200 mg modafinil pre-operatively and placebo immediately post-operatively.

Rey Auditory Verbal Learning Test (RAVLT) scores will be used to assess memory and learning ability in the auditory-verbal domain. The RAVLT begins with a list of 15 words, which an examiner reads aloud at the rate of one per second. The patient's task is to repeat all the words he or she can remember, in any order. This procedure is carried out a total of five times. Then, the examiner presents a second list of 15 words, allowing the patient only one attempt at recall. Immediately following this, the patient is asked to remember as many words as possible from the first list. For each trial a maximum score of 15 can be obtained, which would reflect excellent memory. The obtained scores per individual trial will be compared between the 4 different arms.

The RAVLT will be administered preoperatively, immediately postoperatively in the PACU (except the non-surgical control group), at 1 week and at 3 months postoperatively.