The most cited works in epilepsy surgery: Indicator of scientific progress of the field.

Abstract

Rationale: What articles have been most important in field of epilepsy surgery? Which scientific works, institutions, authors have made the most impact in steering direction of research in epilepsy surgery? Answering these questions would inform us about the scientific landmarks in field of surgical epilepsy, familiarity to which may be important for clinicians and students of the field. We used number of citations an article has received as an indicator of its scientific impact. "Citation Classics", as defined by Garfield in a field like epilepsy surgery would be a publication cited 100 or more times (http://garfield.library.upenn.edu/classics.html). Methods: We searched Institute of Scientific Information's (ISI) Web of Knowledge (Thomson Reuters, Philadelphia) during September 18-20, 2013 for all articles published from 1950 to present. The search strategy included Boolean operator AND between keywords "epilep*'', ''seizure*'' (the asterisk was included 449 in the search string as a wild card character) and "surgery", "surgical", "resection", "lobectomy", "topectomy", "hemispherectomy", "hemispherotomy", "corticectomy", "amygdalohippocampectomy", "multiple subpial transection", "corpus callosotomy", "Corpus callosum transection", "amygdalotomy". Each article that qualified as a "Citation Classic" was accessed and reviewed for details mentioned in results section. Descriptive statistical tools were used for data analysis. Results: A total of 118 "Citation Classics" were found in surgical epilepsy literature. Average citations per article are 164. "A randomized, controlled trial of surgery for temporal-lobe epilepsy" with 869 citations is the most highly cited article and also the only randomized controlled trial on the list, which is primarily composed of case series data. The trend of subject dealt by citation classics has changed over years with 100% of surgical technique citation classics published before 1990 and 90 % of imaging articles published since then. More than 88% of citation classics have been published since 1980. USA has contributed (61% articles) more than all the countries combined to this literature, with Canada and UK making rest of top 3 countries. Top 5 institutes with highest number of citation classics (UCLA, Yale University, Montreal Neurological Institute, Cleveland Clinic and Maudsley Hospital) contributed a combined of more than 50% of literature on the list. Dr. S. S. Spencer authored highest number of citation classics; 12 in total with 6 as single author, though highest total citations were collected by work of Dr. Jerome Engel (total citations = 2032) from 9 articles with 5 as first author. Conclusions: The field of surgical epilepsy has seen tremendous growth in last three decades. Major research work in this field has been dominated by a handful of centers and countries. The fact that the first randomized controlled trial in epilepsy surgery is the most highly cited work of the field signifies the present day emphasis on evidence-based medicine. May be more such studies will help reverse the severe underutilization of this effective therapeutic intervention. (Table Presented).