Neurological and psychiatric effects of hepatitis C virus infection

Table 1 Tests exploring cognitive domains[67-69]

Test	Tested domains	Description
Rey auditory verbal learning test (RAVLT)	Immediate memory and learning	After hearing a list of 15 unrelated words, the patient has to recite as many words as he can recall for a total of five trials.
Hopkins verbal learning test total recall (HVLT)	Verbal memory	This test consists of three parts: total recall, delayed recall and recognition. The test consists firstly of three free recall learning trials with 12 words from three different categories such as professions, food and sports (HVLT total recall). 20-min later, the patient has to name the words from the free recall learning list (HVLT delayed recall). Finally, the yes/no recognition trial is completed (HVLT recognition).
Brief visual memory test revised total recall (BVMT)	Visuospatial memory	In three learning trials, the patient views the stimulus page for 10 s and then has to draw as many figures as possible in their correct location. A delayed recall trial is administered after a 25-min delay. Lastly, a recognition trial, in which the patient has to identify which of the 12 figures were included among the original geometric figures, is administered.
Digit forward span and digit backward	Verbal learning and episodic memory	The Digit Span consists of two different tests: digits forward (repeating digits forward) and digits backward (repeating digits in reverse). This test consists of pairs of sequences of numbers read by the examiner. When the patient repeats correctly the first sequence, the examiner reads the next one, which is longer by one number than the previous one, and continues until the patient fails a pair of sequences or correctly repeats the last sequence consisting of nine numbers.
Letter number sequencing (LNS)	Working memory	During administration, the patient listens to a series of numbers and letters read by the examiner. Then he has to repeat the numbers in ascending order and letters in alphabetic order.
Paced auditory serial addition task (PASAT)	Auditory-verbal divided attention; selective and sustained attention	Numbers are presented orally at a rate of about 1-2 s. The patient has to add pairs of numbers, adding each number to the previous one. In this way, the first number will be added with the second, the second with the third, the third with the fourth and so on.
Rey-Osterrieth complex figure test in the immediate trial (ROCF)	Visoconstructive ability, problem solving, perceptual organization and visual memory	There are 18 elements overall. In the first part, the patient has to copy a figure (ROCF copy). Three minutes later, he has to perform the figure again without the stimulus (ROCF immediate recall). Two points are given when the elements are correctly reproduced; one point when the production is distorted, incomplete but placed properly, or completed but placed poorly; half point when the elements are distorted or incomplete and placed poorly; zero point when the elements are absent or not recognizable.
Phonemic and semantic verbal fluency test	Lexical skills and executive functions; verbal functioning	For the phonemic part, the patient has to list as many words as possible starting with an F, A or S during 60-s intervals. For the semantic part, he has to list as many animals as he can during a 60-s interval.
Color word interference test (Stroop)	Lexical skills, cognitive flexibility, selective attention and response inhibition (or disinhibition)	Patient has to read three different tables as fast as possible. Two of them represent the “congruous condition” in which he has to read names of colors printed in black. Conversely, in the third table, color-words are printed in an inconsistent colour ink. In this incongruent condition, the patient has to name the ink colour instead of reading the word.
Trial making test part B (TMT-B)	Lexical skills, executive functions, cognitive flexibility	In the TMT-B, the patient has to draw lines sequentially connecting numbers and words alternately. The score represents the amount of time required to complete the task.
Wisconsin card sorting test (WCST)	Lexical skills and executive functions; cognitive reasoning	Patient has to classify cards according to different criteria. There are different ways to classify each card and the only feedback is whether the classification is correct or not. Classification possibilities are the color of symbols, the shape of symbols and the number of shapes on each card. The classification rule changes every 10 cards; so, once the patient has figured out the rule, he will start making mistakes when the rule changes. This test measures how well the patient is able to adapt to changing rules.
Verbal judgment test (VJT)	Logical thinking	This test consists of an oral interview. The examiner asks the patient how he would solve a hypothetical situation.
Horn’s performance test system (LPS)	Non-verbal intelligence	This test comprises 40 rows, each with 9 numbers and/or letters. Every row has a logical order with one letter or number that does not fit and the goal is to identify the mismatched character. The outcome parameter is the sum of correct rows.

RAVLT: Rey auditory verbal learning test; HVLT: Hopkins verbal learning test total recall; BVMT: Brief visual memory test revised total recall; LNS: Letter number sequencing; PASAT: Paced auditory serial addition task; ROCF: Rey-Osterrieth complex figure test in the immediate trial; TMT-B: Trial making test part B; WCST: Wisconsin card sorting test; VJT: Verbal judgment test; LPS: Horn’s performance test system.