Focal Cortical Dysplasia Surgery

• The "chapeau de gendarme" sign in focal epilepsy: A systematic review
• Effect of stereo-EEG versus subdural EEG on functional and seizure outcome in pediatric and adult epilepsy surgery: A 21-year single-center experience
• Anatomical-electroclinical phenotypes and SEEG-defined network patterns in pure insular lobe epilepsy: A study of 20 cases
• Critical contributions of neuronal subtypes to pediatric drug-resistant focal dysplasia
• Patterns of phosphorylated tau accumulation in a spectrum of acquired and developmental brain lesions associated with refractory epilepsy
• Computational modeling of frequency-dependent neocortical response to thalamic neurostimulation in epilepsy
• Converting "nonlesional" imaging occult epilepsy into a focal lesional entity using advanced imaging techniques: illustrative case
• Identification of Novel Mosaic Variants in Focal Epilepsy-Associated Patients' Brain Lesions

Surgery is considered in selected cases to achieve seizure control.

• Medically refractory epilepsy (failure of ≥2 anti-seizure medications)
• Well-localized epileptogenic zone
• MRI-visible lesion (especially FCD Type II)
• Concordant findings between MRI, EEG, and functional imaging
• Lesion not involving eloquent cortex or amenable to functional mapping

• High-resolution 3T MRI (epilepsy protocol)
• Video-EEG monitoring to define seizure onset zone
• Functional imaging:
  • PET (interictal hypometabolism)
  • SPECT (ictal/interictal perfusion mismatch)
• Neuropsychological assessment
• MEG or SEEG in MRI-negative or complex cases

• Lesionectomy: Removal of visible lesion
• Extended resection: Includes epileptogenic cortex surrounding the lesion
• Lobectomy / multilobar resection: If larger epileptogenic network
• LITT (Laser interstitial thermal therapy): Minimally invasive alternative for deep or eloquent areas
• Palliative options: Vagus nerve stimulation, corpus callosotomy if non-resectable

• Seizure freedom (Engel Class I):
  • 70–80% in well-selected patients
  • Higher success in FCD Type IIb and MRI-positive cases
• Predictors of good outcome:
  • Complete resection
  • Histology: FCD IIb
  • Concordant EEG/MRI
• Possible complications:
  • Neurological deficits (depending on location)
  • Transient or permanent cognitive impairment

• Type I: Isolated cortical dyslamination
• Type IIa: Dysmorphic neurons without balloon cells
• Type IIb: Dysmorphic neurons with balloon cells (best surgical outcomes)
• Type III: FCD associated with another lesion (e.g., tumor, hippocampal sclerosis)

• Post-op MRI to assess completeness of resection
• EEG monitoring
• Gradual withdrawal of antiepileptic drugs after ≥1–2 years seizure freedom
• Neuropsychological reassessment

Resection for focal cortical dysplasia treatment.