Intraoperative cortico-cortical evoked potentials show disconnection of the motor cortex from the epileptogenic network during subtotal hemispherotomy

Comparing late‐onset epileptic spasm outcomes after corpus callosotomy and subsequent disconnection surgery between post‐encephalitis/encephalopathy and non‐encephalitis/encephalopathy

“…In a subset of the NE group, PMA was spared because of early myelination before birth, whereas the association fiber pathways become gradually myelinated after birth 31–33 . Recent integrated neurophysiological techniques have provided converging evidence for the involvement of abnormal cortico‐cortical networks in multilobar epileptic zones, relatively sparing the PMA in the generation of ES 16,17,33–36 . Subtotal hemispherotomy could be considered the last resort for patients with drug‐resistant LOES in the NE group.…”

“…If lateralization of the EEG is confirmed after CC, the subsequent epilepsy surgery, that is, subtotal hemispherotomy, anterior quadrant disconnection (AQD), or posterior quadrant disconnection (PQD), is actively considered to eliminate all types of seizures. Subtotal hemispherotomy consists of AQD, PQD, and CC of the central part after undergoing intracranial video‐EEG using chronic subdural grid electrodes to identify the seizure network and confirm the primary motor area (PMA) could be preserved 16–18 . In a subset of patients with apparent unilateral MRI lesions and EEG abnormalities, subtotal hemispherotomy, hemispherotomy, or other disconnection surgeries would be chosen, considering age and presence, degree, and extent of hemiplegia.…”

“…Subtotal hemispherotomy consists of AQD, PQD, and CC of the central part after undergoing intracranial video-EEG using chronic subdural grid electrodes to identify the seizure network and confirm the primary motor area (PMA) could be preserved. [16][17][18] In a subset of patients with apparent unilateral MRI lesions and EEG abnormalities, subtotal hemispherotomy, hemispherotomy, or other disconnection surgeries would be chosen, considering age and presence, degree, and extent of hemiplegia.…”

“…Last follow-up Sz Follow-up (y) ES ( 11) FS ( 6) GS ( 7) SS (4) techniques have provided converging evidence for the involvement of abnormal cortico-cortical networks in multilobar epileptic zones, relatively sparing the PMA in the generation of ES. 16,17,[33][34][35][36] Subtotal hemispherotomy could be considered the last resort for patients with drugresistant LOES in the NE group. The etiologies of LOES in the PE group consisted of eight patients with AESD, 6,37 two with other viral encephalitis, 22 and one each with HSES 38 and febrile infectionrelated epilepsy syndrome.…”