Research Activities, September 2013
Surgical rates for intractable epilepsy remain flat while monitoring for epilepsy increases
Epilepsy surgery remains a surprisingly underused treatment option for persons with intractable epilepsy, despite an accumulation of positive outcome data, concludes a new study. It found that between 1998 and 2009, hospitalization rates related to intractable epilepsy rose, but there was no significant increase in surgical rates for this condition.
The Cleveland-based team of researchers analyzed nationwide trends in epilepsy. They derived annual rates of pre-surgical evaluations and surgeries from a random sample of approximately 20 percent of all hospitalizations in the United States over a 12-year period.
Since epilepsy surgery requires specific pre-surgical investigations, including video-electroencephalogram (VEEG) and intracranial EEG (IEEG) monitoring, they also investigated trends in these diagnostic tests. In VEEG, the patient is videotaped at the same time as the EEG is recorded; IEEG involves an operation under general anesthetic to place electrodes either on the surface or deep within the brain.
Although researchers found no increase in IEEG monitoring, hospitalizations for VEEG monitoring rose. Also, the proportion of pre-surgical evaluations and surgery performed in non-teaching hospitals increased. However, the majority of pre-surgical evaluations and surgery were performed in large medical centers.
Part of the reason for the growth in VEEG monitoring, despite the stagnant rate of epilepsy surgery, is that the majority of this monitoring is performed to characterize seizures or paroxysmal events, rather than for pre-surgical workup, even in people with intractable epilepsy. Also, it is very likely that an increase in VEEG monitoring reflects a trend where neurologists with epilepsy or EEG expertise are now widely dispersed to many hospitals outside of academic medical centers.
The researchers did find a significant increase in epilepsy surgery in children over time. This may be a reflection of an expansion in pediatric epilepsy and pediatric epilepsy surgery expertise. Also, older patients with epilepsy are not referred to specialist care as often as their younger counterparts. Only a very small number of surgeries were performed in the elderly. This study was supported in part by AHRQ (T32 HS00059).
See "Temporal trends in pre-surgical evaluations and epilepsy surgery in the U.S. from 1998 to 2009," by Nicholas K. Schiltz, Ph.D., Siran M. Koroukian, M.D., Samden D. Lhatoo, Ph.D., and Kitti Kaiboriboon, M.D., in Epilepsy Research 103, pp. 270-278, 2013.