Table 2.
Epilepsy and seizure characteristics.
| Characteristic | Total N = 213 (100%) | Abnormal ECG N = 100 (47%) | Normal ECG N = 113 (53%) | p1 |
|---|---|---|---|---|
| Age of seizure onset (months), median [IQR] | 30 [7 – 72] | 36 [7–68] | 24 [7–72] | 0.72 |
| Age at ECG encounter (years), median [IQR] | 9.7 [5.7–13.5] | 11.6 [6.7–15.0] | 8.3 [4.8–12.3] | <0.01 |
| Epilepsy duration at enrollment (months), median [IQR] | 59 [22 – 112] | 73 [32–128] | 46 [18–91] | 0.004 |
| Epilepsy type | 0.90 | |||
| Focal | 115 (54) | 52 (52) | 63 (56) | |
| Generalized | 54 (25) | 27 (27) | 27 (24) | |
| Focal and Generalized | 34 (16) | 17 (17) | 17 (15) | |
| Undetermined | 10 (5) | 4 (4) | 6 (5) | |
| Epilepsy etiology | 0.73 | |||
| Structural | 58 (27) | 29 (29) | 29 (26) | |
| Genetic/presumed genetic2 | 41 (19) | 16 (16) | 25 (22) | |
| Infectious | 9 (4) | 5 (5) | 4 (4) | |
| Immune | 6 (3) | 2 (2) | 4 (4) | |
| Unknown/other | 98 (46) | 48 (48) | 51 (45) | |
| Epilepsy syndrome | 61 (29) | 31 (31) | 30 (27) | 0.54 |
| Drug-resistant epilepsy | 130 (61) | 67 (67) | 63 (56) | 0.12 |
| Number of seizures per month median [IQR] | 0.5 [0–30] | 1 [0–60] | 0 [0–30] | 0.74 |
| Predominant seizure type at enrollment | 0.65 | |||
| GTC/focal to bilateral tonic-clonic | 29 (14) | 16 (16) | 13 (12) | |
| Generalized onset, motor | 35 (16) | 18 (18) | 17 (15) | |
| Focal onset, motor | 90 (42 | 37 (37) | 53 (47) | |
| Generalized onset, non-motor | 26 (12) | 11 (11) | 15 (13) | |
| Focal onset, non-motor | 14 (7) | 8 (8) | 6 (5) | |
| Unknown/mixed | 13 (6) | 7 (7) | 6 (5) | |
| Number of lifetime seizure types | 0.23 | |||
| 0/not reported | 13 (6) | 10 (10) | 3 (3) | |
| 1 | 78 (37) | 35 (35) | 43 (38) | |
| 2 | 59 (28) | 25 (25) | 34 (30) | |
| 3 | 38 (18) | 17 (17) | 21 (19) | |
| ≥4 | 25 (12) | 13 (13) | 12 (11) | |
| Number of ASM | 0.32 | |||
| 0 | 13 (6) | 4 (4) | 9 (8) | |
| 1 | 68 (32) | 30 (30) | 38 (34) | |
| 2 | 71 (33) | 32 (32) | 39 (35) | |
| ≥3 | 61 (29) | 34 (34) | 27 (24) | |
| Number of channel-modifying ASM | 0.35 | |||
| 0 | 66 (31) | 26 (26) | 40 (35) | |
| 1 | 109 (51) | 55 (55) | 54 (48) | |
| ≥2 | 38 (18) | 19 (19) | 19 (17) | |
| Number of enzyme-inducing ASM | 0.07 | |||
| 0 | 140 (66) | 67 (67) | 73 (64) | |
| 1 | 66 (31) | 27 (27) | 39 (35) | |
| ≥2 | 7 (3) | 6 (6) | 1 (1) | |
| Vagus nerve stimulator | 0.003 | |||
| No | 191 (90) | 83 (83) | 108 (96) | |
| Yes | 22 (10) | 17 (17) | 5 (4) |
ASM = anti-seizure medication. GTC = generalized tonic/clonic. IQR = interquartile range.
1
Normal ECG vs. Abnormal ECG.
2
Genetic causes include chromosomal abnormalities and non-ion channel associated epilepsy genes.