**6.3 Neuropsychological (paper-and-pencil) tests**

The American Association for the Study of Liver Diseases (AASLD) and the European Association for the Study of the Liver recommended neurophysiological

Patients at risk of accidents


Patients who complain of cognitive symptoms


Patients with decline in work performance observed by relatives or colleagues

Patients with previous history of episodic HE

#### **Table 2.**

*Patients with cirrhosis, portal vein thrombosis, or porto-systemic shunts who should undergo tests for MHE.*


#### **Table 3.**

*Psychometric tests recommended for diagnosing minimal hepatic encephalopathy.*

**11**

**Figure 3.**

*Number connection tests-A.*

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

*6.3.1 Standard neuropsychological assessment*

*6.3.1.1 Number connection tests*

(PHES) [3, 4, 42].

and psychometric tests to diagnose MHE [3, 51]. Many tests are used for diagnosis of MHE (**Table 3**); however, the gold standard and the most frequently used psychometric test for MHE diagnosis is psychometric hepatic encephalopathy score

Neuropsychological testing is a useful methodology for quantifying cognitive impairment. These tests directly measure cognitive functions that are directly related to activities of daily living. These include the number connection test A (NCT-A), number connection test B (NCT-B), figure connection test (FCT A), figure connection test B (FCT B), digit symbol test (DST), and serial-dotting test (SDOT) [77].

The NCT-A accesses the visual-spatial orientation and psychomotor speed. Twenty-five circles numbered from 1 to 25 are scattered randomly on a sheet of paper. The patients must connect the numbers in order in the shortest time possible without mistakes. If a mistake is made, the subject must stop, correct the error, and then continue without stopping the clock. The test score is the time needed to perform the test, including the time needed to correct all errors. Poorer performance is shown by a longer time for completion (**Figure 3**). In the NCT-B **(Figure 4**), the numbers from 1 to 13 and the letters from A to L were included in circles. The patient is asked to connect numbers and letters in alternating manner, that means go from 1-A-2-B-3-C and so on. Test outcome is the time needed by the patient to perform the test, including error correction time. Besides visuospatial orientation and psychomo-

tor speed, this test is suitable to study the ability to shift attention [78]. According to the guidelines of the International Society for Hepatic

Encephalopathy and Nitrogen Metabolism [79], the results of NCT-A will be considered abnormal when the test scores are more than the mean + 2 standard deviations (SDs) from the age-matched normal values. A newly developed electronic number connection test (eNCT) was developed*.* This test flashes the numbers 1–25 on a screen and needs the participant to click them in order while being timed [80]. These tests are time-consuming, and their results are influenced by age and educational status. However, these tests are recommended for diagnosis of MHE [42, 81].

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

*Liver Disease and Surgery*

NCT-A Psychomotor

NCT-B Psychomotor

DST Psychomotor

BDT Visuospatial

SDT Psychomotor

LTT Psychomotor

CFF Visual

ICT Response

Stroop test Psychomotor

EEG Generalized

The SCAN Test

CDR assessment battery

Animalnaming test

**Test Tested domain Time** 

speed

speed, set shifting, divided attention

speed, attention

reasoning, praxis, psychomotor speed

speed

speed, visuomotor ability

Semantic fluency test, verbal retrieval and recall

discrimination and general arousal

> inhibition, working memory, vigilance, attention

speed and cognitive alertness

Working memory, vigilance, attention

Reaction time, memory, and recognition

brain activity

**required (minuets)**

> 1–2 Gold standard for MHE diagnosis validated internationally

4 Very sensitive and is an early indicator

10–20 It can be used for

1–2 Only tests psychomotor speed, a higher sensitivity

2–4 Tests a balance between speed and accuracy

1 Easy test that has the required characteristics of simplicity, speed, for illiterate patients

10 Easy administration, application by a nonspecialist, and results are independent of literacy and age, test can be administered at bedside

15–20 Simple administration,

10 Quick to explain to

15 Appreciable test-retest reliability

10–15 Can be done in comatose

*Psychometric tests recommended for diagnosing minimal hepatic encephalopathy.*

patients, no need of patient cooperation or risk of a learning effect

higher sensitivity/ specificity

patients, and simple to score and evaluate

internationally

dementia testing as well

1–3 Validated

**Advantages Disadvantages Impact factor**

Learning effects Age and culture

Learning effects Age and culture

Learning effects Age and culture

Learning effects Age and culture

Age and culture

Age and culture

Age

Age and education

Age and education

education

and culture

Requires neurological expertise in evaluation

Learning effects Age, education,

Learning effects; only tests psychomotor speed

Learning effects, outcomes are errors and time

Less validated test

Not suitable for red-green blindness and visual impairment

Need highly functional patients, not suitable for non-English-speaking patients

Should be familiar with iPhone/iPad

Nonspecific and may be influenced by accompanying metabolic disturbances

15–20 Simple administration Learning effects Age and

**10**

**Table 3.**

and psychometric tests to diagnose MHE [3, 51]. Many tests are used for diagnosis of MHE (**Table 3**); however, the gold standard and the most frequently used psychometric test for MHE diagnosis is psychometric hepatic encephalopathy score (PHES) [3, 4, 42].
