Utility of the Clamping Bean Test (CBT) for Covert Hepatic Encephalopathy Screening

Hepatic encephalopathy is a brain dysfunction caused by liver insufficiency and/or porto-systemic shunt. It manifests as a wide spectrum of neurological or psychiatric abnormalities ranging from subclinical alterations to coma. According to the symptoms, it is classified as covert HE (CHE) and overt HE (OHE). CHE can progress to OHE and is associated with reduced driving ability, increased risk of accidents and hospitalization and weakened health-related quality of life, resulting in poor prognosis and socio-economic status. However, due to the absence of readily identifiable clinical symptoms and signs, CHE is often neglected in clinical practice. Presently, the diagnosis of CHE depends on psychometric and neurophysiological tests, including the psychometric hepatic encephalopathy score (PHES), critical flicker frequency (CFF) test, continuous reaction time (CRT) test, inhibitory control test, the SCAN test, and electroencephalography. Among them, PHES is most widely used and recommended by several guidelines. However, it is difficult to screen CHE among all cirrhotic patients in the clinic using PHES because of the time required and a dependence on trained experts. Moving beans from one container to another with tweezers involves dexterity, agility and coordination.The hypothesis was that the utility of the Clamping Bean Test (CBT) will enable early screening patients with CHE.