as suggested because anumber of factors can influence the overall score. So the availability of a newer simpler bedside diagnostic tool used for screening of MHE is mandatory. Critical flicker frequency (CFF) is a newer diagnostic test, a bedside tool for the diagnosis of MHE.
Aim :
The aim of the study was to assess the diagnostic accuracy of the critical flickering frequency test in diagnosis of minimal hepatic encephalopathy in comparison to the psychometric tests as a gold standard.
Methods :
This prospective study was conducted on 86 cirrhotic patients with negative history of overt hepatic encephalopathy (OHE) admitted to Hepatology, gastroenterology and infectious diseases department , Benha university hospital in period from June 2013 to February 2014. Full history taking, clinical examination, routine laboratory and radiological investigations were done.The Arabic version of both Number connection test (NCT) (part A), Serial dotting test (SDT) and The line tracing test (LTT) were done for all patients.After The raw value of each test is generated , it’s converted into score points using the scoring norms. Using the age of the patient and the score of each subset we generate the total score for the psychometric test battery.CFF was done using the Hepatonorm@ analyzer (Hepatonorm Analyzer; R&R Medi-Business Freiburg GmbH, Freiburg, Germany) as a test for MHE.
Results :
Then the patients were classified into 2 groups:
Group Ӏ : included 45 patients with MHE.
Group ӀӀ : included 41 patients without MHE.
There werestrong correlations between CFF and Child-Pugh score and model for end-stage liver disease score(p < 0.001 , 0.001 respectively).Also there were strong correlations between patients with MHE and NonMHE regarding serum albumin levels, PT , HB level and bilirubin levels.
CFF at cutoff ≤ 39 had a high Sensitivity91.1 %( 95% C.I 82.77 – 99.42%), specificity 92.5 %( 95% C.I 84.34 – 100%) and PPV (93.2%) and NPV (90.2%) in diagnosis of MHE with AUROC was0.937.
Conclusion:
CFF is a simple, reliable tool for the diagnosis of MHE. A value of CFF below the cutoff of 39 Hz defines a high risk for MHE with higher incidence among Child-Pugh classes B or C. |
