Cortical evolutionary lineage as an organising principle for seizure semiology: implications for intracranial EEG and presurgical hypothesis generation.

BACKGROUND

Seizure semiology is usually interpreted through two main frameworks: anatomical localisation and network dynamics. Both are indispensable, but neither fully explains why certain cortical regions consistently produce particular classes of ictal phenomena, or why the same anatomical structure can generate different semiologies across seizures.

PURPOSE: To examine cortical evolutionary lineage as a complementary level of explanation for seizure semiology, and to explore its implications for intracranial EEG, presurgical hypothesis generation, and epilepsy surgery.

METHODS

This narrative review synthesises evidence from comparative neuroanatomy, cortical cytoarchitecture, stimulation studies, intracranial EEG propagation analyses, developmental myelination research, and surgical outcome literature, organised around Sanides' dual-origin model of cortical development.

RESULTS

In the dual-origin model, mammalian neocortex emerges from two allocortical epicentres-archicortical and paleocortical-forming dorsal and ventral gradients of increasing laminar differentiation. Viewed through this framework, seizures recruiting the ventral paleocortical gradient may preferentially produce autonomic, olfactory, visceral, and affective phenomena, whereas seizures engaging the dorsal archicortical gradient may be more likely to produce spatial, mnemonic, and complex motor features. This perspective offers a potential explanation for intrastructural semiological heterogeneity, patterns of seizure propagation, developmental changes in localising semiology, and a possible sampling blind spot in intracranial EEG implantation. It also suggests that some temporal lobe surgical failures may reflect misclassification of onset zone architecture rather than incomplete resection alone.

CONCLUSIONS

Cortical evolutionary lineage may offer a biologically grounded and testable framework for understanding seizure semiology. Rather than replacing localisationist or network-based models, it may help to anchor them within a broader account of how cortical structure, connectivity, and function are organised across evolutionary gradients.