Dr. van Mierlo on the epilepsie-taging meeting in Vienna (May 2017) speaking about functional brain connectivity that helps to localize seizures from EEG

1. Functional brain connectivity helps
to localize seizures from EEG
W. Staljanssens, G. Strobbe, V. Keereman, G. Birot, A Meurs, E. Carrette,
D. Van Roost, K. Vonck, P. Boon, M. Seeck, S. Vulliémoz, P. van Mierlo

2. Disclosure
Co-founder and shareholder

3. Problem statement
• SOZ determination based on the visual inspection is labor-intensive,
time-consuming, to a certain extent subjective, and sometimes
impossible
• During a seizure, several brain regions participate in the epileptic
network, and the challenge is to isolate the main driver(s) of the
network from the secondarily activated regions
NEED: trustworthy EEG source imaging
to localize the SOZ that can be used in clinical practice

4. Goal
Use functional brain connectivity to localize the SOZ
Structural Functional

5. Method: ESI power vs EEG source connectivity
Ictal epoch selection EEG source imaging Multiple active sources
L R P A
Source 1 Source 3 Source 5
Source 2 Source 4 Source 6
0 1 2 3 4 5 6
1
2
3
4
5
6
Time (s)
Source
Comparison with resectionSeizure onset zone localization
Power
Connectivity
LE connectivity
LE power
Resection

6. Patients
Mean age epilepsy onset: 19
Mean age epilepsy surgery: 34
Inclusion criteria:
• patients who underwent presurgical evaluation
• one-time resective epilepsy surgery
• structural MRI before and after resection
• Engel class 1 with minimum follow-up of 1 year post-operatively
Surgery type:
amygdalo-hippocampectomy: 10
partial lobectomy: 10
tailored lesionectomy: 5
topectomy: 1
Mean follow-up: 3.8 years
111 seizures in 27 patients:
No clear discharges
Right rhythmic
Left rhythmic
Bilateral rhythmic
Ictal EEG findings

7. Patient example

8. Patient example
L R L R
EEG source imaging Multiple active sources
L R
L R

9. ESI+CONNECTIVITY
%
= 0
%
≤ 10
ESI POWER
%
= 0
%
≤ 10
Sz.
Pat.
1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12
1 10 10 10 10 10 10 10 - - - - - 0 100 10 10 10 10 10 38 10 - - - - - 0 86
2 0 0 0 0 0 48 0 - - - - - 86 86 36 36 48 36 48 0 36 - - - - - 14 14
3 5 5 5 5 - - - - - - - - 0 100 5 15 5 5 - - - - - - - - 0 75
4 0 0 0 0 0 - - - - - - - 100 100 17 0 0 32 0 - - - - - - - 60 60
5 0 0 0 0 - - - - - - - - 100 100 0 0 0 0 - - - - - - - - 100 100
6 9 9 9 9 9 9 - - - - - - 0 100 9 9 9 74 50 50 50 - - - - - 0 43
7 0 0 0 - - - - - - - - - 100 100 49 67 20 - - - - - - - - - 0 0
8 0 0 81 35 0 0 - - - - - - 67 67 72 0 89 71 72 0 - - - - - - 33 33
9 0 - - - - - - - - - - - 100 100 33 - - - - - - - - - - - 0 0
10 0 17 0 17 - - - - - - - - 50 50 49 17 0 17 - - - - - - - - 25 25
11 0 0 0 0 0 0 - - - - - - 100 100 0 17 17 17 0 0 - - - - - - 50 50
12 0 12 13 0 0 0 0 0 - - - - 75 75 63 0 13 0 0 0 13 13 - - - - 50 50
13 0 - - - - - - - - - - - 100 100 78 - - - - - - - - - - - 0 0
5 0 0 0 0 - - - - - - - - 100 100 0 0 0 0 - - - - - - - - 100 100
6 9 9 9 9 9 9 - - - - - - 0 100 9 9 9 74 50 50 50 - - - - - 0 43
7 0 0 0 - - - - - - - - - 100 100 49 67 20 - - - - - - - - - 0 0
8 0 0 81 35 0 0 - - - - - - 67 67 72 0 89 71 72 0 - - - - - - 33 33
9 0 - - - - - - - - - - - 100 100 33 - - - - - - - - - - - 0 0
10 0 17 0 17 - - - - - - - - 50 50 49 17 0 17 - - - - - - - - 25 25
11 0 0 0 0 0 0 - - - - - - 100 100 0 17 17 17 0 0 - - - - - - 50 50
12 0 12 13 0 0 0 0 0 - - - - 75 75 63 0 13 0 0 0 13 13 - - - - 50 50
13 0 - - - - - - - - - - - 100 100 78 - - - - - - - - - - - 0 0
14 0 0 0 0 - - - - - - - - 100 100 55 13 13 13 - - - - - - - 0 0
15 5 0 0 - - - - - - - - - 100 100 20 20 31 - - - - - - - - - 0 0
16 0 0 0 0 - - - - - - - - 100 100 0 0 0 0 - - - - - - - - 100 100
17 10 0 0 - - - - - - - - - 67 100 78 19 73 - - - - - - - - - 0 0
18 0 0 0 - - - - - - - - - 100 100 0 0 16 - - - - - - - - - 67 67
19 0 - - - - - - - - - - - 100 100 23 - - - - - - - - - - - 0 0
20 0 0 0 0 0 0 0 0 0 0 0 0 100 100 39 39 29 0 39 0 13 29 52 39 75 39 17 17
21 0 0 - - - - - - - - - - 100 100 0 47 - - - - - - - - - - 50 50
22 0 6 6 0 6 6 0 0 6 - - - 44 100 0 6 36 36 20 53 20 20 0 - - - 22 33
23 0 0 0 - - - - - - - - - 100 100 0 23 0 - - - - - - - - - 67 67
0 - - - - - - - - - - - 0 - - - - - - - - - - -
Patient example
R L R L

10. Results: ESI power vs. ESI + connectivity
%
= 0
%
≤ 10
ESI POWER
%
= 0
%
≤ 10
1 2 3 4 5 6 7 8 9 10 11 12
0 100 10 10 10 10 10 38 10 - - - - - 0 86
86 86 36 36 48 36 48 0 36 - - - - - 14 14
0 100 5 15 5 5 - - - - - - - - 0 75
100 100 17 0 0 32 0 - - - - - - - 60 60
100 100 0 0 0 0 - - - - - - - - 100 100
0 100 9 9 9 74 50 50 50 - - - - - 0 43
100 100 49 67 20 - - - - - - - - - 0 0
67 67 72 0 89 71 72 0 - - - - - - 33 33
100 100 33 - - - - - - - - - - - 0 0
50 50 49 17 0 17 - - - - - - - - 25 25
100 100 0 17 17 17 0 0 - - - - - - 50 50
75 75 63 0 13 0 0 0 13 13 - - - - 50 50
100 100 78 - - - - - - - - - - - 0 0
100 100 55 13 13 13 - - - - - - - 0 0
100 100 20 20 31 - - - - - - - - - 0 0
100 100 0 0 0 0 - - - - - - - - 100 100
67 100 78 19 73 - - - - - - - - - 0 0
100 100 0 0 16 - - - - - - - - - 67 67
8 0 0 81 35 0 0 - - - - - - 67 67 72 0 89 71 72 0 - - - - - - 33 33
9 0 - - - - - - - - - - - 100 100 33 - - - - - - - - - - - 0 0
10 0 17 0 17 - - - - - - - - 50 50 49 17 0 17 - - - - - - - - 25 25
11 0 0 0 0 0 0 - - - - - - 100 100 0 17 17 17 0 0 - - - - - - 50 50
12 0 12 13 0 0 0 0 0 - - - - 75 75 63 0 13 0 0 0 13 13 - - - - 50 50
13 0 - - - - - - - - - - - 100 100 78 - - - - - - - - - - - 0 0
14 0 0 0 0 - - - - - - - - 100 100 55 13 13 13 - - - - - - - 0 0
15 5 0 0 - - - - - - - - - 100 100 20 20 31 - - - - - - - - - 0 0
16 0 0 0 0 - - - - - - - - 100 100 0 0 0 0 - - - - - - - - 100 100
17 10 0 0 - - - - - - - - - 67 100 78 19 73 - - - - - - - - - 0 0
18 0 0 0 - - - - - - - - - 100 100 0 0 16 - - - - - - - - - 67 67
19 0 - - - - - - - - - - - 100 100 23 - - - - - - - - - - - 0 0
20 0 0 0 0 0 0 0 0 0 0 0 0 100 100 39 39 29 0 39 0 13 29 52 39 75 39 17 17
21 0 0 - - - - - - - - - - 100 100 0 47 - - - - - - - - - - 50 50
22 0 6 6 0 6 6 0 0 6 - - - 44 100 0 6 36 36 20 53 20 20 0 - - - 22 33
23 0 0 0 - - - - - - - - - 100 100 0 23 0 - - - - - - - - - 67 67
24 0 - - - - - - - - - - - 100 100 0 - - - - - - - - - - - 100 100
25 0 - - - - - - - - - - - 100 100 40 - - - - - - - - - - - 0 0
26 0 - - - - - - - - - - - 100 100 0 - - - - - - - - - - - 100 100
27 0 - - - - - - - - - - - 100 100 0 - - - - - - - - - - - 100 100
% of seizures inside RZ 72.1 30.6
% of seizures within 10 mm of RZ 93.7 42.3
% of patients correct (> 50% of seiz. = 0 mm) 81.5 29.6
% of patients correct (> 50% of seiz. ≤ 10 mm) 96.3 37.0
ESI+CONNECTIVITY
%
= 0
%
≤ 10
ESI POWER
%
= 0
%
≤ 10
Sz.
Pat.
1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12
1 10 10 10 10 10 10 10 - - - - - 0 100 10 10 10 10 10 38 10 - - - - - 0 86
2 0 0 0 0 0 48 0 - - - - - 86 86 36 36 48 36 48 0 36 - - - - - 14 14
3 5 5 5 5 - - - - - - - - 0 100 5 15 5 5 - - - - - - - - 0 75
4 0 0 0 0 0 - - - - - - - 100 100 17 0 0 32 0 - - - - - - - 60 60
5 0 0 0 0 - - - - - - - - 100 100 0 0 0 0 - - - - - - - - 100 100
6 9 9 9 9 9 9 - - - - - - 0 100 9 9 9 74 50 50 50 - - - - - 0 43
7 0 0 0 - - - - - - - - - 100 100 49 67 20 - - - - - - - - - 0 0
8 0 0 81 35 0 0 - - - - - - 67 67 72 0 89 71 72 0 - - - - - - 33 33
9 0 - - - - - - - - - - - 100 100 33 - - - - - - - - - - - 0 0
10 0 17 0 17 - - - - - - - - 50 50 49 17 0 17 - - - - - - - - 25 25
11 0 0 0 0 0 0 - - - - - - 100 100 0 17 17 17 0 0 - - - - - - 50 50
12 0 12 13 0 0 0 0 0 - - - - 75 75 63 0 13 0 0 0 13 13 - - - - 50 50
13 0 - - - - - - - - - - - 100 100 78 - - - - - - - - - - - 0 0
14 0 0 0 0 - - - - - - - - 100 100 55 13 13 13 - - - - - - - 0 0
15 5 0 0 - - - - - - - - - 100 100 20 20 31 - - - - - - - - - 0 0
16 0 0 0 0 - - - - - - - - 100 100 0 0 0 0 - - - - - - - - 100 100
17 10 0 0 - - - - - - - - - 67 100 78 19 73 - - - - - - - - - 0 0
18 0 0 0 - - - - - - - - - 100 100 0 0 16 - - - - - - - - - 67 67
ESI+CONNECTIVITY
%
= 0
%
≤ 10
ESI POWER
%
= 0
%
≤ 10
Sz.
Pat.
1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12
1 10 10 10 10 10 10 10 - - - - - 0 100 10 10 10 10 10 38 10 - - - - - 0 86
2 0 0 0 0 0 48 0 - - - - - 86 86 36 36 48 36 48 0 36 - - - - - 14 14
3 5 5 5 5 - - - - - - - - 0 100 5 15 5 5 - - - - - - - - 0 75
4 0 0 0 0 0 - - - - - - - 100 100 17 0 0 32 0 - - - - - - - 60 60
5 0 0 0 0 - - - - - - - - 100 100 0 0 0 0 - - - - - - - - 100 100
6 9 9 9 9 9 9 - - - - - - 0 100 9 9 9 74 50 50 50 - - - - - 0 43
7 0 0 0 - - - - - - - - - 100 100 49 67 20 - - - - - - - - - 0 0
8 0 0 81 35 0 0 - - - - - - 67 67 72 0 89 71 72 0 - - - - - - 33 33
9 0 - - - - - - - - - - - 100 100 33 - - - - - - - - - - - 0 0
10 0 17 0 17 - - - - - - - - 50 50 49 17 0 17 - - - - - - - - 25 25
11 0 0 0 0 0 0 - - - - - - 100 100 0 17 17 17 0 0 - - - - - - 50 50
12 0 12 13 0 0 0 0 0 - - - - 75 75 63 0 13 0 0 0 13 13 - - - - 50 50
13 0 - - - - - - - - - - - 100 100 78 - - - - - - - - - - - 0 0
14 0 0 0 0 - - - - - - - - 100 100 55 13 13 13 - - - - - - - 0 0
15 5 0 0 - - - - - - - - - 100 100 20 20 31 - - - - - - - - - 0 0
16 0 0 0 0 - - - - - - - - 100 100 0 0 0 0 - - - - - - - - 100 100
17 10 0 0 - - - - - - - - - 67 100 78 19 73 - - - - - - - - - 0 0
18 0 0 0 - - - - - - - - - 100 100 0 0 16 - - - - - - - - - 67 67
8 0 0 81 35 0 0 - - - - - - 67 67 72 0
9 0 - - - - - - - - - - - 100 100 33 -
10 0 17 0 17 - - - - - - - - 50 50 49 17
11 0 0 0 0 0 0 - - - - - - 100 100 0 17
12 0 12 13 0 0 0 0 0 - - - - 75 75 63 0
13 0 - - - - - - - - - - - 100 100 78 -
14 0 0 0 0 - - - - - - - - 100 100 55 13
15 5 0 0 - - - - - - - - - 100 100 20 20
16 0 0 0 0 - - - - - - - - 100 100 0 0
17 10 0 0 - - - - - - - - - 67 100 78 19
18 0 0 0 - - - - - - - - - 100 100 0 0
19 0 - - - - - - - - - - - 100 100 23 -
20 0 0 0 0 0 0 0 0 0 0 0 0 100 100 39 39
21 0 0 - - - - - - - - - - 100 100 0 47
22 0 6 6 0 6 6 0 0 6 - - - 44 100 0 6
23 0 0 0 - - - - - - - - - 100 100 0 23
24 0 - - - - - - - - - - - 100 100 0 -
25 0 - - - - - - - - - - - 100 100 40 -
26 0 - - - - - - - - - - - 100 100 0 -
27 0 - - - - - - - - - - - 100 100 0 -
% of seizures inside RZ 72.1
% of seizures within 10 mm of RZ 93.7
% of patients correct (> 50% of seiz. = 0 mm) 81.5
% of patients correct (> 50% of seiz. ≤ 10 mm) 96.3
ESI+CONNECTIVITY
%
= 0
%
≤ 10
Sz.
Pat.
1 2 3 4 5 6 7 8 9 10 11 12 1 2
1 10 10 10 10 10 10 10 - - - - - 0 100 10 10
2 0 0 0 0 0 48 0 - - - - - 86 86 36 36
3 5 5 5 5 - - - - - - - - 0 100 5 15
4 0 0 0 0 0 - - - - - - - 100 100 17 0
5 0 0 0 0 - - - - - - - - 100 100 0 0
6 9 9 9 9 9 9 - - - - - - 0 100 9 9
7 0 0 0 - - - - - - - - - 100 100 49 67
8 0 0 81 35 0 0 - - - - - - 67 67 72 0
9 0 - - - - - - - - - - - 100 100 33 -
10 0 17 0 17 - - - - - - - - 50 50 49 17
11 0 0 0 0 0 0 - - - - - - 100 100 0 17
12 0 12 13 0 0 0 0 0 - - - - 75 75 63 0
13 0 - - - - - - - - - - - 100 100 78 -
14 0 0 0 0 - - - - - - - - 100 100 55 13
15 5 0 0 - - - - - - - - - 100 100 20 20
16 0 0 0 0 - - - - - - - - 100 100 0 0
17 10 0 0 - - - - - - - - - 67 100 78 19
18 0 0 0 - - - - - - - - - 100 100 0 0
8 0 0 81 35 0 0 - - - - - - 67 67 72 0
9 0 - - - - - - - - - - - 100 100 33 -
10 0 17 0 17 - - - - - - - - 50 50 49 17
11 0 0 0 0 0 0 - - - - - - 100 100 0 17
12 0 12 13 0 0 0 0 0 - - - - 75 75 63 0
13 0 - - - - - - - - - - - 100 100 78 -
14 0 0 0 0 - - - - - - - - 100 100 55 13
15 5 0 0 - - - - - - - - - 100 100 20 20
16 0 0 0 0 - - - - - - - - 100 100 0 0
17 10 0 0 - - - - - - - - - 67 100 78 19
18 0 0 0 - - - - - - - - - 100 100 0 0
19 0 - - - - - - - - - - - 100 100 23 -
20 0 0 0 0 0 0 0 0 0 0 0 0 100 100 39 39
21 0 0 - - - - - - - - - - 100 100 0 47
22 0 6 6 0 6 6 0 0 6 - - - 44 100 0 6
23 0 0 0 - - - - - - - - - 100 100 0 23
24 0 - - - - - - - - - - - 100 100 0 -
25 0 - - - - - - - - - - - 100 100 40 -
26 0 - - - - - - - - - - - 100 100 0 -
27 0 - - - - - - - - - - - 100 100 0 -
% of seizures inside RZ 72.1
% of seizures within 10 mm of RZ 93.7
% of patients correct (> 50% of seiz. = 0 mm) 81.5
% of patients correct (> 50% of seiz. ≤ 10 mm) 96.3
8 0 0 81 35 0 0 - - - - - - 67 67 72 0 89 71 72 0 - - - - - - 33 33
9 0 - - - - - - - - - - - 100 100 33 - - - - - - - - - - - 0 0
10 0 17 0 17 - - - - - - - - 50 50 49 17 0 17 - - - - - - - - 25 25
11 0 0 0 0 0 0 - - - - - - 100 100 0 17 17 17 0 0 - - - - - - 50 50
12 0 12 13 0 0 0 0 0 - - - - 75 75 63 0 13 0 0 0 13 13 - - - - 50 50
13 0 - - - - - - - - - - - 100 100 78 - - - - - - - - - - - 0 0
14 0 0 0 0 - - - - - - - - 100 100 55 13 13 13 - - - - - - - 0 0
15 5 0 0 - - - - - - - - - 100 100 20 20 31 - - - - - - - - - 0 0
16 0 0 0 0 - - - - - - - - 100 100 0 0 0 0 - - - - - - - - 100 100
17 10 0 0 - - - - - - - - - 67 100 78 19 73 - - - - - - - - - 0 0
18 0 0 0 - - - - - - - - - 100 100 0 0 16 - - - - - - - - - 67 67
19 0 - - - - - - - - - - - 100 100 23 - - - - - - - - - - - 0 0
20 0 0 0 0 0 0 0 0 0 0 0 0 100 100 39 39 29 0 39 0 13 29 52 39 75 39 17 17
21 0 0 - - - - - - - - - - 100 100 0 47 - - - - - - - - - - 50 50
22 0 6 6 0 6 6 0 0 6 - - - 44 100 0 6 36 36 20 53 20 20 0 - - - 22 33
23 0 0 0 - - - - - - - - - 100 100 0 23 0 - - - - - - - - - 67 67
24 0 - - - - - - - - - - - 100 100 0 - - - - - - - - - - - 100 100
25 0 - - - - - - - - - - - 100 100 40 - - - - - - - - - - - 0 0
26 0 - - - - - - - - - - - 100 100 0 - - - - - - - - - - - 100 100
27 0 - - - - - - - - - - - 100 100 0 - - - - - - - - - - - 100 100
% of seizures inside RZ 72.1 30.6
% of seizures within 10 mm of RZ 93.7 42.3
% of patients correct (> 50% of seiz. = 0 mm) 81.5 29.6
% of patients correct (> 50% of seiz. ≤ 10 mm) 96.3 37.0

11. Results: ESI power vs. ESI + connectivity
ESI+CONNECTIVITY
%
= 0
%
≤ 10
ESI POWER
%
= 0
%
≤ 10
Sz.
Pat.
1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12
1 10 10 10 10 10 10 10 - - - - - 0 100 10 10 10 10 10 38 10 - - - - - 0 86
2 0 0 0 0 0 48 0 - - - - - 86 86 36 36 48 36 48 0 36 - - - - - 14 14
3 5 5 5 5 - - - - - - - - 0 100 5 15 5 5 - - - - - - - - 0 75
4 0 0 0 0 0 - - - - - - - 100 100 17 0 0 32 0 - - - - - - - 60 60
5 0 0 0 0 - - - - - - - - 100 100 0 0 0 0 - - - - - - - - 100 100
6 9 9 9 9 9 9 - - - - - - 0 100 9 9 9 74 50 50 50 - - - - - 0 43
7 0 0 0 - - - - - - - - - 100 100 49 67 20 - - - - - - - - - 0 0
8 0 0 81 35 0 0 - - - - - - 67 67 72 0 89 71 72 0 - - - - - - 33 33
9 0 - - - - - - - - - - - 100 100 33 - - - - - - - - - - - 0 0
10 0 17 0 17 - - - - - - - - 50 50 49 17 0 17 - - - - - - - - 25 25
11 0 0 0 0 0 0 - - - - - - 100 100 0 17 17 17 0 0 - - - - - - 50 50
12 0 12 13 0 0 0 0 0 - - - - 75 75 63 0 13 0 0 0 13 13 - - - - 50 50
13 0 - - - - - - - - - - - 100 100 78 - - - - - - - - - - - 0 0
14 0 0 0 0 - - - - - - - - 100 100 55 13 13 13 - - - - - - - 0 0
15 5 0 0 - - - - - - - - - 100 100 20 20 31 - - - - - - - - - 0 0
16 0 0 0 0 - - - - - - - - 100 100 0 0 0 0 - - - - - - - - 100 100
17 10 0 0 - - - - - - - - - 67 100 78 19 73 - - - - - - - - - 0 0
18 0 0 0 - - - - - - - - - 100 100 0 0 16 - - - - - - - - - 67 67
8 0 0 81 35 0 0 - - - - - - 67 67 72 0
9 0 - - - - - - - - - - - 100 100 33 -
10 0 17 0 17 - - - - - - - - 50 50 49 1
11 0 0 0 0 0 0 - - - - - - 100 100 0 1
12 0 12 13 0 0 0 0 0 - - - - 75 75 63 0
13 0 - - - - - - - - - - - 100 100 78 -
14 0 0 0 0 - - - - - - - - 100 100 55 1
15 5 0 0 - - - - - - - - - 100 100 20 2
16 0 0 0 0 - - - - - - - - 100 100 0 0
17 10 0 0 - - - - - - - - - 67 100 78 1
18 0 0 0 - - - - - - - - - 100 100 0 0
19 0 - - - - - - - - - - - 100 100 23 -
20 0 0 0 0 0 0 0 0 0 0 0 0 100 100 39 3
21 0 0 - - - - - - - - - - 100 100 0 4
22 0 6 6 0 6 6 0 0 6 - - - 44 100 0 6
23 0 0 0 - - - - - - - - - 100 100 0 2
24 0 - - - - - - - - - - - 100 100 0 -
25 0 - - - - - - - - - - - 100 100 40 -
26 0 - - - - - - - - - - - 100 100 0 -
27 0 - - - - - - - - - - - 100 100 0 -
% of seizures inside RZ 72.1
% of seizures within 10 mm of RZ 93.7
% of patients correct (> 50% of seiz. = 0 mm) 81.5
% of patients correct (> 50% of seiz. ≤ 10 mm) 96.3
ESI+CONNECTIVITY
%
= 0
%
≤ 10
Sz.
Pat.
1 2 3 4 5 6 7 8 9 10 11 12 1 2
1 10 10 10 10 10 10 10 - - - - - 0 100 10 1
2 0 0 0 0 0 48 0 - - - - - 86 86 36 3
3 5 5 5 5 - - - - - - - - 0 100 5 1
4 0 0 0 0 0 - - - - - - - 100 100 17 0
5 0 0 0 0 - - - - - - - - 100 100 0 0
6 9 9 9 9 9 9 - - - - - - 0 100 9 9
7 0 0 0 - - - - - - - - - 100 100 49 6
8 0 0 81 35 0 0 - - - - - - 67 67 72 0
9 0 - - - - - - - - - - - 100 100 33 -
10 0 17 0 17 - - - - - - - - 50 50 49 1
11 0 0 0 0 0 0 - - - - - - 100 100 0 1
12 0 12 13 0 0 0 0 0 - - - - 75 75 63 0
13 0 - - - - - - - - - - - 100 100 78 -
14 0 0 0 0 - - - - - - - - 100 100 55 1
15 5 0 0 - - - - - - - - - 100 100 20 2
16 0 0 0 0 - - - - - - - - 100 100 0 0
17 10 0 0 - - - - - - - - - 67 100 78 1
18 0 0 0 - - - - - - - - - 100 100 0 0

12. Localization error

13. Conclusions
• ESI + functional connectivity analysis outperformed
ESI power alone to localize the seizure onset zone.
• Spatial dispersion was significantly lower, indicating
more robust method.
• ESI + FCA could be a valuable tool in the presurgical
evaluation of epilepsy to localize seizures
ESI power ESI + conn
seizures inside resection 31% 72%
seizures <= 10mm 42% 93%
patients >50% of seizures in resection 30% 81%
patients >50% of seizures within 10mm 37% 96%

14. Questions?
Thank you for your attention
Prof. M. Seeck
Prof. P. Boon
Prof. S. Vulliemoz
Prof K. Vonck
W. Staljanssens T. VerhoevenDr. G. Strobbe