Molecular EPISTOP, a comprehensive multi-omic analysis of blood from Tuberous Sclerosis Complex infants age birth to two years.

We present a comprehensive multi-omic analysis of the EPISTOP prospective clinical trial of early intervention with vigabatrin for pre-symptomatic epilepsy treatment in Tuberous Sclerosis Complex (TSC), in which 93 infants with TSC were followed from birth to age 2 years, seeking biomarkers of epilepsy development. Vigabatrin had profound effects on many metabolites, increasing serum deoxycytidine monophosphate (dCMP) levels 52-fold. Most serum proteins and metabolites, and blood RNA species showed significant change with age. Thirty-nine proteins, metabolites, and genes showed significant differences between age-matched control and TSC infants. Six also showed a progressive difference in expression between control, TSC without epilepsy, and TSC with epilepsy groups. A multivariate approach using enrollment samples identified multiple 3-variable predictors of epilepsy, with the best having a positive predictive value of 0.987. This rich dataset will enable further discovery and analysis of developmental effects, and associations with seizure development in TSC.

miRNAs and isomiRs: Serum-Based Biomarkers for the Development of Intellectual Disability and Autism Spectrum Disorder in Tuberous Sclerosis Complex.

Tuberous sclerosis complex (TSC) is a rare multi-system genetic disorder characterized by a high incidence of epilepsy and neuropsychiatric manifestations known as tuberous-sclerosis-associated neuropsychiatric disorders (TANDs), including autism spectrum disorder (ASD) and intellectual disability (ID). MicroRNAs (miRNAs) are small regulatory non-coding RNAs that regulate the expression of more than 60% of all protein-coding genes in humans and have been reported to be dysregulated in several diseases, including TSC. In the current study, RNA sequencing analysis was performed to define the miRNA and isoform (isomiR) expression patterns in serum. A Receiver Operating Characteristic (ROC) curve analysis was used to identify circulating molecular biomarkers, miRNAs, and isomiRs, able to discriminate the development of neuropsychiatric comorbidity, either ASD, ID, or ASD + ID, in patients with TSC. Part of our bioinformatics predictions was verified with RT-qPCR performed on RNA isolated from patients' serum. Our results support the notion that circulating miRNAs and isomiRs have the potential to aid standard clinical testing in the early risk assessment of ASD and ID development in TSC patients.

Epilepsy and Language Development in 8-36-Month-Old Toddlers with Tuberous Sclerosis Complex.

This paper aimed to assess language development in infants and toddlers with tuberous sclerosis complex (TSC) and epilepsy, which increase the risk of autism spectrum disorder. We assessed language development in 61 patients with TSC at 8-36 months using a standardized Speech Development and Communication Inventory tool. The results showed differences in outcomes due to the duration of the seizures and the number of drugs (pFDR = 0.007 **-pFDR = 0.037 *). Children with TSC with longer epilepsy duration and receiving more antiepileptic drugs have a greater risk of language development delay.

mTOR Inhibitor Treatment in Patients with Tuberous Sclerosis Complex Is Associated with Specific Changes in microRNA Serum Profile.

The aim of this study was to determine the serum profiles of miRNAs in patients with tuberous sclerosis (TSC) upon sirolimus treatment and compare them with those previously treated with everolimus in a similarly designed experiment. Serum microRNA profiling was performed in ten TSC patients before sirolimus therapy and again after 3-6 months using qPCR panels (Exiqon). Of 752 tested miRNAs, 28 showed significant differences in expression between TSC patients before and after sirolimus treatment. Of these, 11 miRNAs were dysregulated in the same directions as in the sirolimus groupcompared with the previously described everolimus group, miR-142-3p, miR-29c-3p, miR-150-5p, miR-425-5p, miR-376a-3p, miR-376a-3p, miR-532-3p, and miR-136-5p were upregulated, while miR-15b-3p, miR-100-5p, and miR-185-5p were downregulated. The most significant changes of expression, with fold changes exceeding 1.25 for both treatments, were noted for miR-136-5p, miR-376a-3p, and miR-150-5p. The results of a pathway analysis of the possible target genes for these miRNAs indicated the involvement of the Ras and MAPK signaling pathway. Upregulation of miR-136, miR-376a-3p, and miR-150-5p was noted in TSC patients treated with mTOR inhibitors, indicating a role in the downregulation of the mTOR pathway. Further studies are needed to determine the relationship between upregulated microRNAs and treatment efficacy.

Antiepileptic Effect and Safety Profile of Rapamycin in Pediatric Patients With Tuberous Sclerosis Complex.

Background: Epilepsy develops in 70-90% of children with Tuberous Sclerosis Complex (TSC) and is often resistant to medication. Treatment with mTOR pathway inhibitors is an important therapeutic option in drug-resistant epilepsy associated with TSC. Our study evaluated the antiepileptic effect of rapamycin in the pediatric population of patients diagnosed with TSC. Methods: This single center, open-label study evaluated safety and anti-epileptic efficacy of 12 months of rapamycin treatment in 32 patients aged from 11 months to 14 years with drug-resistant TSC- associated epilepsy. Results: After the first 6 months of treatment, the improvement in seizure frequency, defined as at least a 50% reduction in the number of seizures per week compared to baseline, was seen in 18 individuals (56.25%). We observed no change in 12 individuals (37.5%) and worsening, defined as increase in the number of seizures-in 2 patients (6.25%). The overall improvement defined as at least a 50% reduction in seizure frequency was found in 65.6% of all patients after 12 months with 28% of patients obtaining complete remission. Another five patients experienced at least an 80% reduction in the frequency of seizures. Concomitant treatment with vigabatrin, and to a much lesser extent topiramate and levetiracetam, was an additional favorable prognostic factor for the success of the therapy. A linear relationship between the cumulative dose of rapamycin and its therapeutic effect was observed. The safety profile of the drug was satisfactory. In none of the observed cases did the adverse events reach the level that required withdrawal of the rapamycin treatment. The reason for dropouts was insufficient drug efficacy in 3 cases. Conclusions: Long-term use of rapamycin, especially in combination with vigabatrin, might be a beneficial therapeutic option in the treatment of drug-resistant epilepsy in children with TSC.

A multistep approach to the genotype-phenotype analysis of Polish patients with tuberous sclerosis complex.

The aim of this study was to evaluate a cost-effective diagnostic strategy for identification of casual variants for tuberous sclerosis complex (TSC) in the Polish population and to correlate the genetic results with selected phenotypic features. Fifty-five patients, aged 3-44 years, with a clinical diagnosis of TSC were enrolled into the study. All patients received a three-step analysis: next generation sequencing screening (NGS), multiplex ligation-dependent probe amplification (MLPA) and deep sequencing. This multistep approach obtained positive results in 51/55 (93%) patients: of the 51 positives TSC1 variants were observed in 16 (31%) and TSC2 variants in 35 (69%); these included 13 novel variants and two patients with mosaicism. Four patients (7%) had no mutation identified (NMI). Among the TSC1 gene variants, there were five nonsense, four frameshift, three large deletions, two missense and two splicing variants. For the TSC2 gene, 11 were missense, eight splicing, six frameshift, four large deletions, two in-frame deletions and four nonsense variants. The patients with TSC2 changes had their clinical diagnosis of TSC at a younger age than those with TSC1 changes (one year vs three years, p = 0.041). The TSC2 group demonstrated a higher number of major symptoms per patient (p = 0.04). Subependymal giant cell astrocytoma with concomitance of other brain lesions was more common in patients with missense mutations in either gene (23% vs 0%, p = 0.02). Such a multistep molecular diagnostic strategy could increase the possibility of detecting causal variants for TSC and may allow detection of mosaicism at low levels. Missense pathogenic variants in TSC1 or TSC2 gene might be associated with a higher risk of brain lesions.

Prevention of Epilepsy in Infants with Tuberous Sclerosis Complex in the EPISTOP Trial.

OBJECTIVE: Epilepsy develops in 70 to 90% of children with tuberous sclerosis complex (TSC) and is often resistant to medication. Recently, the concept of preventive antiepileptic treatment to modify the natural history of epilepsy has been proposed. EPISTOP was a clinical trial designed to compare preventive versus conventional antiepileptic treatment in TSC infants. METHODS: In this multicenter study, 94 infants with TSC without seizure history were followed with monthly video electroencephalography (EEG), and received vigabatrin either as conventional antiepileptic treatment, started after the first electrographic or clinical seizure, or preventively when epileptiform EEG activity before seizures was detected. At 6 sites, subjects were randomly allocated to treatment in a 1:1 ratio in a randomized controlled trial (RCT). At 4 sites, treatment allocation was fixed; this was denoted an open-label trial (OLT). Subjects were followed until 2 years of age. The primary endpoint was the time to first clinical seizure. RESULTS: In 54 subjects, epileptiform EEG abnormalities were identified before seizures. Twenty-seven were included in the RCT and 27 in the OLT. The time to the first clinical seizure was significantly longer with preventive than conventional treatment [RCT: 364 days (95% confidence interval [CI] = 223-535) vs 124 days (95% CI = 33-149); OLT: 426 days (95% CI = 258-628) vs 106 days (95% CI = 11-149)]. At 24 months, our pooled analysis showed preventive treatment reduced the risk of clinical seizures (odds ratio [OR] = 0.21, p = 0.032), drug-resistant epilepsy (OR = 0.23, p = 0.022), and infantile spasms (OR = 0, p < 0.001). No adverse events related to preventive treatment were noted. INTERPRETATION: Preventive treatment with vigabatrin was safe and modified the natural history of seizures in TSC, reducing the risk and severity of epilepsy. ANN NEUROL 2021;89:304-314.

Is autism driven by epilepsy in infants with Tuberous Sclerosis Complex?

OBJECTIVE: To evaluate the relationship between age at seizure onset and neurodevelopmental outcome at age 24 months in infants with TSC, as well as the effect on neurodevelopmental outcome of early versus conventional treatment of epileptic seizures with vigabatrin (80-150 mg/kg/day). METHODS: Infants with TSC, aged ≤4 months and without previous seizures were enrolled in a prospective study and closely followed with monthly video EEG and serial standardized neurodevelopmental testing (Bayley Scales of Infant Development and Autism Diagnostic Observation Schedule). RESULTS: Eighty infants were enrolled. At the age of 24 months testing identified risk of Autism Spectrum Disorder (ASD) in 24/80 children (30.0%), and developmental delay (DD) in 26/80 (32.5%). Children with epilepsy (51/80; 63.8%) had a higher risk of ASD (P = 0.02) and DD (P = 0.001). Overall, no child presented with moderate or severe DD at 24 months (developmental quotient < 55). In 20% of children abnormal developmental trajectories were detected before the onset of seizures. Furthermore, 21% of all children with risk of ASD at 24 months had not developed seizures at that timepoint. There was no significant difference between early and conventional treatment with respect to rate of risk of ASD (P = 0.8) or DD (P = 0.9) at 24 months. INTERPRETATION: This study confirms a relationship between epilepsy and risk of ASD/DD. However, in this combined randomized/open label study, early treatment with vigabatrin did not alter the risk of ASD or DD at age 2 years.

TSC2 pathogenic variants are predictive of severe clinical manifestations in TSC infants: results of the EPISTOP study.

PURPOSE: To perform comprehensive genotyping of TSC1 and TSC2 in a cohort of 94 infants with tuberous sclerosis complex (TSC) and correlate with clinical manifestations. METHODS: Infants were enrolled at age <4 months, and subject to intensive clinical monitoring including electroencephalography (EEG), brain magnetic resonance imaging (MRI), and neuropsychological assessment. Targeted massively parallel sequencing (MPS), genome sequencing, and multiplex ligation-dependent probe amplification (MLPA) were used for variant detection in TSC1/TSC2. RESULTS: Pathogenic variants in TSC1 or TSC2 were identified in 93 of 94 (99%) subjects, with 23 in TSC1 and 70 in TSC2. Nine (10%) subjects had mosaicism. Eight of 24 clinical features assessed at age 2 years were significantly less frequent in those with TSC1 versus TSC2 variants including cortical tubers, hypomelanotic macules, facial angiofibroma, renal cysts, drug-resistant epilepsy, developmental delay, subependymal giant cell astrocytoma, and median seizure-free survival. Additionally, quantitative brain MRI analysis showed a marked difference in tuber and subependymal nodule/giant cell astrocytoma volume for TSC1 versus TSC2. CONCLUSION: TSC2 pathogenic variants are associated with a more severe clinical phenotype than mosaic TSC2 or TSC1 variants in TSC infants. Early assessment of gene variant status and mosaicism might have benefit for clinical management in infants and young children with TSC.

Dysregulation of the MMP/TIMP Proteolytic System in Subependymal Giant Cell Astrocytomas in Patients With Tuberous Sclerosis Complex: Modulation of MMP by MicroRNA-320d In Vitro.

Tuberous sclerosis complex (TSC), a rare genetic disorder caused by a mutation in the TSC1 or TSC2 gene, is characterized by the growth of hamartomas in several organs. This includes the growth of low-grade brain tumors, known as subependymal giant cell astrocytomas (SEGA). Previous studies have shown differential expression of genes related to the extracellular matrix in SEGA. Matrix metalloproteinases (MMPs), and their tissue inhibitors (TIMPs) are responsible for remodeling the extracellular matrix and are associated with tumorigenesis. This study aimed to investigate the MMP/TIMP proteolytic system in SEGA and the regulation of MMPs by microRNAs, which are important post-transcriptional regulators of gene expression. We investigated the expression of MMPs and TIMPs using previously produced RNA-Sequencing data, real-time quantitative PCR and immunohistochemistry in TSC-SEGA samples and controls. We found altered expression of several MMPs and TIMPs in SEGA compared to controls. We identified the lowly expressed miR-320d in SEGA as a potential regulator of MMPs, which can decrease MMP2 expression in human fetal astrocyte cultures. This study provides evidence of a dysregulated MMP/TIMP proteolytic system in SEGA of which MMP2 could be rescued by microRNA-320d. Therefore, further elucidating microRNA-mediated MMP regulation may provide insights into SEGA pathogenesis and identify novel therapeutic targets.

Preventive Antiepileptic Treatment in Tuberous Sclerosis Complex: A Long-Term, Prospective Trial.

BACKGROUD: Drug-resistant epilepsy is the main risk factor for future intellectual disability in patients with tuberous sclerosis complex. Clinical epileptic seizures are often preceded by electroencephalographic changes, which provide an opportunity for preventive treatment. We evaluated the neuropsychologic and epilepsy outcomes at school age in children with tuberous sclerosis complex who received preventive antiepileptic treatment in infancy. METHODS: We performed a prospective, nonrandomized clinical trial with 14 infants diagnosed with tuberous sclerosis complex in whom serial electroencephalographic recordings were performed and preventive treatment with vigabatrin initiated when active epileptic discharges were detected. An age-matched control group consisted of 31 infants with tuberous sclerosis complex in whom treatment with vigabatrin was given only after onset of clinical seizures. Results of clinical assessment of epilepsy and cognitive outcomes were analyzed. RESULTS: All patients in the preventive group (n = 14) and 25 of 31 patients in the standard treatment group were followed through minimum age five years, median 8.8 and 8.0 years in the preventive and standard groups, respectively. The median intelligence quotient was 94 for the preventive group when compared with 46 for the standard group (P < 0.03). Seven of 14 patients (50%) in the preventive group never had a clinical seizure when compared with one of 25 patients (5%) in the standard treatment group (P = 0.001). CONCLUSIONS: This study provides evidence that preventive antiepileptic treatment in infants with tuberous sclerosis complex improves long-term epilepsy control and cognitive outcome at school age.

Early Clinical Predictors of Autism Spectrum Disorder in Infants with Tuberous Sclerosis Complex: Results from the EPISTOP Study.

Autism spectrum disorder (ASD) is highly prevalent in subjects with Tuberous Sclerosis Complex (TSC), but we are not still able to reliably predict which infants will develop ASD. This study aimed to identify the early clinical markers of ASD and/or developmental delay (DD) in infants with an early diagnosis of TSC. We prospectively evaluated 82 infants with TSC (6-24 months of age), using a detailed neuropsychological assessment (Bayley Scales of Infant Development-BSID, and Autism Diagnostic Observation Schedule-ADOS), in the context of the EPISTOP (Long-term, prospective study evaluating clinical and molecular biomarkers of EPIleptogenesiS in a genetic model of epilepsy-Tuberous SclerOsis ComPlex) project (NCT02098759). Normal cognitive developmental quotient at 12 months excluded subsequent ASD (negative predictive value 100%). The total score of ADOS at 12 months clearly differentiated children with a future diagnosis of ASD from children without (p = 0.012). Atypical socio-communication behaviors (p < 0.001) were more frequently observed than stereotyped/repetitive behaviors in children with ASD at 24 months. The combined use of BSID and ADOS can reliably identify infants with TSC with a higher risk for ASD at age 6-12 months, allowing for clinicians to target the earliest symptoms of abnormal neurodevelopment with tailored intervention strategies.

Early diagnosis of tuberous sclerosis complex: a race against time. How to make the diagnosis before seizures?

BACKGROUND: Tuberous sclerosis complex (TSC) is a genetic disorder with an incidence of 1:6000 live births and associated with the development of benign tumors in several organs. It is also characterized by high rates of neurological and neuropsychiatric abnormalities, including epilepsy affecting 70-90% of patients and being one of the major risk factors of intellectual disability. The first seizures in TSC patients appear usually between the 4th and the 6th months of life. Recent studies have shown the beneficial role of preventative antiepileptic treatment in TSC patients, with the possibility for improvement of cognitive outcome. Moreover, European recommendations suggest early introduction of Vigabatrin if ictal discharges occur on EEG recordings, with or without clinical manifestation. The aim of this study was to define the most useful approach to make the diagnosis of TSC before seizure onset (before age 4th months), in order to start early EEG monitoring with possible preventative treatment intervention. METHODS: We performed a retrospective review of children who were suspected of having TSC due to single or multiple cardiac tumors as the first sign of the disease. We analyzed the medical records in terms of conducted clinical tests and TSC signs, which were observed until the end of the 4th month of age. Subsequently, we described the different clinical scenarios and recommendations for early diagnosis. RESULTS: 82/100 children were diagnosed with TSC within the first 4 months of life. Apart from cardiac tumors, the most frequently observed early TSC signs were subependymal nodules (71/100, 71%), cortical dysplasia (66/100, 66%), and hypomelanotic macules (35/100, 35%). The most useful clinical studies for early TSC diagnosis were brain magnetic resonance imaging (MRI), skin examination and echocardiography. Genetic testing was performed in 49/100 of the patients, but the results were obtained within the first 4 months of life in only 3 children. CONCLUSIONS: Early diagnosis of TSC, before seizure onset, is feasible and it is becoming pivotal for epilepsy management and improvement of cognitive outcome. Early TSC diagnosis is mostly based on clinical signs. Brain MRI, echocardiography, skin examination and genetic testing should be performed early in every patient suspected of having TSC.

Liver Angiomyolipomas in Tuberous Sclerosis Complex-Their Incidence and Course.

BACKGROUND: The purpose of this study was to evaluate the epidemiology and clinical significance of hepatic angiomyolipomas in patients with tuberous sclerosis complex. METHODS: We performed a retrospective analysis of clinical and imaging data from 187 patients with tuberous sclerosis complex. The prevalence, progression, and potential relationship between liver lesions and other clinical findings, including genetic associations, were assessed. RESULTS: Twenty-eight of 187 patients (14.9%) had hepatic lesions. There was a predominance of female over male patients in individuals with liver lesions (17 versus 11), with statistical significance in patients under five years of age (P < 0.05). All individuals having hepatic lesions who also had available genetic testing data (n = 20) were diagnosed with a TSC2 gene mutation. All patients with liver lesions had coexisting renal angiomyolipomas (AMLs) (P < 0.05). The age of onset of renal lesions was lower and their prevalence was significantly higher in patients with liver involvement (P < 0.05). In most instances, hepatic lesions measured several millimeters in diameter and were clinically asymptomatic. Progressive lesion growth was documented in six individuals but with no clinical consequences to date. CONCLUSIONS: This study confirms the association of hepatic lesions with TSC2 mutations, a common origin of liver and renal AMLs, as well as the predominance of female patients in this group. Hepatic AMLs are relatively common but mostly benign lesions.

Tuberous sclerosis complex neuropathology requires glutamate-cysteine ligase.

INTRODUCTION: Tuberous sclerosis complex (TSC) is a genetic disease resulting from mutation in TSC1 or TSC2 and subsequent hyperactivation of mammalian Target of Rapamycin (mTOR). Common TSC features include brain lesions, such as cortical tubers and subependymal giant cell astrocytomas (SEGAs). However, the current treatment with mTOR inhibitors has critical limitations. We aimed to identify new targets for TSC pharmacotherapy. RESULTS: The results of our shRNA screen point to glutamate-cysteine ligase catalytic subunit (GCLC), a key enzyme in glutathione synthesis, as a contributor to TSC-related phenotype. GCLC inhibition increased cellular stress and reduced mTOR hyperactivity in TSC2-depleted neurons and SEGA-derived cells. Moreover, patients' brain tubers showed elevated GCLC and stress markers expression. Finally, GCLC inhibition led to growth arrest and death of SEGA-derived cells. CONCLUSIONS: We describe GCLC as a part of redox adaptation in TSC, needed for overgrowth and survival of mutant cells, and provide a potential novel target for SEGA treatment.

Severe central and peripheral paraneoplastic demyelination associated with tumours of the ovaries.

PURPOSE: The aim of the study is to present MRI examinations of the brain and spinal cord, performed in girls with acute severe neurological presentation of paraneoplastic syndrome associated with ovarian teratomas. Paraneoplastic neurological syndrome (PNS) is a rare disorder caused by remote effects of malignancy in different organs. The pathogenesis of PNS concerns the autoimmune system and specific antibodies. PNS can be seen as encephalomyelitis, limbic encephalitis, progressive multifocal leukoencephalopathy, cerebellar ataxia, brainstem encephalitis, and paraneoplastic cerebellar degeneration. These symptoms are potentially reversible, if the underlying neoplasm is removed. METHODS: We presented three girls, aged 13, 17, and 18 years. They were all referred to the hospital because of an acute onset of severe disseminated encephalomyelitis. All MRI exams were performed on a 1.5 T scanner with a routine brain and spinal cord protocol, including TSE T2-WI and FLAIR sequences. In all cases, a contrast agent was injected in the standard dose. RESULTS: Neurological examination performed at the onset of the disease revealed hemiparesis, seizures, and consciousness disturbances. In one girl, visual field loss was also disclosed. They were all healthy before the onset of the disease. Brain and spinal cord MR imaging revealed multiple hyperintense lesions located supratentorially in the white matter of both hemispheres, in the pons, cerebellum, and spinal cord. Patients were treated with methyloprednisolone IV and IVIG. They all improved but significant sequelae were present. Two of them developed symptoms of acute demyelinating polyradiculoneuropathy within 2 months after the onset of encephalomyelitis. At the same time, brain MRI showed progression of the lesions. In two patients, anti-Yo antibodies were present in blood. Extensive examinations revealed bilateral ovarian teratomas in two patients, and left-sided ovarian teratoma in one case. Surgical resection of teratomas resulted in rapid clinical improvement. CONCLUSIONS: These cases show that in children and adolescents, acute demyelinating disease can be a manifestation of paraneoplastic neurological syndrome. Thus, PNS should always be considered in the differential diagnosis of encephalomyelitis. In female children and adolescents with suspected PNS, it is important to search for ovarian tumours.

Congenital subependymal giant cell astrocytomas in patients with tuberous sclerosis complex.

PURPOSE: Subependymal giant cell astrocytoma (SEGA) is a brain tumor associated with tuberous sclerosis complex (TSC). It usually grows in a second decade of life, but may develop in the first months of life. The aim of this work was to establish the incidence, clinical features, and outcome of congenital SEGA in TSC patients. METHODS: Cohort of 452 TSC patients was reviewed to identify cases with growing or hydrocephalus producing SEGAs in the first 3 months of life. Clinical presentation, size of the tumor, growth rate, mutational analysis, treatment applied, and outcome were analyzed. RESULTS: Ten (2.2 %) patients presented with SEGA in the first 3 months of life. All of them had documented SEGA growth and all developed hydrocephalus. In eight patients, mutational analysis was done, and in all of them, TSC2 gene mutations were identified. Mean maximum SEGA diameter at baseline was 21.8 mm. Mean SEGA growth rate observed postnatally was 2.78 mm per month and tended to be higher (5.43 mm per month) in patients with TSC2/PKD1 mutation than in other cases. Seven patients underwent SEGA surgery and surgery-related complications were observed in 57.1 % cases. One patient was successfully treated with everolimus as a primary treatment. CONCLUSIONS: Congenital SEGA develops 2.2 % of TSC patients. Patients with TSC2 mutations, and especially with TSC2/PKD1 mutations, are more prone to develop SEGA earlier in childhood and should be screened for SEGA from birth. In young infants with SEGA, both surgery and mTOR inhibitor should be considered as a treatment option.

Epilepsy in newborns with tuberous sclerosis complex.

BACKGROUND: Epilepsy affects up to 90% of TSC patients and majority of them have seizure at the age of 3-5 months, after a period of latent epileptogenesis, but some develop epilepsy earlier. AIMS: The aim of this work was to identify incidence, clinical characteristics, and risk factors for neonatal onset of epilepsy in a large cohort of TSC patients. METHODS: A retrospective review of medical data of 421 TSC patients was performed. Patients who developed epilepsy within first 4 weeks of life were included in the study. Clinical and treatment data, EEG, MRI, and genetic analyses were assessed. RESULTS: Epilepsy was present in 366 (86.9%) patients. Twenty-one (5.7%) developed epilepsy as newborns. Mean follow-up was 44.86 (6-170) months. Six patients were seizure free and 15 had drug-resistant seizures at the end of follow-up. Mental retardation was found in 81% of patients. In 11 (52.4%) patients brain MRI revealed large malformations of cerebral cortex, meeting the criteria for focal cortical dysplasia (FCD). FCD was revealed in both TSC1 and TSC2 mutation cases. Other risk factors for neonatal epilepsy included: perinatal complications and congenital SEGAs. Presence of FCD was associated with more severe epilepsy and worse neuropsychological outcome. Epilepsy surgery resulted in improvement in seizure control. CONCLUSIONS: Neonatal onset of epilepsy in TSC is frequently associated with large malformations of cerebral cortex. Patients with FCD are at high risk of severe drug-resistant epilepsy and poor neuropsychological outcome. Early epilepsy surgery may be beneficial and should be considered in such cases.

Surgical treatment of subependymal giant cell astrocytoma in tuberous sclerosis complex patients.

BACKGROUND: Subependymal giant cell astrocytoma is a brain tumor associated with tuberous sclerosis complex. There are two treatment options for subependymal giant cell astrocytomas: surgery or mammalian target of rapamycin inhibitor. The analysis of outcome of subependymal giant cell astrocytoma surgery may help characterize the patients who may benefit from pharmacotherapy. METHODS: Sixty-four subependymal giant cell astrocytoma surgeries in 57 tuberous sclerosis complex patients with at least a 12-month follow-up were included in the study. The tumor size, age of the patients, mutation in the TSC1 or TSC2 gene, indication for the surgery, and postsurgical complications were analyzed. RESULTS: The mean age of patients at surgery was 9.7 years. Mean follow-up after surgery was 63.7 months. Thirty-seven (57.8%) tumors were symptomatic and 27 (42.2%) were asymptomatic. Patients with TSC2 mutations developed subependymal giant cell astrocytoma at a significantly younger age than individuals with TSC1 mutations. Four patients (6.2% of all surgeries) died after surgery. Surgery-related complications were reported in 0%, 46%, 83%, 81%, and 67% of patients with tumors <2 cm, between 2 and 3 cm, between 3 and 4 cm, >4 cm, and bilateral subependymal giant cell astrocytomas, respectively, and were most common in children younger than 3 years of age. The most common complications included hemiparesis, hydrocephalus, hematoma, and cognitive decline. CONCLUSIONS: Our study indicates that subependymal giant cell astrocytoma surgery is associated with significant risk in individuals with bilateral subependymal giant cell astrocytomas, tumors bigger than 2 cm, and in children younger than 3 years of age. Therefore, tuberous sclerosis complex patients should be thoroughly screened for subependymal giant cell astrocytoma growth, and early treatment should be considered in selected patients.

Possible prevention of tuberous sclerosis complex lesions.

Tuberous sclerosis complex (TSC) is a genetic disorder characterized by mammalian target of rapamycin (mTOR) activation and growth of benign tumors. Some TSC lesions, such as cardiac rhabdomyomas and cortical tubers in the brain, occur in fetuses, and some, such as renal angiomyolipomas (AMLs) and skin angiofibromas, develop over years. Recently, the mTOR inhibitor everolimus was shown to be effective in the treatment of subependymal giant cell astrocytomas (a brain tumor) and renal AMLs (kidney tumors) in TSC patients. We present monozygotic twin sisters affected with TSC. Since age 4 years, 1 of the sisters has been treated with everolimus; the other sister received no mTOR inhibitor treatment. After 24-month follow-up, everolimus treatment resulted in a significant brain tumor volume decrease in the treated twin. This child presents no facial angiofibroma, and no renal AMLs. The brain tumor in the nontreated sister is stable in size, but in the meantime, she has developed significant facial angiofibroma and renal AMLs. This observation indicates that early mTOR inhibition in TSC patients may prevent the development of TSC lesions and alter the natural history of the disease.