Table 5.
Comparison of patients with uni-hemispheric versus bi-hemispheric structural abnormalities on MRI
| Uni-hemispheric abnormalitiesa (n = 44) | Bi-hemispheric abnormalities (n = 38) | P-value | |
|---|---|---|---|
| Years (SD) | Years (SD) | ||
| Average age at onset | 6.1 (4.5) | 3.6 (3.8) | 0.008 |
| Average time to second drug failure | 1.9 (2.5) | 1.7 (2.4) | 0.73 |
| Average follow-upa | 11.6 (2.8) | 9.3 (4.5) | 0.008 |
| N (%) | N (%) | ||
| Pharmacoresistant | 18 (40.9) | 22 (57.9) | 0.12 |
| Deceased | 0 (0) | 8 (21.1) | 0.001 |
| FSIQ <80 | 15 (34.1) | 29 (76.3) | 0.0001 |
| Abnormal neurological exam | 15 (34.1) | 25 (65.8) | 0.004 |
| Type of epilepsy | |||
| Focal | 38 (86.4) | 21 (55.3) | 0.0002 |
| Other generalized | 2 (4.6) | 16 (42.1) | |
| Idiopathic | 4 (9.1) | 1 (2.6) |
Of the uni-hemispheric lesions, 39 were focal, 4 multi-lobar and 1 involved the entire hemisphere. In the bi-hemispheric group, 12 involved bilateral homologous regions (e.g. bi-temporal), 2 were multi-lobar, 9 multifocal and 15 involved both hemispheres diffusely.
The P-value is driven by the differences in the focal and other generalized group.
a
Most (although not quite all) of the difference in follow-up is due to the higher mortality in the bilateral MRI positive group.