Table 1. Prognostic factors for subsequent epilepsy.
| Clinical factor | Total (n=249) | Febrile seizure only (n=224) | Subsequent epilepsy (n=25) | P value† |
|---|---|---|---|---|
| Age at onset of febrile seizure (mo) | 0.172 | |||
| Mean±SD | 21.8±13.8 | 21.3±12.5 | 26.3±22.9 | |
| Range | 3–95 | 3–95 | 5–93 | |
| Gender | 0.757 | |||
| Male | 137 (55.0) | 124 (90.5) | 13 (52.0) | |
| Female | 112 (45.0) | 100 (90.1) | 12 (48.0) | |
| No. of total seizures‡ | 2.7±2.7 | 2.2±2.2 | 6.9±3.1 | 0.000* |
| Multiple seizures (≥2/episode) in one attack | 112 (45.0) | 94 (42.0) | 18 (72.0) | 0.005* |
| Duration | 0.064 | |||
| <30 sec | 17 (6.8) | 15 (6.7) | 2 (8.0) | |
| 30 sec–15 min | 211 (84.7) | 193 (86.2) | 18 (72.0) | |
| ≥15 min | 21 (8.4) | 16 (7.1) | 5 (20.0) | |
| Peak temperature | 0.079 | |||
| <39℃ | 100 (40.2) | 86 (38.4) | 14 (56.0) | |
| ≥39℃ | 149 (59.8) | 138 (61.6) | 11 (44.0) | |
| Focal seizure | 16 (6.4) | 15 (6.7) | 1 (4.0) | 1.000 |
| Unilateral clonic | 4 (26.7) | 4 (26.7) | - | |
| Asymmetric tonic | 3 (20.0) | 3 (20.0) | - | |
| Hypokinetic | 8 (53.3) | 8 (53.3) | - | |
| Versive | 1 (4.0) | - | 1 (4.0) | |
| Developmental delay | 17 (6.8) | 8 (3.6) | 9 (36.0) | 0.000* |
| Preterm birth | 10 (4.0) | 5 (2.2) | 5 (20.0) | 0.001* |
| Family history of febrile seizure | 72 (28.9) | 61 (27.2) | 11 (44.0) | 0.102 |
| Family history of epilepsy | 10 (4.0) | 5 (2.2) | 2 (8.0) | 0.162 |
| Abnormal EEG | 52/183 (28.4) | 39/158 (24.7) | 13/25 (52.0) | 0.008* |
| Focal slowing | 23/52 (44.2) | 17/39 (43.6) | 6/13 (46.1) | |
| Spike/sharp wave | 27/52 (51.9) | 21/39 (53.8) | 6/13 (46.1) | |
| Generalized | 2/52 (3.8) | 1/39 (2.6) | 1/13 (7.7) | |
| Abnormal brain MRI | 9/50 (18.0) | 4/27 (14.8) | 5/23 (21.7) | 0.715 |
Values are presented as mean±standard deviation (SD) or number (%) unless otherwise indicated.
EEG, electroencephalography; MRI, magnetic resonance imaging.
*P<0.05, statistical significance. †P values were calculated using the Pearson chi-square or Fisher exact test for categorical variables. ‡During first 2 years after febrile seizure onset.