Critical Flicker Frequency is a non-invasive portable test that can be used to diagnose minimal hepatic encephalopathy (MHE) which may affect up to 80% of patients with cirrhosis. Sometimes, MHE is only detectable on this kind of testing with no obvious clinical signs or symptoms that we would see with overt hepatic encephalothy (OHE) which is where patients have clear obvious findings on clinical examination. Key features include slowing of responses, deficits in attention and visual perception, impaired fine motor performance (that is, the ability to move) and driving ability. A CFF of >39Hz indicates the presence of MHE. This test is usually performed by a clinical liver nurse specialist in clinic when indicated. The results of these tests may mean that your doctor or specialist nurse may change your medication or give you advice about driving or your occupation.
Hand Grip Strength is a non-invasive test that in the context of liver disease can be used to screen for malnutrition and frailty in patients with cirrhosis (particularly those awaiting liver transplant) and has been shown to be an important determinant of outcome. That is, patients who are more frail on the scoring or found to be more malnourished, do less well longer term. HGS is a measure of upper body and whole body muscular strength and can be quantified by measuring the amount of static force the hand can generate around a dynanometer.
This is a device which you hold with you hand and squeeze. The force is most commonly measured in kilograms or pounds and a normal HGS value varies according to age and gender. HGS is usually performed by a clinical liver nurse specialist in clinic when indicated. It is often used in conjunction with the liver frailty index (LFI) which is composed of 3 performance based tests (HGS, chair stands and balance) to objectively assess physical function in patients with cirrhosis.