Supplemental data appendix e-1, NSTAPS Neuropsychological examination

Attention and working memory

The Stroop color-word test [11] consisted of three conditions: Stroop word reading: read words, red, yellow, blue, green, while printed in black ink, Stroop color naming: name colors printed in small rectangles, Stroop color-word interference: name colors of printed words, while the words are printed in non-matching ink. The score for each condition is the time in seconds to complete 100 items. In the TMTA numbers had to be connected, and in the TMTB numbers and letters had to be connected while alternating [12]. Score for each condition represents the time in seconds needed for completion. The score for the subtest Letter and Number Sequencing of the WAIS-III represents the number of trails correctly completed [13]. Forward and backward digit span were combined into one total score, which represents the number of items correctly answered [13]. The Vienna Test System simple and choice reaction speed test (VTS S1 and S3) is a computerized test [19]. The score for VTS S1reaction is the time it took a patient to remove his finger from a sensor when a yellow circle displayed on the screen. The score for VTS S1motoric, is the time it took a patient to press a button when his finger was already removed from to the sensor. VTS

S3reaction and VTS S3motoric were measured similarly with the note that in addition to the yellow circle a beep had to be present as well. The score for each sub measure represents time in milliseconds.

Executive functions

A computerized version of the WCST was used [15]. Cards had to be sorted according to one of the possible rules (by color, number, or form) without prior knowledge of these rules. Feedback was given after each sort. Scores are the number of completed categories, the number of errors, and the number of perseverative errors. The COWAT, letter fluency, consisted of three trails with different letters, each during one minute [16]. Total score is the number of correct items in 3 minutes, referred to as phonemic fluency. Category fluency consisted of two trails, animals and occupation, each during one minute [16]. Total score is the number of correct items for both categories, referred to as semantic fluency.

Language

An abbreviated 30-item version of the BNT was used; scores of the original version were estimated by extrapolation [17]. During the subtest Similarities of the WAIS-III a common aspect in objects or concepts had to be identified [13]. Score is the number of trails correctly completed.

Memory

For the AVLT, the sum of items recalled during trail 1 to 5 is the immediate recall score [18]. The number of items recalled after 20 minutes is the delayed recall score.

The immediate recall score for the RBMT is the number of elements correctly recalled, the delayed recall score is the number of elements recalled after a 15- minute interval [19].

Spatial functioning

During the subtest Matrix Reasoning of the WAIS-III a series of incomplete gridded patterns had to be completed by choosing from five possible options [13]. Score is the number of trails correctly completed.