P300 auditory event-related potential for the diagnosis of subclinical hepatic encephalopathy and prediction of overt encephalopathy in cirrhotic children

ABSTRACT

Subclinical hepatic encephalopathy [SHE] has been recognized in patients with cirrhosis, irrespective of its etiology. It is of special clinical relevance to identify this condition and to assess its progression to overt encephalopathy. This study was conducted [I] to evaluate the diagnostic usefulness of auditory P3ERP in the detection of SHE in cirrhotic children, to compare it with that of an EEG and a standard psychometric test, and [ii] to examine the clinical progression of SHE to overt HE during follow up. Thirty-four non-encephalopathic cirrhotic children [19M and 15F, mean age 9.84 +/- 3.13 yr] were studied using auditory P300 event related potential [P3ERP], EEG and the number connection test [NCT]. Cut off values for abnormalities in the tests were developed from 45 ages matched controls. Patients were followed regularly for the development of overt HE and the precipitating factors were noted. P3ERP latencies [342.0 +/- 29.4 ms vs. 296.4 +/- 28. 5ms] and NCT time [62.6 +/- 31.3s vs. 43.8 +/- 15.2s] were significantly prolonged in cirrhotics compared to controls. 16 [47%] children had SHE based on at least one abnormal test result. P3ERP detected SHE in maximum number of patients [30%] followed by EEG [23.5%] and NCT [17.6%]. About 55% of patients with SHE progressed to overt SHE within a mean duration of 4 months. Multivariate analysis showed that abnormality on P3ERP and EEG as well as prior episode of HE, occurrence of G.I bleed, dehydration and infection had significantly higher risk for development of overt HE. P3ERP method was more sensitive in detection of SHE in cirrhotic children. Abnormal P3ERP and EEG along with the precipitating factors were significantly associated with development of overt HE