Presurgical evaluation for drug refractory epilepsy

- Presurgical evaluation for drug refractory epilepsy must be multimodal.
- Basic investigations are a video EEG documenting 3 habitual seizures more seizures must be recorded if there are multiple lesions, combination with pseudoseizures, normal MRI and discordance in localization between these.
- A 3 Tesla epilepsy protocol MRI which is elctroclinically guided to its reading is a must.
- When there is discordance of these basic investigations or when the MRI is normal and shows multiple lesions- PET, Ictal and interictal SPECT (SISCOS) and MEG must be done.
- When the hypothesis is clear but not sufficient to go for direct surgery Stereo EEG implantation and grids (for mapping eloquent cortex) specially should be used.

Surgical management of epilepsy is an established safe and effective way in improving patients' seizure frequency and overall morbidity. A robust array of options is available to carry out an in-depth evaluation of a surgical candidate in epilepsy. However, underutilisation of the available options may seriously challange post-operative outcomes. In this paper, we discuss the different aspects of various non-invasive and invasive procedures available to evaluate a surgical candidate of epilepsy and discuss their relative advantages and position in the diagnostic algorithm.