Validation of Korean Stroop Test in the Screening of Minimal Hepatic Encephalopathy = Validation of Korean Stroop Test in the Screening of Minimal Hepatic Encephalopathy

다국어 초록 (Multilingual Abstract)

Aims: Minimal hepatic encephalopathy (mHE) has poor prognosis but hardly drawn attention when patients have no symptoms. We aimed to validate Korean stroop test in the screening of mHE.
Methods: Chronic hepatitis B related liver cirrhosis (LC) patients without history of overt hepatic encephalopathy were recruited prospectively from 13 centers for two years. All participants completed Portosystemic encephalopathy syndrome test (PHES) and Korean stroop test. Korean stroop test is consisted of 2 On-states (color, word) and 2 Off-states (inhibition, switching). Correct response rates and response times were measured. Four types of “OnTime+OffTime” have been analyzed (color+inhibition, color+switching, word+inhibition, and word+switching). mHE was diagnosed when PHES scores less than -4. Healthy controls (HC) were also recruited (n=376).
Results: Among 223 LC patients, 67.3% was male. Mean age was 53 years. Prevalence of mHE was 20.6%. Response times for each states showed negative correlation with PHES scores (P<0.001). Also color+inhibition, color+switching, word+inhibition, and word+switching showed negative correlation with PHES scores, -0.361, -0.310, -0.442, and -0.336, respectively(all P<0.001). The highest AUC in the discrimination of mHE among various “OnTime+OffTime” was word+inhibition (AUC 0.75, 95% C.I 0.67-0.84, P<0.001). Mean values of word+inhibition were significantly different among the three groups, which were 54.6±13.2sec, 63.4±18.2sec, and 83.4±27.8sec in HC, LC without mHE, and LC with mHE, respectively (all P<0.001). Among various factors, time for word+inhibition was the only significant factor (OR 1.04, 95% C.I 1.02-1.06, P<0.001) in multivariate analysis for diagnosis of mHE.
Conclusions: Korean stroop test is simple and valid method for screening of mHE.