Table 2.

Number and frequency of patients with multiple sclerosis (MS) having abnormal performances at neuropsychological tests and distribution across centers

Cognitive domains	All centres (N = 42)	Amsterdam (N = 6)	Barcelona (N = 6)	Graz (N = 6)	London (N = 7)	Milan (N = 10)	Naples (N = 7)
Attention/information processing speed (%)	16 (38%)	2 (33%)	2 (33%)	2 (33%)	2 (29%)	6 (60%)	2 (29%)
Executive functions (%)	12 (29%)	2 (33%)	0 (0%)	1 (17%)	5 (71%)	4 (40%)	0 (0%)
Verbal memory (%)	11 (26%)	3 (50%)	0 (0%)	1 (17%)	2 (29%)	2 (20%)	3 (43%)
Spatial memory (%)	7 (17%)	0 (0%)	0 (0%)	1 (17%)	2 (29%)	3 (30%)	1 (17%)
Verbal fluency (%)	9 (21%)	1 (17%)	2 (33%)	3 (50%)	0 (0%)	1 (10%)	2 (29%)

Abnormalities of attention/information processing speed, verbal memory, spatial memory and verbal fluency domains were derived from the scores obtained at the Brief Repeatable Battery‐Neuropsychological (BRB‐N) battery, abnormalities of the executive functions were derived from the scores obtained at the Wisconsin Card Sorting Test (WCST). See text for further details.