Tuberous Sclerosis Complex and the kidneys: what nephrologists need to know / Complexo da Esclerose Tuberosa e rins: o que os nefrologistas devem saber

Abstract Tuberous sclerosis complex (TSC) is an autosomal dominant disease characterized by the development of hamartomas in the central nervous system, heart, skin, lungs, and kidneys and other manifestations including seizures, cortical tubers, radial migration lines, autism and cognitive disability. The disease is associated with pathogenic variants in the TSC1 or TSC2 genes, resulting in the hyperactivation of the mTOR pathway, a key regulator of cell growth and metabolism. Consequently, the hyperactivation of the mTOR pathway leads to abnormal tissue proliferation and the development of solid tumors. Kidney involvement in TSC is characterized by the development of cystic lesions, renal cell carcinoma and renal angiomyolipomas, which may progress and cause pain, bleeding, and loss of kidney function. Over the past years, there has been a notable shift in the therapeutic approach to TSC, particularly in addressing renal manifestations. mTOR inhibitors have emerged as the primary therapeutic option, whereas surgical interventions like nephrectomy and embolization being reserved primarily for complications unresponsive to clinical treatment, such as severe renal hemorrhage. This review focuses on the main clinical characteristics of TSC, the mechanisms underlying kidney involvement, the recent advances in therapy for kidney lesions, and the future perspectives.

Resumo O complexo da esclerose tuberosa (CET) é uma doença autossômica dominante caracterizada pelo desenvolvimento de hamartomas no sistema nervoso central, coração, pele, pulmões e rins e outras manifestações, incluindo convulsões, tubérculos corticais, linhas de migração radial, autismo e deficiência cognitiva. A doença está associada a variantes patogênicas nos genes TSC1 ou TSC2, resultando na hiperativação da via mTOR, um importante regulador do crescimento e metabolismo celular. Consequentemente, a hiperativação da via mTOR leva à proliferação anormal do tecido e ao desenvolvimento de tumores sólidos. O envolvimento renal no CET é caracterizado pelo desenvolvimento de lesões císticas, carcinoma de células renais e angiomiolipomas renais, que podem progredir e causar dor, sangramento e perda da função renal. Nos últimos anos, houve uma mudança notável na abordagem terapêutica do CET, especialmente no tratamento das manifestações renais. Os inibidores de mTOR surgiram como a principal opção terapêutica, enquanto intervenções cirúrgicas como nefrectomia e embolização são reservadas principalmente para complicações que não respondem ao tratamento clínico, como hemorragia renal grave. Esta revisão se concentra nas principais características clínicas do CET, nos mecanismos subjacentes ao envolvimento renal, nos recentes avanços na terapia para lesões renais e nas perspectivas futuras.

Endovascular Treatment of a Bilateral, Ruptured Angiomyolipoma in a Patient With Tuberous Sclerosis Complex.

A renal angiomyolipoma (AML) is a rare, usually benign tumor consisting of smooth muscle cells, abnormal blood vessels, and fat tissue. Although AMLs are often asymptomatic, they can present with flank pain, hematuria, and a palpable mass in the abdomen. A significant complication involves rupture and hemorrhage into the retroperitoneal cavity, which can be life-threatening. The treatment approach has evolved from surgical removal to more conservative management, such as nephron-sparing embolization and mammalian target of rapamycin (mTOR) inhibitors for tuberous sclerosis complex (TSC)-associated AML. In March 2024, a 36-year-old female patient diagnosed with TSC was admitted to our department and underwent several endovascular embolizations after a life-threatening hemorrhage from a ruptured multilocular AML. The treatment was successful, with complete exclusion of the AMLs from circulation and without any complications during the postoperative period. This case emphasizes the effectiveness of selective arterial embolization using the Onyx liquid embolic system in managing AMLs and highlights the importance of preserving renal function. Methods used in AML diagnosis include ultrasound and computed tomography scans, with magnetic resonance imaging and biopsy recommended in difficult cases. Treatment depends on aspects such as tumor size, symptoms, and patient's general condition, with options ranging from active surveillance for small, asymptomatic AMLs to more invasive procedures for larger, symptomatic tumors. The main goal is to minimize symptoms and preserve renal function.

Subependymal Giant Cell Astrocytomas Without Tuberous Sclerosis: A Case Report on a Rare Medical Condition.

Subependymal giant cell astrocytomas (SEGAs) are benign, slow-growing, noninvasive tumors frequently associated with the tuberous sclerosis complex (TSC). The tumor's location and the patient's age should be considered carefully before diagnosis. Considering SEGA as a differential diagnosis, even in adult patients without TSC, is essential. In the present case, a 22-year-old male presented with a progressive headache, dizziness, and blurring of vision. Radiological investigations confirmed the site of the tumor, and a positive expression of thyroid transcription factor 1 in the ganglion cell component, along with the absence of germline mutation in TSC1 and TSC2, led to the final diagnosis of SEGA without TSC.

Case Report: Patent ductus arteriosus with tuberous sclerosis complex.

A 33-year-old patient presented with a chief complaint of patent ductus arteriosus (PDA) persisting for over 30 years. Physical examination revealed bilateral facial angiofibromas, multiple nail fibromas, intraoral fibromas, and a 'shagreen patch' on the left lumbar region. Genetic testing was performed using a peripheral venous blood sample, which confirmed the diagnosis of Tuberous Sclerosis Type 2 (TSC2). Subsequently, the patient underwent cardiac color Doppler ultrasound and chest computed tomography angiography, which confirmed the presence of PDA. Tuberous sclerosis complex (TSC) is associated with cardiovascular diseases. The initial clinical manifestation of TSC is usually cardiac rhabdomyoma in children, and it is rarely reported in adults with PDA. In this case, the patient was diagnosed with PDA when he was young, and the genetic test showed heterozygous variation of TSC2 gene. The purpose of this article is to explore the correlation between TSC and PDA at the gene level through literature review.

Genotypic and phenotypic analysis of Korean patients with tuberous sclerosis complex.

Tuberous sclerosis complex (TSC) is a rare autosomal dominant disorder caused by mutations in the TSC1 or TSC2 gene. The aim of this study was to analyze the genotypes and phenotypes of Korean patients diagnosed with TSC and expand our understanding of this disorder. This retrospective observational study included 331 patients clinically diagnosed with TSC between November 1990 and April 2023 at Severance Children's Hospital, Seoul, South Korea. The demographic and clinical characteristics of the patients were investigated. Thirty novel variants were identified. Of the 331 patients, 188 underwent genetic testing, and genotype-phenotype variation was analyzed according to the type of gene mutation and functional domain. Fourty-nine patients (49/188, 26%) were had TSC1 mutations, 103 (55%) had TSC2 mutations, and 36 (19%) had no mutation identified (NMI). Hotspots were identified in exons 8 of TSC1 and exons 35 and 41 of TSC2. Patients with TSC2 mutations exhibited a significantly younger age at the time of seizure onset and had refractory epilepsy. Infantile epileptic spasms syndrome (IESS) was more common in the middle mutation domain of TSC2 than in the hamartin domain. Additionally, retinal hamartoma, cardiac rhabdomyoma, and renal abnormalities were significantly associated with TSC2 compared with other gene types. This study contributes to our understanding of TSC by expanding the genotypic spectrum with novel variants and providing insights into the clinical spectrum of patients with TSC in Korea.

Experience of the first adult-focussed undiagnosed disease program in Australia (AHA-UDP): solving rare and puzzling genetic disorders is ageless.

BACKGROUND: Significant recent efforts have facilitated increased access to clinical genetics assessment and genomic sequencing for children with rare diseases in many centres, but there remains a service gap for adults. The Austin Health Adult Undiagnosed Disease Program (AHA-UDP) was designed to complement existing UDP programs that focus on paediatric rare diseases and address an area of unmet diagnostic need for adults with undiagnosed rare conditions in Victoria, Australia. It was conducted at a large Victorian hospital to demonstrate the benefits of bringing genomic techniques currently used predominantly in a research setting into hospital clinical practice, and identify the benefits of enrolling adults with undiagnosed rare diseases into a UDP program. The main objectives were to identify the causal mutation for a variety of diseases of individuals and families enrolled, and to discover novel disease genes. METHODS: Unsolved patients in whom standard genomic diagnostic techniques such as targeted gene panel, exome-wide next generation sequencing, and/or chromosomal microarray, had already been performed were recruited. Genome sequencing and enhanced genomic analysis from the research setting were applied to aid novel gene discovery. RESULTS: In total, 16/50 (32%) families/cases were solved. One or more candidate variants of uncertain significance were detected in 18/50 (36%) families. No candidate variants were identified in 16/50 (32%) families. Two novel disease genes (TOP3B, PRKACB) and two novel genotype-phenotype correlations (NARS, and KMT2C genes) were identified. Three out of eight patients with suspected mosaic tuberous sclerosis complex had their diagnosis confirmed which provided reproductive options for two patients. The utility of confirming diagnoses for patients with mosaic conditions (using high read depth sequencing and ddPCR) was not specifically envisaged at the onset of the project, but the flexibility to offer recruitment and analyses on an as-needed basis proved to be a strength of the AHA-UDP. CONCLUSION: AHA-UDP demonstrates the utility of a UDP approach applying genome sequencing approaches in diagnosing adults with rare diseases who have had uninformative conventional genetic analysis, informing clinical management, recurrence risk, and recommendations for relatives.

Multiparameter quantitative analyses of diagnostic cells in brain tissues from tuberous sclerosis complex.

The advent of high-dimensional imaging offers new opportunities to molecularly characterize diagnostic cells in disorders that have previously relied on histopathological definitions. One example case is found in tuberous sclerosis complex (TSC), a developmental disorder characterized by systemic growth of benign tumors. Within resected brain tissues from patients with TSC, detection of abnormally enlarged balloon cells (BCs) is pathognomonic for this disorder. Though BCs can be identified by an expert neuropathologist, little is known about the specificity and broad applicability of protein markers for these cells, complicating classification of proposed BCs identified in experimental models of this disorder. Here, we report the development of a customized machine learning pipeline (BAlloon IDENtifier; BAIDEN) that was trained to prospectively identify BCs in tissue sections using a histological stain compatible with high-dimensional cytometry. This approach was coupled to a custom 36-antibody panel and imaging mass cytometry (IMC) to explore the expression of multiple previously proposed BC marker proteins and develop a descriptor of BC features conserved across multiple tissue samples from patients with TSC. Here, we present a modular workflow encompassing BAIDEN, a custom antibody panel, a control sample microarray, and analysis pipelines-both open-source and in-house-and apply this workflow to understand the abundance, structure, and signaling activity of BCs as an example case of how high-dimensional imaging can be applied within human tissues.

Subpial resection of epileptogenic tubers: operative nuances and lessons learned.

Tuberous sclerosis complex (TSC) is an autosomal dominant neurocutaneous disorder. Tubers of the central nervous system are a hallmark of the disorder and often cause epilepsy. Many TSC patients fail to achieve seizure control with medication alone. Several case series have demonstrated high seizure freedom rates after resective surgery. However, the technique for the resection of epileptogenic tubers has largely been unreported. Here the authors present 2 cases to illustrate their multistage approach for localizing and resecting the seizure onset zone in patients with TSC. At their institution, they have excellent seizure outcomes and a low complication rate with this technique. The video can be found here: https://stream.cadmore.media/r10.3171/2024.4.FOCVID2411.

Beyond Benign: A Case of Subependymal Giant Cell Astrocytomas Provoking Hydrocephalus in Tuberous Sclerosis Complex.

22-year-old male diagnosed with Tuberous Sclerosis Complex (TSC), a genetic disorder characterized by benign tumors in various organs, with a focus on neurological implications. Central to the study is the development of Subependymal Giant Cell Astrocytomas (SEGAs), leading to hydrocephalus in the patient. The diagnosis of TSC was made in the patient's childhood, and he was monitored regularly. The study highlights a significant growth in a subependymal nodule, leading to monoventricular hydrocephalus. MRI scans played a crucial role in identifying the progression of SEGAs and the subsequent hydrocephalus. The treatment approach involved endoscopic surgical removal of the SEGA, with histopathology confirming the diagnosis. Post-surgical outcomes over an eight-year follow-up period showed a normalization in ventricular size and the stability of other subependymal nodules, without any complications. This case underscores the importance of regular monitoring for TSC patients, early intervention for complications like hydrocephalus, and the need for a multidisciplinary treatment approach. The case study provides valuable insights into the management of neurodevelopmental disorders and the complexities surrounding TSC and SEGAs.

Association of earlier surgery with improved postoperative language development in children with tuberous sclerosis complex.

OBJECTIVE: The authors evaluated the impact of the timing of epilepsy surgery on postoperative neurocognitive outcomes in a cohort of children followed in the multiinstitutional Tuberous Sclerosis Complex (TSC) Autism Center of Excellence Research Network (TACERN) study. METHODS: Twenty-seven of 159 patients in the TACERN cohort had drug-refractory epilepsy and underwent surgery. Ages at surgery ranged from 15.86 to 154.14 weeks (median 91.93 weeks). Changes in patients' first preoperative (10-58 weeks) to last postoperative (155-188 weeks) scores on three neuropsychological tests-the Mullen Scales of Early Learning (MSEL), the Vineland Adaptive Behavior Scales, 2nd edition (VABS-2), and the Preschool Language Scales, 5th edition (PLS-5)-were calculated. Pearson correlation and multivariate linear regression models were used to correlate test outcomes separately with age at surgery and duration of epilepsy prior to surgery. Analyses were separately conducted for patients whose seizure burdens decreased postoperatively (n = 21) and those whose seizure burdens did not (n = 6). Regression analysis was specifically focused on the 21 patients who achieved successful seizure control. RESULTS: Age at surgery was significantly negatively correlated with the change in the combined verbal subtests of the MSEL (R = -0.45, p = 0.039) and predicted this score in a multivariate linear regression model (ß = -0.09, p = 0.035). Similar trends were seen in the total language score of the PLS-5 (R = -0.4, p = 0.089; ß = -0.12, p = 0.014) and in analyses examining the duration of epilepsy prior to surgery as the independent variable of interest. Associations between age at surgery and duration of epilepsy prior to surgery with changes in the verbal subscores of VABS-2 were more variable (R = -0.15, p = 0.52; ß = -0.05, p = 0.482). CONCLUSIONS: Earlier surgery and shorter epilepsy duration prior to surgery were associated with greater improvement in postoperative language in patients with TSC. Prospective or comparative effectiveness clinical trials are needed to further elucidate surgical timing impacts on neurocognitive outcomes.

Unveiling Tuberous Sclerosis in a Diagnosed Patient With Systemic Lupus Erythematosus: A Rare Coincidence.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease presenting a variable clinical course ranging from mild to severe multiorgan dysfunction. While the exact etiology of SLE remains elusive, genetic and environmental factors are known to play crucial roles in its pathogenesis. Similarly, tuberous sclerosis complex (TSC) is a multisystem autosomal dominant genetic condition that manifests as benign hamartomatous proliferation in various organs. We present the case of a 46-year-old woman diagnosed with SLE who exhibited clinical features of TSC two decades after the initial diagnosis of SLE. The definitive diagnosis of TSC was made based on major clinical criteria, including facial angiofibroma and bilateral renal angiomyolipomas. As the patient remained asymptomatic without neurological complications, specific treatment for TSC was not initiated. The coexistence of SLE and TSC is exceedingly rare and has been scarcely reported in medical literature.

Resting state EEG in young children with Tuberous Sclerosis Complex.

Background: Tuberous Sclerosis Complex (TSC) manifests behaviorally with features of autism, epilepsy, and intellectual disability. Resting state electroencephalography (EEG) offers a window into neural oscillatory activity and may serve as an intermediate biomarker between gene expression and behavioral manifestations. Such a biomarker could be useful in clinical trials as an endpoint or predictor of treatment response. However, seizures and antiepileptic medications also affect resting neural oscillatory activity and could undermine the utility of resting state EEG features as biomarkers in neurodevelopmental disorders such as TSC. Methods: This paper compares resting state EEG features in a cross-sectional cohort of young children with TSC (n=49, ages 12-37 months) to 49 age- and sex-matched typically developing controls. Within children with TSC, associations were examined between resting state EEG features, seizure severity composite score, and use of GABA agonists. Results: Compared to matched typically developing controls, children with TSC showed significantly greater alpha and beta power in permutation cluster analyses iterated across a broad frequency range (2-50Hz). Children with TSC also showed significantly greater aperiodic offset after power spectra were parameterized using SpecParam into aperiodic and periodic components. Within children with TSC, greater seizure severity was significantly related to increased periodic peak beta power. Use of GABA agonists was also independently and significantly associated with increased periodic peak beta power; the interaction between seizure severity and GABA agonist use had no significant effect on peak beta power. Conclusions: The elevated peak beta power observed in children with TSC compared to matched typically developing controls may be driven by both seizures and GABA agonist use. It is recommended to collect seizure and mediation data alongside EEG data for clinical trials. These results highlight the challenge of using resting state EEG features as biomarkers in trials with neurodevelopmental disabilities when epilepsy and anti-epileptic medication are common.

Cytoplasmic vacuolization and ectopic formation of perineuronal nets are characteristic pathologies of cytomegalic neurons in tuberous sclerosis.

Cytomegalic neurons, characterized by increased size and a hyperactive mechanistic target of rapamycin complex 1 (mTORC1), are pathognomonic for tuberous sclerosis complex (TSC). To model these neurons, we recently generated a murine Tsc1 conditional knockout model in which Tsc1 deletion in late embryonic radial glia results in neuronal hypertrophy of a subset of isocortical pyramidal neurons. In the current study, we compared the cellular pathology of these cytomegalic neurons to those of the enlarged neurons in human cortical tubers. Neurons from the mice showed unique features, such as cytoplasmic vacuoles associated with Golgi complexes and the ectopic formation of perineuronal nets (PNNs), a feature of inhibitory neurons, rarely present in excitatory cortical neurons. The membranes of these vacuoles were enriched for the plasma membrane proteins CD44, KCC2, and Na+/K+ ATPase, suggesting deficits in Golgi membrane trafficking. These aberrant features in the mouse appeared only after the onset of seizures, probably due to the prolonged seizure activity in the context of constitutive mTORC1 activation. Similar PNNs and cytoplasmic vacuoles were present in the cytomegalic neurons of human cortical tubers. Our findings reveal novel pathological features of Golgi complexes and PNNs in the cytomegalic neurons in TSC.

Case report: Liver PEComa after kidney transplantation in recipient with tuberous sclerosis complex.

Introduction: Perivascular epithelioid cell tumors (PEComa) are rare tumors of mesenchymal origin that exhibit perivascular epithelioid cell phenotype. One of its most common localizations is uterus, whereas only a few studies reported PEComa localization as liver. There is a correlation between the presence of PEComa and tuberous sclerosis complex (TSC). TSC is a rare disease which leads to the development of mostly non-cancerous tumors in various organs. We would like to present a case of a kidney transplant recipient with a PEComa detected post-transplant in the liver. Case report: A 27-year-old patient, 3 years after kidney transplantation (KTx) due to chronic renal failure in the course of autosomal dominant polycystic kidney disease and concomitant TSC, was admitted to the Clinic and Department of General and Transplant Surgery for abnormal findings in computed tomography (CT). A CT scan was conducted for oncological follow-up after a kidney transplant (KTx) because before the transplantation, a small cystic lesion measuring 7 mm in diameter was removed from the donor kidney and diagnosed as papillary renal cell carcinoma (PRCC). Two tumors in the liver were detected - one 27mm in diameter in segment VII/VIII and the other 8mm in diameter in segment II/III. Because of typical radiological signs hepatocellular carcinoma was suspected, but the serum level of alpha fetoprotein was within normal limits and liver function was preserved. The intraoperative biopsy and the radiofrequency ablation (RFA) of the larger tumor were performed three months later. In the histopathological examination benign PEComa (HMB45 +, Melan A +) was detected. Conclusion: The oncological surveillance made it possible to detect liver lesion in early stage and in 3,5-year follow-up no sign of recurrence of PEComa was found. This case is the second to show RFA as treatment method of liver PEComa and first in kidney transplant recipient.

The emotional burden of caring for patients with Lennox-Gastaut syndrome, Dravet syndrome, and tuberous sclerosis complex-associated epilepsy: A qualitative study in Japan.

INTRODUCTION: Lennox-Gastaut syndrome (LGS) and Dravet syndrome (DS) are rare, childhood-onset conditions associated with severe, treatment-resistant epilepsy and developmental issues, including motor and cognitive impairment. Tuberous sclerosis complex (TSC) is a rare genetic disease commonly associated with epilepsy and other neuropsychiatric disorders. This cross-sectional, interview-based study examined the qualitative impact of caring for patients with LGS, DS, and TSC-associated epilepsy on caregivers in Japan, from the perspective of both caregivers and physicians. METHODS: The survey included a pre-interview worksheet to describe caregivers' emotional journeys, followed by a ≤ 60-minute one-on-one interview. Eligible participants were Japanese caregivers of patients with LGS, DS, or TSC treated for epilepsy symptoms, and Japan-residing pediatricians or neurologists treating ≥ 3 patients with LGS, DS, and/or TSC. Interview question responses were subjected to content analysis to identify the most common response tendencies and themes. RESULTS: Twenty-six caregivers responded (mean [standard deviation (SD)] age, 45.9 [9.5] years; age range 29-68; 92 % female), caring for patients with LGS (n = 5), DS (n = 10), and TSC (n = 11); patient mean (SD) age, 13.6 (10.0) years; age range 2-44; 27 % adults; 50 % female. Nineteen physicians, treating patients with LGS (n = 9), DS (n = 7), and TSC (n = 10), participated. Caregivers and physicians generally aligned on the factors affecting caregivers' emotional states / quality of life (QoL). The most frequently reported caregiver emotions at the time of diagnosis were shock and discouragement, anxiety for the future, and relief at receiving a diagnosis. Negative emotions throughout disease progression up until the time of survey were mainly caused by worsening of seizures, burden of constant caregiving / lack of free time, and patient's developmental issues. Positive emotions were linked to effective treatment / reduced seizures; more free time owing to the use of facilities, services, or other caregiving support; and developmental progress. Physicians acknowledged that caregivers required consultation services to support their emotional needs. In terms of unmet needs, caregiver and physician responses were aligned on the insufficient availability of services/facilities, the lack of effective treatments, and the uncertainties of adult patient care. CONCLUSIONS: Caregivers of patients with LGS, DS, or TSC-associated epilepsy in Japan reported a high degree of emotional burden related to frequent seizures, developmental issues, and constant caregiving. The burden of suboptimal treatment effectiveness, limited access to support services, and uncertainties in long-term care emphasize important unmet treatment needs.

Do metabolic deficits contribute to sleep disruption in monogenic intellectual disability syndromes?

Intellectual disability is defined as limitations in cognitive and adaptive behavior that often arise during development. Disordered sleep is common in intellectual disability and, given the importance of sleep for cognitive function, it may contribute to other behavioral phenotypes. Animal models of intellectual disability, in particular of monogenic intellectual disability syndromes (MIDS), recapitulate many disease phenotypes and have been invaluable for linking some of these phenotypes to specific molecular pathways. An emerging feature of MIDS, in both animal models and humans, is the prevalence of metabolic abnormalities, which could be relevant for behavior. Focusing on specific MIDS that have been molecularly characterized, we review sleep, circadian, and metabolic phenotypes in animal models and humans and propose that altered metabolic state contributes to the abnormal sleep/circadian phenotypes in MIDS.

A Rare Case of Renal Angiomyolipoma and Polycystic Kidney Disease in a Patient with Tuberous Sclerosis.

Renal angiomyolipoma (AML) is a rare benign tumor that follows an autosomal dominant inheritance pattern. Its association with polycystic kidney disease is uncommon, with only a handful of cases documented in the literature. The growth of lesions to a significant size may lead to life-threatening complications. We report a case of a 32-year-old female who presented with a palpable mass and bilateral flank pain. Following clinical assessment and CT examination, the patient underwent a left radical nephrectomy. The resected mass measured 9.3 x 8.2 x 7.5 cm, and the subsequent histopathological examination confirmed the diagnosis as renal AML.

Radiotherapy for subependymal giant cell astrocytoma: time to challenge a historical ban? A case report and review of the literature.

BACKGROUND: Subependymal giant cell astrocytoma is a benign brain tumor that occurs in patients with tuberous sclerosis complex. Surgical removal is the traditional treatment, and expert opinion is strongly against the use of radiotherapy. Recently, success has been reported with the mTor inhibitor everolimus in reducing tumor volume, but regrowth has been observed after dose reduction or cessation. CASE REPORT: We present the case of a 40-year-old Asian female patient treated successfully for growing bilateral subependymal giant cell astrocytoma with fractionated stereotactic radiotherapy before everolimus became available. After a follow-up of 8 years, everolimus was administered for renal angiomyolipoma and the patient was followed up until 13 years after radiotherapy. Successive magnetic resonance imaging demonstrated an 80% volume reduction after radiotherapy that increased to 90% with everolimus. A review of the literature was done leveraging Medline via PubMed, and we assembled a database of 1298 article references and 780 full-text articles in search of evidence for contraindicating radiotherapy in subependymal giant cell astrocytoma. Varying results of single-fraction radiosurgery were described in a total of 13 cases. Only in two published cases was the radiation dose of fractionated radiotherapy mentioned. One single publication mentions an induced secondary brain tumor 8 years after whole-brain radiotherapy. CONCLUSION: There is no evidence of contraindication and exclusion of fractionated radiotherapy in treating subependymal giant cell astrocytoma. Our experience demonstrates that subependymal giant cell astrocytoma, as other benign intracranial tumors, responds slowly but progressively to radiotherapy and suggests that fractionated stereotactic radiotherapy holds promise to consolidate responses obtained with mTor inhibitors avoiding regrowth after cessation.

Increased susceptibility to kainate-induced seizures in a mouse model of tuberous sclerosis complex: Importance of sex and circadian cycle.

OBJECTIVE: Comorbidity of epilepsy and autism in tuberous sclerosis complex 2 (TSC2) is very frequent, but the link between these conditions is still poorly understood. To study neurological problems related to autism, the scientific community has been using an animal model of TSC2, Tsc2+/- mice. However, it is still unknown whether this model has the propensity to exhibit increased seizure susceptibility. Further, the importance of sex and/or the circadian cycle in this biological process has never been addressed. This research aimed to determine whether male and female Tsc2+/- mice have altered seizure susceptibility at light and dark phases. METHODS: We assessed seizure susceptibility and progression in a Tsc2+/- mouse model using the chemical convulsant kainic acid (KA), a potent agonist of the AMPA/kainate class of glutamate receptors. Both male and female animals at adult age were evaluated during non-active and active periods. Seizure severity was determined by integrating individual scores per mouse according to a modified Racine scale. Locomotor behavior was monitored during control and after KA administration. RESULTS: We found increased seizure susceptibility in Tsc2+/- mice with a significant influence of sex and circadian cycle on seizure onset, progression, and behavioral outcomes. While, compared to controls, Tsc2+/- males overall exhibited higher susceptibility independently of circadian cycle, Tsc2+/- females were more susceptible during the dark and post-ovulatory phase. Interestingly, sexual dimorphisms related to KA susceptibility were always reported during light phase independently of the genetic background, with females being the most vulnerable. SIGNIFICANCE: The enhanced susceptibility in the Tsc2 mouse model suggests that other neurological alterations, beside brain lesions, may be involved in seizure occurrence for TSC. Importantly, our work highlighted the importance of considering biological sex and circadian cycle for further studies of TSC-related epilepsy research. PLAIN LANGUAGE SUMMARY: Tuberous sclerosis complex (TSC) is a rare genetic disorder. It causes brain lesions and is linked to epilepsy, intellectual disability, and autism. We wanted to investigate epilepsy in this model. We found that these mice have more induced seizures than control animals. Our results show that these mice can be used in future epilepsy research for this disorder. We also found that sex and time of day can influence the results. This must be considered in this type of research.