Epilepsy Surgery
Core concepts
Understand the presurgical evaluation: semiology, video-EEG, MRI (hippocampal sclerosis, focal cortical dysplasia), and when invasive monitoring (SEEG, subdural grids) is needed. Know the common surgically remediable syndromes: mesial temporal lobe epilepsy (anterior temporal lobectomy), lesional epilepsy, and hemispheric syndromes in children (hemispherectomy, functional hemispherectomy). Understand the concept of the epileptogenic zone vs the irritative zone vs the seizure-onset zone. Know the role of vagus nerve stimulation (VNS), responsive neurostimulation (RNS), and ketogenic diet for medically refractory epilepsy. Understand the risks of surgery (memory decline with dominant temporal resection, visual field deficits).
Traps
A frequent trap is offering surgery without confirming the epileptogenic zone, or confusing the irritative zone (interictal spikes) with the seizure-onset zone. Another is missing that dominant temporal resection risks verbal memory decline. Questions may test that VNS is palliative, not curative, and that RNS is for focal-onset seizures with limited resection options. Watch for misclassifying psychogenic nonepileptic spells as epilepsy.
Worked rule of thumb
Medically refractory epilepsy with a concordant MRI lesion and EEG focus is a strong surgical candidate. If noninvasive data are discordant, proceed to invasive monitoring. Counsel about memory risk before dominant temporal lobectomy.