Background: Minimal hepatic encephalopathy (MHE) is defined as hepatic encephalopathy (HE)
without symptoms on clinical/neurological examination, but with deficits in some cognitive areas
that can only be measured by neuropsychometric testing. Aim: Our aim was to study serum zinc
levels in cirrhotic patients with and without MHE and correlate it with the results of neuropsychological
tests and P300 event related potential. Patients and Methods: Fifty-five patients with liver
cirrhosis were recruited for the present study. All patients were subjected to full history taking,
clinical examination, abdominal ultrasonography, laboratory investigations including liver function
tests and serum zinc, psychometric studies (line tracing test and serial dotting test) and P300
event related potential. According to the results of psychometric studies and P300 event related
potential, the patients were divided into 3 groups in addition to the control group. Results: Among
the 55 patients included in the study, 30 patients had no clinical evidence of HE and 25 patients
had overt HE with different grades. In patients with no clinical evidence of HE, psychometric tests
and P300 event related potential revealed that 13 patients had MHE, while 17 had no HE. There
were significantly lower serum zinc levels in patients with MHE and in cirrhotic patients without
HE compared with the healthy controls. Also, zinc levels were significantly lower in higher grades
of hepatic encephalopathy. Serum zinc levels showed positive correlation with serum albumin
levels and inverse correlation with serial dotting test and P300 latency. Conclusion: Reduced
serum zinc level and prolonged P300 latency can serve as predictors of minimal hepatic encephalopathy
in cirrhotic patients. Zinc deficiency is common in cirrhotic patients with MHE.
These findings may have important prognostic and therapeutic implications in MHE and overt HE
patients with zinc deficiency.