Epilepsy surgery trends in the United
D.J. Englot, MD, PhD
D. Ouyang, BS
P.A. Garcia, MD
N.M. Barbaro, MD
E.F. Chang, MD
Objective: To examine national time trends of resective surgery for the treatment of medically
refractory epilepsy before and after Class I evidence demonstrating its efficacy and subsequent
practice guidelines recommending early surgical evaluation.
Methods: We performed a population-based cohort study with time trends of patients admitted to
US hospitals for medically refractory focal epilepsy between 1990 and 2008 who did or did not
undergo lobectomy, as reported in the Nationwide Inpatient Sample.
Results: Weighted data revealed 112,026 hospitalizations for medically refractory focal epilepsy
and 6,653 resective surgeries (lobectomies and partial lobectomies) from 1990 to 2008. A trend
of increasing hospitalizations over time was not accompanied by an increase in surgeries, produc-
ing an overall trend of decreasing surgery rates (F ? 13.6, p ? 0.01). Factors associated with this
trend included a decrease in epilepsy hospitalizations at the highest-volume epilepsy centers, and
increased hospitalizations to lower-volume hospitals that were found to be less likely to perform
surgery. White patients were more likely to have surgery than racial minorities (relative risk [RR],
1.13; 95% confidence interval [CI], 1.10–1.17), and privately insured individuals were more likely
to receive lobectomy than those with Medicaid or Medicare (RR, 1.28; 95% CI, 1.25–1.30).
Conclusion: Despite Class I evidence and subsequent practice guidelines, the utilization of lobec-
tomy has not increased from 1990 to 2008. Surgery continues to be heavily underutilized as a
treatment for epilepsy, with significant disparities by race and insurance coverage. Patients who
are medically refractory after failing 2 antiepileptic medications should be referred to a compre-
hensive epilepsy center for surgical evaluation. Neurology®2012;78:1200–1206
AED ? antiepileptic drug; CI ? confidence interval; HCUP ? Healthcare Cost and Utilization Project; NIS ? Nationwide
Inpatient Sample; RR ? relative risk; TLE ? temporal lobe epilepsy; VNS ? vagus nerve stimulation.
Epilepsy is a debilitating neurologic disorder affecting nearly 1% of the world’s population.1
Medically refractory focal epilepsies are potentially surgically remediable. The most common
localized epileptic disorder is temporal lobe epilepsy (TLE).2Anterior temporal lobectomy is a
safe, effective, and well-established surgical treatment resulting in seizure freedom in two-thirds
of patients with intractable TLE, and targeted resections can eliminate seizures in one-third to
one-half of patients with frontal lobe epilepsy.3,4However, surgery is thought to be underuti-
lized in the treatment of epilepsy.5Patients with intractable focal epilepsy often fail to receive
surgical evaluation, despite evidence suggesting that individuals who fail just 2 antiepileptic
drugs (AEDs) are unlikely to respond completely to further drug combinations.6,7A survey in
1990 found that while 100,000 to 300,000 patients with intractable epilepsy in the United
States were potential candidates for surgical treatment, only 1,500 underwent surgery that
year.8,9Underscoring this missed opportunity, a recent analysis using conservative assumptions
From the UCSF Epilepsy Center (D.J.E., D.O., P.A.G., N.M.B., E.F.C.), Department of Neurological Surgery (D.J.E., D.O., N.M.B., E.F.C.), and
Department of Neurology (P.A.G., N.M.B.), University of California, San Francisco.
Study funding: Supported in part by the Clinical and Translational Science Institute at UCSF. Statistical support was provided by Dr. Cheng at the
Clinical and Translational Science Institute Consultations Services at UCSF.
Disclosure: Author disclosures are provided at the end of the article.
Correspondence & reprint
requests to Dr. Chang:
Copyright © 2012 by AAN Enterprises, Inc.
estimated that temporal lobectomy in a 35-
year-old patient with TLE would, on average,
increase survival by 5 years.10
In 2001, the first randomized, controlled
trial of anterior temporal lobectomy for pa-
tients with medically refractory epilepsy
showed that 58% of patients with TLE who
received temporal lobectomy were seizure-free
1 year after treatment, but only 8% of those
randomized to continued medical treatment
achieved this outcome.11These results led to a
recommendation by the American Academy of
Neurology that patients with intractable epi-
lepsy be referred to a comprehensive epilepsy
center for surgical evaluation.12However, it re-
mains unknown whether the utilization of epi-
METHODS Standard protocol approvals, registra-
tions, and patient consents. No human subjects or identifi-
able patient data were used in this study. All aspects of this study
are in compliance with UCSF Clinical and Translational Science
Data source. Data were obtained from the Nationwide Inpa-
tient Sample (NIS) hospital discharge database (online at http://
www.hcup-us.ahrq.gov/nisoverview.jsp). This database is part of
the Healthcare Cost and Utilization Project (HCUP), federal-
state-industry partnership sponsored, and is the largest database
of US inpatient hospital stays that incorporates data from all
payers.13Data include 100% of inpatient hospitalizations from a
stratified random sample of approximately 20% of nonfederal
hospitals in the United States. Veterans Hospitals and other fed-
eral facilities are excluded. Each NIS entry includes all diagnosis
time of discharge. Patient-level observations in the NIS datasets are
weighted to account for the complex sampling scheme of the data-
base, thus providing estimates for the entire US population.
Data extraction and plotting. All available data from 1990
through 2008 were queried. Patients admitted for medically re-
fractory localized epilepsy were identified (primary or secondary
diagnosis code 345.41 or 345.51), including those who did or
did not receive lobectomy/partial lobectomy (procedure code
01.53) during their hospitalization. These diagnosis and proce-
dure codes have been utilized in other NIS-based studies of lo-
bectomy for epilepsy.14,15The total number of hospitalizations
for intractable localized epilepsy, lobectomy procedures, and the
percentage of intractable localized epilepsy patients receiving lo-
bectomy were plotted annually from 1990 to 2008, and were
also measured for each individual hospital in the database.
Hospital-level data during 1990–1994 and 2004–2008 were
stratified by hospital caseload of lobectomy for epilepsy to com-
pare the 20 hospitals performing the most procedures to all other
hospitals performing the procedure. Patient age, gender, race,
and primary payer was extracted for all hospitalizations and strat-
ified by whether or not hospitalization included lobectomy.
Both adults and pediatric patients were included. Hospital-
related data, including hospital size by number of beds, teaching
vs nonteaching institution, urban vs nonurban location, and
geographical region and state were similarly recorded for each
hospitalization. To isolate hospital size (by number of beds) as a
solitary factor of interest, the NIS takes into account hospital
location and teaching status as potential confounding variables.
Statistical analysis. We evaluated trends in the number of
hospitalizations for intractable localized epilepsy, lobectomies
performed in this population, and the percentage of hospitaliza-
tions including lobectomy from 1990 to 2008 using negative
binomial regression. Hospitalization count, procedure count, or
proportional procedure rate were the dependent variables and
calendar year was the key independent variable. Data stratified
by white race vs racial minority patients and privately insured vs
Medicare/Medicaid patients were similarly tracked from 1990 to
2008 and analyzed. Total hospitalizations and procedures during
1990–1994 vs 2004–2008, and between the top 20 hospitals by
caseload vs all other hospitals performing lobectomy for epilepsy,
were compared using a ?2test. Overall hospital caseload during
1990–1994 vs 2004–2008 was compared using Wilcoxon rank
sum test. Patient and hospital characteristics were compared be-
tween intractable focal epilepsy patients who did or did not re-
ceive lobectomy using ?2tests for categorical variables and a t
test for age. Patient-level variables were entered into a multivari-
ate analysis logistic regression model in a stepwise backward fash-
ion, controlling for hospital-level variables. Within this statistical
model, potential interactions between patient-level variables (e.g.,
race) and hospital-level variables (e.g., size) were also specifically
tested. Relative risks for all categorical analyses were calculated with
a 95% confidence interval (CI). Probability values were 2-sided and
statistical significance was assessed at p ? 0.05. All analyses were
performed using SPSS version 17 (IBM, Somers, NY).
RESULTS We identified 20,808 hospitalizations to
US hospitals for medically refractory localized epi-
lepsy from 1990 to 2008, with patient age ranging
from 0 to 101 years. Among these, 1,326 (6.4%)
hospitalizations included surgical lobectomy or par-
tial lobectomy. Data were provided by approximately
20% of registered nonfederal hospitals in the United
States at any given time. Weighted data, extrapolated
to the entire US population, revealed 112,026 esti-
mated hospitalizations for intractable focal epilepsy
from 1990 to 2008, with 6,653 (5.9%) including
Hospitalizations for medically refractory focal ep-
ilepsy increased by approximately 100% from
?4,000 to 8,000 hospitalizations between 1990 and
2008 (figure 1A), resulting in a positive trend (F ?
37.5, p ? 0.001). No significant trend was observed
in the annual number of lobectomies (?300–450
per year) performed on these patients over the same pe-
riod (figure 1A; F ? 0.4, p ? 0.56). However, the
percentage of intractable epilepsy hospitalizations in-
cluding lobectomy showed a downward trend over
time (figure 1B; F ? 13.6, p ? 0.01), as the proce-
dure was performed during only 4.3% of hospitaliza-
tions during 2004–2008 compared to 6.9% of
hospitalizations during 1990–1994. These data sug-
gest that while an increasing number of patients were
Neurology 78April 17, 2012
hospitalized for uncontrolled focal epilepsy between
1990 and 2008, the yearly number of lobectomies
performed on these patients did not change apprecia-
bly, and the rate of surgery during epilepsy hospital-
ization actually decreased during this time.
To determine if lobectomy trends differed be-
tween high-volume epilepsy centers and lower-
volume hospitals, we stratified data by hospital
caseload and compared 2 5-year periods: 1990–1994
and 2004–2008 (table 1). Of the 20 US hospitals
performing the highest yearly number of lobectomies
for epilepsy from 1990 to 2008, 90% were teaching
institutions and all were located in urban regions.
The total number of institutions performing the proce-
dure grew by 131% from 1990–1994 (table 1, top) to
2004–2008 (table 1, bottom), but the average annual
caseload per hospital performing lobectomy was dra-
matically lower during 2004–2008 (4.4 ? 4.6, mean
cases ? SD) compared to 1990–1994 (9.0 ? 10.6;
p ? 0.001). At the 20 highest-volume centers, un-
controlled focal epilepsy hospitalizations decreased
by 32% between 1990–1994 and 2004–2008, but
the rate of lobectomy (9.5%–9.6%) did not change
(relative risk, 1.01; 95% CI, 0.90–1.13). However,
among lower-volume hospitals (all other institutions
performing any lobectomies for epilepsy), epilepsy
hospitalizations quadrupled while the rate of surgery
decreased considerably from 9.4% during 1990–
1994 to 4.5% during 2004–2008 (relative risk, 0.38;
95% CI, 0.35–0.41). These results suggest that the
overall decreased utilization of lobectomy for epi-
lepsy from 1990 to 2008 is associated with a de-
creased number of patients being admitted to the
highest-volume epilepsy centers, as well as increased
hospitalizations to lower-volume hospitals that are
significantly less likely to perform the procedure.
We next compared demographics of patients hos-
pitalized for medically refractory localized epilepsy
who did or did not undergo lobectomy (table 2, top).
Both adults and pediatric patients were included, and
individuals who underwent lobectomy were slightly
younger (30.6 ? 14.3 years, mean age ? SD) than
those who did not have surgery (31.9 ? 19.3 years;
p ? 0.001), but males and females received the pro-
cedure at similar rates (5.9%–6.0%; relative risk,
1.02; 95% CI, 0.97–1.07). While 6.5% of white pa-
tients received lobectomy during hospitalization, sur-
gery rates were lower in racial minorities, including
black, Hispanic, Asian/Pacific Islander, and Native
American patients (2.4%–5.9% each; all relative
risks and 95% CI ? 1). We also found differences by
insurance status, as while 7.4% of privately insured
patients received lobectomy, surgical rates were lower
among Medicaid (4.8%; relative risk, 0.65; 95% CI,
0.61–0.69) and Medicare patients (3.9%; relative risk,
0.52; 95% CI, 0.49–0.56). Procedure rates in white vs
minority patients and privately insured vs Medicare/
Medicaid patients between 1990 and 2008 did not re-
veal significant trends over time (data not shown).
Differences in hospital-related factors were also
examined among all patients with medically refrac-
tory focal epilepsy (table 2, bottom). While 7.4% of
hospitalizations at small hospitals included surgery,
the rates of lobectomy at medium and large hospitals
were lower (5.3%–6.0%; all relative risks and 95%
CI ? 1). The designation of hospital size takes into
Figure 1Trends of hospitalizations for medically refractory focal epilepsy
and lobectomy procedure rates, 1990–2008
to 2008 (F ? 37.5, p ? 0.001). No significant trend was observed in the annual number of
lobectomies (right y-axis) performed on this these patients over the same period (F ? 0.4,
p ? 0.56). (B) The percent of intractable epilepsy hospitalizations including lobectomy
showed a downward trend over time (F ? 13.6, p ? 0.01). Dashed line represents publica-
tion year (2001) of a randomized, controlled trial examining surgical lobectomy for uncon-
Neurology 78April 17, 2012
account hospital location (urban vs nonurban) and
teaching status as potential confounding variables
(see table 2, footnote c). Surgery rates were also lower
at nonteaching hospitals (3.6%) vs teaching hospitals
(6.5%; relative risk, 0.54; 95% CI, 0.50–0.58) and
at hospitals located in a nonurban (3.1%) vs urban
location (6.1%; relative risk, 0.50; 95% CI 0.43–
0.59). Differences were observed by geographic re-
gion within the United States, as 6.8%–7.0% of
hospitalizations in the South and West included lo-
bectomy, but only 4.4%–5.4% of hospitalizations in
the Northeast and Midwest did so (see table 2 for
relative risks). By US state, while New York and Cal-
ifornia had the largest number of hospitalizations for
intractable focal epilepsy over the study period, the
highest percentages of patients receiving surgery were
and Connecticut (figure e-1 on the Neurology®Web
site at www.neurology.org).
Multivariate analysis was performed to identify
potential patient-level predictors of lobectomy while
controlling for hospital-level variables. Statistically
significant predictors of receiving surgery during hos-
pitalization included age ?30 years (relative risk,
1.10; 95% CI, 1.07–1.17), white race (relative risk,
1.13; 95% CI, 1.10–1.17), and private insurance
(relative risk, 1.28; 95% CI, 1.25–1.30). Further-
more, an interaction between patient race and insur-
ance payer was observed, as white patients were more
likely to have private insurance than nonwhite indi-
viduals (relative risk, 1.31; 95% CI, 1.28–1.34).
DISCUSSION Between 1990 and 2008, the num-
ber of lobectomies and partial lobectomies for medi-
cally refractory focal epilepsy in the United States did
not change appreciably despite Class I evidence and
new clinical practice guidelines. When adjusted for
hospitalizations for epilepsy, the overall rate of lobec-
tomy during hospitalization actually decreased dur-
ing this time. While surgery is the standard of care
for candidate patients with intractable localized epi-
lepsy,5,7,16it remains significantly underutilized.
One possible interpretation of these findings is
that patient referrals to epilepsy centers did increase
over time, but these patients were found to be un-
suitable candidates for surgery. However, we found
that the rate of lobectomy at the 20 highest-volume
epilepsy centers remained constant over the study pe-
riod. Instead, the overall decrease in surgical rates
between 1990 and 2008 was associated with 2 con-
current trends: decreased hospitalizations of uncon-
trolled focal epilepsy patients to high-volume
epilepsy centers, and increased hospitalizations to
low-volume hospitals that were considerably less
likely to perform the procedure.
Another possible explanation is that fewer pa-
tients were candidates for surgery in 2008 vs 1990,
perhaps as a result of novel pharmacologic therapies.
While several new AEDs have become available since
1990,17these newer and heavily marketed agents
have had only a modest impact on the rate of intrac-
table epilepsy, and have not altered the proportion of
patients who are surgical candidates.18–20In fact, the
opposite trend was observed in the present study: an
increasing number of intractable epilepsy hospitaliza-
tions from 1990 to 2008, suggesting a persistent and
significant disease burden. While the reasons for in-
creasing hospitalizations for epilepsy are not fully
known, our data suggest that practitioners may be
Table 1Number of hospitals, hospitalizations for medically refractory epilepsy, and lobectomies stratified by hospital caseload:
1990–1994 vs 2004–2008
epilepsy, n (%)
Top 20 hospitals performing lobectomy
20 (1.1)6,450 (30.6) 614 (42.5) 9.51 ?Reference?
Other hospitals performing lobectomy
140 (7.6)6,704 (31.8) 831 (57.5) 9.41 ?Reference?
Hospitals not performing lobectomy
1,685 (91.3) 7,936 (37.6)0 (0)0—
1,845 (100)21,090 (100) 1,446 (100) 6.91 ?Reference?
Top 20 hospitals performing lobectomy
20 (0.9)4,406 (11.0) 423 (24.8)9.6 1.01 (0.90–1.13)
Other hospitals performing lobectomy
350 (15.6)27,285 (67.9)1,286 (75.2)4.50.38 (0.35–0.41)b
Hospitals not performing lobectomy
1,880 (83.6)8,520 (21.2)0 (0)0—
2,250 (100)40,210 (100)1,709 (100)4.30.62 (0.58–0.65)b
Abbreviation: CI ? confidence interval.
aStatistically significant value (p ? 0.05).
bRelative risk comparing likelihood of lobectomy during hospitalization from 1990–1994 vs 2004–2008.
Neurology 78April 17, 2012
referring more patients to smaller, local institutions.
This may result in a larger number of epilepsy pa-
tients being evaluated in the inpatient setting, but
fewer ultimately receiving definitive resective ther-
apy. It is also possible that more patients are receiving
palliative surgical therapy, such as vagus nerve stimu-
lation (VNS), instead of resection. VNS implanta-
tion is technically less challenging for surgeons, and
may reduce seizure burden in certain patients, but it
rarely results in complete seizure freedom, making it
a less optimal treatment choice for patients who are
good candidates for resection.21Finally, refinements
of the temporal lobectomy technique, such as the
selective amygdalohippocampectomy, have become
increasingly utilized in TLE patients with encourag-
ing results.22However, these techniques remain clas-
sified as surgical resection for epilepsy in the NIS
database, and are thus captured in our study. Further
study comparing treatment trends of VNS, amygda-
lohippocampectomy, partial lobectomy, and lobec-
tomy for epilepsy are warranted to further clarify
Why has utilization of lobectomy for intractable
localized epilepsy not increased despite Class I clini-
cal evidence supporting its efficacy? The answer is
not fully known, but there are several issues to con-
sider. It is known that changes in practice patterns
can often lag considerably after evidence-based
ilepsy referral guidelines may be seen by some practitio-
ners as impractical and autonomy-limiting.24Other
reasons are the perceived morbidity of surgery, lack of
awareness of epilepsy-related morbidity and mortality,
or perceived advantages of pharmacologic management
held by some patients, primary care practitioners, and
In TLE patients who have failed 2 AED regimens,
lobectomy produces seizure freedom in two-thirds of
individuals; furthermore, it abolishes seizures in one-
third to one-half of patients with less common focal
epilepsies such as frontal lobe epilepsy.3,4,7In contrast,
less than 5% of patients who do not undergo surgery
(but continue receiving aggressive anticonvulsant man-
agement) enter remission each year.6,11,16,19,20,25Also,
uncontrolled epilepsy is associated with cognitive and
neuropsychological deficits and diminished quality
of life,5,26,27a 0.5%–1% annual mortality rate, and a
lifetime standardized mortality ratio of 2–3 times the
general population.3,16,28In contrast, lobectomy is as-
sociated with only 2% significant morbidity and
0.24% total surgical mortality,3,16,28as well as im-
provement in overall life span, neuropsychological
profile,29,30and quality-adjusted life-years.10Thus,
while the risks of surgery must be carefully consid-
ered, they are small compared to the cumulative life-
time risk of uncontrolled epilepsy.
In the present study, we observed fewer hospital-
izations to the most active surgical epilepsy centers
during 2004–2008 compared to 1990–1994, and a
dramatic increase in hospitalizations to lower-
volume centers that were significantly less likely to
perform surgery. We recommend that patients with
medically refractory epilepsy be referred early to an
epilepsy center with the capacity for comprehensive
Table 2Patient and hospital characteristics of hospitalizations for medically
refractory epilepsy with or without lobectomya
Did not receive
Relative risk (95% CI)
or Student t (p value)
Age, y, mean ? SD
30.6 ? 14.331.9 ? 19.32.25 (?0.001)b
Sex, n (%)
3,146 (5.9)50,371 (94.1)1 ?Reference?
3,507 (6.0) 55,002 (94.0)1.02 (0.97–1.07)
Race, n (%)
3,998 (6.5)57,517 (93.5)1 ?Reference?
260 (3.3)7,720 (96.7)0.50 (0.44–0.58)b
429 (5.9)6,861 (94.1)0.91 (0.82–1.00)b
47 (4.2)1,067 (95.8)0.65 (0.49–0.86)b
19 (2.4)769 (97.6)0.37 (0.24–0.58)b
Other or unknown
1900 (5.7)31,441 (94.3)0.88 (0.83–0.92)b
Primary payer, n (%)
4,185 (7.4)52,524 (92.6) 1 ?Reference?
1,180 (4.8)23,586 (95.2)0.65 (0.61–0.69)b
907 (3.9)22,571 (96.1) 0.52 (0.49–0.56)b
108 (5.0)2,059 (95.0) 0.68 (0.56–0.81)b
Other or unknown
273 (5.6)4,633 (94.4) 0.75 (0.67–0.85)b
Hospital size, n (%)c
688 (7.4)8,633 (92.6) 1 ?Reference?
1,213 (5.3) 21,675 (94.7)0.72 (0.66–0.79)b
4,752 (6.0)75,065 (94.0)0.81 (0.75–0.87)b
Hospital type, n (%)
5,839 (6.5)83,654 (93.5)1 ?Reference?
814 (3.6)21,719 (96.4) 0.54 (0.50–0.58)b
Hospital location, n (%)
6,490 (6.1)100,200 (93.9)1 ?Reference?
163 (3.1)5,173 (96.9)0.50 (0.43–0.59)b
1,326 (4.6) 27,782 (95.4)1 ?Reference?
1,465 (5.5)25,414 (94.5)1.20 (1.11–1.29)b
2,202 (6.8) 30,096 (93.2)1.50 (1.40–1.60)b
1,661 (7.0)22,081 (93.0)1.54 (1.43–1.65)b
Total, n (%)
6,653 (5.9)105,373 (94.1)
Abbreviation: CI ? confidence interval.
aData are cumulative, 1990–2008.
bStatistically significant value (p ? 0.05).
cHospital size classification is dependent on number of beds and hospital type. For exam-
ple, for urban, teaching hospitals, “small” signifies ?300 beds and “large” signifies ?500
Neurology 78April 17, 2012
surgical treatment. This recommendation is consis-
tent with guidelines by the National Association of
Epilepsy Centers and the American Academy of
Neurology,12,31as well as International League
Against Epilepsy guidelines regarding pediatric epi-
lepsy surgery.32At high-volume epilepsy centers,
evaluation is performed by a comprehensive treat-
ment team consisting of epileptologists, neuropsy-
chologists, neurosurgeons, and neuroradiologists,
and many of these centers have one or more neuro-
surgeons specialized in the surgical treatment of epi-
lepsy. These specialized and experienced providers
help ensure thorough patient evaluation and the de-
livery of appropriate treatment, whether it be medi-
cal optimization, surgical resection, or other surgical
therapy.31It is also potentially concerning that the
average annual caseload of hospitals performing lo-
bectomy in our study was approximately 50% lower
during 2004–2008 compared to 1990–1994. Lower
hospital volume and experience has been associated
with worse outcomes and increased morbidity in
neurosurgery33,34and other surgical fields.35,36
In addition to an overall underutilization of epi-
lepsy surgery, our results suggest significant dispari-
ties in treatment by both race and insurance
coverage. We found that racial minorities were sig-
nificantly less likely to receive surgical treatment than
white individuals, and patients with Medicare or
Medicaid had surgery at notably lower rates than
those with private insurance. Previous studies have
also found similar inequalities in the epilepsy surgery,
noting in particular underutilization among black
patients,14,37as well as significant treatment dispari-
ties by socioeconomic status.14,38,39While the reasons
for this disparity are not fully understood, we did
observe that white patients were more likely to have
private insurance than nonwhite individuals. There-
fore, it is possible that lower rate of surgery among
racial minorities is influenced by access to care or
financial considerations of treating institutions.
There are important limitations to the present
study. First, while the overall number of lobectomies
and the percentage of hospitalizations for intractable
focal epilepsy including lobectomy were known, it
was not known whether patients who did not receive
surgery were surgical candidates, and readmission for
the procedure to another hospital cannot be ex-
cluded. Also, current diagnosis codes do not specify
brain lobe in hospitalizations for intractable focal ep-
ilepsies, but it is known that in the past, the majority
of epilepsy resections have been temporal lobectomy
for TLE.3,7,28Next, examining all lobectomies for in-
tractable epilepsy provides a useful mechanism to 1)
estimate overall epilepsy surgery utilization over time
and 2) compare surgical rates between patient sub-
groups. Finally, as the NIS only includes hospitaliza-
tions from a stratified random subset (20%) of
nonfederal hospitals in the United States, our results
may reflect bias due to exclusion of potentially useful
Medically refractory epilepsy is a devastating neu-
rologic disorder. Lobectomy is a safe and effective
procedure for patients with intractable localized epi-
lepsy, but it is significantly underutilized, particularly
among racial minorities and the underinsured. Pa-
tients with medically refractory epilepsy should be
referred to a comprehensive epilepsy center for surgi-
cal evaluation by an experienced epilepsy treatment
team. Early referral is important, given the signifi-
cantly deleterious effects of persistent seizures on pa-
tient quality of life and survival.
Study concept and design: Drs. Englot and Chang. Acquisition of data:
Dr. Englot, D. Ouyang, and Dr. Chang. Analysis and interpretation of
data: Dr. Englot, D. Ouyang, and Drs. Garcia, Barbaro, and Chang.
Drafting of the manuscript: Drs. Englot and Chang. Critical revision of
the manuscript for important intellectual content: Dr. Englot, D. Ouy-
ang, and Drs. Garcia, Barbaro, and Chang. Statistical analysis: Dr. Englot
and D. Ouyang. Obtained funding: Drs. Englot and Chang. Study super-
vision: Dr. Chang.
The authors thank Drs. Boudourakis, Soni, Wang, and Rolston for com-
ments on the manuscript.
Dr. Englot and D. Ouyang report no disclosures. Dr. Barbaro serves on a
data safety monitoring board for the NIH/NINDS; has received funding
for travel from Elekta AB; and serves on the editorial board of Journal of
Neurosurgery. Dr. Garcia serves on a Special Emphasis Panel for the Cen-
ters for Disease Control; serves on the editorial board of Epilepsia; receives
research support from UCB, Medtronics, Inc., and the NIH; and has
served as an expert witness in medico-legal cases. Dr. Chang receives re-
search support from the NIH/NINDS.
Received July 5, 2011. Accepted in final form September 29, 2011.
1. Devinsky O. Diagnosis and treatment of temporal lobe
epilepsy. Rev Neurol Dis 2004;1:2–9.
2.Engel J Jr. Outcome with respect to epileptic seizures. In:
Engel J Jr, ed. Surgical Treatment of the Epilepsies. New
York: Raven Press; 1987:553–571.
3.Spencer S, Huh L. Outcomes of epilepsy surgery in adults
and children. Lancet Neurol 2008;7:525–537.
4. Jeha L, Najm I, Bingaman W, Dinner D, Widdess-Walsh
P, Ludders H. Surgical outcome and prognostic factors of
frontal lobe epilepsy surgery. Brain 2007;130:574–584.
5.Engel J Jr. Surgical treatment for epilepsy: too little, too
late? JAMA 2008;300:2548–2550.
6.Kwan P, Sperling MR. Refractory seizures: try addi-
tional antiepileptic drugs (after two have failed) or go
directly to early surgery evaluation? Epilepsia 2009;
7.Haneef Z, Stern J, Dewar S, Engel J Jr. Referral pattern for
epilepsy surgery after evidence-based recommendations: a
retrospective study. Neurology 2010;75:699–704.
Neurology 78April 17, 2012
8. Engel J Jr. Finally, a randomized, controlled trial of epi-
lepsy surgery. N Engl J Med 2001;345:365–367.
Engel J Jr, Shewman D. Overview: who should be consid-
ered a surgical candidate? In: Engel J Jr, ed. Surgical Treat-
ment of the Epilepsies, 2nd ed. New York: Raven Press;
Choi H, Sell RL, Lenert L, et al. Epilepsy surgery for phar-
macoresistant temporal lobe epilepsy: a decision analysis.
Wiebe S, Blume WT, Girvin JP, Eliasziw M. A random-
ized, controlled trial of surgery for temporal-lobe epilepsy.
N Engl J Med 2001;345:311–318.
Engel J Jr, Wiebe S, French J, et al. Practice parameter: tem-
poral lobe and localized neocortical resections for epilepsy:
report of the Quality Standards Subcommittee of the Ameri-
can Academy of Neurology, in association with the American
Epilepsy Society and the American Association of Neurologi-
cal Surgeons. Neurology 2003;60:538–547.
Steiner C, Elixhauser A, Schnaier J. The healthcare cost
and utilization project: an overview. Eff Clin Pract 2002;5:
McClelland S 3rd, Guo H, Okuyemi KS. Racial disparities
in the surgical management of intractable temporal lobe
epilepsy in the United States: a population-based analysis.
Arch Neurol 2010;67:577–583.
McClelland S 3rd, Guo H, Okuyemi KS. Population-
based analysis of morbidity and mortality following sur-
gery for intractable temporal lobe epilepsy in the United
States. Arch Neurol 2011;68:725–729.
Thom M, Mathern GW, Cross JH, Bertram EH. Mesial
temporal lobe epilepsy: How do we improve surgical out-
come? Ann Neurol 2010;68:424–434.
Arzimanoglou A, Ben-Menachem E, Cramer J, Glauser T,
Seeruthun R, Harrison M. The evolution of antiepileptic
drug development and regulation. Epileptic Disord 2010;
Prunetti P, Perucca E. New and forthcoming anti-epileptic
drugs. Curr Opin Neurol 2011;24:159–164.
Choi H, Heiman GA, Munger Clary H, Etienne M, Resor
SR, Hauser WA. Seizure remission in adults with long-
standing intractable epilepsy: an extended follow-up. Epi-
lepsy Res 2011;93:115–119.
Gazzola DM, Balcer LJ, French JA. Seizure-free outcome
in randomized add-on trials of the new antiepileptic drugs.
Englot DJ, Chang EF, Auguste KI. Vagus nerve stimula-
tion for epilepsy: a systematic review of efficacy and predic-
tors of response. J Neurosurg 2011;115:1248–1255.
Yasargil MG, Krayenbuhl N, Roth P, Hsu SP, Yasargil DC.
The selective amygdalohippocampectomy for intractable
temporal limbic seizures. J Neurosurg 2010;112:168–185.
Committee of Quality of Health Care in America IoM.
Crossing the Quality Chasm: A New Health System for
the 21st Century. Washington, DC: National Academy
24.Wiebe S. Still an elusive target: guiding practice for epi-
lepsy surgery. Neurology 2010;75:678–679.
Kwan P, Brodie MJ. Early identification of refractory epi-
lepsy. N Engl J Med 2000;342:314–319.
Englot DJ, Blumenfeld H. Consciousness and epilepsy:
why are complex-partial seizures complex? Prog Brain Res
Helmstaedter C, Kockelmann E. Cognitive outcomes in
patients with chronic temporal lobe epilepsy. Epilepsia
Wiebe S. Effectiveness and safety of epilepsy surgery: what
is the evidence? CNS Spectr 2004;9:120–122, 126–132.
Wachi M, Tomikawa M, Fukuda M, et al. Neuropsycho-
logical changes after surgical treatment for temporal lobe
epilepsy. Epilepsia 2001;42(suppl 6):4–8.
Westerveld M, Sass KJ, Chelune GJ, et al. Temporal lo-
bectomy in children: cognitive outcome. J Neurosurg
Labiner DM, Bagic AI, Herman ST, et al. Essential ser-
vices, personnel, and facilities in specialized epilepsy
centers: revised 2010 guidelines. Epilepsia 2010;51:
Cross JH, Jayakar P, Nordli D, et al. Proposed criteria for
referral and evaluation of children for epilepsy surgery: rec-
ommendations of the Subcommission for Pediatric Epi-
lepsy Surgery. Epilepsia 2006;47:952–959.
Smith ER, Butler WE, Barker FG 2nd. In-hospital mortal-
ity rates after ventriculoperitoneal shunt procedures in the
United States, 1998 to 2000: relation to hospital and sur-
geon volume of care. J Neurosurg 2004;100:90–97.
Kalkanis SN, Eskandar EN, Carter BS, Barker FG 2nd.
Microvascular decompression surgery in the United States,
1996 to 2000: mortality rates, morbidity rates, and the
effects of hospital and surgeon volumes. Neurosurgery
2003;52:1251–1261; discussion 1261–1252.
Thabut G, Christie JD, Kremers WK, Fournier M, Halp-
ern SD. Survival differences following lung transplantation
among US transplant centers. JAMA 2010;304:53–60.
Boudourakis LD, Wang TS, Roman SA, Desai R, Sosa JA.
Evolution of the surgeon-volume, patient-outcome rela-
tionship. Ann Surg 2009;250:159–165.
Szaflarski M, Szaflarski JP, Privitera MD, Ficker DM,
Horner RD. Racial/ethnic disparities in the treatment of
epilepsy: what do we know? What do we need to know?
Epilepsy Behav 2006;9:243–264.
Burneo JG, Jette N, Theodore W, et al. Disparities in epi-
lepsy: report of a systematic review by the North American
Commission of the International League Against Epilepsy.
Begley CE, Basu R, Reynolds T, et al. Sociodemographic
disparities in epilepsy care: Results from the Houston/New
York City health care use and outcomes study. Epilepsia
Neurology 78 April 17, 2012