*6.3.2.2 Continuous reaction time (CRT) test*

This test assesses the motor reaction time by having the patient press a button in response to auditory stimuli (through headphones). The most important test result is the CRT index, which measures the stability of the reaction times. The test result can differentiate between organic and metabolic brain impairment. The test is not affected by the patient's age, gender with no learning or tiring impact [90, 91].

## *6.3.2.3 The inhibitory control test (ICT)*

It is a computerized test of response inhibition and working. The ICT requires highly functional patients (**Figure 6**). The ICT can be done using a laptop and is analyzed using an automatic computerized system that significantly improves the

#### **Figure 6.**

*Inhibitory control test. A continuous sequence of letters is displayed on the computer screen every 500 ms. The patient is educated to respond only if an X is preceded by a Y, or a Y is preceded by an X, but responses must be inhibited if an X is followed by an X, or a Y is followed by a Y.*

convenience and flexibility of using this test in the clinical situation [92]. It has been validated for the diagnosis and follow-up of MHE in the USA. It was found that the ICT is simple to administer and has higher sensitivity/specificity for screening MHE than the standard psychometric test (SPT). On the other side, Taneja et al. found that the ICT is not as useful as the PHES in diagnosing MHE in patients with cirrhosis [93].

#### *6.3.2.4 The Stroop test*

In 2013, Bajaj et al. developed an application, the EncephalApp-Stroop App, for screening MHE that is operated by the iOS system on the iPhone and iPad. The core of this innovative application is the Stroop test, which assesses psychomotor speed and cognitive alertness by measuring the time required to correctly identify a series of symbols and printed words with different colors [86]. The Stroop test evaluates psychomotor speed and cognitive flexibility by the interference between recognition reaction time to a colored field and a written color name. [86]. In a multicenter study that compared the EncephalApp-Stroop App to the PHES and ICT, the EncephalApp-Stroop App had good sensitivity (70–80%) for MHE screening and was predictive of the progression to OHE [94].

#### *6.3.2.5 The SCAN test*

It is a computerized test that measures the patient's speed and accuracy to perform a digit recognition memory task of increasing complexity [40, 95]. It is done by randomly displaying a series of 72 sorted pairs of numbers for 3 s on a computer screen. Patients are instructed to press the appropriate number on a keyboard if they identify a common digit in the sequence of numbers presented. The mean reaction times and the percentage of errors are recorded, and the results are evaluated using the reaction times weighted by the number of errors [96].

**15**

*Minimal Hepatic Encephalopathy: Silent Tragedy DOI: http://dx.doi.org/10.5772/intechopen.88231*

respectively [10].

**7. Treatment**

**7.1 Rifaximin**

*6.3.2.6 Cognitive drug research (CDR) assessment battery*

*6.3.3 Electroencephalography examination (EEG)*

EEG machine across the HE spectrum [97].

It is a computerized battery of cognitive tests designed by the Cognitive Drug

EEG can discover changes in cortical cerebral activity across the spectrum of HE without patient cooperation or risk of a learning effect [97]. Newly, an-economy friendly device has been found to produce similar results compared with a standard

Treatment of minimal hepatic encephalopathy with lactulose, probiotics, or l-ornithine-l-aspartate was seen to be effective in reducing abnormal tests and delay or eradicating risky motor car accident [47, 98–103]. It is therefore rational, especially if the patients or their family/caregivers report symptoms/signs compatible with MHE, to introduce treatment specially in patients who are at particular risk of the consequences of MHE, such as falls, impaired, and driving ability.

Rifaximin is an orally administered, non-absorbable, semi-synthetic antibiotic with a broad spectrum of effect on both Gram-positive and Gram-negative bacteria [11, , 104]. It was found that patients with MHE treated with rifaximin for an 8-week period showed significantly greater improvements in driving and cognitive performance and in the psychosocial dimension of the Sickness Impact Profile than those given a placebo [67]. Recently, a randomized controlled trial compared the efficacy of rifaximin with lactulose in reversal of MHE and improvement in HRQoL in cirrhotic patients with MHE. The study concluded that both drugs improve

The recommended standard of care for people with hepatic encephalopathy includes use of the non-absorbable disaccharides (lactulose and lactitol) [106, 107]. It was found that cirrhotic patients with MHE had improvement in health-related quality of life and psychometric performance after lactulose therapy [108]. Lactulose and lactitol, both, have effects on gut flora and are regarded as intestinal prebiotics. Adding lactulose to food can produce a bifidogenic effect connected to a favorable effect on colonic ammonia metabolism [109]. However, a recent meta-analysis evaluating the role of non-absorbable disaccharides in patients with MHE failed to

show clear evidence in improving cognitive function and HRQoL [110].

HRQoL equally well, in cirrhotic patients with MHE [105].

**7.2 Non-absorbable disaccharides**

Research Ltd. (Goring-on-Thames, UK). The test contains five psychometric subsets that test attention power, attention continuity, speed of memory, and quality of episodic and working memory. It measures reaction time, memory, and recognition. The task stimuli are existing on a laptop, and patients provide the correct response using the "YES" and "NO" buttons on a two-button response box, which records both accuracy and reaction time. The sensitivity and specificity of the CDR assessment battery for screening MHE are 86.4 and 81%,

#### *6.3.2.6 Cognitive drug research (CDR) assessment battery*

It is a computerized battery of cognitive tests designed by the Cognitive Drug Research Ltd. (Goring-on-Thames, UK). The test contains five psychometric subsets that test attention power, attention continuity, speed of memory, and quality of episodic and working memory. It measures reaction time, memory, and recognition. The task stimuli are existing on a laptop, and patients provide the correct response using the "YES" and "NO" buttons on a two-button response box, which records both accuracy and reaction time. The sensitivity and specificity of the CDR assessment battery for screening MHE are 86.4 and 81%, respectively [10].

#### *6.3.3 Electroencephalography examination (EEG)*

EEG can discover changes in cortical cerebral activity across the spectrum of HE without patient cooperation or risk of a learning effect [97]. Newly, an-economy friendly device has been found to produce similar results compared with a standard EEG machine across the HE spectrum [97].
