Slowing of Alpha Waves on EEG, an Early Marker of Minimal Hepatic Encephalopathy

Abstract

Introduction: Minimal Hepatic Encephalopathy (MHE) is the mildest form of spectrum of Hepatic Encephalopathy (HE) which remains undiagnosed due to lack of awareness. MHE has a negative effect on patient's daily functioning due to cognitive impairment. Electro-Encephalo-Gram (EEG) and Mini Mental State Examination (MMSE) are useful in early diagnosis and follow up of MHE. Aim: To study evidence of MHE in patients with liver cirrhosis by psychometric tests and also its correlation with EEG changes. Materials and Methods: The study was carried out as a prospective case control study of 70 patients diagnosed with Cirrhosis of liver, over a period of two years in accordance with European Association for the Study of the Liver (EASL) and Asociacion Latinoamericana parael Estudio del Higado (ALEH) criteria with MMSE score >24 and were diagnosed as Minimal Hepatic Encephalopathy if 2 out of 3 psychometric tests were abnormal EEG was performed in them and was compared with 70 healthy controls. Results: Study showed male predominance (90%) with mean age of 45.49 ± 11.76. Alcohol related cirrhosis (70%) was found to be more common than HBV (8.57%) and HCV (2.86%) infection related cirrhosis. Pedal edema, icterus, pallor and ascites were the most common presenting manifestations. Most cirrhotic cases (80%) were under Child Pugh Class-A. On USG of abdomen all cases had Coarse echotexture and nodular surface of liver among them 11 cases had Hepatomegaly, 10 cases had splenomegaly, 42 cases had ascites and 24 cases had increased portal venous diameter of mean size 14.02 ± 0.48 mm. MMSE score of all selected cirrhotic cases was >24. Psychometric Tests i.e. Number Connection Test-A, Number Connection Test-B and Line tracing test were performed in all selected cirrhotic cases and they were not able to perform it within designated time. All cases were subjected to EEG and compared with equal number of comparable healthy controls, which shows change in frequency and amplitude of Alpha wave which was highly significant whereas no significant changes of frequency and amplitude of Beta, Theta and Delta waves between cases and controls. Conclusion: There is significant changes in alpha wave frequency and amplitude in patients with minimal hepatic encephalopathy.