean less than -1SD were given a score of +1 points. SDT results found between the mean±1SD were given a score of 0 points. Test results found between the mean-1SD and -2SD, -2 and-3 SD and less than -3SD were respectively given -1, -2, -3 points. Test results greater than the mean +1SD were given a score of +1 point. PHES was the sum of these 5 tests expressed in terms of the number of standard deviations. Patients were classified as having MHE when their PHES was less than -3.

**Statistical analysis **

Data was analysed using Statistical Package for Social Sciences (SSPS Inc, Chicago, Illinois, USA) version 23.0. Depending on quantitative data distribution, they were expressed as mean ± SD or median and interquartile range. Categorical data was expressed as numbers and proportions. Means and medians were compared using the *t* test and the Mann-Whitney *U*-test respectively. Proportions were compared using the chi-squared test or Fisher’s exact test. Levene’s test was used in the evaluation of differences in variance. Non-parametric tests were applied if homogeneity of variance assumptions were not met. The Shapiro–Wilk test was performed to test the hypothesis that the variables came from a normally distributed population. The regression equations were used to calculate scores for individual tests. Correlations were tested with Pearson’s r or Spearman’s R, as needed. A two-sided *P* value < 0.05 was considered significant.