 Patients underwent an extensive neuropsychological battery including test of attention, working memory, processing speed, verbal memory learning and recall, verbal fluency and executive functioning. Sustained attention was measured using the Brief Test of Attention. For working memory, the Backward Digits subtest of the Weschler Adult Intelligence Scale III was used. Processing speed was assessed through the Symbol Digit Modalities Test, the three and six letter version of the Salthouse Perceptual Comparison Test and the Trail Making Test A. Verbal memory was determined based on the Hopkins Verbal Learning Test , learning and long-term recall performance. For verbal fluency, the Category animals and supermarket and Letter P Word Fluency Test from the Calibrated Ideational Fluency Assessment were utilized . Executive functioning was calculated by the word-color and interference scores of the Stroop Word-Color Test. 