Table 4 Comparing cognitive functions between tramadol group and healthy controls

Benton visual retention test (BVRT)

BVRT (Mean ± SD)

0.5 ± 0.5

10.4 ± 3.2

< 0.001^(T)**

Impaired BVRT (%)

0 (0%)

29 (96.7%)

< 0.001^(c)**

Trail making test (TMT)

Trail making test Part A (Mean ± SD)

28.9 ± 9.1

74.3 ± 18.5

< 0.001^(T)**

Trail making test Part B (Mean ± SD)

58.7 ± 16.7

212.9 ± 35

< 0.001^(T)**

Impaired Trail making test (%)

0 (0%)

22 (73.3%)

< 0.001^(C)**

Wechsler memory scale (WMS)

Information (Mean ± SD)

16 ± 0

12.9 ± 1.4

< 0.001^(T)**

Information Impaired (%)

0 (0%)

16 (53.3%)

< 0.001^(C)**

Verbal PAI (Mean ± SD)^#

22.6 ± 1

11.5 ± 3.3

< 0.001^(T)**

Verbal PAI Impaired (%)

0 (0%)

30 (100%)

< 0.001^(c)**

Visual PAI (Mean ± SD)^§

16.2 ± 0.9

6.6 ± 2

< 0.001^(T)**

Visual PAI Impaired (%)

0 (0%)

30 (100%)

< 0.001^(c)**

Digit span (Mean ± SD)

19.9 ± 1.9

7.1 ± 2.2

< 0.001^(T)**

Digit span Impaired (%)

0 (0%)

30 (100%)

< 0.001^(c)**

Visual MS (Mean ± SD)^£

18.7 ± 1.5

5.3 ± 1

< 0.001^(T)**

Visual MS Impaired (%)

0 (0%)

30 (100%)

< 0.001^(c)**

Verbal PAII (Mean ± SD)^#

8.1 ± 0.3

4.6 ± 1.3

< 0.001^(T)**

Verbal PAII Impaired (%)

0 (0%)

30 (100%)

< 0.001^(c)**

Visual PAII (Mean ± SD)^§

6 ± 0

2.9 ± 1

< 0.001^(T)**

Visual PAII Impaired (%)

0 (0%)

30 (100%)

< 0.001^(c)**