Table 1.
Demographic and clinical characteristics of the children according to seizure freedom after their epilepsy surgery.
| a) Presurgical Characteristics | ||||
|---|---|---|---|---|
| OUTCOME |
||||
| Overall group n = 132 (except where specified) | Seizure-free | Not seizure-free | p-value | |
| (n = 94) | (n = 38) | |||
| Gender (males) | 69 (52) | 47 (50) | 22 (58) | 0.41 |
| Mean age at seizure onset (years) | 3.5 (range 0.003–15.7) | 3.9 (0–15.7) | 2.4 (0–14) | 0.04* |
| Mean number ASM’s trialled | 4.0 (range 1–14) | 4 (1–14) | 5 (1–9) | 0.03* |
| Seizure frequency and duration | ||||
| Seizure frequency >1/day | 103 (78) | 73 (78) | 30 (79) | 0.87 |
| Seizure duration >1 min | 51 (39) | 33 (35) | 18 (47) | 0.19 |
| Seizure characteristics (categories not exclusive) | ||||
| Focal | 58 (44) | 46 (49) | 12 (32) | 0.07 |
| Focal impaired awareness | 79 (60) | 63 (67) | 16 (42) | 0.008* |
| Generalized seizures | 46 (35) | 28 (30) | 18 (47) | 0.055 |
| Focal to bilateral tonic clonic | 50 (38) | 34 (36) | 16 (42) | 0.52 |
| History of status epilepticus | 33 (25) | 21 (22) | 12 (32) | 0.27 |
| Presence of DEE | ||||
| Yes | 39 (29.5) | 20 (51) | 19 (48.7) | 0.001* |
| No | 93 (70.5) | 74 (79.5) | 19 (20.5) | |
| MRI findings | ||||
| Focal lesion | 82 (62) | 61 (74) | 21 (26) | 0.66 |
| Multifocal lesion | 29 (22) | 18 (62) | 11 (38) | |
| Hemispheric lesion | 11 (8) | 8 (73) | 3 (27) | |
| Normal | 10 (8) | 7 (70) | 3 (30) | |
| Interictal EEG findings (n = 130) | ||||
| Regional discharges | 63 (48) | 50 (79) | 13 (21) | 0.1 |
| Multiregional discharges | 51 (39) | 31 (60) | 20 (39) | |
| Hemispheric discharges | 8 (6) | 5 (63) | 3 (38) | |
| Normal | 8 (6) | 7 (88) | 1 (13) | |
| Ictal EEG findings (n = 120) | ||||
| Regional discharges | 73 (61) | 54 (74) | 19 (26) | 0.46 |
| Multiregional discharges | 34 (27) | 21 (62) | 13 (34) | |
| Hemispheric discharges | 10 (8) | 6 (60) | 4 (40) | |
| Normal | 3 (3) | 2 (67) | 1 (33) | |
| FDG-PET findings (n = 86) | ||||
| Focal hypometabolism | 58 (67) | 43 (74) | 15 (25) | 0.03* |
| Multifocal hypometabolism | 15 (17) | 6 (40) | 9 (60) | 0.016* |
| Hemispheric hypometabolism | 3 (3) | 3 (100) | 0 (0) | 0.98 |
| No localising metabolic focus | 10 (12) | 8 (80) | 2 (20) | 0.69 |
| SPECT findings (n = 67) | ||||
| Focal hyperperfusion | 41 (62) | 31 (76) | 10 (24) | 0.1 |
| Multifocal hyperperfusion | 12 (18) | 5 (42) | 7 (58) | |
| Hemispheric hyperperfusion | 2 (3) | 1 (50) | 1 (50) | |
| No perfusion abnormality | 12 (18) | 6 (50) | 6 (50) | |
| b) Surgery and histopathology characterstics | ||||
|---|---|---|---|---|
| OUTCOME |
||||
| Overall group n=132 (except where specified) | Seizure-free | Not seizure-free | p-value | |
| (n=94) | (n=38) | |||
| Mean age at surgery (years) | 7.8 (0.2–17.9) | 8.3 (0.5–17.9) | 6.6 (0.2–17.9 | 0.66 |
| Mean duration epilepsy to surgery | 4.2 (0.1–15) | 4.3 (0.1–14.6) | 4.2 (0.1–13.4) | 0.83 |
| Surgery side (Left) | 70 (53) | 52 (55) | 18 (47) | 0.79 |
| Surgery location | ||||
| Frontal | 45 (34) | 33 (73) | 12 (27) | 0.89 |
| Temporal | 38 (29) | 27 (71) | 11 (29) | |
| Parietal | 9 (7) | 5 (56) | 4 (44) | |
| Occipital | 5 (4) | 3 (60) | 2 (40) | |
| Insular | 2 (2) | 2 (100) | 0 (0) | |
| Hypothalamic | 1 (0.8) | 1 (100) | 0 (0) | |
| Hemispheric | 13 (10) | 10 (77) | 3 (23) | |
| Multi-lobar | 19 (14) | 13 (68) | 6 (32) | |
| Extent of surgical resection | ||||
| Focal (lesionectomy) | 81 (61) | 63 (78) | 18 (22) | 0.06 |
| Unilobar Lobectomy | 33 (25) | 19 (58) | 14 (42) | |
| Multilobar Lobectomy | 5 (4) | 2 (40) | 3 (60) | |
| Hemispherectomy | 13 (10) | 10 (77) | 3 (23) | |
| Use of invasive monitoring | 23 (17) | 18 (19) | 5 (22) | 0.41 |
| Use of ECoG | 74 (56) | 52 (55) | 22 (58) | 0.79 |
| Complete resection | 116 (88) | 86 (91) | 30 (79) | 0.046* |
| Acute postoperative seizures | 25 (20) | 14 (15) | 11 (29) | 0.06 |
| Histopathology | ||||
| FCD1 | 19 | 9 (47%) | 10 (53) | 0.045* |
| FCD2 | 34 | 26 (77%) | 8 (23%) | |
| FCD3 | 15 | 11 (73%) | 4 (27) | |
| Other cortical malformations | ||||
| -Hemimegalencephaly | 2 | 1 (50%) | 1 (50%) | |
| - Tuberous sclerosis | 7 | 3 (43%) | 4 (57%) | |
| - Heterotopia | 10 | 6 (60%) | 4 (40%) | |
| - Polymicrogyria | 2 | 2 (100%) | 0 (0%) | |
| Tumours | 25 | 23 (92%) | 2 (8%) | |
| Vascular | ||||
| - Previous stroke | 3 | 3 (100%) | (0%) | |
| Vascular malformation | 7 | 5 (71%) | 2 (29%) | |
| Postencephalitis | ||||
| - Rasmussens | 3 | 3 (100%) | 0 (0%) | |
| - Other encephalitis | 1 | 0 (0%) | 1 (100%) | |
| Others | 4 | 2 (50%) | 2 (50%) | |
Abbreviations: OR, Odd Ratio; ASM, Anti seizure medication; GTCS, Generalized tonic clonic seizures; DEE, developmental and epileptic encephalopathy; MRI, Magnetic resonance imaging; EEG, Electroencephalogram; FDG-PET, Fluorodeoxyglucose positron emission tomography; SPECT, Single-photon emission computed tomography; FCD, Focal cortical dysplasia;
*See Results section for more details.