A multi-center comparison of surgical techniques for corpus Callosotomy in pediatric drug-resistant epilepsy.

OBJECTIVES: Corpus callosotomy (CC) is used to reduce seizures, primarily in patients with generalized drug-resistant epilepsy (DRE). The invasive nature of the procedure contributes to underutilization despite its potential superiority to other palliative procedures. The goal of this study was to use a multi-institutional epilepsy surgery database to characterize the use of CC across participating centers. METHODS: Data were acquired from the Pediatric Epilepsy Research Consortium (PERC) Surgery Database, a prospective observational study collecting data on children 0-18 years referred for surgical evaluation of DRE across 22 U.S. pediatric epilepsy centers. Patient, epilepsy, and surgical characteristics were collected across multiple CC modalities. Outcomes and complications were recorded and analyzed statistically. RESULTS: Eighty-three patients undergoing 85 CC procedures at 14 participating epilepsy centers met inclusion criteria. Mean age at seizure onset was 2.3 years (0-9.4); mean age for Phase I evaluation and surgical intervention were 9.45 (.1-20) and 10.46 (.2-20.6) years, respectively. Generalized seizure types were the most common (59%). Complete CC was performed in 88%. The majority of CC procedures (57%) were via open craniotomy, followed by laser interstitial thermal therapy (LiTT) (20%) and mini-craniotomy/endoscopic (mc/e) (22%). Mean operative times were significantly longer for LiTT, whereas mean estimated blood loss was greater in open cases. Complications occurred in 11 cases (13%) and differed significantly between surgical techniques (p < .001). There was no statistically significant difference in length of postoperative stay across approaches. Mean follow-up was 12.8 months (range 1-39). Favorable Engel outcomes were experienced by 37 (78.7%) of the patients who underwent craniotomy, 10 (58.8%) with LiTT, and 12 (63.2%) with mc/e; these differences were not statistically significant. SIGNIFICANCE: CC is an effective surgical modality for children with DRE. Regardless of surgical modality, complication rates are acceptable and seizure outcomes generally favorable. Newer, less-invasive, surgical approaches may lead to increased adoption of this efficacious therapeutic option for pediatric DRE.

Cranial bone thickness and density anomalies quantified from CT images can identify chronic increased intracranial pressure.

PURPOSE: The diagnosis of chronic increased intracranial pressure (IIP)is often based on subjective evaluation or clinical metrics with low predictive value. We aimed to quantify cranial bone changes associated with pediatric IIP using CT images and to identify patients at risk. METHODS: We retrospectively quantified local cranial bone thickness and mineral density from the CT images of children with chronic IIP and compared their statistical differences to normative children without IIP adjusting for age, sex and image resolution. Subsequently, we developed a classifier to identify IIP based on these measurements. Finally, we demonstrated our methods to explore signs of IIP in patients with non-syndromic sagittal craniosynostosis (NSSC). RESULTS: We quantified a significant decrease of bone density in 48 patients with IIP compared to 1,018 normative subjects (P < .001), but no differences in bone thickness (P = .56 and P = .89 for age groups 0-2 and 2-10 years, respectively). Our classifier demonstrated 83.33% (95% CI: 69.24%, 92.03%) sensitivity and 87.13% (95% CI: 84.88%, 89.10%) specificity in identifying patients with IIP. Compared to normative subjects, 242 patients with NSSC presented significantly lower cranial bone density (P < .001), but no differences were found compared to patients with IIP (P = .57). Of patients with NSSC, 36.78% (95% CI: 30.76%, 43.22%) presented signs of IIP. CONCLUSION: Cranial bone changes associated with pediatric IIP can be quantified from CT images to support earlier diagnoses of IIP, and to study the presence of IIP secondary to cranial pathology such as non-syndromic sagittal craniosynostosis.

Somatic variants in diverse genes leads to a spectrum of focal cortical malformations.

Post-zygotically acquired genetic variants, or somatic variants, that arise during cortical development have emerged as important causes of focal epilepsies, particularly those due to malformations of cortical development. Pathogenic somatic variants have been identified in many genes within the PI3K-AKT-mTOR-signalling pathway in individuals with hemimegalencephaly and focal cortical dysplasia (type II), and more recently in SLC35A2 in individuals with focal cortical dysplasia (type I) or non-dysplastic epileptic cortex. Given the expanding role of somatic variants across different brain malformations, we sought to delineate the landscape of somatic variants in a large cohort of patients who underwent epilepsy surgery with hemimegalencephaly or focal cortical dysplasia. We evaluated samples from 123 children with hemimegalencephaly (n = 16), focal cortical dysplasia type I and related phenotypes (n = 48), focal cortical dysplasia type II (n = 44), or focal cortical dysplasia type III (n = 15). We performed high-depth exome sequencing in brain tissue-derived DNA from each case and identified somatic single nucleotide, indel and large copy number variants. In 75% of individuals with hemimegalencephaly and 29% with focal cortical dysplasia type II, we identified pathogenic variants in PI3K-AKT-mTOR pathway genes. Four of 48 cases with focal cortical dysplasia type I (8%) had a likely pathogenic variant in SLC35A2. While no other gene had multiple disease-causing somatic variants across the focal cortical dysplasia type I cohort, four individuals in this group had a single pathogenic or likely pathogenic somatic variant in CASK, KRAS, NF1 and NIPBL, genes previously associated with neurodevelopmental disorders. No rare pathogenic or likely pathogenic somatic variants in any neurological disease genes like those identified in the focal cortical dysplasia type I cohort were found in 63 neurologically normal controls (P = 0.017), suggesting a role for these novel variants. We also identified a somatic loss-of-function variant in the known epilepsy gene, PCDH19, present in a small number of alleles in the dysplastic tissue from a female patient with focal cortical dysplasia IIIa with hippocampal sclerosis. In contrast to focal cortical dysplasia type II, neither focal cortical dysplasia type I nor III had somatic variants in genes that converge on a unifying biological pathway, suggesting greater genetic heterogeneity compared to type II. Importantly, we demonstrate that focal cortical dysplasia types I, II and III are associated with somatic gene variants across a broad range of genes, many associated with epilepsy in clinical syndromes caused by germline variants, as well as including some not previously associated with radiographically evident cortical brain malformations.

Surgical evaluation in children <3 years of age with drug-resistant epilepsy: Patient characteristics, diagnostic utilization, and potential for treatment delays.

OBJECTIVE: Drug-resistant epilepsy (DRE) occurs at higher rates in children <3 years old. Epilepsy surgery is effective, but rarely utilized in young children despite developmental benefits of early seizure freedom. The present study aims to identify unique patient characteristics and evaluation strategies in children <3 years old who undergo epilepsy surgery evaluation as a means to assess contributors and potential solutions to health care disparities in this group. METHODS: The Pediatric Epilepsy Research Consortium Epilepsy Surgery Database, a multicentered, cross-sectional collaboration of 21 US pediatric epilepsy centers, collects prospective data on children <18 years of age referred for epilepsy surgery evaluation. We compared patient characteristics, diagnostic utilization, and surgical treatment between children <3 years old and those older undergoing initial presurgical evaluation. We evaluated patient characteristics leading to delayed referral (>1 year) after DRE diagnosis in the very young. RESULTS: The cohort included 437 children, of whom 71 (16%) were <3 years of age at referral. Children evaluated before the age of 3 years more commonly had abnormal neurological examinations (p = .002) and daily seizures (p = .001). At least one ancillary test was used in 44% of evaluations. Fifty-nine percent were seizure-free following surgery (n = 34), with 35% undergoing limited focal resections. Children with delayed referrals more often had focal aware (p < .001) seizures and recommendation for palliative surgeries (p < .001). SIGNIFICANCE: There are relatively few studies of epilepsy surgery in the very young. Surgery is effective, but may be disproportionally offered to those with severe presentations. Relatively low utilization of ancillary testing may contribute to reduced surgical therapy for those without evident lesions on magnetic resonance imaging. Despite this, a sizeable portion of patients have favorable outcome after focal epilepsy surgery resections.

Vascularized Pericranial Flap as a Method to Prevent Persistent Skull Defects After Craniectomy for Sagittal Synostosis.

ABSTRACT: Some cranial defects resulting from sagittal craniectomy for craniosynostosis never completely close and require cranioplasty. This study evaluates the results of 2 methods to minimize such defects: (1) trapezoidal craniectomy that is narrower posteriorly (2) vascularized pericranial flap that is sewn to the dura under a rectangular craniectomy.Children who underwent primary open sagittal craniectomy with biparietal morcellation (with/without frontal cranioplasty) for single-suture nonsyndromic sagittal synostosis from 2013 through 2018 were included. Children were excluded if there was a dural tear, if they had no 1-year follow-up, or if they had unmeasured and/or uncounted skull defects. Surgeries were divided into (1) standard craniectomy, (2) trapezoidal craniectomy, or (3) craniectomy with pericranial flap. Differences in percentage of children with defects and mean total defect area 1 year postsurgery were compared between the 3 groups.We reviewed 148 cases. After exclusions, 34 of 53 children (64%) who underwent standard craniectomy, 6 of 17 children (35%) who had pericranial flaps, and 5 of 11 children (46%) who underwent trapezoidal craniectomy had defects 1 year postsurgery. The percentage of children with defects (P = 0.0364) but not the defect area was significantly higher in the standard craniectomy than in the pericranial flap group. The percentage of subjects with defects was not significantly different between the standard and the trapezoidal craniectomy groups.Sewing a vascularized pericranial flap to the dura at the craniectomy site may protect against persistent bony defects after sagittal craniectomy for craniosynostosis. Longer follow-up is needed to determine if this technique leads to lower rates of cranioplasty.

Evolution of a Virtual Multidisciplinary Cleft and Craniofacial Team Clinic During the COVID-19 Pandemic: Children's Hospital Colorado Experience.

Multidisciplinary care in the era of COVID mitigation presented a unique opportunity to evolve a multidisciplinary Telehealth experience at the Children's Hospital Colorado. We describe our experience in developing unique programming to remain in compliance with an experience as recommended by the Parameters of Care while integrating information technology accessible via the electronic health record, multimedia adjuncts, and the integration of multiple institutional participants in creating a platform to offer care via Telehealth. Visit structure, planning, implementation, and advantages and disadvantages of the programming are discussed.

Albumin induces excitatory synaptogenesis through astrocytic TGF-ß/ALK5 signaling in a model of acquired epilepsy following blood-brain barrier dysfunction.

Post-injury epilepsy (PIE) is a common complication following brain insults, including ischemic, and traumatic brain injuries. At present, there are no means to identify the patients at risk to develop PIE or to prevent its development. Seizures can occur months or years after the insult, do not respond to anti-seizure medications in over third of the patients, and are often associated with significant neuropsychiatric morbidities. We have previously established the critical role of blood-brain barrier dysfunction in PIE, demonstrating that exposure of brain tissue to extravasated serum albumin induces activation of inflammatory transforming growth factor beta (TGF-ß) signaling in astrocytes and eventually seizures. However, the link between the acute astrocytic inflammatory responses and reorganization of neural networks that underlie recurrent spontaneous seizures remains unknown. Here we demonstrate in vitro and in vivo that activation of the astrocytic ALK5/TGF-ß-pathway induces excitatory, but not inhibitory, synaptogenesis that precedes the appearance of seizures. Moreover, we show that treatment with SJN2511, a specific ALK5/TGF-ß inhibitor, prevents synaptogenesis and epilepsy. Our findings point to astrocyte-mediated synaptogenesis as a key epileptogenic process and highlight the manipulation of the TGF-ß-pathway as a potential strategy for the prevention of PIE.

What to do with an incidental finding of a fused sagittal suture: a modified Delphi study.

OBJECTIVE: As many as 5% of normocephalic children may have a prematurely fused sagittal suture, yet the clinical significance and best course of management of this finding remain unclear. Providers in the Synostosis Research Group were surveyed to create a multicenter consensus on an optimal treatment and monitoring algorithm for this condition. METHODS: A four-round modified Delphi method was utilized. The first two rounds consisted of anonymous surveys distributed to 10 neurosurgeons and 9 plastic surgeons with expertise in craniosynostosis across 9 institutions, and presented 3 patients (aged 3 years, 2 years, and 2 months) with incidentally discovered fused sagittal sutures, normal cephalic indices, and no parietal dysmorphology. Surgeons were queried about their preferred term for this entity and how best to manage these patients. Results were synthesized to create a treatment algorithm. The third and fourth feedback rounds consisted of open discussion of the algorithm until no further concerns arose. RESULTS: Most surgeons preferred the term "premature fusion of the sagittal suture" (93%). At the conclusion of the final round, all surgeons agreed to not operate on the 3- and 2-year-old patients unless symptoms of intracranial hypertension or papilledema were present. In contrast, 50% preferred to operate on the 2-month-old. However, all agreed to utilize shared decision-making, taking into account any concerns about future head shape and neurodevelopment. Panelists agreed that patients over 18 months of age without signs or symptoms suggesting elevated intracranial pressure (ICP) should not undergo surgical treatment. CONCLUSIONS: Through the Delphi method, a consensus regarding management of premature fusion of the sagittal suture was obtained from a panel of North American craniofacial surgeons. Without signs or symptoms of ICP elevation, surgery is not recommended in patients over 18 months of age. However, for children younger than 18 months, surgery should be discussed with caregivers using a shared decision-making process.

Pediatric neuromodulation for drug-resistant epilepsy: Survey of current practices, techniques, and outcomes across US epilepsy centers.

Neuromodulation via Responsive Neurostimulation (RNS) or Deep Brain Stimulation (DBS) is an emerging treatment strategy for pediatric drug-resistant epilepsy (DRE). Knowledge gaps exist in patient selection, surgical technique, and perioperative care. Here, we use an expert survey to clarify practices. Thirty-two members of the Pediatric Epilepsy Research Consortium were surveyed using REDCap. Respondents were from 17 pediatric epilepsy centers (missing data in one): Four centers implant RNS only while 13 implant both RNS and DBS. Thirteen RNS programs commenced in or before 2020, and 10 of 12 DBS programs began thereafter. The busiest six centers implant 6-10 new RNS devices per year; all DBS programs implant <5 annually. The youngest RNS patient was 3 years old. Most centers (11/12) utilize MP2RAGE and/or FGATIR sequences for planning. Centromedian thalamic nuclei were the unanimous target for Lennox-Gastaut syndrome. Surgeon exposure to neuromodulation occurred mostly in clinical practice (14/17). Clinically significant hemorrhage (n = 2) or infection (n = 3) were rare. Meaningful seizure reduction (>50%) was reported by 81% (13/16) of centers. RNS and DBS are rapidly evolving treatment modalities for safe and effective treatment of pediatric DRE. There is increasing interest in multicenter collaboration to gain knowledge and facilitate dialogue. PLAIN LANGUAGE SUMMARY: We surveyed 32 pediatric epilepsy centers in USA to highlight current practices of intracranial neuromodulation. Of the 17 that replied, we found that most centers are implanting thalamic targets in pediatric drug-resistant epilepsy using the RNS device. DBS device is starting to be used in pediatric epilepsy, especially after 2020. Different strategies for target identification are enumerated. This study serves as a starting point for future collaborative research.

Pediatric Palliative Epilepsy Surgery: A Report From the Pediatric Epilepsy Research Consortium (PERC) Surgery Database.

BACKGROUND: Epilepsy surgery is an underutilized resource for children with drug-resistant epilepsy. Palliative and definitive surgical options can reduce seizure burden and improve quality of life. Palliative epilepsy surgery is often seen as a "last resort" compared to definitive surgical options. We compare patient characteristics between palliative and definitive epilepsy surgical patients and present palliative surgical outcomes from the Pediatric Epilepsy Research Consortium surgical database. METHODS: The Pediatric Epilepsy Research Consortium Epilepsy Surgery database is a prospective registry of patients aged 0-18 years undergoing evaluation for epilepsy surgery at 20 pediatric epilepsy centers. We included all children with completed surgical therapy characterized as definitive or palliative. Demographics, epilepsy type, age of onset, age at referral, etiology of epilepsy, treatment history, time-to-referral/evaluation, number of failed anti-seizure medications (ASMs), imaging results, type of surgery, and postoperative outcome were acquired. RESULTS: Six hundred forty patients undergoing epilepsy surgery were identified. Patients undergoing palliative procedures were younger at seizure onset (median: 2.1 vs 4 years, P= 0.0008), failed more ASM trials before referral for presurgical evaluation (P=<0.0001), and had longer duration of epilepsy before referral for surgery (P=<0.0001). During presurgical evaluation, patients undergoing palliative surgery had shorter median duration of video-EEG data collected (P=0.007) but number of cases where ictal data were acquired was similar between groups. The most commonly performed palliative procedure was corpus callosotmy (31%), followed by lobectomy (21%) and neuromodulation (82% responsive neurostimulation vs 18% deep brain stimulation). Palliative patients were further categorized into traditionally palliative procedures vs traditionally definitive procedures. The majority of palliative patients had 50% reduction or better in seizure burden. Seizure free outcomes were significantly higher among those with traditional definitive surgeries, 41% (95% confidence interval: 26% to 57%) compared with traditional palliative surgeries and 9% (95% confidence interval: 2% to 17%). Rate of seizure freedom was 46% at 24 months or greater of follow-up in the traditional definitive group. CONCLUSIONS: Patients receiving palliative epilepsy surgery trialed more ASMs, were referred later after becoming drug resistant, and had longer gaps between drug resistance and epilepsy surgery compared with patients undergoing definitive epilepsy surgery. The extent of surgical evaluation is impacted if surgery is thought to be palliative. A majority of palliative surgery patients achieved >50% seizure reduction at follow-up, both in groups that received traditionally palliative and traditionally definitive surgical procedures. Palliative surgical patients can achieve greater seizure control and should be referred to an epilepsy surgery center promptly after failing two appropriate anti-seizure medications.

Two-photon microendoscope for label-free imaging in stereotactic neurosurgery.

We demonstrate a gradient refractive index (GRIN) microendoscope with an outer diameter of ∼1.2 mm and a length of ∼186 mm that can fit into a stereotactic surgical cannula. Two photon imaging at an excitation wavelength of 900 nm showed a field of view of ∼180 microns and a lateral and axial resolution of 0.86 microns and 9.6 microns respectively. The microendoscope was tested by imaging autofluorescence and second harmonic generation (SHG) in label-free human brain tissue. Furthermore, preliminary image analysis indicates that image classification models can predict if an image is from the subthalamic nucleus or the surrounding tissue using conventional, bench-top two-photon autofluorescence.

Responsive Neurostimulation in Drug-Resistant Pediatric Epilepsy: Findings From the Epilepsy Surgery Subgroup of the Pediatric Epilepsy Research Consortium.

BACKGROUND: Responsive neurostimulation (RNS), a closed-loop intracranial electrical stimulation system, is a palliative surgical option for patients with drug-resistant epilepsy (DRE). RNS is approved by the US Food and Drug Administration for patients aged ≥18 years with pharmacoresistant partial seizures. The published experience of RNS in children is limited. METHODS: This is a combined prospective and retrospective study of patients aged ≤18 years undergoing RNS placement. Patients were identified from the multicenter Pediatric Epilepsy Research Consortium Surgery Registry from January 2018 to December 2021, and additional data relevant to this study were retrospectively collected and analyzed. RESULTS: Fifty-six patients received RNS during the study period. The mean age at implantation was 14.9 years; the mean duration of epilepsy, 8.1 years; and the mean number of previously trialed antiseizure medications, 4.2. Five patients (9%) previously trialed dietary therapy, and 19 patients (34%) underwent prior surgery. Most patients (70%) underwent invasive electroencephalography evaluation before RNS implantation. Complications occurred in three patients (5.3%) including malpositioned leads or transient weakness. Follow-up (mean 11.7 months) was available for 55 patients (one lost), and four were seizure-free with RNS off. Outcome analysis of stimulation efficacy was available for 51 patients: 33 patients (65%) were responders (≥50% reduction in seizure frequency), including five patients (10%) who were seizure free at follow-up. CONCLUSIONS: For young patients with focal DRE who are not candidates for surgical resection, neuromodulation should be considered. Although RNS is off-label for patients aged <18 years, this multicenter study suggests that it is a safe and effective palliative option for children with focal DRE.

Epilepsy surgery in children with genetic etiologies: A prospective evaluation of current practices and outcomes.

OBJECTIVE: This study assesses current practices and outcomes of epilepsy surgery in children with a genetic etiology. It explores the pre-surgical workup, types of surgeries, and post-surgical outcomes in a broad array of disorders. METHODS: Patients ≤18 years who completed epilepsy surgery and had a known genetic etiology prior to surgical intervention were extrapolated from the Pediatric Epilepsy Research Consortium (PERC) surgery database, across 18 US centers. Data were assessed univariably by neuroimaging and EEG results, genetic group (structural gene, other gene, chromosomal), and curative intent. Outcomes were based on a modified International League Against Epilepsy (ILAE) outcome score. RESULTS: Of 81 children with genetic epilepsy, 72 % had daily seizures when referred for surgery evaluation, which occurred a median of 2.2 years (IQR 0.3, 5.2) after developing drug resistance. Following surgery, 68 % of subjects had >50 % seizure reduction, with 33 % achieving seizure freedom [median follow-up 11 months (IQR 6, 17). Seizure freedom was most common in the monogenic structural group, but significant palliation was present across all groups. Presence of a single EEG focus was associated with a greater likelihood of seizure freedom (p=0.02). SIGNIFICANCE: There are meaningful seizure reductions following epilepsy surgery in the majority of children with a genetic etiology, even in the absence of a single structural lesion and across a broad spectrum of genetic causes. These findings highlight the need for expedited referral for epilepsy surgery and support of a broadened view of which children may benefit from epilepsy surgery, even when the intent is palliative.

Intracranial pressure monitoring during stereoelectroencephalography implantation: a technical note.

Stereoelectroencephalography (SEEG) has become increasingly employed as a critical component of epilepsy workups for patients with drug-resistant epilepsy when information from noninvasive studies is not conclusive and sufficient to guide epilepsy surgery. Although exceedingly rare, clinically significant hemorrhagic complications can be caused during SEEG implantation procedures. Intracranial hemorrhage (ICH) can be difficult to recognize due to the minimally invasive nature of SEEG. The authors describe their technique using a commercially available intraparenchymal intracranial pressure (ICP) monitor as a method for early intraoperative detection of ICH during SEEG implantation. Between May 2019 and July 2021, 18 pediatric patients underwent SEEG implantation at a single, freestanding children's hospital with the use of an ICP monitor during the procedure. No patients experienced complications resulting from this technique. The authors have relayed their rationale for ICP monitor use during SEEG, the technical considerations, and the safety profile. In addition, they have reported an illustrative case in which the ICP monitor proved crucial in early detection of ICH during SEEG implantation.

Postoperative general medical ward admission following Chiari malformation decompression.

OBJECTIVE: Prior to 2019, the majority of patients at Children's Hospital Colorado were admitted to the pediatric intensive care unit (PICU) following Chiari malformation (CM) decompression surgery. This study sought to identify the safety and efficacy of postoperative general ward management for these patients. METHODS: After a retrospective baseline assessment of 150 patients, a quality improvement (QI) initiative was implemented, admitting medically noncomplex patients to the general ward postoperatively following CM decompression. Twenty-one medically noncomplex patients were treated during the QI intervention period. All patients were assessed for length of stay, narcotic use, time to ambulation, and postoperative complications. RESULTS: PICU admission rates postoperatively decreased from 92.6% to 9.5% after implementation of the QI initiative. The average hospital length of stay decreased from 3.4 to 2.6 days, total doses of narcotic administration decreased from 12.3 to 8.7, and time to ambulation decreased from 1.8 to 0.9 days. There were no major postoperative complications identified that were unsuitable for management on a conventional pediatric medical/surgical nursing unit. CONCLUSIONS: Medically noncomplex patients were safely admitted to the general ward postoperatively at Children's Hospital Colorado after decompression of CM. This approach afforded decreased length of stay, decreased narcotic use, and decreased time to ambulation, with no major postoperative complications.

Smaller Knife, Fewer Seizures? Recent Advances in Minimally Invasive Techniques in Pediatric Epilepsy Surgery.

Children with drug-resistant epilepsy are at high risk for developmental delay, increased mortality, psychiatric comorbidities, and requiring assistance with activities of daily living. Despite the advent of new and effective pharmacologic therapies, about one in 5 children will develop drug-resistant epilepsy, and most of these children continue to have seizures despite trials of other medication. Epilepsy surgery is often a safe and effective option which may offer seizure freedom or at least a significant reduction in seizure burden in many children. However, despite published evidence of safety and efficacy, epilepsy surgery remains underutilized in the pediatric population. Patient and family fears about the risks of surgery may contribute to this gap. Less invasive surgical techniques may be more palatable to children with epilepsy and their caregivers. In this review, we present recent advances in minimally invasive techniques for the surgical treatment of epilepsy as well as intriguing possibilities for the future. We describe the indications for, benefits of, and limits to minimally-invasive techniques including Stereo-encephalography, laser interstitial thermal ablation, deep brain stimulation, focused ultrasound, stereo-encephalography-guided radiofrequency ablation, endoscopic disconnections, and responsive neurostimulation.

Comparison of subdural grid and stereoelectroencephalography in a cohort of pediatric patients.

OBJECTIVE: To compare adverse events and outcomes between stereoelectroencephalography (SEEG) and subdural electrode (SDE) implantation in children. METHODS: This was a retrospective analysis of 108 patients who underwent intracranial monitoring with SEEG or SDE implantation at Children's Hospital Colorado between January 2011 and June 2019. RESULTS: There were 47 patients who underwent 53 SEEG implantations and 61 patients who underwent 64 SDE implantations, with an average age of 12.45 years (range: 1.22-19.96 years). Post-implantation imaging was performed in all SEEG implantations and 42 SDE implantations. 38 % and 88 % of SEEG and SDE implantations, respectively, had a hemorrhage of any kind (p < 0.01). Clinically significant hemorrhages did not differ between the two groups, though one death was reported in the SEEG group. No patient undergoing SEEG implantation received blood products compared to 20 % of SDE patients (p < 0.01). The rate of infection in SEEG patients was 4% compared to 33 % for SDE patients (p = 0.01). Resection was completed in 60 % of SEEG patients versus 93 % for SDE patients (p < 0.01). Rate of seizure response was not significantly different between the two groups, with 81 % and 71 % of SEEG and SDE patients, respectively, reaching Engel class I or II at 12 months (p = 0.76). SIGNIFICANCE: In pediatric patients at a single institution, SEEG is associated with less adverse effects overall yet similar rates of seizure freedom compared to SDE implantation. This includes significantly lower rates of asymptomatic hemorrhage, infection and need for blood transfusion associated with SEEG monitoring. There was no statistical difference in clinically significant hemorrhages between the two groups, although rare in both.

Putative dendritic correlates of chronic traumatic encephalopathy: A preliminary quantitative Golgi exploration.

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disorder that is associated with repetitive head impacts. Neuropathologically, it is defined by the presence of perivascular hyperphosphorylated tau aggregates in cortical tissue (McKee et al., 2016, Acta Neuropathologica, 131, 75-86). Although many pathological and assumed clinical correlates of CTE have been well characterized, its effects on cortical dendritic arbors are still unknown. Here, we quantified dendrites and dendritic spines of supragranular pyramidal neurons in tissue from human frontal and occipital lobes, in 11 cases with (Mage = 79 ± 7 years) and 5 cases without (Mage = 76 ± 11 years) CTE. Tissue was stained with a modified rapid Golgi technique. Dendritic systems of 20 neurons per region in each brain (N = 640 neurons) were quantified using computer-assisted morphometry. One key finding was that CTE neurons exhibited increased variability and distributional changes across six of the eight dendritic system measures, presumably due to ongoing degeneration and compensatory reorganization of dendritic systems. However, despite heightened variation among CTE neurons, CTE cases exhibited lower mean values than Control cases in seven of the eight dendritic system measures. These dendritic alterations may represent a new pathological marker of CTE, and further examination of dendritic changes could contribute to both mechanistic and functional understandings of the disease.

Real-World Preliminary Experience With Responsive Neurostimulation in Pediatric Epilepsy: A Multicenter Retrospective Observational Study.

BACKGROUND: Despite the well-documented utility of responsive neurostimulation (RNS, NeuroPace) in adult epilepsy patients, literature on the use of RNS in children is limited. OBJECTIVE: To determine the real-world efficacy and safety of RNS in pediatric epilepsy patients. METHODS: Patients with childhood-onset drug-resistant epilepsy treated with RNS were retrospectively identified at 5 pediatric centers. Reduction of disabling seizures and complications were evaluated for children (<18 yr) and young adults (>18 yr) and compared with prior literature pertaining to adult patients. RESULTS: Of 35 patients identified, 17 were <18 yr at the time of RNS implantation, including a 3-yr-old patient. Four patients (11%) had concurrent resection. Three complications, requiring additional surgical interventions, were noted in young adults (2 infections [6%] and 1 lead fracture [3%]). No complications were noted in children. Among the 32 patients with continued therapy, 2 (6%) achieved seizure freedom, 4 (13%) achieved ≥90% seizure reduction, 13 (41%) had ≥50% reduction, 8 (25%) had <50% reduction, and 5 (16%) experienced no improvement. The average follow-up duration was 1.7 yr (median 1.8 yr, range 0.3-4.8 yr). There was no statistically significant difference for seizure reduction and complications between children and young adults in our cohort or between our cohort and the adult literature. CONCLUSION: These preliminary data suggest that RNS is well tolerated and an effective off-label surgical treatment of drug-resistant epilepsy in carefully selected pediatric patients as young as 3 yr of age. Data regarding long-term efficacy and safety in children will be critical to optimize patient selection.