Authors: Curatolo P., Franz D.N., Lawson J.A., Yapici Z., Ikeda H., Polster T., Nabbout R., de Vries P.J., Dlugos D.J., Fan J., Ridolfi A., Pelov D., Voi M., French J.A.

Lancet Child Adolesc Health 2018 Jul;2(7):495-504. doi: 10.1016/S2352-4642(18)30099-3.

Abstract

BACKGROUND:

Epilepsy occurs in 70-90% of patients with tuberous sclerosis complex. We aimed to assess the efficacy and safety of adjunctive everolimus for treatment-refractory seizures associated with tuberous sclerosis complex in paediatric patients enrolled in the EXIST-3 trial, a double-blind, placebo-controlled, randomised, phase 3 study.

METHODS:

This post-hoc analysis focused on paediatric patients (age <18 years) in the EXIST-3 trial, which consisted of baseline (8 weeks), core (18 weeks), and extension phases (≥48 weeks) and was done at 99 centres in 25 countries worldwide. Briefly, patients with tuberous sclerosis complex-associated treatment-refractory seizures, who were receiving a stable dose of one to three antiepileptic drugs, were randomly assigned (1:1:1) to receive placebo, low-exposure everolimus (3-7 ng/mL), or high-exposure everolimus (9-15 ng/mL). Following the core phase, patients could enter the extension phase to receive everolimus at a targeted exposure range of 3-15 ng/mL up to 48 weeks after the last patient had completed the core phase. Efficacy endpoints were response rate (≥50% of reduction from baseline in average weekly seizure frequency) and median percentage reduction in seizure frequency during the 12-week maintenance period of the core phase, and at 12-week intervals throughout the extension phase. This study is registered with ClinicalTrials.gov, number NCT01713946.

FINDINGS:

Between July 3, 2013, and May 29, 2015, 299 paediatric patients enrolled in the trial. In the younger subgroup (<6 years; n=104), 34 received placebo, 33 low-exposure everolimus, and 37 high-exposure everolimus; in the older subgroup (≥6 years to <18 years; n=195), 62 received placebo, 63 low-exposure everolimus, and 70 high-exposure everolimus. At the end of the core phase, response rate was higher in the treatment groups than placebo in both the younger subgroup (17·6% [6·8-34·5] for placebo vs 30·3% [95% CI 15·6-48·7; p=0·2245] for low-exposure everolimus vs 59·5% [42·1-75·2; p=0·0003] for high-exposure everolimus) and the older subgroup (12·9% [5·7-23·9] vs 27·0% [16·6-39·7; p=0·0491] vs 30·0% [19·6-42·1; p=0·0179]), as were median reduction in seizure frequency (12·3% [95% CI -10·1 to 24·8] vs 29·3% [95% CI 13·4 to 46·3; p=0·0474] vs 54·7% [43·5 to 73·1; p<0·0001] in younger patients; 13·5% [-3·0 to 26·8] vs 31·0% [16·1 to 42·9; p=0·0128] vs 34·8% [26·7 to 41·3; p=0·0006] in older patients). The efficacy persisted, with sustained seizure reduction after 1 year of treatment across both paediatric subgroups (response rate 48·9% [95% CI 38·1-59·8] for the younger subgroup vs 47·2% [39·3-55·2] for the older subgroup; median percentage reduction in seizure frequency 48·4% [95% CI 34·3-73·6] vs 48·0% [38·2-57·5]). At the cutoff date for the extension phase, grade 3 or 4 adverse events were reported in 45 (45%) younger patients (commonly pneumonia [n=16]) and 74 (38%) older patients (commonly pneumonia [n=8] and stomatitis [n=6]). Two deaths (pneumonia, which was suspected to be treatment-related, and sudden unexplained death due to epilepsy) were reported.

INTERPRETATION:

Adjunctive everolimus resulted in sustained reductions in seizure frequency after 1 year and was well tolerated in paediatric patients with treatment-refractory seizures associated with tuberous sclerosis complex.

FUNDING:

Novartis Pharmaceuticals Corporation.

Authors: Canevini M.P., Kotulska-Jozwiak K., Curatolo P., La Briola F., Peron A., Slowinska M., Strzelecka J., Vignoli A., Jozwiak S.

Am J Med Genet C Semin Med Genet. 2018 Sep;26. doi: 10.1002/ajmg.c.31652

Abstract

Tuberous sclerosis complex (TSC) is an autosomal dominant neurocutaneous disease affecting approximately 1 in 6,000 people, and represents one of the most common genetic causes of epilepsyEpilepsy affects 90% of the patients and appears in the first 2 years of life in the majority of them. Early onset of epilepsy in the first 12 months of life is associated with high risk of cognitive decline and neuropsychiatric problems including autism. Prenatal or early infantile diagnosis of TSC, before the onset of epilepsy, provides a unique opportunity to monitor EEG before the onset of clinical seizures, thus enabling early intervention in the process of epileptogenesis. In this review, we discuss the current status of knowledge on epileptogenesis in TSC, and present recommendations of American and European experts in the field of epilepsy.

Authors: Bongaarts A., Prabowo A.S., Arena A., Anink J.J., Reinten R.J., Jansen F.E., Spliet W.G.M., Thom M., Coras R., Blümcke I., Kotulska K., Jozwiak S., Grajkowska W., Söylemezoglu F., Pimentel J., Schouten-van Meeteren A.Y.N., Mills J.D., Iyer A.M., van Vliet E.A., Mühlebner A., Aronica E.

Oncotarget 2018 Jun 15;9(46):28103-28115. doi: 10.18632/oncotarget.25563

Abstract

Glioneuronal tumours, including gangliogliomas and dysembryoplasticneuroepithelialtumours, represent the most common low-grade epilepsy-associated brain tumours and are a well-recognized cause of intractable focal epilepsy in children and young adults. Classification is predominantly based on histological features, which is difficult due to the broad histological spectrum of these tumours. The aim of the present study was to find molecular markers that can be used to identify entities within the histopathology spectrum of glioneuronal tumours. The focus of this study was on microRNAs (miRNAs). miRNAs are important post-transcriptional regulators of gene expression and are involved in the pathogenesis of different neurological diseases and oncogenesis. Using a miRNA array, miR-519d and miR-4758 were found to be upregulated in gangliogliomas (n=26) compared to control cortex (n=17), peritumoural tissue (n=7), dysembryoplasticneuroepithelialtumours (n=9) and astrocytomas (grade I-IV; subependymal giant cell astrocytomas, n=10; pilocytic astrocytoma, n=15; diffuse astrocytoma grade II, n=10; grade III, n=14 and glioblastoma n=15). Furthermore, the PI3K/AKT3/P21 pathway, which is predicated to be targeted by miR-519d and miR-4758, was deregulated in gangliogliomas. Functionally, overexpression of miR-519d in an astrocytic cell line resulted in a downregulation of CDKN1A (P21) and an increase in cell proliferation, whereas co-transfection with miR-4758 counteracted this effect. These results suggest that miR-519d and miR-4758 might work in concert as regulators of the cell cycle in low grade gliomas. Furthermore, these miRNAs could be used to distinguish gangliogliomas from dysembryoplasticneuroepithelialtumours and other low and high grade gliomas and may lead to more targeted therapy.

Authors: Baumer F.M., Peter J.M., Clancy S., Prohl A.K., Prabhu S.P., Scherrer B., Jansen F.E., Braun K.P.J., Sahin M., Stamm A., Warfield S.K.

Cereb Cortex 2018 Oct 1;28(10):3665-3672. doi: 10.1093/cercir/bhx247.

Abstract

INTRODUCTIONNeurological manifestations in Tuberous Sclerosis Complex (TSC) are highly variable. Diffusion tensor imaging (DTI) may reflect the neurological disease burden. We analyzed the association of autism spectrum disorder (ASD), intellectual disability (ID) and epilepsy with callosal DTI metrics in subjects with and without TSC.

METHODS:

186 children underwent 3T MRI DTI: 51 with TSC (19 with concurrent ASD), 46 with non-syndromic ASD and 89 healthy controls (HC). Subgroups were based on presence of TSC, ASD, ID, and epilepsy. Density-weighted DTI metrics obtained from tractography of the corpus callosum were fitted using a 2-parameter growth model. We estimated distributions using bootstrapping and calculated half-life and asymptote of the fitted curves.

RESULTS:

TSC was associated with a lower callosal fractional anisotropy (FA) than ASD, and ASD with a lower FA than HC. ID, epilepsy and ASD diagnosis were each associated with lower FA values, demonstrating additive effects. In TSC, the largest change in FA was related to a comorbid diagnosis of ASD. Mean diffusivity (MD) showed an inverse relationship to FA. Some subgroups were too small for reliable data fitting.

CONCLUSIONS:

Using a cross-disorder approach, this study demonstrates cumulative abnormality of callosal whitematter diffusion with increasing neurological comorbidity.

Authors: Arena A., Zimmer T.S., van Scheppingen J., Korotkov A., Anink J.J., Mühlebner A., Jansen F.E., van Hecke W., Spliet W.G., van Rijen P.C., Vezzani A., Baayen J.C., Idema S., Iyer A.M., Perluigi M., Mills J.D., van Vliet E.A., Aronica E. 

Brain Pathol 2018 Oct 10. doi: 10.1111/bpa.12661.

Abstract

Oxidative stress (OS) occurs in brains of patients with epilepsy and coincides with brain inflammation, and both phenomena contribute to seizure generation in animal models. We investigated whether expression of OS and brain inflammation markers co-occurred also in resected brain tissue of patients with epileptogeniccorticalmalformations: hemimegalencephaly (HME), focal cortical dysplasia (FCD) and cortical tubers in tuberous sclerosis complex (TSC). Moreover, we studied molecular mechanisms linking OS and inflammation in an in vitro model of neuronal function. Untangling interdependency and underlying molecular mechanisms might pose new therapeutic strategies for treating patients with drug-resistant epilepsy of differing etiologies. Immunohistochemistry was performed for specific OS markers xCT and iNOS and brain inflammation markers TLR4, COX-2 and NF-κB in cortical tissue derived from patients with HME, FCD IIa, IIb and TSC. Additionally, we studied gene expression of these markers using the human neuronal cell line SH-SY5Y in which OS was induced using H2 O2 . OS markers were increased in dysmorphic neurons, and balloon/giant cells in cortex of patients with FCD IIb or TSC. Expression of OS markers was positively correlated to expression of brain inflammation markers. In vitro, 100 μM, but not 50 μM, of H2 O2 increased expression of TLR4, IL-1β and COX-2. We found that NF-κB signaling was activated only upon stimulation with 100 μM H2 O2leading to upregulation of TLR4 signaling and IL-1β. The NF-κB inhibitor TPCA-1 completely reversed this effect. Our results show that OS positively correlates with neuroinflammation and is particularly evident in brain tissue of patients with FCD IIb and TSC. In vitro, NF-κB is involved in the switch to an inflammatory state after OS. We propose that the extent of OS can predict the neuroinflammatory state of the brain. Additionally, anti-oxidant treatments may prevent the switch to inflammation in neurons thus targeting multiple epileptogenic processes at once.