SUPPLEMENT MATERIAL
Material and Methods
Clinical parameters and presurgical evaluation of patients
In all patients, video-EEG recording (Vangard System) was done using scalp electrodes (10/20 associated with temporal 10/10 system and sphenoidal). Interictal spikes (IS) were assessed by visual analysis as previously described 23 and classified as: 1) unilateral IS, if all the spikes (one-hundred percent) occurred exclusively in one temporal lobe, or 2) bilateral IS, if they arose independently from both temporal lobes.
Neuroimaging included high-resolution MRI (1.5T) with special protocols for MTLE-HS. Based on visual MRI analysis by an experienced neuroradiologist, MTLE-HS were classified as: 1) unilateral, when hippocampal atrophy (on T1-weighted, proton density) and/or increased signal (on T2-weighted, or fluid-attenuated inversion-recovery sequences) were observed only on one side; 2) bilateral, when the hippocampal alterations were observed on both sides.
In all cases, the epileptogenic zone (EZ) was inferred by clinical, neuroimaging, neuropsychological and electrophysiological findings. When the EZ could not be estimated non-invasively, patients underwent semi-invasive intracranial EEG recordings with foramen ovale electrodes (n = 7).
TABLE IV: Clinical, demographic and pre-surgical parameters according to Prnp genotype
/ Position 117 / Position 129 / Position 171 / Octarepeat /Variable / All cases
n = 100 / Ala/Ala
n = 91 / Ala/AlaSilent
n = 9 / Met/Met
n = 57 / Met/Val
n = 32 / Val/Val
n = 11 / Asn/Asn n = 77 / Asn/Ser
n = 23 / R12234
n = 95 / R12234/R1234
n = 5 /
Sex
Male / 44 / 42 / 2 / 25 / 14 / 5 / 35 / 9 / 41 / 3
Female / 56 / 49 / 7 / 32 / 18 / 6 / 42 / 14 / 54 / 2
Ethnicity
European-Brazilians / 88 / 80 / 8 / 50 / 28 / 10 / 70 / 18 / 85 / 3
African-Brazilians / 12 / 11 / 1 / 7 / 4 / 1 / 08 / 4 / 10 / 2
Febrile seizure
Yes / 26 / 24 / 2 / 16 / 7 / 3 / 24 / 2 / 19 / 7
No / 74 / 67 / 7 / 41 / 25 / 8 / 71 / 3 / 58 / 16
History of IPI
Yes / 38 / 35 / 3 / 24 / 11 / 3 / 30 / 8 / 36 / 2
No / 62 / 56 / 6 / 33 / 21 / 8 / 47 / 15 / 59 / 3
Family history of epilepsy
Yes / 31 / 27 / 4 / 14 / 11 / 6 / 22 / 9 / 29 / 2
No / 69 / 64 / 5 / 43 / 21 / 5 / 55 / 14 / 66 / 3
Side of surgery
Right / 38 / 35 / 3 / 22 / 13 / 3 / 31 / 7 / 36 / 2
Left / 62 / 56 / 6 / 35 / 19 / 8 / 46 / 16 / 59 / 3
MRI findings
Unilateral / 92 / 83 / 9 / 54 / 28 / 10 / 72 / 20 / 87 / 5
Bilateral / 8 / 8 / 0 / 3 / 4 / 1 / 5 / 3 / 8 / 0
Interictal spikes*
Unilateral (%) / 43 (44.8) / 38 (39.2) / 5 (5.2) / 21 (21.6) / 15 (15.5) / 7 (7.2) / 34 (35.1) / 9 (9.3) / 42 (43.3) / 1 (1.1)
Bilateral (%) / 54 (55.2) / 50 (51.5) / 4 (4.1) / 34 (35.1) / 16 (16.5) / 4 (4.1) / 40 (41.2) / 14 (14.4) / 50 (51.5) / 4 (4.1)
Age at surgery (y)
Mean / 36.2 / 36.7 / 37.7 / 36.3 / 31.7 / 35.7 / 36.2 / 36.1 / 36.5 / 30.6
SD / 10.7 / 11.0 / 5.2 / 10.7 / 10.9 / 10.8 / 10.6 / 11.3 / 10.7 / 8.0
Age at epilepsy onset (y)
Mean / 11.2 / 11.2 / 12.0 / 11.2 / 9.9 / 15.3 / 11.6 / 9.9 / 11.3 / 8.8
SD / 7.9 / 7.8 / 9.1 / 8.2 / 6.7 / 8.7 / 7.9 / 8.0 / 8.0 / 5.9
Disease duration (y)
Mean / 25.2 / 25.0 / 25.0 / 25.1 / 26.3 / 21.4 / 24.7 / 26.3 / 25.2 / 21.8
SD / 10.5 / 10.9 / 6.2 / 9.7 / 11.8 / 10.5 / 11.0 / 8.9 / 10.7 / 5.6
Seizure frequency/month
Mean / 8.5 / 8.6 / 7.8 / 8.1 / 7.8 / 12.8 / 9.0 / 7.0 / 8.4 / 10.0
SD / 7.6 / 7.5 / 8.7 / 6.4 / 8.4 / 10.4 / 7.7 / 7.2 / 7.6 / 7.1
* In three cases the interictal spikes were not observed during the VEEG monitoring.
TABLE V: Surgical outcome according to the patients’ characteristics
/ All / Overall surgical outcome / Cumulative % / p / Crude HR to / 95% CI / p /Variable / Patients
n = 98 (%) / Seizure-free
n = 85 (%) / Seizure
n = 13 (%) / of Seizure-Free / Value / remain with seizuresc / Value /
Sex
Male / 42 (42.9) / 35 (41.2) / 7 (53.8) / 81.5 / 1.00
Female / 56 (56.1) / 50 (58.8) / 6 (46.2) / 89.2 / 0.26 / 0.60 / 0.20 - 1.80 / 0.36
Ethnicity
European-Brazilians / 87 (88.8) / 74 (87.1) / 13 (100.0) / 84.4
African-Brazilians / 11 (11.2) / 11 (12.9) / 0 (0.0) / 100.0 / 0.18 / NA / - / -
Febrile seizure
No / 74 (75.0) / 65 (76.5) / 4 (30.8) / 87.5 / 1.00
Yes / 24 (24.5) / 20 (23.5) / 9 (69.2) / 82.5 / 0.62 / 0.63 / 0.41 - 4.40 / 0.63
History of IPI
No / 60 (61.2) / 54 (63.5) / 6 (46.2) / 89.2 / 1.00
Yes / 38 (38.8) / 31 (36.5) / 7 (53.8) / 81.3 / 0.23 / 1.93 / 0.65 - 5.73 / 0.24
Family history of epilepsy
No / 67 (68.4) / 59 (69.4) / 8 (61.5) / 87.7 / 1.00
Yes / 31 (31.6) / 26 (30.6) / 5 (38.5) / 82.3 / 0.53 / 0.68 / 0.22 - 2.09 / 0.50
Side of surgery
Right / 37 (37.8) / 31 (36.5) / 6 (46.2) / 82.7 / 1.00
Left / 61 (62.2) / 54 (63.5) / 7 (53.8) / 88.3 / 0.50 / 0.71 / 0.24 - 2.11 / 0.53
MRI findings (n=93)a
Unilateral / 91 (92.9) / 80 (94.1) / 11 (84.6) / 87.5 / 1.00
Bilateral / 7 (7.1) / 5 (5.9) / 2 (15.4) / 68.6 / 0.21 / 2.53 / 0.53 - 11.4 / 0.23
Interictal spikes (n=95)
Unilateral / 42 (44.2) / 39 (47.0) / 3 (25.0) / 92.6 / 1.00
Bilateral / 53 (55.8) / 44 (53.0) / 9 (75.0) / 82.3 / 0.16 / 2.45 / 0.67 - 9.11 / 0.18
Age at surgery
Mean / 36.1 / 35.9 / 36.9
SD / 10.7 / 9.1 / 15.5
Before the third decade / 27 (27.6) / 22 (25.9) / 5 (38.5) / 79.8 / 1.00
After the third decade / 71 (72.4) / 63 (74.1) / 8 (61.5) / 88.4 / 0.34 / 0.58 / 0.19 - 1.78 / 0.34
Disease duration (y)
Mean / 25.1 / 24.4 / 29.2
SD / 10.5 / 9.5 / 15.3
Up to 20 years / 31 (31.6) / 28 (32.9) / 3 (23.1) / 89.2 / 1.00
More than 20 years / 67 (68.4) / 57 (67.1) / 10 (76.9) / 84.8 / 0.48 / 1.58 / 0.44 - 5.75 / 0.45
Age at epilepsy onset
Mean / 11.2 / 11.7 / 7.9
SD / 7.9 / 8.1 / 5.6
After the first decade / 49 (50.0) / 40 (47.1) / 9 (69.2) / 81.2 / 1.00
First decade / 49 (50.0) / 45 (52.9) / 4 (30.8) / 91.2 / 0.14 / 2.36 / 0.72 - 7.65 / 0.15
Seizures/month
Mean / 8.42 / 8.7 / 6.8
SD / 7.7 / 8.0 / 4.3
Up to four / 43 (43.9) / 37 (43.5) / 6 (46.2) / 85.6 / 1.00
More than four / 55 (56.1) / 48 (56.5) / 7 (53.8) / 86.6 / 0.84 / 0.89 / 0.30 - 2.66 / 0.84
Resectionb
Satisfactory / 82 (88.2) / 72 (88.9) / 10 (83.3) / 87.2 / 1.00
Unsatisfactory / 11 (11.8) / 9 (11.1) / 2 (16.7) / 81.2 / 0.65 / 1.4 / 0.31 - 6.41 / 0.66