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Surgically remediable epilepsy of the eloquent brain poses the added challenge of preserving function while curing disease. Long-standing epileptogenic lesions have tenacious seizure networks and significant functional reorganizations. Large multilobar lesions may involve multiple functional areas, thereby challenging the limits of functional brain mapping. In this video, the authors describe a dominant hemisphere fronto-parieto-temporo-occipital malformation of cortical development, involving the language, sensorimotor, and visual cortices, placing multiple eloquent cortical and subcortical regions at risk. They illustrate the technique of hexamodal mapping/monitoring involving the language sensorimotor areas, optic radiation, auditory pathway, and ictal irritative zone for a multilobar resection, with good seizure outcome and function preservation. The video can be found here: https://stream.cadmore.media/r10.3171/2024.10.FOCVID24111., Competing Interests: Disclosures Dr. Thomas reported grants from DST, Government of India; and ICMR, Government of India, outside the submitted work.Dr. Thomas reported grants from DST, Government of India; and ICMR, Government of India, outside the submitted work., (© 2025, The Authors.)

Objective: The authors studied the clinical characteristics and postoperative outcomes of drug-resistant epilepsy associated with focal gliosis., Methods: From their epilepsy surgery database, the authors selected the patients with drug-resistant epilepsy and MRI-defined focal gliosis who underwent focal resective surgery. All patients underwent standard presurgical evaluation. Intracranial electroencephalography (EEG) was performed in patients with discordant presurgical data, ill-defined lesions, and lesions close to eloquent regions. Completeness of resection was defined on the basis of extraoperative and intraoperative electrocorticography studies. Favorable postoperative outcome was defined as Engel class I outcome during the last 2 years of follow-up., Results: Sixty-six patients fulfilled inclusion criteria. An initial precipitating injury was present in 38 (57.6%) patients, mainly in the form of perinatal injury (n = 10), trauma (n = 10), and meningoencephalitis (n = 8). Gliosis involved a single lobe in 38 (57.6%) patients and 2 adjacent lobes in 14 (21.2%) patients; the remaining 14 (21.2%) patients had multilobar gliosis. In patients with unilobar or bilobar gliosis, the posterior region of the head was involved in 34 (65%) patients and the frontal lobes in 12 (23%) patients. During a median follow-up of 4 years (range 2-9 years), 41 (62.1%) patients had favorable outcome. On multivariate analysis, the presence of a well-defined aura (p = 0.019), electrocorticographically defined completeness of resection (p = 0.024), and normal postoperative EEG findings at 1 year (p = 0.003) were predictive of favorable postoperative seizure outcome., Conclusions: Focal gliosis is a common etiology for drug-resistant extratemporal epilepsy in developing countries and is most often located in the posterior region of the head. The majority of these patients have perinatal injuries or neurological infections as initial precipitating injuries. Patients with focal gliosis have good postoperative seizure outcomes after well-planned resective surgery.