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Epilepsy surgery can potentially cure pharmacoresistant temporal lobe epilepsy (TLE) in children. However, surgical failures, where patients continue to experience seizures, still exist. We evaluated outcomes in pediatric patients after resective temporal lobe surgery to identify risk factors for failure. Data on pediatric patients with TLE who underwent surgery were prospectively collected at our institution. Minimum follow-up (FU) was three years after surgery. Resections were stratified into extended resections, i.e., anterior temporal lobectomies, and sparing resections, i.e., lesionectomies and selective amygdalohippocampectomies. Ongoing seizures and relapses within the first three years were considered surgical failures. We included 96 patients after 43 sparing and 52 extended resections from 1993 to 2019 with a median FU of 10.1 years (range 3.0 to 28.3 years). Pathohistology most frequently revealed epilepsy-associated tumors (44.8%), hippocampal sclerosis (37.5%), and focal cortical dysplasias (12.5%). One year postoperatively, 69.8% were seizure free, increasing to 78.5% after five and 72.9% after 10 years. Sparing resections increased the odds for surgical failure in a multivariate analysis (odds ratio: 4.63, P = 0.006). Preoperative focal onset to bilateral tonic-clonic seizures increased the likelihood of seizure relapses (hazard ratio: 3.89, P = 0.006) and contributed to higher odds of surgical failure (odds ratio: 2.79, P = 0.002). Pediatric patients with TLE undergoing surgery have high rates of long-lasting favorable seizure outcomes. Resection strategy is a prognostic factor for early surgical success in favor of larger resections. Relapses were more frequent in children with focal onset to bilateral tonic-clonic seizures beforesurgery. [ABSTRACT FROM AUTHOR]

• Amino acid PET imaging in suspected LEAT provide a high diagnostic sensitivity for gangliogliomas. • ECoG and neuronavigation in extratemporal GG resections provide excellent seizure outcome. • In temporal GG an AMTLR (antero-mesial TLR) gave highest postoperative seizure freedom. Imaging and resection strategies for pediatric gangliogliomas (GG) and dysembryoplastic neuroepitheliomas (DNET) presenting with epilepsy were retrospectively analyzed in a consecutive institutional series of surgically treated patients. Twenty-two children (median 8 years, 3–18 years) presented with seizures for 30 months median (14–55.2 months) due to a histologically verified GG/DNET. There were 20 GG and 2 DNT, 68 % located temporal, 32 % extra-temporal. Seizure history was significantly longer in temporal cases (38 versus 14 months median, p < 0.01). MRI contrast enhancement was present in 50 % and methionine (MET) positron emission tomography (PET) uptake in 70 % (standard uptake values (SUVs) 2.92 mean, from 1.6 to 6.4). 27 % had glucose PET hypometabolism. Primarily, in temporal GG, ECoG (electrocorticography) -guided lesionectomies were performed in 87 % and antero-mesial temporal lobe resections (AMTLR) in 13 %, whereas in extra-temporal GG/DNETs, lesionectomies were performed in 100 %. ILAE Class 1 seizure outcome was primarily achieved in 73 % of the temporal cases, and was increased to 93 % by performing six repeat surgeries using AMTLR. Extratemporal patients experienced ILAE Class 1 seizure outcomes in 86 % without additional surgeries, although harboring significantly more residual tumor (p < 0.005, mean follow-up 28 months). In children, MET PET imaging for suspected GG is proposed preoperatively showing a high diagnostic sensitivity and an option to delineate the lesions for navigated resection, whereas MRI contrast behavior was of no differential diagnostic use. As a surgical strategy we propose primarily lesionectomies for extratemporal but AMTLR for temporal GG respecting eloquent brain areas. [ABSTRACT FROM AUTHOR]

Objectives: We recently introduced a frameless, navigated, robot-driven laser tool for depth electrode implantation as an alternative to frame-based procedures. This method has only been used in cadaver and non-recovery studies. This is the first study to test the robot-driven laser tool in an in vivo recovery animal study. Methods: A preoperative computed tomography (CT) scan was conducted to plan trajectories in sheep specimens. Burr hole craniotomies were performed using a frameless, navigated, robot-driven laser tool. Depth electrodes were implanted after cut-through detection was confirmed. The electrodes were cut at the skin level postoperatively. Postoperative imaging was performed to verify accuracy. Histopathological analysis was performed on the bone, dura, and cortex samples. Results: Fourteen depth electrodes were implanted in two sheep specimens. Anesthetic protocols did not show any intraoperative irregularities. One sheep was euthanized on the same day of the procedure while the other sheep remained alive for 1 week without neurological deficits. Postoperative MRI and CT showed no intracerebral bleeding, infarction, or unintended damage. The average bone thickness was 6.2 mm (range 4.1-8.0 mm). The angulation of the planned trajectories varied from 65.5° to 87.4°. The deviation of the entry point performed by the frameless laser beam ranged from 0.27 mm to 2.24 mm. The histopathological analysis did not reveal any damage associated with the laser beam. Conclusion: The novel robot-driven laser craniotomy tool showed promising results in this first in vivo recovery study. These findings indicate that laser craniotomies can be performed safely and that cut-through detection is reliable. [ABSTRACT FROM AUTHOR]

Magnetic resonance thermography−guided laser interstitial thermal therapy (LITT) provides a minimally invasive treatment option in children with central nervous system tumors or medically intractable epilepsy. However, transporting anesthetized children between an operating room (OR) and a radiologic suite creates logistical challenges. Thus we describe advantages of using a 2-room intraoperative magnetic resonance imaging (MRI) concept for LITT. Patients were pinned in a head frame that doubles as the lower part of the MRI head coil. Preoperative MRI was performed for accurate neuronavigation, after which laser fibers were stereotactically implanted. Transport between OR and MRI was achieved by sliding the top of the OR table onto a trolly. We performed 12 procedures in 11 children, mean age 7.1 years (range: 2 to 14 years). Ten children suffered from medically intractable epilepsy, and 1 child had a pilocytic midbrain astrocytoma. Two fibers were placed in 8 and 1 fiber in 4 procedures. Mean entry point and target errors were 2.8 mm and 3.4 mm, respectively. Average transfer time from OR to MRI and vice versa was 9 minutes (±1 minute, 40 seconds). Altogether, 50% of the seizure patients were seizure free (Engel grade I) at 22 months' follow-up time. One hemorrhagic event, which could be managed nonoperatively, occurred. We recorded no surgical site or intracranial infections. All LITT procedures were successfully carried out with head frame in the sterile environment. The intraoperative MRI suite proved to be advantageous for minimally invasive procedures, especially in young children resulting in short transports while maintaining high accuracy and safety. [ABSTRACT FROM AUTHOR]