Objective Few studies have explored the efficacy of laser interstitial thermal therapy in pediatric epilepsy surgery. This study aims to evaluate seizure-free outcomes in children and adolescents with mesial temporal lobe epilepsy who underwent laser interstitial thermal therapy.Methods This was a retrospective cohort study performed at a level 4 epilepsy center. All patients had comprehensive presurgical epilepsy evaluations with a consensus treatment decision made by a multidisciplinary team. Brain magnetic resonance imaging (MRI) data were used to determine lesional vs nonlesional groups. All laser interstitial thermal therapy procedures were performed using Visualase laser ablation systems by the neurosurgical team. Seizure-free outcomes were measured according to the Engel surgical outcome scale.Results This study included 19 patients (12 girls, 7 boys). Age of epilepsy onset ranged from 2 to 17 years (mean 9.9 years), and age at time of surgery ranged from 8 to 20 years (mean 15.1 years). Ten patients (52.5%) had signs of hippocampal sclerosis on MRI (lesional group), and 9 patients (47.5%) had a normal brain MRI (nonlesional group). Engel 1 score was achieved by 14 of 19 patients (73.5%): 9 of 10 patients (90%) in the lesional group and 5 of 9 patients (55.5%) in the nonlesional group. Younger age of seizure onset was a predictor of better postsurgical outcome, but no other outcome predictors could be established.Conclusion Laser interstitial thermal therapy is safe and effective for the treatment of drug-resistant mesial temporal lobe epilepsy in children, rendering more favorable seizure-free outcomes in pediatric patients with hippocampal atrophy than in those with nonlesional mesial temporal lobe epilepsy.
INTRODUCTION: The Responsive Neurostimulation System (RNS) (NeuroPace, Mountain View) is a direct intracranial neurostimulator that is FDA-approved for adults with medically refractory focal epilepsy. There currently exists limited data regarding its efficacy and safety in pediatric populations. METHODS: A retrospective chart review was conducted of pediatric patients treated with the RNS System between January 1, 2019 and December 31, 2021 at Rady Children’s Hospital for at least one year. Data collected included percent change in median disabling seizure frequency from baseline at years 1, 2, and 3, as well as device-related serious adverse events. RESULTS: Twenty patients with medically refractory focal epilepsy were identified who had been treated with the RNS System for at least one year. Median duration of follow-up was 24 months (interquartile range [IQR]: 15-35 months) The median percent reduction in disabling seizures was 29% (N = 20, IQR = 0-84%) at 1 year, 53% (N = 12, IQR = -5-81%) at 2 years, and 67% (N = 4, IQR = 25-100%) at 3 years. 40% of patients reported a >90% reduction in median disabling seizure frequency, and 25% were seizure-free at last follow-up. Reductions in median seizure frequency were comparable based on patient age, age at seizure onset, neuroimaging findings, and prior intracranial monitoring. Zero patients experienced implant site infections. One patient (5%) required lead revision, and another patient (5%) had a spontaneous intraparenchymal hemorrhage at the generator site 2 years after implantation that resolved with expectant management. Neither of these events were associated with long-lasting neurological complications. CONCLUSIONS: The RNS System is a safe and efficacious treatment for pediatric patients with medically refractory focal epilepsy.
Purpose Variants in NUS1 are associated with a congenital disorder of glycosylation, developmental and epileptic encephalopathies, and are possible contributors to Parkinson disease pathogenesis. How the diverse functions of the NUS1-encoded Nogo B receptor (NgBR) relate to these different phenotypes is largely unknown. We present three patients with de novo heterozygous variants in NUS1 that cause a complex movement disorder, define pathogenic mechanisms in cells and zebrafish, and identify possible therapy. Methods Comprehensive functional studies were performed using patient fibroblasts, and a zebrafish model mimicking NUS1 haploinsufficiency. Results We show that de novo NUS1 variants reduce NgBR and Niemann–Pick type C2 (NPC2) protein amount, impair dolichol biosynthesis, and cause lysosomal cholesterol accumulation. Reducing nus1 expression 50% in zebrafish embryos causes abnormal swim behaviors, cholesterol accumulation in the nervous system, and impaired turnover of lysosomal membrane proteins. Reduction of cholesterol buildup with 2-hydroxypropyl-ß-cyclodextrin significantly alleviates lysosomal proteolysis and motility defects. Conclusion Our results demonstrate that these NUS1 variants cause multiple lysosomal phenotypes in cells. We show that the movement deficits associated with nus1 reduction in zebrafish arise in part from defective efflux of cholesterol from lysosomes, suggesting that treatments targeting cholesterol accumulation could be therapeutic.
Objective Prolonged continuous video-electroencephalography (cEEG) is recommended for neonates at risk of seizures. The cost and expertise required to provide a real-time response to detected seizures often limits its utility. We hypothesised that the first hour of cEEG could predict subsequent seizures. Design and setting Retrospective multicentre diagnostic accuracy study. Patients 266 term neonates at risk of seizure or with suspected seizures. Intervention The first hour of cEEG was graded by expert and novice interpreters as normal, mildly, moderately or severely abnormal; seizures were identified. Main outcome measures Association between abnormalities in the first hour of cEEG and the presence of seizures during total cEEG monitoring. Results 50/98 (51%) of neonates who developed seizures had their first seizure in the first hour of cEEG monitoring. The 'time-to-event' risk of seizure from 0 to 96 hours was 0.38 (95% CI 0.32 to 0.44) while the risk in the first hour was 0.19 (95% CI 0.15 to 0.24). cEEG background was normal in 48% of neonates, mildly abnormal in 30%, moderately abnormal in 13% and severely abnormal in 9%. Inter-rater agreement for determination of background was very good (weighted kappa=0.81, 95% CI 0.72 to 0.91). When neonates with seizures during the first hour were excluded, an abnormal background resulted in 2.4 times increased risk of seizures during the subsequent monitoring period (95% CI 1.3 to 4.4, p<0.003) while a severely abnormal background resulted in a sevenfold increased risk (95% CI 3.4 to 14.3, p<0.0001). Conclusions The first hour of cEEG in at-risk neonates is useful in identifying and predicting whether seizures occur during cEEG monitoring up to 96 hours. This finding enables identification of high-risk neonates who require closer observation.
BACKGROUND AND OBJECTIVES: There are no US Food and Drug Administration–approved therapies for neonatal seizures. Phenobarbital and phenytoin frequently fail to control seizures. There are concerns about the safety of seizure medications in the developing brain. Levetiracetam has proven efficacy and an excellent safety profile in older patients; therefore, there is great interest in its use in neonates. However, randomized studies have not been performed. Our objectives were to study the efficacy and safety of levetiracetam compared with phenobarbital as a first-line treatment of neonatal seizures. METHODS: The study was a multicenter, randomized, blinded, controlled, phase IIb trial investigating the efficacy and safety of levetiracetam compared with phenobarbital as a first-line treatment for neonatal seizures of any cause. The primary outcome measure was complete seizure freedom for 24 hours, assessed by independent review of the EEGs by 2 neurophysiologists. RESULTS: Eighty percent of patients (24 of 30) randomly assigned to phenobarbital remained seizure free for 24 hours, compared with 28% of patients (15 of 53) randomly assigned to levetiracetam (P < .001; relative risk 0.35 [95% confidence interval: 0.22–0.56]; modified intention-to-treat population). A 7.5% improvement in efficacy was achieved with a dose escalation of levetiracetam from 40 to 60 mg/kg. More adverse effects were seen in subjects randomly assigned to phenobarbital (not statistically significant). CONCLUSIONS: In this phase IIb study, phenobarbital was more effective than levetiracetam for the treatment of neonatal seizures. Higher rates of adverse effects were seen with phenobarbital treatment. Higher-dose studies of levetiracetam are warranted, and definitive studies with long-term outcome measures are needed.
Early-life adversity increases the risk for emotional disorders such as depression and schizophrenia. Anhedonia, thought to be a core feature of these disorders, is provoked by our naturalistic rodent model of childhood adversity (i.e., rearing pups for one week in cages with limited bedding and nesting, LBN). Drug use and addiction are highly comorbid with psychiatric disorders featuring anhedonia, yet effects of LBN on drug-seeking behavior and the reward and stress-related circuits that underlie it remain unknown. Here we examined the effects of LBN on cocaine intake and seeking, using a battery of behavioral tests measuring distinct aspects of cocaine reward, and for comparison, chocolate intake. We also examined activation of neurons within the pleasure/reward and stress circuits following cocaine in LBN and control rats. Early-life adversity reduced spontaneous intake of palatable chocolate, extending prior reports of sucrose and social-play anhedonia. In a within-session cocaine behavioral economic test, LBN rats self-administered lower dosages of cocaine under low-effort conditions, consistent with a reduced hedonic set-point for cocaine, and potentially anhedonia. In contrast, cocaine demand elasticity was not consistently affected, indicating no major changes in motivation to maintain preferred cocaine blood levels. These changes were selective, as LBN did not cause an overt anxiety-like phenotype, nor did it affect sensitivity to self-administered cocaine dose, responding for cocaine under extinction conditions, cocaine- or cue-induced reinstatement of cocaine seeking, or locomotor response to acute cocaine. However, high Fos expression was seen after cocaine in both reward- and stress-related brain regions of LBN rats, including nucleus accumbens core, central amygdala, and lateral habenula. In contrast, hypothalamic orexin neuron activation after cocaine was significantly attenuated in LBN rats. Together, these findings demonstrate enduring effects of early-life adversity on both reward- and fear/anxiety-related neural circuits, as well as anhedonia-like reductions in consumption of natural and drug rewards.
In a subset of children experiencing prolonged febrile seizures (FSs), the most common type of childhood seizures, cognitive outcomes are compromised. However, the underlying mechanisms are unknown. Here we identified significant, enduring spatial memory problems in male rats following experimental prolonged FS (febrile status epilepticus; eFSE). Remarkably, these deficits were abolished by transient, post hoc interference with the chromatin binding of the transcriptional repressor neuron restrictive silencing factor (NRSF or REST). This transcriptional regulator is known to contribute to neuronal differentiation during development and to programmed gene expression in mature neurons. The mechanisms of the eFSE-provoked memory problems involved complex disruption of memory-related hippocampal oscillations recorded from CA1, likely resulting in part from impairments of dendritic filtering of cortical inputs as well as abnormal synaptic function. Accordingly, eFSE provoked region-specific dendritic loss in the hippocampus, and aberrant generation of excitatory synapses in dentate gyrus granule cells. Blocking NRSF transiently after eFSE prevented granule cell dysmaturation, restored a functional balance of γ-band network oscillations, and allowed treated eFSE rats to encode and retrieve spatial memories. Together, these studies provide novel insights into developing networks that underlie memory, the mechanisms by which early-life seizures influence them, and the means to abrogate the ensuing cognitive problems. SIGNIFICANCE STATEMENT Whereas seizures have been the central focus of epilepsy research, they are commonly accompanied by cognitive problems, including memory impairments that contribute to poor quality of life. These deficits often arise before the onset of spontaneous seizures, or independent from them, yet the mechanisms involved are unclear. Here, using a rodent model of common developmental seizures that provoke epilepsy in a subset of individuals, we identify serious consequent memory problems. We uncover molecular, cellular, and circuit-level mechanisms that underlie these deficits and successfully abolish them by targeted therapeutic interventions. These findings may be important for understanding and preventing cognitive problems in individuals suffering long febrile seizures.
OBJECTIVE: To evaluate factors associated with the development of epilepsy after resolution of presumed childhood encephalitis. METHODS: A total of 217 patients with suspected encephalitis who met criteria for the California Encephalitis Project were identified. Evaluable outcome information was available for 99 patients (40 girls, 59 boys, ages 2 months to 17 years) without preexisting neurological conditions, including prior seizures or abnormal brain magnetic resonance imaging scans. We identified factors correlated with the development of epilepsy after resolution of the acute illness. RESULTS: Development of epilepsy was correlated with the initial presenting sign of seizure (P < 0.001). With each additional antiepileptic drug used to control seizures, the odds ratio of developing epilepsy was increased twofold (P < 0.001). An abnormal electroencephalograph (P < 0.05) and longer hospital duration (median of 8 versus 21 days) also correlated with development of epilepsy (P < 0.01). The need for medically induced coma was associated with epilepsy (P < 0.001). Seizures in those patients were particularly refractory, often requiring longer than 24 hours to obtain seizure control. Individuals who required antiepileptic drugs at discharge (P < 0.001) or were readmitted after their acute illness (p < 0.001) were more likely to develop epilepsy. Of our patients who were able to wean antiepileptic drugs after being started during hospitalization, 42% were successfully tapered off within 6 months. CONCLUSIONS: Limited data are available on the risk of developing epilepsy after childhood encephalitis. This is the first study that not only identifies risk factors for the development of epilepsy, but also provides data regarding the success rate of discontinuing antiepileptic medication after resolution of encephalitis.
OBJECTIVE:To evaluate factors during acute presumed childhood encephalitis that are associated with development of long-term neurological sequelae.METHODS:A total of 217 patients from Rady Children's Hospital San Diego with suspected encephalitis who met criteria for the California Encephalitis Project were identified. A cohort of 99 patients (40 females, 59 males, age 2 months-17 years) without preexisting neurological conditions, including prior seizures or abnormal brain magnetic resonance imaging scans was studied. Mean duration of follow-up was 29 months. Factors that had a relationship with the development of neurological sequelae (defined as developmental delay, learning difficulties, behavioral problems, or focal neurological findings) after acute encephalitis were identified.RESULTS:Neurological sequelae at follow-up was associated with younger age (6.56 versus 9.22 years) at presentation (P = 0.04) as well as an initial presenting sign of seizure (P = 0.03). Duration of hospital stay (median of 7 versus 15.5 days; P = 0.02) was associated with neurological sequelae. Of the patients with neurological sequelae, a longer hospital stay was associated with patients of an older age (P = 0.04). Abnormalities on neuroimaging (P = 1.00) or spinal fluid analysis (P = 1.00) were not uniquely associated with neurological sequelae. Children who were readmitted after their acute illness (P = 0.04) were more likely to develop neurological sequelae. There was a strong relationship between the patients who later developed epilepsy and those who developed neurological sequelae (P = 0.02).SIGNIFICANCE:Limited data are available on the long-term neurological outcomes of childhood encephalitis. Almost half of our patients were found to have neurological sequelae at follow-up, indicating the importance of earlier therapies to improve neurological outcome.
Internuclear ophthalmoplegia (INO) is a rare disorder of conjugate lateral gaze that has been described in a number of neurologic conditions including multiple sclerosis, stroke and less commonly brain tumors. We describe a series of 3 boys (11, 12, 15 years) diagnosed with primary central nervous system tumors (pilomyxoid variant astrocytoma, anaplastic oligoastrocytoma, gliomatosis cerebri) who developed bilateral INO as a manifestation of progressive disease. Time from diagnosis to development of bilateral INO ranged from 13-36 months. All children died of their disease 1-9 months following diagnosis of bilateral INO and had significant dorsal pontine invasion on magnetic resonance imaging at progression. Only one child had brainstem involvement at diagnosis. Our case series highlights this rare ophthalmologic syndrome of bilateral INO in association with tumor progression and provides a literature review of brain tumor associations with INO.
The endoplasmic reticulum (ER) consists of tubules that are shaped by the reticulons and DP1/Yop1p, but how the tubules form an interconnected network is unknown. Here, we show that mammalian atlastins, which are dynamin-like, integral membrane GTPases, interact with the tubule-shaping proteins. The atlastins localize to the tubular ER and are required for proper network formation in vivo and in vitro. Depletion of the atlastins or overexpression of dominant-negative forms inhibits tubule interconnections. The Sey1p GTPase in S. cerevisiae is likely a functional ortholog of the atlastins; it shares the same signature motifs and membrane topology and interacts genetically and physically with the tubule-shaping proteins. Cells simultaneously lacking Sey1p and a tubule-shaping protein have ER morphology defects. These results indicate that formation of the tubular ER network depends on conserved dynamin-like GTPases. Since atlastin-1 mutations cause a common form of hereditary spastic paraplegia, we suggest ER-shaping defects as a neuropathogenic mechanism.
The hereditary spastic paraplegias (SPG1-33) comprise a cluster of inherited neurological disorders characterized principally by lower extremity spasticity and weakness due to a length-dependent, retrograde axonopathy of corticospinal motor neurons. Mutations in the gene encoding the large oligomeric GTPase atlastin-1 are responsible for SPG3A, a common autosomal dominant hereditary spastic paraplegia. Here we describe a family of human GTPases, atlastin-2 and -3 that are closely related to atlastin-1. Interestingly, while atlastin-1 is predominantly localized to vesicular tubular complexes and cis-Golgi cisternae, mostly in brain, atlastin-2 and -3 are localized to the endoplasmic reticulum (ER) and are most enriched in other tissues. Knockdown of atlastin-2 and -3 levels in HeLa cells using siRNA (small interfering RNA) causes disruption of Golgi morphology, and these Golgi structures remain sensitive to brefeldin A treatment. Interestingly, expression of SPG3A mutant or dominant-negative atlastin proteins lacking GTPase activity causes prominent inhibition of ER reticularization, suggesting a role for atlastin GTPases in the formation of three-way junctions in the ER. However, secretory pathway trafficking as assessed using vesicular stomatitis virus G protein fused to green fluorescent protein (VSVG-GFP) as a reporter was essentially normal in both knockdown and dominant-negative overexpression conditions for all atlastins. Thus, the atlastin family of GTPases functions prominently in both ER and Golgi morphogenesis, but they do not appear to be required generally for anterograde ER-to-Golgi trafficking. Abnormal morphogenesis of the ER and Golgi resulting from mutations in atlastin-1 may ultimately underlie SPG3A by interfering with proper membrane distribution or polarity of the long corticospinal motor neurons.
Emerging evidence suggests that ESCRT proteins, well characterized in their role in multivesicular body trafficking, contribute to various cellular processes including cytokinesis. Structural and functional analyses indicate that the ESCRT-III protein CHMP1B promotes the midbody localization of spastin, a microtubule-severing protein required for membrane abscission. The endosomal sorting complex required for transport (ESCRT) machinery, including ESCRT-III, localizes to the midbody and participates in the membrane-abscission step of cytokinesis. The ESCRT-III protein charged multivesicular body protein 1B (CHMP1B) is required for recruitment of the MIT domain–containing protein spastin, a microtubule-severing enzyme, to the midbody. The 2.5-Å structure of the C-terminal tail of CHMP1B with the MIT domain of spastin reveals a specific, high-affinity complex involving a noncanonical binding site between the first and third helices of the MIT domain. The structural interface is twice as large as that of the MIT domain of the VPS4–CHMP complex, consistent with the high affinity of the interaction. A series of unique hydrogen-bonding interactions and close packing of small side chains discriminate against the other ten human ESCRT-III subunits. Point mutants in the CHMP1B binding site of spastin block recruitment of spastin to the midbody and impair cytokinesis.
Signal‐transducing adaptor molecules (STAMs) are involved in growth factor and cytokine signaling as well as receptor degradation, and they form complexes with a number of endocytic proteins, including Hrs and Eps15. In this study, we demonstrate that STAM proteins also localize prominently to early exocytic compartments and profoundly regulate Golgi morphology. Upon STAM overexpression in cells, the Golgi apparatus becomes extensively fragmented and dispersed, but when STAMs are depleted, the Golgi becomes highly condensed. Under both scenarios, vesicular stomatitis virus G protein–green fluorescent protein trafficking to the plasma membrane is markedly inhibited, and recovery of Golgi morphology after Brefeldin A treatment is substantially impaired in STAM‐depleted cells. Furthermore, STAM proteins interact with coat protein II (COPII) proteins, probably at endoplasmic reticulum (ER) exit sites, and Sar1 activity is required to maintain the localization of STAMs at discrete sites. Thus, in addition to their roles in signaling and endocytosis, STAMs function prominently in ER‐to‐Golgi trafficking, most likely through direct interactions with the COPII complex.
Mitochondrial morphology within cells is controlled by precisely regulated rates of fusion and fission . During programmed cell death (PCD), mitochondria undergo extensive fragmentation and ultimately caspase-independent elimination through a process known as mitoptosis . Though this increased fragmentation is due to increased fission through the recruitment of the dynamin-like GTPase Drp1 to mitochondria , as well as to a block in mitochondrial fusion , cellular mechanisms underlying these processes remain unclear. Here, we describe a mechanism for the increased mitochondrial Drp1 levels and subsequent stimulation of mitochondrial fission seen during PCD. We observed Bax/Bak-mediated release of DDP/TIMM8a, a mitochondrial intermembrane space (IMS) protein , into the cytoplasm, where it binds to and promotes the mitochondrial redistribution of Drp1, a mediator of mitochondrial fission. Using both loss- and gain-of-function assays, we also demonstrate that the Drp1- and DDP/TIMM8a-dependent mitochondrial fragmentation observed during PCD is an important step in mitoptosis, which in turn is involved in caspase-independent cell death. Thus, following Bax/Bak-mediated mitochondrial outer membrane permeabilization (MOMP), IMS proteins released comprise not only apoptogenic factors such as cytochrome c involved in caspase activation but also DDP/TIMM8a, which activates Drp1-mediated fission to promote mitochondrial fragmentation and subsequently elimination during PCD.
Recent literature suggests that bone marrow stromal cells (BMSCs) may be differentiated into neuron-like and/or glia-like cells, implying that differentiated BMSCs may have potential use in cell replacement therapy for central nervous system disorders. However, many questions remain concerning the nature of BMSCs differentiated to express CNS antigens. For example, how long after differentiation do cells express CNS markers, and do differentiation procedures alter cell viability? This study compared neuronal differentiation methods in sister cell preparations, evaluating cell death and maintenance of the CNS antigen positivity after the Deng or Woodbury methods. Rat BMSCs were harvested, passaged, differentiated, placed in growth or maintenance media, and processed for cell viability or immunocytochemistry for NeuN and GFAP post-differentiation. We report that the Woodbury differentiation protocol produced maximally 51% neuron-like cells, yet also produced significant cell death. The Deng differentiation method produced 13% neuron-like cells and without marked cell death. No significant increases in GFAP immunoreactivity (IR) were seen after differentiation by either protocol. Following both protocols, removal of cells from the maintenance media significantly decreased expression of NeuN. Thus, differentiation procedures may be substantially affected BMSC potential, and maintenance of immunoreactivity to neuronal antigens was dependent on specific, nonphysiological environmental conditions.