Value of the critical flicker frequency in patients with minimal hepatic encephalopathy†

Abstract

Minimal hepatic encephalopathy (MHE) is mainly diagnosed using psychometric tests such as the psychometric hepatic encephalopathy score (PHES). Despite the clinical and social relevance of MHE, psychometric testing is not widespread in routine clinical care. We assessed the usefulness of the critical flicker frequency (CFF), for the diagnosis of MHE and for the prediction of the development of overt episodes of HE. The normal range of PHES in the Spanish population was evaluated in a control group. Subsequently, 114 patients with cirrhosis and 103 healthy controls underwent both PHES and CFF tests. A diagnosis of MHE was made when the PHES was lower than ؊4 points. Patients were followed-up every 6 months for a total of 1 year. CFF did not correlate with age, education, or sex in the control group. The mean CFF was significantly lower in patients with MHE versus non-MHE or controls. Mean CFF correlated with individual psychometric tests as well as PHES (r ‫؍‬ 0.54; P < 0.001). CFF <38 Hz was predictive of further bouts of overt HE (log-rank: 14.2; P < 0.001). There was a weak correlation between mean CFF and Child-Pugh score but not with model for end-stage liver disease score. In multivariate analysis using Cox regression, CFF together with Child-Pugh score was independently associated with the development of overt HE. Conclusion: CFF is a simple, reliable, and accurate method for the diagnosis of MHE. It is not influenced by age or education and could predict the development of overt HE. H epatic encephalopathy (HE) is a major complication of cirrhosis and is associated with a poor prognosis. 1,2 Minimal hepatic encephalopathy (MHE) is the first stage in the clinical spectrum of HE. 3,4 MHE is associated with an impaired quality of life, 5 and patients become unfit to safely drive a motor vehicle. 6 Moreover, patients with MHE and altered oral glutamine challenge have a shortened life span. 7 Although no definitive treatment is currently available, evaluating MHE in patients with cirrhosis could be recommended because of its prognostic value. Nevertheless, in a recent Spanish questionnaire, only 41% of hepatologists test for MHE in routine clinical practice. 8 The major obstacles to the evaluation of MHE include: (1) a lack of consensus diagnostic criteria; (2) the fact that most psychometric tests used in the diagnosis of MHE are time-consuming; (3) a lack of normal distribution values corrected for educational level and age; (4) the high cost of neurophysiological assessment; and (5) the need for experienced personnel and specialized equipment.The psychometric hepatic encephalopathy score (PHES) includes a battery of 5 psychometric tests that have been found useful for the diagnosis of MHE. In a recent consensus meeting, 9 the PHES was recommended as the gold standard in the diagnosis of MHE because: (1) it covered the spectrum of cognitive aspects that are affected in HE; (2) normative age-corrected data are available; and (3)

Minimal Hepatic Encephalopathy Impairs Quality of Life

“…7,10,12,[16][17][18] MHE predicts the development of overt HE and also adversely affects survival as shown by several studies. 7,10,18,[84][85][86][87] Das et al 10 studied the progression of MHE to overt HE in relation to severity of liver dysfunction and found that overt HE were more frequent in patients with MHE and Child-Turcotte-Pugh (CTP) score >6. Hartmann et al 7 found that survival was determined only by CTP score irrespective of presence or absence of MHE.…”

Minimal Hepatic Encephalopathy: The Reality Beyond Our Eyes

“…20,21 Furthermore, MHE is of prognostic significance as it is a risk factor for the development of overt HE 20,[22][23][24][25] and death. 20,26 Recognizing MHE is important because its treatment can improve cognitive functions [27][28][29][30][31] and quality of life, [27][28][29]31,32 and avert progression to overt HE.…”

Inhibitory Control Test for the Detection of Minimal Hepatic Encephalopathy in Patients with Cirrhosis of Liver

“…1 The psychometric hepatic encephalopathy score (PHES), which measures multiple domains of cognitive function, is a reliable test battery for the assessment of cognitive impairment in patients with MHE. 1,2,[11][12][13][14] The inhibitory control test (ICT) is a computerized test of attention and response inhibition that has been used to characterize attention deficit disorder, schizophrenia, and traumatic brain injury. [15][16][17][18] The ICT has recently been added to the list of tests for the diagnosis of MHE.…”