Stereoelectroencephalography-guided radiofrequency thermocoagulation.

Within the neurosurgeon's armamentarium, stereoelectroencephalography (SEEG)-guided radiofrequency thermocoagulation (RFTC) is an elegant tool to manage epilepsy in selected cases. This technique can 1) be curative when targeting small-volume ictal onset zones, 2) be used as a diagnostic tool by observing the consequences of coagulation on seizures or by recording the epileptic network in SEEG, and 3) offer palliative treatment through multiple lesions within a wide epileptic network. It is performed on awake patients, under continuous neurological evaluation, while monitoring impedance, time, and energy delivered.

Insights on cognitive reorganization after hemispherectomy in Rasmussen's encephalitis. A narrative review.

Rasmussen's encephalitis is a rare neurological pathology affecting one cerebral hemisphere, therefore, posing unique challenges. Patients may undergo hemispherectomy, a surgical procedure after which cognitive development occurs in the isolated contralateral hemisphere. This rare situation provides an excellent opportunity to evaluate brain plasticity and cognitive recovery at a hemispheric level.

Targeting pathological cells with senolytic drugs reduces seizures in neurodevelopmental mTOR-related epilepsy.

Cortical malformations such as focal cortical dysplasia type II (FCDII) are associated with pediatric drug-resistant epilepsy that necessitates neurosurgery. FCDII results from somatic mosaicism due to post-zygotic mutations in genes of the PI3K-AKT-mTOR pathway, which produce a subset of dysmorphic cells clustered within healthy brain tissue. Here we show a correlation between epileptiform activity in acute cortical slices obtained from human surgical FCDII brain tissues and the density of dysmorphic neurons.

Deep retroinsular and parieto-opercular origin of vestibular symptoms: A stereoelectrocenphalography (SEEG) study.

Several studies have shown that the retroinsular and posterior parietal operculum regions play a central role in vestibular processing. Electrical stimulations performed during stereoelectroencephalography (SEEG) in patients with focal drug-resistant epilepsy could contribute to the analysis of this area. Among the 264 SEEGs performed in both an adult and a paediatric epilepsy surgery centre, we retrospectively identified 24 patients (9%) reporting vertigo during electrical stimulations (ES).

Detection of brain somatic mutations in focal cortical dysplasia during epilepsy presurgical workup.

Brain-restricted somatic variants in genes of the mechanistic target of rapamycin signalling pathway cause focal epilepsies associated with focal cortical dysplasia type II. We hypothesized that somatic variants could be identified from trace tissue adherent to explanted stereoelectroencephalography electrodes used in the presurgical epilepsy workup to localize the epileptogenic zone. We investigated three paediatric patients with drug-resistant focal epilepsy subjected to neurosurgery.

Cognitive outcome after left functional hemispherectomy on dominant hemisphere in patients with Rasmussen encephalitis: beyond the myth of aphasia. Patient series.

Background: Rasmussen encephalitis is a rare chronic neurological pathology frequently treated with functional hemispherectomy (or hemispherotomy). This surgical procedure frees patients of their severe epilepsy associated with the disease but may induce cognitive disorders and notably language alterations after disconnection of the left hemisphere.

Observations: The authors describe longitudinally 3 cases of female patients with Rasmussen encephalitis who underwent left hemispherotomy in childhood and benefited from a favorable cognitive outcome.

Preservation of frontal white matter tracts in ventricular surgery: favoring an anterior interhemispheric transcallosal approach vs a transcortical transfrontal transventricular approach.

Secondary to the creation of a surgical corridor and retraction, white matter tracts degenerate, causing long-term scarring with potential neurological consequences. Third and lateral ventricle tumors require surgery that may lead to cognitive impairment. Our objective is to compare the long-term consequences of a transcortical transfrontal approach and an interhemispheric transcallosal approach on corpus callosum and frontal white matter tracts degeneration.

Hypothalamic hamartoma associated with polymicrogyria and periventricular nodular heterotopia in children: report of three cases and discussion of the origin of the seizures.

Purpose: Hypothalamic hamartomas (HH) are malformations responsible for drug-resistant epilepsy. HH are usually isolated or part of a genetic syndrome, such as Pallister-Hall. Exceptionally they can be associated with other brain malformations such as polymicrogyria (PMG) and periventricular nodular heterotopia (PNH).

Complete callosotomy in children with drop attacks; A retrospective monocentric study of 50 patients.

Purpose: Corpus callosotomy is a palliative surgical procedure for patients with drug-resistant epilepsy and suffering from drop attacks, which are a source of major deterioration in quality of life and can be responsible for severe traumatic injury. The objective of this study is to identify clinical markers that would predict a better outcome in terms of drop attacks and other types of epileptic seizures.

Methods: We reviewed a retrospective series of children who underwent complete corpus callosotomy at our institution, between January 1998 and February 2019.

Vertical parasagittal hemispherotomy: a case report of postoperative mesio-temporal seizures via amygdalofugal pathway.

Vertical parasagittal hemispherotomy (VPH) is a well-established surgical treatment which is proposed for children with widespread unilateral onset of intractable epileptic seizures. VPH allows to disconnect from a vertical transventricular approach all white matter fibers of the hemisphere around a central core including the thalamus. We present the case of a girl who underwent VPH for hemimegalencephaly in early infancy.

Clinical semiology of temporal lobe seizures in preschool children: contribution of invasive recording to anatomical classification.

Focal seizure semiology is often inadequately studied, specifically in preschool children. Among drug-resistant epilepsies amenable to surgery, temporal lobe seizure semiology has been widely described in this age group. Nevertheless, a systematic anatomo-electroclinical study has never been performed.

F-FDG-PET hypometabolic pattern reveals multifocal epileptic foci despite limited unique stereotyped seizures.

Purpose: Interictal positron emission tomography (PET) with F-FDG has largely proved its utility in presurgical evaluation of drug-resistant epilepsies (DRE) and in the surgical outcomes. Interictal hypometabolism topography is related to the neuronal networks involved in the seizure onset zone (SOZ) and spread pathways. F-FDG PET has a good prognostic value for post-surgical outcome, especially in cases with unique focal ictal semiology and a limited extent of hypometabolism.

Focal polymicrogyria in children: Contribution of invasive explorations and epileptogenicity mapping in the surgical decision.

Objective: Report of the contribution of invasive EEG (iEEG) and epileptogenicity mappings (EM) in a pediatric cohort of patients with epilepsy associated with focal polymicrogyria (PMG) and candidates for resective surgery.

Method: Retrospective pediatric case series of patients presenting focal PMG-related refractory epilepsy undergoing an invasive exploration (iEEG) at Fondation Rothschild Hospital. We reviewed clinical data, structural MRI, and visual analysis of iEEG recordings.

Management and results of epilepsy surgery associated with acyclovir prophylaxis in four pediatric patients with drug-resistant epilepsy due to herpetic encephalitis and review of the literature.

Purpose: Herpes simplex virus encephalitis (HSE) is the most common cause of sporadic viral encephalitis in children and is responsible for epilepsy in approximately half of patients. In addition to medical treatment, epilepsy surgery may be offered to drug-resistant patients but carries a high risk of relapse of herpetic encephalitis. We are reporting our series of patients operated on between 2000 and 2019 with the systematic administration of acyclovir (ACV).

Seizure outcome and prognostic factors for surgical management of hypothalamic hamartomas in children.

Purpose: Hypothalamic hamartomas (HH) are rare benign lesions frequently associated with gelastic seizures early in life. Epilepsy can progress to multiple seizure types with cognitive impairment and behavioural disturbance, leading in some cases to epileptic encephalopathy.

Methods: We reviewed a retrospective series of 112 children treated in a single center, between 1998 and 2017.

Dissecting the genetic basis of focal cortical dysplasia: a large cohort study.

Genetic malformations of cortical development (MCDs), such as mild MCDs (mMCD), focal cortical dysplasia (FCD), and hemimegalencephaly (HME), are major causes of severe pediatric refractory epilepsies subjected to neurosurgery. FCD2 are characterized by neuropathological hallmarks that include enlarged dysmorphic neurons (DNs) and balloon cells (BCs). Here, we provide a comprehensive assessment of the contribution of germline and somatic variants in a large cohort of surgical MCD cases.

Parasagittal hemispherotomy in hemispheric polymicrogyria with electrical status epilepticus during slow sleep: Indications, results and follow-up.

Purpose: Polymicrogyria (PMG), although the most common brain malformation, represents a low percentage among patients operated on for epilepsy. In cases of hemispheric PMG, electrical status epilepticus during slow sleep (ESESS) may occur leading to an aggravation of the neurological condition and a risk of drug resistance. In such cases, surgical treatment can be offered.

SEEG-guided radiofrequency thermocoagulation of epileptic foci in the paediatric population: Feasibility, safety and efficacy.

Purpose: Focal epilepsy in children may be refractory to pharmacological treatment and surgical resection may be an appropriate option. When invasive electroencephalogram is required in the presurgical evaluation, depth electrodes can be used to create focal lesions in the epileptogenic zone using radiofrequency thermocoagulation (RFTC), to disrupt the epileptogenic zone.

Methods: This study aimed to assess the efficacy and safety of RFTC in a paediatric population of 46 patients.

Invasive evaluation in children (SEEG vs subdural grids).

Designed from the 60s to the 80s for adults, and despite the development of many new techniques, invasive explorations still have indications in children with focal drug-resistant epilepsy. The main types are stereoelectroencephalography (SEEG) and subdural explorations (SDE). They provide precise information on the localization of the epileptogenic zone (EZ), its relationships with eloquent cortex, and the feasibility of performing a tailored surgical resection.

Investigation of paediatric occipital epilepsy using stereo-EEG reveals a better surgical outcome than in adults, especially when the supracalcarine area is affected.

Occipital epilepsy is the least common among surgical series because: (1) the location makes it hard to asses by EEG; (2) the seizure semiology often reflects propagation; and (3) surgery entails a high risk of neurological deficits. In children, subjective symptoms are harder to assess, adding to the difficulty of a proper diagnosis. We aimed to determine electroclinical characteristics of occipital lobe epilepsy in a paediatric population by reviewing 20 children between one and 16 years, who had undergone intracranial recordings with depth electrodes.