Epilepsy Surgery evaluation guidelines process and outcomes in children

1. Epilepsy Surgery
in Children
Lalit Bansal, M.D.
10/11/2019

2. The way to cure an epileptic (Epilepticus sic curabitur) is the
inscription of this picture showing a person with epilepsy
undergoing trepanation and cauterization. The picture is from
the Sloane manuscript, a collection of medical manuscripts
from the end of the 12th century (British Library, London).
The French ‘encyclopedie’ depicting a trepanation
(Diderot, 1763, cited by Ruisinger, 2003)
Photograph of the Burzahom skull showing trephination
(white arrow) and attempted trephination (black arrow)
on the left parietal bone. This trephination is estimated
to have been done 4000 to 4300 years ago in the
northwestern Himalayan region. (Cited from Sankhyan
AR, Weber GHJ, Int J Osteoarcheol 20011)

3. • Neurosurgery for epilepsy was initiated in Europe in the late 1800’s
• Predates the development of clinical EEG and all the anti-epilepsy drugs used today
• Earliest patients were mostly adults
• Epilepsy surgery in children was relatively rare until the pioneering work of neurosurgeon Sidney Goldring
(Goldring S. Pediatric epilepsy surgery. Epilepsia 1987;28(Suppl 1):S82-102)
• Multidisciplinary specialty groups were started in 1980’s after the introduction of c-EEG, MRI, PET and ictal
SPECT
• Surgery for epilepsy in the pediatric population is not the treatment of last resort
• It has an important therapeutic role in the early treatment of children with surgically remedial syndromes
who are at risk for epilepsy-induced cognitive and behavioral disabilities

4. Expert consensus recommends:
Children be referred to a pediatric epilepsy center that includes surgery as one of the therapeutic options
The purpose of referral is to evaluate children to be sure they have an accurate diagnosis of epilepsy and to
consider optional therapies, including surgery, in an attempt to stop refractory epilepsy
In almost 20-30% of the referred patients, seizures could be controlled with medical management and are
returned to primary physician after thorough work up
Referral reason:
• Children with seizures uncontrolled by medical treatment (ie, failure of 2 to 3 appropriate drugs)
• Disabling medication side effects
• Children <2 year with uncontrolled seizures should be referred promptly
• Child with an MRI lesion
• Focal epilepsy from low-incidence etiologies (hemimegalencephaly, Rasmussen syndrome, Sturge-Weber
syndrome, tuberous sclerosis complex, Landau-Kleffner syndrome, hypothalamic hamartomas,
and polymicrogyria)

5. Trends of hospitalizations for medically refractory focal
epilepsy and lobectomy procedure rates, 1990–2008
(A)Hospitalizations for medically refractory focal epilepsy (left
y-axis) increased from 1990 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 publication year
(2001) of a randomized, controlled trial examining surgical
lobectomy for uncontrolled epilepsy.
Englot, D.J., Ouyang, D., Garcia, P.A., Barbaro, N.M. and Chang, E.F., 2012. Epilepsy surgery trends in the United States, 1990–2008. Neurology, 78(16), pp.1200-1206.

6. 1997 2000 2003 2006 2009
Number of cases
(weighted)
375 410 589 683 706
Age, n (%)
<1 18 (5) 16 (4) 37 (6) 31 (4) 18 (3)
1 to 4 67 (18) 81 (20) 86 (15) 110 (16) 120 (17)
5 to 9 86 (23) 79 (19) 136 (23) 170 (25) 182 (26)
10 to 14 85 (23) 110 (27) 168 (29) 189 (28) 208 (29)
15 to 17 120 (32) 124 (30) 157 (27) 176 (26) 173 (25)
Sex, n (%)
Boys 205 (55) 245 (60) 293 (50) 356 (52) 381 (54)
Girls 170 (45) 165 (40) 290 (49) 320 (47) 319 (45)
Race, n (%)
White 197 (52) 267 (65) 294 (50) 371 (54) 385 (54)
Black 23 (6) 26 (6) 18 (3) 32 (5) 37 (5)
Hispanic 24 (6) 33 (8) 52 (9) 61 (9) 110 (16)
Other 26 (7) 27 (7) 29 (5) 44 (6) 50 (7)
Missing 105 (28) 57 (14) 196 (33) 175 (26) 706 (18)
Primary Payer, n (%)
Public (Medicaid and
CHIP)
64 (17) 88 (21) 133 (23) 196 (29) 196 (28)
Private 259 (69) 290 (71) 396 (67) 439 (64) 448 (63)
Others 52 (14) 29 (7) 50 (9) 48 (7) 63 (9)
Region, n (%)
Northeast 99 (26) 139 (34) 103 (18) 104 (15) 113 (16)
Midwest 45 (12) 27 (7) 219 (37) 195 (29) 195 (28)
South 162 (43) 140 (34) 188 (32) 212 (31) 248 (35)
West 69 (18) 104 (25) 79 (13) 172 (25) 150 (21)
Children's Hospital,
n (%)
285 (76) 345 (84) 530 (90) 642 (94) 672 (95)
Teaching Hospital, n
(%)
304 (81) 397 (97) 561 (94) 639 (92) 611 (85)
Pediatric epilepsy surgery in the US
Pediatric epilepsy surgery numbers
have increased significantly in the
past decade, however, epilepsy
surgery remains an underutilized
treatment for children with epilepsy
Pestana Knight, E.M., Schiltz, N.K., Bakaki, P.M., Koroukian, S.M., Lhatoo,
S.D. and Kaiboriboon, K., 2015. Increasing utilization of pediatric epilepsy
surgery in the United States between 1997 and 2009. Epilepsia, 56(3),
pp.375-381.
Lamberink et al found a threefold
increase in surgical interventions per
year in a retrospective Dutch cohort of
234 children between 1990 and 2011
Barba et al reported an increase from
56 resective surgeries in 2008 to 182 in
2013‐2014 in a survey from nine Italian
epilepsy surgery centers

7. Multilobar or non-limbic % Limbic or temporal %
Cortical dysplasia
Infarct or ischemia
Rasmussen encephalitis
Tuberous Sclerosis
Remote infection
Tumor
Sturge-Weber
Post trauma
Arachnoid cyst
Leukodystrophy
50.2%
16.9%
12.4%
2.0%
5.4%
2.0%
2.0%
1.0%
0.5%
0.5%
Hippocampal sclerosis
Lesion only
Dual pathology
Cryptogenic
44.7%
27.0%
21.2%
7.1%
Pathological Substrates of Intractable Surgically Treated Patients Age 20 Years or Less at UCLA
Most common etiologies of surgery in children ≤20 years of age
Extra-temporal (70%) Temporal (30%)

8. The boxes indicate the 25th to 75th percentile, the lines in the boxes the median, the lines outside the boxes at
1.5 standard deviations of the mean and filled circles individual cases that exceed the standard deviation.
ANOVA found the age at surgery different based on type of procedure, with hemispherectomy and multilobar
resections occurring at a younger age than temporal resections and vagus nerve stimulator implantations

9. Epileptogenic Zone: the area of cortex that is necessary and sufficient for initiating seizures and whose removal (or
disconnection) is necessary for complete abolition of seizures

11. Goal of Epilepsy Surgery Evaluation
• Lateralize and localize the epileptic focus
• Determine the function of the cortex with the epileptic focus (brain mapping)
• Determine which surgical procedure has the greatest chance of controlling seizures without
causing a neurological deficit

12. Testing Modalities for Epilepsy Surgery Evaluation
• Clinical Semiology of seizure
• Scalp EEG – looking for Interictal and Ictal features
• MRI brain (including thin cut flair and DTI sequences)
• PET Scan
• SPECT – Interictal and Ictal
• fMRI
• EEG source localization (eg: Curry)
• MEG
• Functional Mapping
• Neuropsychological evaluation
• WADA (Intra-carotid amobarbital)
• ECoG – intraoperative and extraoperative

13. Categorization of the utility of all tests in each clinical cohort derived through consensus voting. Interictal EEG and MRI were the only tests unanimously agreed
to be mandatory across many clinical cohorts. Most ancillary tests mostly achieved a majority consensus across all clinical groups, although a 50/50 split vote
was recorded for a few categories
Jayakar, P., Gaillard, W.D., Tripathi, M., Libenson, M.H., Mathern, G.W., Cross, J.H. and Task Force for Paediatric Epilepsy Surgery, Commission for Paediatrics, and the Diagnostic Commission of the International League Against Epilepsy, 2014. Diagnostic test utilization in
evaluation for resective epilepsy surgery in children. Epilepsia, 55(4), pp.507-518.

15. Localization of auras to seizure onset zone
Olfactory, fear, epigastric, psychic and autonomic auras predominantly localize (≥ 70 %) to mesial temporal region
Gustatory auras and visual illusions commonly originate from lateral temporal (70%) and occipital cortex (60%) respectively.
Remaining auras (simple hallucination, ictal blurring, complex visual hallucination, vestibular, auditory and somatosensory auras) have variable distribution and have poor localization
value (≤ 50 %) Russo A, Arbune A, Bansal L, Mindruta I, Gobbi G, Duchowny M. The localizing value of epileptic auras: pitfalls in semiology and involved networks. (Accepted for publication in Epileptic Disorder – 09/2019)

17. Positron Emission Tomography (PET) Brain
• Various PET studies – measurement of glucose, serotonin & oxygen metabolism, cerebral blood flow, receptor binding
• FDG-18 (18 Fluoro-2-dexoxyglucose) PET is most commonly used - measure brain glucose metabolism
• Glucose metabolism is tightly connected to neuronal activity
• 18F-FDG is transported from blood into cells by GLUT-1 (predominantly)
• Inside cell FDG is metabolized to FDG-6-phosphate which is trapped in the cell
• Pre-requisite: fasting 4-6 hours, glucose <150mg/dl, c-EEG to look at spike count (Interictal/Ictal)
• Sensitivity of FDG-PET: TLE – 84-90% , Extra-TLE – 33-55%
• PET localized seizure focus – 95% MRI positive and 84% MRI negative patients
• PET can help in decision making in ~53% presurgical patients with normal or discordant MRI

18. Focal right temporal hypometabolism with subtle right
hemispheric hypometabolism
Focal left frontal hypometabolism (in area of
cortical dysplasia)
Focal hypermetabolism in right occipital
region in area of cortical malformation

19. Receptors PET tracer Receptor subtypes
GABA
11
C flumazenil (FMZ)
*
GABAA-cBZR
Opioid
11
C-carfentanil (CFN)
**
mu
11
C-MeNTI
*
delta
11
C-diprenorphine (DPN)
*
mu, delta, kappa
18
F-cyclofoxy
*
mu, kappa
Serotonin
18
F-MPPF
*
5-HT1A
11
C-WAY-100635
*
5-HT1A
18
F-FCWAY
*
5-HT1A
Dopamine
18
F-fallypride
*
D2/D3
Acetylcholine
18
F-FA-85380 (2FA)
**
nicotinic-α4β2
76
Br-BDEX
*
muscarinic
GABAA-cBZR: γ Aminobutyric acid A-central benzodiazepine receptor; MeNTI: N1’-methylnaltrindole MeNTI; MPPF: 2’-methoxyphenyl-(N-2’-pyridinyl)-p-fluoro-benzamidoethyipiperazine; 5-HT1A: 5-hydroxytryptamine
1A receptor WAY-100635: (3) H-(N-(2-(1-(4-(2-methoxyphenyl)-1-piperazinyl) ethyl)-N-(2-pyridyl) cyclohexane-carboxamide; FCWAY: N-{2-[4-(2-methoxyphenyl) piperazino]}-N-(2-pyridinyl) trans-4-
fluorocyclohexanecarboxamide; FA-85380: fluoro-A-85380; BDEX: 4-bromodexetimide.
*Receptor antagonist;
**Receptor agonist;
PET tracers for receptor imaging in patients with epilepsy

20. PET study Findings
Interictal
18
F-FDG Usually reduced metabolism
Ictal
18
F-FDG (or High spike count; >10/min) Increased and decreased metabolism (complex
pattern)
*
Post-ictal
18
F-FDG metabolism
**
Complex pattern, increased or decreased
GABAA-cBZR receptor (
11
C-flumazenil) (accurate >FDG) Reduced binding
Opioid receptor (
11
C-Cerfentanil) Increased mu and delta receptor bindings
Serotonin receptor Reduced binding
Dopamine receptor Reduced binding
11
C-alpha-methyl-L-tryptophan (Tuberous Sclerosis) Increased uptake
Interictal
15
O-H2O Usually reduced perfusion
Ictal
15
O-H2O Increased perfusion
*due to long brain uptake period of FDG
**depending on the time of injection after seizure
PET findings in the area of seizure focus in patients with epilepsy
Sarikaya, I., 2015. PET studies in epilepsy. American journal of nuclear medicine and molecular imaging, 5(5), p.416.

21. Increased AMT uptake in cortical tubers
Fluid-attenuated inversion recovery (FLAIR) MR imaging (left), 18F-FDG PET (middle), and 11C-AMT PET (right) in tuberous
sclerosis patient with multiple brain tubers (enhancing lesions on FLAIR MR imaging), intractable epilepsy, and nonlocalizing
scalp EEG. Although 18F-FDG PET showed hypometabolism in all tubers and overlying cortices, interictal 11C-AMT PET
revealed increased 11C-AMT uptake in left parietal tuber (arrow) only, which likely is epileptogenic, considering the almost
100% specificity of this test in detecting epileptogenic tubers

22. • Semiquantitative analysis of PET data and co-registration of PET image with MR increase the sensitivity of PET
and help identify mild abnormalities not apparent on visual inspection
• Presurgical PET provides important information on the functional status of rest of the brain and assess the
functional deficit zone (FDZ)
• Greater severity of preoperative hypometabolism in the resected temporal lobe is associated with significantly
better postoperative seizure control
• Severe extratemporal and bilateral hypometabolism is associated with a higher incidence of postoperative
seizures
• Extratemporal hypometabolism (not uncommon in TLE) is associated with a poor seizure outcome after surgery
• PET scan if possible, should be performed 2 days after the last seizure to prevent conflict of bilateral temporal
hypometabolism in patients with unilateral temporal lobe epilepsy

23. SPECT
(Single-photon Emission Computed Tomography)
In
Evaluation
of
Epilepsy Surgery

24. Team Work
Team Effort of Multiple People and Specialties
Nuclear Medicine
Technologist
Neurophysiology EEG
Technologist
Epileptologist Radiologist

25. When do we use SPECT Scan in Patient’s with Epilepsy
• Useful in patients with MRI negative epilepsy
• Helpful in patients who have previous resection/gliosis/encephalocele (PET may not be helpful as shows
hypometabolism in peri-resection/encephalocele/gliosis regions)
• Tuberous Sclerosis (FDG-PET shows hypometabolism in all tubers)
• Tc-99m hexamethyl-propylene amine oxime (Tc-99m HMPAO) – most commonly used radioisotope
• SPECT: localizes in 82% TLE and 70% neocortical epilepsy
• SISCOM (subtraction ictal SPECT co-registered to MRI) demonstrates similar results with a significantly
higher concordance rate

26. Ictal injection 10 seconds
12-year old male presenting with seizures as teeth clenching, 2-3/week
• 1 stage resection w/ ECOG – lesion + SPECT area
• SPECT helped in identifying primary focus of seizure
• Patient seizure free post surgery - 2 years

27. Ictal injection 8 seconds
17-year old female presenting with seizures as right arm stiffening and h/o interhemispheric lipoma resection
• Helped localize the ictal area
• MRI lesion was identified after SPECT focus

28. Ictal Injection 2 seconds
6-year old male with focal onset absence seizures (eye rolling and beh arrest) – 5-10/day, failed 3 medicines
MRI negative HyperPET Ictal SPECT
MRI Brain HyperPET Ictal SPECT

30. Functional Brain Mapping
• Functional MRI Brain (uses BOLD [blood oxygenation level dependent] signals, spatial resolution ~ 1mm, including
deep locations)
• Transcranial Magnetic Stimulation (neuronavigation TMS – using patient MRI)
• WADA Testing (intracarotid amobarbital test – allows lateralization, not localization of verbal/memory function)
• Cortical Brain Stimulation

31. • Alternatively, monophasic pulses at rapid rates of 200 to 500 Hz in brief trains of 4 to 5 stimulus pulses.
• Stimulus voltage is titrated by starting at 25 V followed by increments of 5 to 10 V

33. Persistent postoperative language deficits reported in an international survey of 56 international epilepsy centers
(Reprinted from Hamberger et al)

34. Distribution of postsurgical outcome by Engel scale
according to pre-resection intraoperative
electrocorticography patterns
Temporal – 86%
Frontal – 13%
Parietal- 1%
San-Juan, D., Alonso-Vanegas, M.A., Trenado, C., Hernández-Segura, N., Espinoza-López, D.A., González-Pérez, B., Cobos-
Alfaro, E., Zúñiga-Gazcón, H. and Hernandez-Ruiz, A., 2017. Electrocorticographic patterns in epilepsy surgery and long-
term outcome. Journal of Clinical Neurophysiology, 34(6), pp.520-526.
Intraoperative ECOG

35. Surgical Approaches for Epilepsy
Resection:
• Hemispherectomy: Rasmussen’s, Hemimegaloencephaly
• Lobectomy: MTS, FLE, OLE etc
• Topectomy: resection of focal area – tumor, FCD
Disconnection:
• Corpus callosotomy
• Multiple Subpial transection
• Hemispherectomy
Stimulation:
• Vagal Nerve Stimulation
• Anterior thalamic stimulation (DBS)
• Responsive neurostimulation
Minimally Invasive:
• Laser Ablation (visualase)
• Focused ultrasound (MRI guided for subcortical epilepsy – eg hypothalamic hamartoma)

36. Engel classification ILAE classification
Class I. Free from disabling seizures Class 1. Completely seizure free; no auras
Class 2 . Only auras; no other seizures
A. Completely seizure free since surgery
B. Nondisabling simple partial seizures only since surgery
C. Some disabling seizures after surgery, but free from disabling seizures for ≥2 years
D. Generalized convulsions w/AED discontinuation only
Class II. Rare disabling seizures (almost seizure free) Class 3. 1–3 seizure days/yr; ±auras
A. Initially free from disabling seizures, but still has rare seizures
B. Rare disabling seizures since surgery
C. Occasional disabling seizures since surgery, but rare seizures for the last 2 years
D. Nocturnal seizures only
Class III. Worthwhile improvement Class 4. 4 seizure days/yr—50% reduction in baseline no. of seizure days; ±auras
A. Worthwhile seizure reduction
B. Prolonged seizure-free intervals amounting to >50% of follow-up period, but not <2
years
Class IV. No worthwhile improvement Class 5. <50% reduction in baseline no. of seizure days – 100% increase in baseline no. of
seizure days; ±auras
A. Significant seizure reduction
B. No appreciable change
C. Seizures worse Class 6. >100% increase in baseline no. of seizure days; ±auras
Durnford, A.J., Rodgers, W., Kirkham, F.J., Mullee, M.A., Whitney, A., Prevett, M., Kinton, L., Harris, M. and Gray, W.P., 2011. Very good inter-rater reliability of Engel and ILAE epilepsy surgery outcome classifications in a series of 76 patients. Seizure, 20(10), pp.809-812.
Inter-rater reliability of Engel and ILAE epilepsy surgery outcome classifications in a series of 76 patients

37. • Older age at seizure onset
• Shorter duration of epilepsy
• Lesional MRI
• Unifocal lesions
• IQ > 70
• Absence of psychiatric comorbidities
• Unilobar resections
• Temporal lobe resections
• Pathology
• Tumors fare better than cortical dysplasia
• In dysplasia, high grades tend to have better outcome (likely related to completeness of
resection)
• Completeness of resection (most important predictor of seizure free outcome)
Predictors of Favorable Outcome

38. Outcome Parameters
 Seizure freedom/reduction
 Developmental and cognitive outcome
 Behavioral and psychosocial outcome
 Quality of life improvement

39. Temporal Lobe Surgery Outcomes
 75% seizure free – surgery before 12 year1
 74 % preadolescent, 80% adolescent – seizure free2
 63% seizure free children (12/19 patients) – mean resection 5cm3
 89% temporal tumor 4 (drug responsive – 98% Sz free, drug resistant 88% Sz free), (40% patients off
medication post-surgery)
 Seizure recurrence 55% in first 6 month and 93% within 2 year; 5-year seizure freedom 70%. 5 (adult data)
 Selective amygdalohippocampectomy (SAH) vs Anterior temporal lobectomy (ATL).
ATL better in children, 33% seizure free post SAH in children (9patient) vs 71% in adults (14 patients)6,
although SAH may give slightly better cognitive outcome due to preserved neocortex/white matter.7
1. Duchowny M, Levin B, Jayakar P, Resnick T, Alvarez L, Morrison G, et al. Temporal lobectomy in early childhood. Epilepsia. 1992;33:298–303
2. Wyllie E, Chee M, Granstrom ML, DelGiudice E, Estes M, Comair Y, et al. Temporal lobe epilepsy in early childhood. Epilepsia. 1993;34:859–868
3. Lee, Y.J., Kang, H.C., Bae, S.J., Kim, H.D., Kim, J.T., Lee, B.I., Heo, K., Jang, J.W., Kim, D.S., Kim, T.S. and Lee, J.S., 2010. Comparison of temporal lobectomies of children and adults with intractable temporal lobe epilepsy. Child's Nervous System, 26(2), pp.177-183
4. Giulioni, M., Marucci, G., Pelliccia, V., Gozzo, F., Barba, C., Didato, G., Villani, F., Di Gennaro, G., Quarato, P.P., Esposito, V. and Consales, A., 2017. Epilepsy surgery of “low grade epilepsy associated neuroepithelial tumors”: A retrospective nationwide Italian
study. Epilepsia.
5. Sperling, M.R., O'connor, M.J., Saykin, A.J. and Plummer, C., 1996. Temporal lobectomy for refractory epilepsy. Jama, 276(6), pp.470-475.
6. Datta, A., Sinclair, D.B., Wheatley, M., Jurasek, L., Snyder, T., Quigley, D., Ahmed, S.N. and Gross, D., 2009. Selective amygdalohippocampectomy: surgical outcome in children versus adults. Canadian Journal of Neurological Sciences, 36(2).
7. Wieser, H.G., Ortega, M., Friedman, A. and Yonekawa, Y., 2003. Long-term seizure outcomes following amygdalohippocampectomy. Journal of neurosurgery, 98(4), pp.751-763.

40. Extratemporal Neocortical Resection Outcomes
 Outcome is generally better in well circumscribed lesion eg: ganglioglioma, DNET, pleomorphic xanthoastrocytoma
– range 60-80% with complete lesion resection
 Occipital lobe: Tumor resection – 85% (excellent/good)
Developmental abnormalities 45% (excellent/good; FCD>hamartoma/hetrotropias)1
 Parietal resection: High seizure recurrence as compared to occipital or parieto-occipital resection.
Seizure freedom P-52%, O- 89%, PO- 93% at 5 years.2
Seizure recurrence is more with lesionectomy vs lobectomy/multilobar resection.
 Children extratemporal3: FCD 55 %
Tumor-77%,
TS-59%,
Vascular malformation – 79%
Gliosis- 43%
Non-lesional/idiopathic – 34%
 Frontal lobe resection – 59% Sz free 1st year, 53% sz free at 2 year; Relapse 83% with in first 12 months.4
1. Aykut‐Bingol, C., Bronen, R.A., Kim, J.H., Spencer, D.D. and Spencer, S.S., 1998. Surgical outcome in occipital lobe epilepsy: implications for pathophysiology. Annals of neurology, 44(1), pp.60-69.
2. Jehi, L.E., O’Dwyer, R., Najm, I., Alexopoulos, A. and Bingaman, W., 2009. A longitudinal study of surgical outcome and its determinants following posterior cortex epilepsy surgery. Epilepsia, 50(9), pp.2040-2052.
3. Englot, D.J., Breshears, J.D., Sun, P.P., Chang, E.F. and Auguste, K.I., 2013. Seizure outcomes after resective surgery for extra–temporal lobe epilepsy in pediatric patients: A systematic review. Journal of Neurosurgery: Pediatrics, 12(2), pp.126-133.
4. Bonini, F., McGonigal, A., Scavarda, D., Carron, R., Régis, J., Dufour, H., Péragut, J.C., Laguitton, V., Villeneuve, N., Chauvel, P. and Giusiano, B., 2017. Predictive Factors of Surgical Outcome in Frontal Lobe Epilepsy Explored with
Stereoelectroencephalography. Neurosurgery.

41. MRI Negative Cases Outcomes
1. Temporal Lobe Surgery:
• 30% patient are MRI negative1
• 51% patient seizure free1
• Concordant EEG + PET hypometabolism– surgical outcome = 75% (similar to MTLS+HS)1
• MRI negative cases – eg: small temporal lobe encephalocele, amygdala enlargement
2. Extratemporal Resection:
• Overall – 29-56% seizure freedom 2-4
• In recent study (2017) Seizure freedom – 46% (ILAE 1, 2, 3 – 64%)2
1. Muhlhofer, W., Tan, Y.L., Mueller, S.G. and Knowlton, R., 2017. MRI‐negative temporal lobe epilepsy—What do we know?. Epilepsia, 58(5), pp.727-742.
2. Shi, J., Lacuey, N. and Lhatoo, S., 2017. Surgical outcome of MRI-negative refractory extratemporal lobe epilepsy. Epilepsy Research, 133, pp.103-108
3. Jeha, L.E., Najm, I., Bingaman, W., Dinner, D., Widdess-Walsh, P. and Lüders, H., 2007. Surgical outcome and prognostic factors of frontal lobe epilepsy surgery. Brain, 130(2), pp.574-584.
4. Wetjen, N.M., Marsh, W.R., Meyer, F.B., Cascino, G.D., So, E., Britton, J.W., Stead, S.M. and Worrell, G.A., 2009. Intracranial electroencephalography seizure onset patterns and surgical outcomes in nonlesional extratemporal epilepsy. Journal of
neurosurgery, 110(6), pp.1147-1152

42. Hemispherectomy
• Seizure freedom – 66- 86%1-2
• Outcome better with non-MCD pathologies – 82% (perinatal infarct, encephalitis) vs progressive epilepsies – 53%
(Rasmussens, Sturge weber) vs developmental abnormalities – 31% (MCD)3
• Rasmussen’s – studies have shown 65-81% seizure freedom4-5
Corpus Callosotomy
• Anterior 2/3, complete callosotomy and selective posterior callosotomy
• Selective posterior callosotomy for drops: 47% sz free, (83% Engel I+II)6
• Drops seizure 60% seizure free (1or 2 stage complete callosotomy @ mayo clinic, adult+child)7
• Complete callosotomy Seizure freedom (all children): Drops – 73% (91% engel I+II), GTC – 66% (88% engel I + II),
myoclonic – 37% (87% engel I+II), Tonic – 100% (only 2 cases).8
• Complete callosotomy as 1 stage preferred in children < 10 years vs children > 10 years; due to concern of acute
disconnection or split-brain syndrome (unless marked intellectual disability).
1. González‐Martínez, J.A., Gupta, A., Kotagal, P., Lachhwani, D., Wyllie, E., Lüders, H.O. and Bingaman, W.E., 2005. Hemispherectomy for catastrophic epilepsy in infants. Epilepsia, 46(9), pp.1518-1525.
2. Melikyan, A.G., Kushel, Y.V., Vorob'ev, A.N., Arkhipova, N.A., Sorokin, V.S., Lemeneva, N.V., Savin, I.A., Pronin, I.N., Kozlova, A.B., Grinenko, O.A. and Buklina, S.B., 2016. Hemispherectomy in the treatment of pediatric symptomatic epilepsy of children. Zhurnal voprosy
neirokhirurgii imeni NN Burdenko, 80(3), pp.13-24.
3. Devlin, A.M., Cross, J.H., Harkness, W., Chong, W.K., Harding, B., Vargha‐Khadem, F. and Neville, B.G.R., 2003. Clinical outcomes of hemispherectomy for epilepsy in childhood and adolescence. Brain, 126(3), pp.556-566.
4. Kossoff EH, Vining EP, Pillas DJ, et al. Hemispherectomy of intractable unihemispheric epilepsy: etiology vs outcome. Neurology 2003;61:887-90.
5. Granata T, Matricardi S, Ragona F, et al. Hemispherotomy in Rasmussen encephalitis: long-term outcome in an Italian series of 16 patients. Epilepsy Res 2014;108(6):1106-19.
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43. Thank You

44. Post Program Evaluation
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