Table 2 2013 International League against Epilepsy classification of MTS and the average age of initial precipitating lesion (IPL) occurrence [43, 44]
From: Mesial temporal sclerosis and epilepsy: a narrative review
MTS classification | Age of IPL | Description |
|---|---|---|
Type 1 (classic): 60–80% of cases | < 3 years | CA1-predominant severe loss of pyramidal neurons (PNs); also significant PN loss in CA2, CA3 and CA4 |
Type 2 5–10% of cases | 6 years | CA1-predominant PN loss; slight cell loss in the other sectors |
Type 3 (folium terminal sclerosis) | > 13 years | Predominant PN loss in CA4 and the dentate gyrus, associated with moderate loss of PN in the other sectors. |
Type 4 (No- hippocampal sclerosis) | > 16 years | No evidence of hippocampal sclerosis; only focal gliosis |