Validation of a paper and pencil test battery for the diagnosis of minimal hepatic encephalopathy in Korea

Abstract

The aim of this study was to validate a new paper and pencil test battery to diagnose minimal hepatic encephalopathy (MHE) in Korea. A new paper and pencil test battery was composed of number connection test-A (NCT-A), number connection test-B (NCT-B), digit span test (DST), and symbol digit modality test (SDMT). The norm of the new test was based on 315 healthy individuals between the ages of 20 and 70 years old. Another 63 healthy subjects (n=31) and cirrhosis patients (n= 32) were included as a validation cohort. All participants completed the new paper and pencil test, a critical flicker frequency (CFF) test and computerized cognitive function test (visual continuous performance test [CPT]). The scores on the NCT-A and NCT-B increased but those of DST and SDMT decreased according to age. Twelve of the cirrhotic patients (37.5%) were diagnosed with MHE based on the new paper and pencil test battery. The total score of the paper and pencil test battery showed good positive correlation with the CFF (r= 0.551, P< 0.001) and computerized cognitive function test. Also, this score was lower in patients with MHE compared to those without MHE (P< 0.001). Scores on the CFF (32.0 vs. 28.7 Hz, P= 0.028) and the computer base cognitive test decreased significantly in patients with MHE compared to those without MHE. Test-retest reliability was comparable. In conclusion, the new paper and pencil test battery including NCT-A, NCT-B, DST, and SDMT showed good correlation with neuropsychological tests. This new paper and pencil test battery could help to discriminate patients with impaired cognitive function in cirrhosis