Determinants of quality of life after epilepsy surgery: systematic review and evidence summary. 
We systematically reviewed evidence-based determinants of health-related quality of life (QOL) in adults undergoing epilepsy surgery and assessed the effect of study methods.  Medline, Embase, and the Cochrane library (1950-2008) were searched systematically.  Two authors independently performed every step of the review.  We obtained the proportion of studies reporting statistically significant positive or negative impact on QOL.  Of 39 eligible studies, 32 assessed the impact of surgery on QOL and 29 (90.6%) found a significant positive effect.  The most prevalent preoperative determinant was psychological function.  Seizure freedom was the most prevalent postoperative determinant (80% of studies), followed by antiepileptic drug adverse events, employment status, and psychological function.  Psychosocial (95%), physical (91%), and overall QOL (90%) domains improved most frequently, whereas role limitation (63%) and cognition (78%) improved least frequently.  Methods, choice of instrument, and time of measurement influenced QOL outcomes and should be carefully chosen in future studies.