Epilepsy in tuberous sclerosis complex: Findings from the TOSCA Study

Intersection of two rare conditions: Clinical reflection on tuberous sclerosis combined with primary lymphedema

This editorial discusses a case report recently published in the World Journal of Clinical Cases. The report describes the clinical presentation, imaging, diagnosis, and treatment of a patient with tuberous sclerosis complex (TSC) combined with primary lymphedema (PLE). Additionally, it retrospectively analyzes the data of 16 previously reported cases of children with TSC combined with PLE to summarize the epidemiology, genetic diagnosis, and current main treatments of these patients. The report also speculates on the pathological and physiological mechanisms underlying TSC combined with PLE. TSC combined with PLE is rare; therefore, the report provides a theoretical basis for understanding the pathophysiological mechanisms and treatment options for patients with TSC and PLE. Comprehensive clinical management of TSC is essential due to the diverse and multiorgan nature of its manifestations, often requiring a multidisciplinary approach for newly diagnosed cases.

Caregiver burden associated with caring for individuals with tuberous sclerosis complex-associated seizures: A descriptive, non-interventional survey in Sweden

Tuberous sclerosis complex (TSC)-associated seizures result in a significant burden for caregivers. To quantify time spent and describe activities undertaken by caregivers of individuals with TSC-associated seizures in Sweden, primary caregivers participated in a cross-sectional, non-interventional online survey. Questions comprised patient/caregiver characteristics, care provision, time, and activities associated with generalized seizures or non-seizure-related care. Twenty-three primary caregivers participated; 96 % parents, 100 % female. Median number of caregivers per individual was three. In the last month, median (interquartile range [IQR]) hours for caregiving per week was 52.0 (25.7-100.0; n = 21); median (IQR) hours for non-seizure-related care was 46.7 (20.0-93.3; n = 21) and for generalized seizure-related care was 4.7 (1.7-15.8; n = 12). Beyond the last month, hours/week of generalized seizure-related care varied from 1.9 (0-8.8) to 14.0 (0.5-77.0). Professional/paid carers contributed 99.2 (73.5-127.5) hours/week of care. Non-seizure-related care activities included assisting with routine medical care (n = 22, 96 %) and daily activities (n = 22, 96 %). Activities relating to generalized seizures included assessing the need for (n = 16, 84 %) and giving (n = 17, 89 %) rescue medication, providing physical support (n = 16, 84 %), and clearing the individual's environment during generalized seizures (n = 13, 68 %). During generalized seizure recovery, activities included taking the individual to bed (n = 18, 95 %), emotional support (n = 14, 74 %), and managing behavioral issues (n = 14, 74 %). In Sweden, despite contributions of paid caregivers, individuals with TSC-associated seizures require substantial time from unpaid primary caregivers, including seizure- and non-seizure-related care. Generalized seizures have a considerable impact on time spent caregiving and the care activities undertaken.

Vigabatrin-associated brain magnetic resonance imaging abnormalities and clinical symptoms in infants with tuberous sclerosis complex

OBJECTIVE

Previous retrospective studies have reported vigabatrin-associated brain abnormalities on magnetic resonance imaging (VABAM), although clinical impact is unknown. We evaluated the association between vigabatrin and predefined brain magnetic resonance imaging (MRI) changes in a large homogenous tuberous sclerosis complex (TSC) cohort and assessed to what extent VABAM-related symptoms were reported in TSC infants.

METHODS

The Dutch TSC Registry and the EPISTOP cohort provided retrospective and prospective data from 80 TSC patients treated with vigabatrin (VGB) before the age of 2 years and 23 TSC patients without VGB. Twenty-nine age-matched non-TSC epilepsy patients not receiving VGB were included as controls. VABAM, specified as T2/fluid-attenuated inversion recovery hyperintensity or diffusion restriction in predefined brain areas, were examined on brain MRI before, during, and after VGB, and once in the controls (at approximately age 2 years). Additionally, the presence of VABAM accompanying symptoms was evaluated.

RESULTS

Prevalence of VABAM in VGB-treated TSC patients was 35.5%. VABAM-like abnormalities were observed in 13.5% of all patients without VGB. VGB was significantly associated with VABAM (risk ratio [RR] = 3.57, 95% confidence interval [CI] = 1.43-6.39), whereas TSC and refractory epilepsy were not. In all 13 VGB-treated patients with VABAM for whom posttreatment MRIs were available, VABAM entirely resolved after VGB discontinuation. The prevalence of symptoms was 11.7% in patients with VABAM or VABAM-like MRI abnormalities and 4.3% in those without, implicating no significant association (RR = 2.76, 95% CI = .68-8.77).

SIGNIFICANCE

VABAM are common in VGB-treated TSC infants; however, VABAM-like abnormalities also occurred in children without either VGB or TSC. The cause of these MRI changes is unknown. Possible contributing factors are abnormal myelination, underlying etiology, recurrent seizures, and other antiseizure medication. Furthermore, the presence of VABAM (or VABAM-like abnormalities) did not appear to be associated with clinical symptoms. This study confirms that the well-known antiseizure effects of VGB outweigh the risk of VABAM and related symptoms.

Neuronal cell type specific roles for Nprl2 in neurodevelopmental disorder-relevant behaviors

Loss of function in the subunits of the GTPase-activating protein (GAP) activity toward Rags-1 (GATOR1) complex, an amino-acid sensitive negative regulator of the mechanistic target of rapamycin complex 1 (mTORC1), is implicated in both genetic familial epilepsies and Neurodevelopmental Disorders (NDDs) (Baldassari et al., 2018). Previous studies have found seizure phenotypes and increased activity resulting from conditional deletion of GATOR1 function from forebrain excitatory neurons (Yuskaitis et al., 2018; Dentel et al., 2022); however, studies focused on understanding mechanisms contributing to NDD-relevant behaviors are lacking, especially studies understanding the contributions of GATOR1's critical GAP catalytic subunit, nitrogen permease regulator like-2 (Nprl2). Given the clinical phenotypes observed in patients with Nprl2 mutations, in this study, we sought to investigate the neuronal cell type contributions of Nprl2 to NDD behaviors. We conditionally deleted Nprl2 broadly in most neurons (Synapsin1cre), in inhibitory neurons only (Vgatcre), and in Purkinje cells within the cerebellum (L7cre). Broad neuronal deletion of Nprl2 resulted in seizures, social and learning deficits, and hyperactivity. In contrast, deleting Nprl2 from inhibitory neurons led to increased motor learning, hyperactive behavior, in addition to social and learning deficits. Lastly, Purkinje cell (PC) loss of Nprl2 also led to learning and social deficits but did not affect locomotor activity. These phenotypes enhance understanding of the spectrum of disease found in human populations with GATOR1 loss of function and highlight the significance of distinct cellular populations to NDD-related behaviors. SIGNIFICANCE STATEMENT: We aim to elucidate the neuronal-specific contributions of nitrogen permease regulator like-2 (Nprl2) to its neurodevelopmental disorder (NDD)-relevant phenotypes. We conditionally deleted Nprl2 broadly in neurons (Syn1cre), in inhibitory neurons (Vgatcre), and in cerebellar Purkinje cells (L7cre). We identify seizures only in the Syn1cre conditional mutant (cKO); hyperactivity, learning difficulties, social deficits, and impulsivity in the Syn1cre and Vgatcre cKOs; and social deficits, and fear learning deficits in L7cre cKOs. To our knowledge, we are the first to describe the behavioral contributions of Nprl2's function across multiple cell types. Our findings highlight both critical roles for Nprl2 in learning and behavior and also distinct contributions of select neuronal populations to these NDD-relevant behaviors.

Intellectual disability and autistic behavior and their modifying factors in children with tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is classified among developmental epileptic encephalopathies, where epilepsy is often associated with comorbidities such as intellectual disability and autistic behavior. The recently introduced term TAND (TSC-associated neuropsychiatric disorders) encompasses the wide range of cognitive, behavioral, psychiatric, and psychosocial manifestations seen in TSC. The severity of these comorbidities is influenced by several factors, including the TSC1/TSC2 genotype, the age of epilepsy onset, the number, volume and type of cortical tubers, the interval between epilepsy onset and treatment initiation, and the presence of infantile spasms, hypsarrhythmia, or drug-resistant epilepsy. Clinical, genetic, EEG, and neuroimaging biomarkers enable the early identification of infants at high risk of developing intellectual disability or autism spectrum disorder. Early preventive intervention targeting seizures and tailored strategies during a sensitive developmental window may modify these contributing factors, leading to improved neurodevelopmental outcomes in infants with TSC.

Human TSC2 mutant cells exhibit aberrations in early neurodevelopment accompanied by changes in the DNA Methylome

Tuberous Sclerosis Complex (TSC) is a debilitating developmental disorder characterized by a variety of clinical manifestations. While benign tumors in the heart, lungs, kidney, and brain are all hallmarks of the disease, the most severe symptoms of TSC are often neurological, including seizures, autism, psychiatric disorders, and intellectual disabilities. TSC is caused by loss of function mutations in the TSC1 or TSC2 genes and consequent dysregulation of signaling via mechanistic Target of Rapamycin Complex 1 (mTORC1). While TSC neurological phenotypes are well-documented, it is not yet known how early in neural development TSC1/2-mutant cells diverge from the typical developmental trajectory. Another outstanding question is the contribution of homozygous-mutant cells to disease phenotypes and whether phenotypes are also present in the heterozygous-mutant populations that comprise the vast majority of cells in patients. Using TSC patient-derived isogenic induced pluripotent stem cells (iPSCs) with defined genetic changes, we observed aberrant early neurodevelopment in vitro, including misexpression of key proteins associated with lineage commitment and premature electrical activity. These alterations in differentiation were coincident with hundreds of differentially methylated DNA regions, including loci associated with key genes in neurodevelopment. Collectively, these data suggest that mutation or loss of TSC2 affects gene regulation and expression at earlier timepoints than previously appreciated, with implications for whether and how prenatal treatment should be pursued.

Tuberous sclerosis complex: one disorder, three generations and an assortment of radiological and clinical presentations

This case report presents markedly different clinical and radiological manifestations of the same disease in a family over three consecutive generations with varying treatment strategies. The index case/proband primarily presented with gastrointestinal symptoms, including diarrhoea, bleeding per rectum and seizures. Further evaluation revealed bilateral renal angiomyolipoma and cerebral subependymal nodules, in conjunction with facial adenoma sebaceum, periungual fibromas and hypomelanotic ash-leaf macules. Genetic testing confirmed the diagnosis of tuberous sclerosis complex, identifying a mutation in the TSC2 gene.The entire family was evaluated for inherited disorders, leading to the detection of tuberous sclerosis in three adult offspring and a grandchild. The uncharacteristic neurological and cardiac manifestations in the proband are noteworthy. Another important aspect is the missed diagnosis in patients despite obvious clinical features and interaction with healthcare facilities, reflecting a gap in disease awareness and a lack of clinical vigilance.

Distinct peripheral pro-inflammatory profile associated with tuberous sclerosis complex and epilepsy

OBJECTIVE

Tuberous sclerosis complex (TSC) is a monogenetic disorder associated with sustained mechanistic target of rapamycin (mTOR) activation, leading to heterogeneous clinical manifestations. Epilepsy and renal angiomyolipoma are the most important causes of morbidity in adult people with TSC (pwTSC). mTOR is a key player in inflammation, which in turn could influence TSC-related clinical manifestations. Reliable biomarkers are lacking to monitor and predict evolution and response to treatment for epilepsy in pwTSC. Inflammation has been implicated in epileptogenesis in non-TSC-related epilepsy. We aimed to characterize the relation between markers of neuroglial activation/injury, markers of peripheral inflammation, and active epilepsy in pwTSC to identify accessible biomarkers and potential new therapeutic targets.

METHODS

We performed a cross-sectional study to investigate markers of central nervous system (CNS) (neurofilament light [NfL] and glial fibrillary acidic protein [GFAP]) and peripheral (45 cytokines) inflammation in the peripheral blood of pwTSC (n = 46) vs age- and sex-matched healthy controls (HCs) (n = 26). In pwTSC, markers associated with active epilepsy (n = 23/46) were compared to non-TSC epilepsy controls (n = 18). Observations on markers of neuroglial activation/injury (GFAP, NfL) were confirmed in an independent TSC cohort (n = 45; 69% with active epilepsy).

RESULTS

We report that TSC is characterized by elevated serum levels of marker of astrogliosis (GFAP), pro-inflammatory molecules (interleukin 1β [IL-1β], CXCL8) and trophic factor (epidermal growth factor [EGF]) compared to HCs and to non-TSC-related epilepsy controls. Among pwTSC, renal angiomyolipoma presence and size was associated with IL-15. It is notable that active epilepsy in pwTSC was associated with higher levels of GFAP compared to pwTSC without epilepsy, which was confirmed in an external validation cohort, and with elevated levels of pro-inflammatory cytokines (IL-17A, IL-17C, tumor necrosis factor α [TNF-α]), not significantly related to seizure activity or treatment with mTOR inhibitor. These associations remained significant after adjusting for age and sex.

SIGNIFICANCE

These results suggest that key inflammatory mediators could contribute to epileptogenesis and represent novel biomarkers and therapeutic targets in TSC.

Neuropsychiatric profile in tuberous sclerosis complex patients with epilepsy

Background

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by mutations in the TSC1 or TSC2 genes, leading to dysregulation of the mTOR pathway and multisystemic manifestations. Epilepsy is a common neurologic feature of TSC, frequently accompanied by neuropsychiatric comorbidities. Understanding the relationship between epilepsy severity, TSC-associated neuropsychiatric disorders (TAND), and cognitive outcomes is crucial for optimizing patient care.

Methods

A retrospective study was conducted at a pediatric tertiary care hospital in Qatar, involving 38 TSC patients (20 female, 18 male) aged 1-18 years, diagnosed between October 2018 and March 2020. Epilepsy severity was assessed using the Early Childhood Epilepsy Severity Scale (E-Chess), and TAND was evaluated using the TAND checklist. Genetic analysis was performed for all patients, and statistical analyses were used to explore correlations between epilepsy severity, TAND, and cognitive outcomes.

Results

The majority (82%) of TSC patients had epilepsy, with a mean onset age of 9.2 months. Uncontrolled seizures were associated with higher rates of intellectual disability and more pronounced TAND manifestations compared to controlled seizures. Autism spectrum disorder (ASD) was reported in 42% of the cohort, with significant correlations found between epilepsy severity and ASD-related domains on the TAND checklist. Intellectual disability was prevalent (67.6%), with variability attributed to genetic background and early severe neurological presentations.

Discussion

This study reinforces the link between epilepsy severity and neuropsychiatric comorbidities in TSC, confirming earlier findings. Significant correlations were observed between epilepsy severity and ASD-related domains, and the high prevalence of intellectual disability in TSC patients was highlighted. However, the relationship between ASD, TSC, and epilepsy remains complex and requires further investigation. Despite advances in treatment options, including mTOR inhibitors and newer antiepileptic drugs, unmet needs remain in the comprehensive care of TSC patients. Optimizing seizure control is a clear priority, but equally important is the need for addressing the cognitive and behavioral components of TAND. Early intervention with tailored, multidisciplinary approaches including neurology, psychiatry, psychology, and educational specialists could mitigate the long-term impact of these comorbidities, particularly in children. These approaches must be individualized to each patient's unique set of challenges, emphasizing not only seizure control but also psychosocial support and educational adaptation to improve their overall quality of life.

Conclusion

This study sheds light on the intricate interactions between epilepsy severity, neuropsychiatric manifestations, and cognitive outcomes in TSC patients. The findings emphasize the need for tailored management approaches, focusing on early seizure control and comprehensive multidisciplinary care. Further research is required to clarify the mechanisms underlying these associations and to develop targeted interventions for improving the quality of life for individuals with TSC and epilepsy.

Accumulated seizure burden predicts neurodevelopmental outcome at 36 months of age in patients with tuberous sclerosis complex

OBJECTIVE

Epilepsy and intellectual disability are common in tuberous sclerosis complex (TSC). Although early life seizures and intellectual disability are known to be correlated in TSC, the differential effects of age at seizure onset and accumulated seizure burden on development remain unclear.

METHODS

Daily seizure diaries, serial neurodevelopmental testing, and brain magnetic resonance imaging were analyzed for 129 TSC patients followed from 0 to 36 months. We used machine learning to identify subgroups of patients based on neurodevelopmental test scores at 36 months of age and assessed the stability of those subgroups at 12 months. We tested the ability of candidate biomarkers to predict 36-month neurodevelopmental subgroup using univariable and multivariable logistic regression. Candidate biomarkers included age at seizure onset, accumulated seizure burden, tuber volume, sex, and earlier neurodevelopmental test scores.

RESULTS

Patients clustered into two neurodevelopmental subgroups at 36 months of age, higher and lower scoring. Subgroup was mostly (75%) the same at 12 months. Significant univariable effects on subgroup were seen only for accumulated seizure burden (largest effect), earlier test scores, and tuber volume. Neither age at seizure onset nor sex significantly distinguished 36-month subgroups, although for girls but not boys there was a significant effect of age at seizure onset. In the multivariable model, accumulated seizure burden and earlier test scores together predicted 36-month neurodevelopmental group with 82% accuracy and an area under the curve of .86.

SIGNIFICANCE

These results untangle the contributions of age at seizure onset and accumulated seizure burden to neurodevelopmental outcomes in young children with TSC. Accumulated seizure burden, rather than the age at seizure onset, most accurately predicts neurodevelopmental outcome at 36 months of age. These results emphasize the need to manage seizures aggressively during the first 3 years of life for patients with TSC, not only to promote seizure control but to optimize cognitive function.

Evolving treatment strategies for early-life seizures in Tuberous Sclerosis Complex: A review and treatment algorithm

Tuberous sclerosis Complex (TSC) is a genetic disorder characterized by multisystem involvement, with epilepsy affecting 80-90% of patients, often beginning in infancy. Early-life seizures in TSC are associated with poor neurodevelopmental outcomes, underscoring the importance of timely and effective management. This review explores the evolving treatment landscape for TSC-associated seizures in young children, focusing on three recently approved or license-expanded therapies: vigabatrin, everolimus, and cannabidiol. The efficacy and safety profiles of these treatments are examined based on clinical trials and real-world evidence, with a focus on their use in treating seizures in young children. The preemptive use of vigabatrin in clinical studies has also been carefully reviewed. A treatment algorithm is proposed, emphasizing early diagnosis, prompt initiation of appropriate therapy, and a stepwise approach to managing both infantile spasms and focal seizures. The algorithm incorporates these newer therapies alongside traditional antiseizure medications and non-pharmacological approaches. Challenges in optimizing treatment strategies, minimizing side effects, and improving long-term outcomes are discussed. This review aims to guide clinicians in navigating the complex landscape of early-life seizures associated with TSC, ultimately striving for improved seizure control and better developmental outcomes in this vulnerable population.

Severe Epilepsy in an Individual With a TSC2 R905Q Variant Prompting Late Diagnosis in Affected Family Members

BACKGROUND

Tuberous sclerosis complex (TSC) is a multisystemic disorder caused by inactivating variants in the mTOR pathway inhibitor genes TSC1 and TSC2. Individuals with TSC are predisposed to benign tumors in multiple organs as well as TSC-associated neuropsychiatric disorders (TAND) and epilepsy. Pathogenic variants in TSC2 are typically associated with a more severe phenotype compared with TSC1; the TSC2 R905Q variant has been shown to be an exception, where patients have been reported to present with unusually mild TSC features that may be undetected.

METHODS

We studied the TSC phenotype of a 13-year-old individual and three family members with a TSC2 c.2714G>A (R905Q) pathogenic variant.

RESULTS

Patient 1 presented with severe medically refractory epilepsy without tubers or subependymal nodules and only mild dermatologic features of TSC missed on virtual examinations. Her mother and maternal aunt (Patients 2 and 3-diagnosed after age 50 years) presented with a mild phenotype, with dermatologic features and TAND. Her maternal uncle (Patient 4-diagnosed at age 47 years) displayed the most severe phenotype, presenting with intellectual disability, medically refractory epilepsy, obsessive-compulsive disorder, post-traumatic stress disorder, and psychosis.

CONCLUSIONS

This study expands the possible phenotypic spectrum of TSC2 R905Q variant, demonstrating an association with severe epilepsy without associated neuroradiological stigmata. This presentation highlights the possibility of occult focal cortical dysplasia in TSC and emphasizes the importance of genetic testing in individuals with severe epilepsy. Moreover, a late adult diagnosis was subsequently made in other family members allowing for appropriate TSC surveillance to occur.

Clinical trials for Lennox-Gastaut syndrome: Challenges and priorities

OBJECTIVE

Lennox-Gastaut syndrome (LGS) is a severe, childhood-onset epilepsy that is typically refractory to treatment. We surveyed the current landscape of LGS treatment, aiming to identify challenges to the development of efficacious therapies, and to articulate corresponding priorities toward clinical trials that improve outcomes.

METHODS

The LGS Special Interest Group of the Pediatric Epilepsy Research Consortium integrated evidence from the literature and expert opinion, into a narrative review.

RESULTS

We provide an overview of approved and emerging medical, dietary, surgical and neuromodulation approaches for LGS. We note that quality of care could be improved by standardizing LGS treatment based on expert consensus and empirical data. Whereas LGS natural history is incompletely understood, prospective studies and use of large retrospective datasets to understand LGS across the lifespan would enable clinical trials that address these dynamics. Recent discoveries related to LGS pathophysiology should enable development of disease-modifying therapies, which are currently lacking. Finally, clinical trials have focused chiefly on seizures involving "drops," but should incorporate additional patient-centered outcomes, using emerging measures adapted to people with LGS.

INTERPRETATION

Clinicians and researchers should enact these priorities, with the goal of patient-centered clinical trials that are tailored to LGS pathophysiology and natural history.

Central nervous system manifestations of tuberous sclerosis complex: A single centre experience in Qatar

OBJECTIVES

To review the clinical and radiological correlation of the central nervous system manifestations of tuberous sclerosis complex (TSC).

METHODS

All patients under the age of 18 years with TSC seen at the Department of Pediatrics, Sidra Medicine, Doha, Qatar, between January 2003 and February 2021 were included in this retrospective study. Severity of epilepsy was determined using the early childhood epilepsy severity score (E-CHESS) tool.

RESULTS

The study sample included 38 patients (50% male), 8 (21%) of whom were native to Qatar. The median age at diagnosis was 4 (range: 0-72) months. A family history of TSC was present in 10 (26%) cases, while 33 (86%) patients had a TSC2 gene mutation. Common presentations included seizures (79%), rhabdomyoma (26%), and developmental delay (13%). On MRI scans, cortical tubers were seen in all patients, subependymal nodules in 37 (97%), and subependymal giant cell astrocytoma was diagnosed in 8 (21%) cases. A total of 30 children developed epilepsy, 9 of whom had favorable and 21 had unfavorable E-CHESS scores, and 6 required pharmaceutical management. A total of 13 children were diagnosed with autistic spectrum disorder and 12 with attention deficit hyperactivity disorder.

CONCLUSION

Multidisciplinary management and further research is needed to optimize the care and quality of life of TSC affected individuals and their families.

Prediction of epileptogenicity in patients with tuberous sclerosis complex using multimodal cerebral MRI

OBJECTIVE

Epilepsy is the most common complication and cause of morbidity and mortality in tuberous sclerosis complex (TSC). Surgery is associated with an increased probability of achieving seizure-freedom. However, the preoperative noninvasive localisation of epileptogenic tubers remains challenging. This study aimed to identify multimodal magnetic resonance imaging (MRI) biomarkers of epilepsy in patients with TSC and develop a prediction model of epileptogenicity in these patients.

METHODS

Patients with TSC, with or without epilepsy, were recruited. All patients underwent MRI scanning, including T1WI, T2WI, T2W-FLAIR, DTI, and multi-parametric MR with a flexible design (MULTIPLEX). We compared the multimodal cerebral MRI characteristics of the cortical tubers, subependymal nodules, and perilesional tissue between patients with TSC with or without epilepsy and developed a prediction model for epileptogenicity.

RESULTS

Among the patients with TSC, 32 with and 16 without epilepsy underwent MRI. Higher proton-density mapping (PD) of cortical tubers and decreased fractional anisotropy (FA), increased mean diffusivity (MD), and increased radial diffusivity (RD) of subependymal nodules were associated with epileptogenicity in both the centre and perilesional tissue, independent of TSC gene variation. Based on the above findings, we developed a prediction model for epileptogenicity with an area under the curve of 0.973, specificity of 0.909, and sensitivity of 0.963 (P < 0.001).

CONCLUSION

In patients with TSC, high PD of the cortical tubers, decreased FA, and elevated MD/RD of the subependymal nodules were significantly associated with epileptogenicity. A prediction model based on multimodal cerebral MRI characteristics has the potential to evaluate the likelihood of epilepsy in patients with TSC.

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.

Tuberous sclerosis complex: Diagnostic features, surveillance, and therapeutic strategies

Tuberous sclerosis complex (TSC) is a rare neurocutaneous disorder of mTOR pathway dysregulation resulting from pathogenic variants in the TSC1 or TSC2 genes. Expression of this disorder may involve abnormal tissue growth and dysfunction within the brain, kidneys, heart, lungs, eyes, skin, bones, and teeth. Neurological manifestations can include subependymal giant cell astrocytomas (SEGAs), high rates of infantile spasms, drug-resistant epilepsy, developmental delay, cognitive impairment, autism spectrum disorder, and other neurobehavioral manifestations. Here we review the potential clinical manifestations of TSC by system, recommended diagnostic and surveillance testing, genetic testing, currently available therapeutic options, and considerations for education and social support resources given the unique challenges of this multi-system disorder.

Pathways to epilepsy surgery in children with tuberous sclerosis complex-associated epilepsy

BACKGROUND

Previous studies showed the efficacy of epilepsy surgery in carefully selected children with epilepsy associated with tuberous sclerosis complex. However, how this selection is conducted, and the characteristics of the patients brought to surgery are still poorly described. By conducting a multicentric retrospective cohort study covering the practice of the last twenty years, we describe the paths leading to epilepsy surgery in children with epilepsy associated with tuberous sclerosis complex.

METHODS

We identified 84 children diagnosed with tuberous sclerosis complex and epilepsy by matching two exhaustive registries of genetic diseases and subsequent medical records reviews within two French neuropediatric and epilepsy centers. Demographic, clinical, longitudinal, and diagnostic and surgical procedures data were collected.

RESULTS

Forty-six percent of the children were initially drug-resistant and 19% underwent resective surgery, most often before the age of four. Stereotactic electroencephalography was performed prior to surgery in 44% of cases. Fifty-seven and 43% of patients remained seizure-free one and ten years after surgery, respectively. In addition, 52% of initially drug-resistant patients who did not undergo surgery were seizure-free at the last follow-up. The number of anti-seizure medications required decreased in 50% of cases after surgery. Infantile spasms, intellectual disability, autism spectrum disorder or severe behavioral disorders were not contraindications to surgery but were associated with a higher rate of complications and a lower rate of seizure freedom after surgery.

CONCLUSION

Despite the assumption of complex multifocal epilepsy and practical difficulties in young children with tuberous sclerosis complex, successful surgery results are comparable with other populations of patients with drug-resistant epilepsy, and a spontaneous evolution to drug-sensitive epilepsy may occur in non-operated patients.

Have epilepsy outcomes changed for children with tuberous sclerosis complex in Queensland, Australia?

OBJECTIVE

Historically, epilepsy has been the most frequently presenting feature of tuberous sclerosis complex (TSC). Advances in TSC health care have occurred over the past decade; thus, we studied whether TSC epilepsy outcomes have changed.

METHOD

A retrospective chart review was undertaken for all children with TSC in Queensland, Australia. Epilepsy outcome and TSC diagnosis data were extracted, and data were compared between children born before 2012 with those born in or after 2012.

RESULTS

In this retrospective cohort, TSC diagnosis in children born in or after 2012 is now predominantly antenatal (51%, p < .05). Most patients with epilepsy are now known to have TSC before they develop epilepsy. Despite earlier TSC diagnosis, the frequency of epilepsy (85%) has not changed (p = .92), but diagnosis trends toward an earlier age (median = 3 months for patients born in or after 2012 vs. 5.5 months for those born before 2012, p = .23). Most (95%) patients had focal seizures as their initial clinical seizure type; it was rare (5%) for epileptic spasms (ES) to be the initial seizure type. The frequency of ES was lower in patients born in or after 2012 (36% vs. 50%, p = .27). Infantile (<24 months) onset ES was not associated with worse epilepsy outcome. Late onset ES was seen in 14%, and these patients had a lower rate of epilepsy remission. Lennox-Gastaut syndrome was seen in 7%. Febrile/illness-related status epilepticus occurred in 12% of patients, between 1 and 4 years of age. Despite many (78%) patients having multiple daily seizures at maximal seizure frequency, and 74% meeting criteria for treatment-refractory epilepsy, most patients achieved epilepsy remission (66%), either with epilepsy surgery (47%) or with age (53%). At the time of inclusion in this study, only 21% of patients had uncontrolled frequent (daily to 3 monthly) seizures and 14% had uncontrolled infrequent (3 monthly to <2 yearly) seizures.

SIGNIFICANCE

This study provides updated information that informs the counseling of parents of newly diagnosed pediatric TSC patients.

Epileptic seizures revealing tuberous sclerosis in a tropical environment: A study of 12 case series

Background

Epilepsy remains a significant public health concern in Sub-Saharan Africa (SSA) where diverse etiological factors contribute to its prevalence. Among these factors are conditions originating from the neuroectoderm, such as tuberous sclerosis. Insufficient medical attention and a lack of comprehensive multidisciplinary care contribute to its under-recognition.

Materials and methods

We conducted a retrospective descriptive study, involving 12 patients admitted to the neurology and pediatric departments of the University Hospital Ignace Deen between 2010 and 2022 due to recurring epileptic seizures. Subsequently, these patients were diagnosed with Tuberous sclerosis using the Schwartz 2007 criteria. The aim of this study is to reassess this condition from a clinical and paraclinical point of view in a tropical environment.

Results

Tuberous sclerosis, also known as Bourneville disease, was diagnosed in 12 patients exhibiting focal motor seizures and complex focal seizures likely associated with cortical and subcortical tubers detectable by EEG and neuroimaging, including CT and MRI. Delayed treatment resulted in varying degrees of mental decline. Additionally, some patients displayed cardiac hamartomas and intracranial posterior and anterior aneurysms as minor diagnostic indicators.

Conclusion

The study reveals a consistent clinical presentation accompanied by deteriorating neurological and psychological symptoms attributed to delayed multidisciplinary management. These findings are utilized to assess therapeutic strategies and prognostic outcomes.

Seizure freedom but not epilepsy surgery is associated with fewer neuropsychiatric difficulties in patients with tuberous sclerosis

BACKGROUND

Drug-resistant epilepsy (DRE) in selected individuals with the rare tuberous sclerosis complex (TSC) may benefit from resective epilepsy surgery. Furthermore, associated neuropsychiatric disorders (TAND) are common in patients with TSC; however, long-term data on how surgery affects neuropsychiatric comorbidities are sparse.

MATERIALS AND METHODS

Two retrospective approaches were used to identify children with TSC and DRE with onset at < 18 years of age. The study group (surgical) was identified through the Swedish National Epilepsy Surgery Registry (n = 17), a registry with complete national coverage since 1990 and prospective patient enrolment since 1995. The reference group (non-surgical) was identified by searching medical records retrieved from the tertiary hospital of Southern Sweden (n = 52). Eligible participants were invited to complete the validated TAND lifetime checklist. Those who did not complete the checklist, never had DRE, or were aged < 7 years old were excluded from the study. The reference group was balanced with the study group for putative confounders, in the following hierarchical order: DRE at the survey, age at seizure onset, age at follow-up, and sex.

RESULTS

After the balancing procedure, both groups comprised 13 participants. The median time from epilepsy onset to the survey was 18.5 (range: 7.75-40.25) and 16.0 (7.33-33.5) years in the study and reference groups, respectively. The median time from surgery to the survey was 13 years (range: 4-22). No significant differences were found in behavioural problems, autism spectrum disorder diagnosis or symptoms, or intellectual disability between the groups, regardless of surgery. Seizure-free individuals (n = 11) performed better in social skills (p = 0.016), intellectual skills (p = 0.029), and overall TAND scores (p = 0.005) than the non-seizure-free group (n = 15).

CONCLUSION

This is the first study to evaluate TAND comorbidities during the long-term follow-up after epilepsy surgery in patients with TSC. We found no evidence of the adverse effects of TAND comorbidities after tuberectomy. However, a larger study that allows for a better adjustment for confounders is needed. Following previous studies, seizure-free individuals had fewer symptoms within most TAND domains compared with the group with uncontrolled epilepsy, indicating less severe symptomatology.

Screening for biomarkers of tuberous sclerosis complex-associated epilepsy: a bioinformatics analysis

Background

The optimal biomarkers for early diagnosis, treatment, and prognosis of tuberous sclerosis complex (TSC)-associated epilepsy are not yet clear. This study identifies the crucial genes involved in the pathophysiology of TSC-associated epilepsy via a bioinformatics analysis. These genes may serve as novel therapeutic targets.

Methods

Gene chip data sets (GSE62019 and GSE16969) comprising the data of patients with TSC-associated epilepsy and healthy control participants were obtained from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) in the GEO database were identified using the GEO2R gene expression analysis tool. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, Gene Ontology function, and protein-protein interaction (PPI) network analyses were then conducted. The results were analyzed using R language, and are presented in volcano plots, Venn diagrams, heatmaps, and enrichment pathway bubble charts. A gene set enrichment analysis (GSEA), was conducted to examine the KEGG pathways and crucial genes linked to TSC-associated epilepsy. The potential genes were compared with the genes listed in the Online Mendelian Inheritance in Man (OMIM) database and analyzed against the literature to determine their clinical significance. Finally, the expression of the key genes in the TSC-associated epilepsy mice cerebral cortex was examined through immunohistochemical staining.

Results

The intersection of the GSE62019 and GSE16969 data sets revealed 151 commonly upregulated DEGs. The KEGG enrichment analysis indicated that these DEGs affected the occurrence and development of TSC-associated epilepsy by modulating complement and coagulation cascades, glycosaminoglycans in cancer, and extracellular matrix-receptor interactions. Four high-scoring clusters emerged, and podoplanin (PDPN) was identified as a key gene through the construction of a PPI network of the common DEGs using the Cytoscape software. A GSEA of the DEGs revealed that the common DEG PDPN was enriched in both data sets in pathways related to platelet activation, aggregation, and the glycoprotein VI (GPVI)-mediated activation cascade. Immunohistochemical staining revealed a significant elevation in PDPN expression in the cerebral cortex of mice with TSC-associated epilepsy. Conversely, the control group mice did not display any significantly positive neurons.

Conclusions

The discovery of these crucial genes and signaling pathways extends understanding of the molecular processes underlying the development of TSC-associated epilepsy. Additionally, our findings may provide a theoretical basis for research into targeted clinical treatments.

Identification and treatment of surgically-remediable causes of infantile epileptic spasms syndrome

INTRODUCTION

Infantile epileptic spasms syndrome (IESS) is a common developmental and epileptic encephalopathy with poor long-term outcomes. A substantial proportion of patients with IESS have a potentially surgically remediable etiology. Despite this, epilepsy surgery is underutilized in this patient group. Some surgically remediable etiologies, such as focal cortical dysplasia and malformation of cortical development with oligodendroglial hyperplasia in epilepsy (MOGHE), are under-diagnosed in infants and young children. Even when a surgically remediable etiology is recognised, for example, tuberous sclerosis or focal encephalomalacia, epilepsy surgery may be delayed or not considered due to diffuse EEG changes, unclear surgical boundaries, or concerns about operating in this age group.

AREAS COVERED

In this review, the authors discuss the common surgically remediable etiologies of IESS, their clinical and EEG features, and the imaging techniques that can aid in their diagnosis. They then describe the surgical approaches used in this patient group, and the beneficial impact that early epilepsy surgery can have on developing brain networks.

EXPERT OPINION

Epilepsy surgery remains underutilized even when a potentially surgically remediable cause is recognized. Overcoming the barriers that result in under-recognition of surgical candidates and underutilization of epilepsy surgery in IESS will improve long-term seizure and developmental outcomes.

A Cost-Utility Analysis of Add-On Cannabidiol Versus Usual Care Alone for the Treatment of Seizures Associated with Tuberous Sclerosis Complex in England and Wales

OBJECTIVES

The aim of this study was to evaluate the cost effectiveness of plant-derived highly purified cannabidiol (Epidyolex® in the UK; 100 mg/mL oral solution) as an add-on treatment to usual care for the management of treatment-refractory seizures associated with tuberous sclerosis complex (TSC) in patients aged ≥ 2 years.

METHODS

A cohort-based model was developed using a National Health Service perspective and lifetime horizon. Health states were based on weekly seizure frequency and seizure-free days, utilizing patient-level data from the GWPCARE6 trial (ClinicalTrials.gov identifier: NCT02544763). Two independent regression models were applied to individual patient-level data to predict seizure-free days and seizure frequency. Healthcare resource utilization data were sourced from a Delphi panel, and patient and caregiver health-related quality of life values were elicited using vignettes valued by the general public. Outcomes relating to TSC-associated neuropsychiatric disorders were modeled with costs and quality-adjusted life-years sourced from published literature.

RESULTS

In the base case, compared with usual care alone, 12 mg/kg/day cannabidiol was associated with an incremental cost-effectiveness ratio (ICER) of £23,797. The National Institute for Health and Care Excellence disease severity modifier reduced the ICER to £19,831. Probabilities of cost effectiveness at willingness-to-pay thresholds of £20,000 and £30,000 were 30% and 52%, respectively, for the base case and 39% and 66%, respectively, for the disease severity modifier. Results were robust to sensitivity and scenario analyses.

CONCLUSIONS

At 12 mg/kg/day and an ICER threshold of £20,000-£30,000, we provide evidence for the cost effectiveness of add-on cannabidiol treatment for patients with TSC-associated seizures aged ≥ 2 years who are refractory to current treatment.

Human TSC2 Mutant Cells Exhibit Aberrations in Early Neurodevelopment Accompanied by Changes in the DNA Methylome

Tuberous Sclerosis Complex (TSC) is a debilitating developmental disorder characterized by a variety of clinical manifestations. While benign tumors in the heart, lungs, kidney, and brain are all hallmarks of the disease, the most severe symptoms of TSC are often neurological, including seizures, autism, psychiatric disorders, and intellectual disabilities. TSC is caused by loss of function mutations in the TSC1 or TSC2 genes and consequent dysregulation of signaling via mechanistic Target of Rapamycin Complex 1 (mTORC1). While TSC neurological phenotypes are well-documented, it is not yet known how early in neural development TSC1/2-mutant cells diverge from the typical developmental trajectory. Another outstanding question is the contribution of homozygous-mutant cells to disease phenotypes and whether such phenotypes are also seen in the heterozygous-mutant populations that comprise the vast majority of cells in patients. Using TSC patient-derived isogenic induced pluripotent stem cells (iPSCs) with defined genetic changes, we observed aberrant early neurodevelopment in vitro, including misexpression of key proteins associated with lineage commitment and premature electrical activity. These alterations in differentiation were coincident with hundreds of differentially methylated DNA regions, including loci associated with key genes in neurodevelopment. Collectively, these data suggest that mutation or loss of TSC2 affects gene regulation and expression at earlier timepoints than previously appreciated, with implications for whether and how prenatal treatment should be pursued.

Neuropsychiatric comorbidities in tuberous sclerosis complex patients with epilepsy: results of the TAND checklist survey

PURPOSE

In addition to epilepsy, individuals with tuberous sclerosis complex (TSC) experience a wide range of behavioral, psychiatric, intellectual, academic, and psychosocial problems. They usually exert a large psychological burden on individuals with these illnesses.

METHODS

This cross-sectional study used TSC-associated neuropsychiatric disorders (TAND) checklist interviews conducted at a single medical center. The enrollment of all subjects was > 6 years, and the comorbidities of neurodevelopmental disorders were assessed by clinical psychologists before enrollment. To assess the spectrum of TAND, the TAND checklist was applied as stated in the protocol, and the responses to the TAND checklist were evaluated by clinical psychologists.

RESULTS

In the behavioral concerns of patients with TSC without epilepsy, those with epilepsy had excessive shyness, language delay, lack of eye contact, rigid behavior, inattentiveness, and restlessness. In psychiatric disorders, autism spectrum disorder and attention-deficit/hyperactivity disorder are significantly correlated with epilepsy history. Diminished academic skills, including reading, writing, and mathematics skills, are significantly associated with epilepsy history. For intellectual ability, TSC patients without epilepsy is associated normal intelligence level. Among neuropsychological skills, deficits in attention, dual tasking/multi-tasking, visuospatial tasking, and executive skills are significantly associated with epilepsy history.

CONCLUSIONS

Epilepsy in patients with TSC contributes to comorbid neuropsychiatric disorders. In addition to epilepsy evaluation, it is crucial to evaluate the heterogeneous spectrum of neuropsychiatric disorders using a standard checklist during the annual clinical follow-up of patients with TSC.

A multicenter, matched case-control analysis comparing burden of illness among patients with tuberous sclerosis complex related epilepsy, generalized idiopathic epilepsy, and focal epilepsy in Germany

BACKGROUND

Depending on the underlying etiology and epilepsy type, the burden of disease for patients with seizures can vary significantly. This analysis aimed to compare direct and indirect costs and quality of life (QoL) among adults with tuberous sclerosis complex (TSC) related with epilepsy, idiopathic generalized epilepsy (IGE), and focal epilepsy (FE) in Germany.

METHODS

Questionnaire responses from 92 patients with TSC and epilepsy were matched by age and gender, with responses from 92 patients with IGE and 92 patients with FE collected in independent studies. Comparisons were made across the main QoL components, direct costs (patient visits, medication usage, medical equipment, diagnostic procedures, ancillary treatments, and transport costs), indirect costs (employment, reduced working hours, missed days), and care level costs.

RESULTS

Across all three cohorts, mean total direct costs (TSC: €7602 [median €2620]; IGE: €1919 [median €446], P < 0.001; FE: €2598 [median €892], P < 0.001) and mean total indirect costs due to lost productivity over 3 months (TSC: €7185 [median €11,925]; IGE: €3599 [median €0], P < 0.001; FE: €5082 [median €2981], P = 0.03) were highest among patients with TSC. The proportion of patients with TSC who were unemployed (60%) was significantly larger than the proportions of patients with IGE (23%, P < 0.001) or FE (34%, P = P < 0.001) who were unemployed. Index scores for the EuroQuol Scale with 5 dimensions and 3 levels were significantly lower for patients with TSC (time-trade-off [TTO]: 0.705, visual analog scale [VAS]: 0.577) than for patients with IGE (TTO: 0.897, VAS: 0.813; P < 0.001) or FE (TTO: 0.879, VAS: 0.769; P < 0.001). Revised Epilepsy Stigma Scale scores were also significantly higher for patients with TSC (3.97) than for patients with IGE (1.48, P < 0.001) or FE (2.45, P < 0.001). Overall Quality of Life in Epilepsy Inventory-31 items scores was significantly lower among patients with TSC (57.7) and FE (57.6) than among patients with IGE (66.6, P = 0.004 in both comparisons). Significant differences between patients with TSC and IGE were also determined for Neurological Disorder Depression Inventory for Epilepsy (TSC: 13.1; IGE: 11.2, P = 0.009) and Liverpool Adverse Events Profile scores (TSC: 42.7; IGE: 37.5, P = 0.017) with higher score and worse results for TSC patients in both questionnaires.

CONCLUSIONS

This study is the first to compare patients with TSC, IGE, and FE in Germany and underlines the excessive QoL burden and both direct and indirect cost burdens experienced by patients with TSC.

A quantitative cross-sectional study of the burden of caring for patients with Lennox-Gastaut syndrome, Dravet syndrome, and tuberous sclerosis complex-associated epilepsy in Japan

INTRODUCTION

Lennox-Gastaut syndrome (LGS), Dravet syndrome (DS), and tuberous sclerosis complex (TSC)-associated epilepsy are rare conditions associated with severe childhood-onset epilepsy. Caregivers play a critical role in the patients' care and may experience significant psychosocial and socioeconomic burden. This cross-sectional study determined the burden of caring for patients with these rare epilepsy conditions in Japan.

METHODS

A quantitative online survey was used to assess patients' and caregivers' characteristics and the caregivers' emotional state, among others. Several validated questionnaires were used: the Hospital Anxiety and Depression Scale (HADS; 0-21 score) assessed the caregivers' emotional wellbeing, the Pediatric Quality of Life Inventory Family Impact Module (PedsQL FIM; 0-100 score) assessed the health-related quality of life (HRQoL) of the caregivers and their families, and the Work Productivity and Activity Impairment General Health (WPAI:GH; 0-100 % score) questionnaire assessed work productivity.

RESULTS

A total of 36 caregivers responded (median [interquartile range (IQR)] age 43.5 [39.5, 48.3] years; 33/36 [92 %] female; 13/36 [36 %] working part-time and 13/36 [36 %] not working). Participants cared for 7/36 (19 %), 19/36 (53 %), and 10/36 (28 %) patients with LGS, DS, and TSC, respectively (median [IQR] age, 11.0 [6.8, 16.3] years; age at first seizure, 0 [0, 0] years). Patients received a median (IQR) of 4 (3, 5) treatment drug types. Patients experienced median (IQR) 3.0 (0, 21.0) epileptic seizures in the previous week; 28/36 (78 %) had severe intellectual disabilities, and 34/36 (94 %) had developmental delays. Caregivers reported stress (17/36 [47 %]), sleep problems (13/36 [36 %]), and anxiety (12/36 [33 %]). They spent a median (IQR) of 50.0 (17.5, 70.0) hours caregiving in the previous week, with 3.0 (1.0, 11.0) hours of seizure-specific care. Caregivers reported that their lives would be easier with a median (IQR) of 1.5 (0, 5.0) hours fewer per week caring for patients during/following seizures. Median HADS scores were 9.5 ('suspected anxiety diagnosis') and 7.5 ('no depression') for caregivers, and PedsQL FIM Total median score was 60.1, indicating HRQoL impairment for the caregiver and their family. WPAI:GH scores for paid workers indicated important work impairment. Higher caregiving hours (≥ 21 h vs. < 21 h in the previous week) resulted in higher caregiver burden as indicated by the HADS Total score (p = 0.0062) and PedsQL FIM Total score (p = 0.0007).

CONCLUSIONS

Caregivers of patients with LGS, DS, or TSC in Japan experience a significant time burden, reduced HRQoL, and high level of work/activity impairment. Caregivers provide round-the-clock care to patients and rely on family and specialized caring services to help manage the increased caregiving time, which tends to be associated with greater emotional burden and HRQoL impact.

Review of the spectrum of tuberous sclerosis complex: The Saudi Arabian Experience

OBJECTIVES

To determine the prevalence of tuberous sclerosis complex (TSC) in the paediatric Saudi population and to characterise the range of clinical symptoms, neurocutaneous findings, neuroimaging results, and complications of the disease.

METHODS

A total of 61 genetically confirmed TSC patients from the National Guard Health Affairs (NGHA) in Saudi Arabia were the subject of this retrospective descriptive analysis. The data were presented using descriptive measures.

RESULTS

The mean age at diagnosis was found to be 4.9 years. Subependymal nodules (86.9%), numerous cortical tubers and/or radial migration lines (63.9%), and hypomelanotic macules (63.9%) were the 3 most common significant criteria. The vast majority (86.9%) of those diagnosed had epilepsy, of which 50% were considered medically intractable. Nearly half of our subjects underwent genetic testing, which revealed that TSC2 predominated over TSC1. Symptoms of Tuberous Sclerosis Complex-Associated Neuropsychiatric Disorders (TAND) were present in 66.7% of TSC1 patients and 73.9% of TSC2 patients.

CONCLUSION

The findings of this study demonstrate that the clinical spectrum of TSC among Saudi children is consistent with the body of existing literature. The TSC2 was more prevalent than TSC1. The most frequent signs were cutaneous and neurological. Monitoring TSC patients regularly is crucial to identify any issues as soon as possible.

The profile of epilepsy and its characteristics in children with neurocutaneous syndromes

OBJECTIVES

The profile of seizures in neurocutaneous syndromes is variable. We aimed to define the characteristics of epilepsy in children with neurocutaneous syndromes.

MATERIALS AND METHODS

Cross-sectional study over 18 months at a tertiary care pediatric hospital, including children with neurocutaneous syndromes aged between 1 and 15 years, using the 2017-International League Against Epilepsy classification.

RESULTS

In 119 children with neurocutaneous syndromes, 94 (79%) had epilepsy. In eight children with neurofibromatosis one with epilepsy, 5 (62.5%) had generalized motor tonic-clonic seizures, 1 (12.5%) had generalized motor epileptic spasms, 1 (12.5%) had generalized motor automatism, and 1 (12.5%) had a focal seizure. In 69 children with tuberous sclerosis complex with epilepsy, 30 (43.5%) had generalized motor epileptic spasms, 23 (33.3%) had focal seizures, and nine (13.0%) had generalized motor tonic-clonic seizures. In 14 children with Sturge-Weber syndrome with epilepsy, 13 (92.8%) had focal seizures, and 1 (7.2%) had generalized motor tonic seizures. Statistically significant associations were found between epilepsy and intellectual disability (P = 0.02) and behavioral problems (P = 0.00).

CONCLUSION

Profiling seizures in children with neurocutaneous syndromes are paramount in devising target-specific treatments as the epileptogenesis in each syndrome differs in the molecular pathways leading to the hyperexcitability state. Further multicentric studies are required to unravel better insights into the epilepsy profile of neurocutaneous syndromes.

Tuberous sclerosis complex in adulthood: focus on epilepsy prognosis

OBJECTIVE

Typically diagnosed in early childhood or adolescence, TSC is a chronic, multisystemic disorder with age-dependent manifestations posing a challenge for transition and for specific surveillance throughout the lifetime. Data on the clinical features and severity of TSC in adults and on the prognosis of epilepsy are scarce. We analyzed the clinical and genetic features of a cohort of adult patients with TSC, to identify the prognostic predictors of seizure remission after a long follow-up.

METHOD

We conducted a retrospective analysis of patients diagnosed with TSC according to the updated international diagnostic criteria. Pearson's chi-square or Fisher's exact test and Mann Whitney U test were used to compare variables among the Remission (R) and Non-Remission (NR) group. Univariate and multivariate logistic regression analyses were performed.

RESULTS

We selected 43 patients with TSC and neurological involvement in terms of epilepsy and/or brain lesions, attending the Epilepsy Center of our Institute: of them, 16 (37.2%) were transitioning from the pediatric care and 6 (13.9%) were referred by other specialists. Multiorgan involvement includes cutaneous (86.0%), nephrological (70.7%), hepatic (40.0%), ocular (34.3%), pneumological (28.6%) and cardiac (26.3%) manifestations. Thirty-nine patients (90.7 %) had epilepsy. The mean age at seizure onset was 4 ± 7.3 years: most patients (29, 76.3 %) presented with focal seizures or spasms by age 3 years; only 2 (5.3 %) had seizure onset in adulthood. Twenty-seven patients (69.2 %) experienced multiple seizure types overtime, 23 (59.0 %) had intellectual disability (ID). At last assessment, 14 (35.9 %) were seizure free (R group) and 25 (64.1 %) had drug-resistant seizures (NR group). At logistic regression univariate analysis, ID (OR 7.9, 95 % CI 1.8--34.7), multiple seizure types lifelong (OR 13.2, 95 % CI 2.6- 67.2), spasms/tonic seizures at presentation (OR 6.5, 95 % CI 1.2--35.2), a higher seizure frequency at onset (OR 5.4, 95 % CI 1.2--24.3), abnormal neurological examination (OR 9.8, 95 % CI 1.1--90.6) and pathogenic variants in TSC2 (OR 5.4, 95 % CI 1.2--24.5) were significantly associated with non-remission. In the multivariate analysis, both ID and multiple seizure types lifelong were confirmed as independent predictors of poor seizure outcome.

CONCLUSIONS

In our cohort of adult patients with TSC, epilepsy remains one of the main neurological challenges with only 5.3% of cases manifesting in adulthood. Approximately 64% of these patients failed to achieve seizure remission. ID and multiple seizure types were the main predictors of poor outcome. Nephrological manifestations require continuous specific follow-up in adults.

Patients' and physicians' awareness of clinical symptoms and disease severity in tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is a rare inherited disease with the potential to affect virtually every organ system. Clinical presentation is age- and partly sex-dependent and varies broadly with respect to disease manifestations including treatment-refractory epilepsy, intellectual disability and TSC-associated neuropsychiatric disorders, chronic kidney disease or progressive lung function decline. Given the complexity of this disease, multidisciplinary care in specialized TSC centres is recommended. We aimed to elucidate the state of knowledge of patients/caregivers and physicians on individual disease manifestations. We further examined whether the association to a TSC centre has an impact on the comprehensive consideration of potential disease manifestations. Therefore, a survey was performed in a cohort of German TSC patients and their physicians. Complete information was available for 94 patients with a median age of 18 years [range 1-55] and a sex distribution of 53.2% (male): 48.8% (female). Using almost identical questionnaires for patients/caregivers and their respective physician, there was a good correlation for disease assessments associated with relevant morbidity and mortality like epilepsy, renal angiomyolipoma, cardiac rhabdomyomas or intellectual disability. Correlation was moderate for several neuropsychiatric disorders and only poor for hypomelanotic macules, dental pits or retinal achromic patches. Estimation of overall disease severity using a numeric rating scale correlated highly significantly (Pearson correlation coefficient = 0.767; p < 0.001) between patients/caregivers and physicians. In general, physicians more likely quoted items as 'unknown' than patients (822 answers vs. 435 answers in the respective groups). Questionnaires completed by physicians who were associated with a specialized TSC centre declared a significantly lower proportion of items as unknown (mean 8.7% vs. 20.5%; p < 0.001). These findings indicate that patients treated by specialized TSC centres seem to obtain a more comprehensive surveillance. Furthermore, it shows that there were reasonable surveillance strategies in general and sufficient patient/caregiver interaction and education in the examined cohort. However, for the most prominent disease characteristics there was a good awareness within both the patients/caregivers and the physicians group.

The Genetics of Tuberous Sclerosis Complex and Related mTORopathies: Current Understanding and Future Directions

The mechanistic target of rapamycin (mTOR) pathway serves as a master regulator of cell growth, proliferation, and survival. Upregulation of the mTOR pathway has been shown to cause malformations of cortical development, medically refractory epilepsies, and neurodevelopmental disorders, collectively described as mTORopathies. Tuberous sclerosis complex (TSC) serves as the prototypical mTORopathy. Characterized by the development of benign tumors in multiple organs, pathogenic variants in TSC1 or TSC2 disrupt the TSC protein complex, a negative regulator of the mTOR pathway. Variants in critical domains of the TSC complex, especially in the catalytic TSC2 subunit, correlate with increased disease severity. Variants in less crucial exons and non-coding regions, as well as those undetectable with conventional testing, may lead to milder phenotypes. Despite the assumption of complete penetrance, expressivity varies within families, and certain variants delay disease onset with milder neurological effects. Understanding these genotype-phenotype correlations is crucial for effective clinical management. Notably, 15% of patients have no mutation identified by conventional genetic testing, with the majority of cases postulated to be caused by somatic TSC1/TSC2 variants which present complex diagnostic challenges. Advancements in genetic testing, prenatal screening, and precision medicine hold promise for changing the diagnostic and treatment paradigm for TSC and related mTORopathies. Herein, we explore the genetic and molecular mechanisms of TSC and other mTORopathies, emphasizing contemporary genetic methods in understanding and diagnosing the condition.

Retrospective Analysis of Presymptomatic Treatment In Sturge-Weber Syndrome

Background

Ninety percent of infants with Sturge-Weber syndrome (SWS) brain involvement have seizure onset before 2 years of age; this is associated with worse neurologic outcome. Presymptomatic treatment before seizure onset may delay seizure onset and improve outcome, as has been shown in other conditions with a high-risk of developing epilepsy such as tuberous sclerosis complex. Electroencephalogram (EEG) may be a biomarker to predict seizure onset. This retrospective clinical data analysis aims to assess impact of presymptomatic treatment in SWS.

Methods

This two-centered, IRB-approved, retrospective study analyzed records from patients with SWS brain involvement. Clinical data recorded included demographics, age of seizure onset (if present), brain involvement extent (unilateral versus bilateral), port-wine birthmark (PWB) extent, family history of seizure, presymptomatic treatment if received, neuroscore, and anti-seizure medication. EEG reports prior to seizure onset were analyzed.

Results

Ninety-two patients were included (48 females), and 32 received presymptomatic treatment outside of a formal protocol (5 aspirin, 16 aspirin and levetiracetam; 9 aspirin and oxcarbazepine, 2 valproic acid). Presymptomatically-treated patients were more likely to be seizure-free at 2 years (15 of 32; 47% versus 7 of 60; 12%; p<.001). A greater percentage of presymptomatically-treated patients had bilateral brain involvement (38% treated versus 17% untreated; p=.026). Median hemiparesis neuroscore at 2 years was better in presymptomatically-treated patients. In EEG reports prior to seizure onset, the presence of slowing, epileptiform discharges, or EEG-identified seizures was associated with seizure onset by 2 (p=.001).

Conclusion

Presymptomatic treatment is a promising approach to children diagnosed with SWS prior to seizure onset. Further study is needed, including prospective drug trials, long-term neuropsychological outcome, and prospective EEG analysis to assess this approach and determine biomarkers for presymptomatic treatment.

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.

Treatment guidelines for rare, early-onset conditions associated with epileptic seizures: a literature review on Rett syndrome and tuberous sclerosis complex

BACKGROUND

Rett syndrome (RTT) and tuberous sclerosis complex (TSC) are two rare disorders presenting with a range of different epileptic seizures. Seizure management requires careful therapy selection, thereby necessitating development of high-quality treatment guidelines. This targeted literature review (TLR) aimed to characterise country-specific and international treatment guidelines available for pharmacological management of seizures in RTT and TSC.

METHODS

A TLR was performed between 25-Jan and 11-Mar 2021. Manual searches of online rare disease and guideline databases, and websites of national heath technology assessment bodies were conducted for the following countries: Australia, Canada, France, Germany, Israel, Italy, Japan, Spain, Switzerland, UK, and US as defined by pre-specified eligibility criteria. Search terms were developed for each condition and translated into local languages where appropriate. Eligible publications were defined as guidelines/guidance reporting pharmacological management of seizures in patients with RTT and TSC. Guideline development methodology, geographical focus, author information and treatment recommendations were extracted from guidelines. An author map was generated using R version 3.5.1 to visualise extent of collaboration between authors.

RESULTS

24 total guidelines were included, of which three and six contained only recommendations for RTT and TSC, respectively (some provided recommendations for ≥ 1 condition). Guideline development processes were poorly described (50% [12 guidelines] had unclear/absent literature review methodologies); reported methodologies were variable, including systematic literature reviews (SLRs)/TLRs and varying levels of expert consultation. Most (83% [20/24]) were country-specific, with guideline authors predominantly publishing in contained national groups; four guidelines were classified as 'International,' linking author groups in the US, UK, Italy and France. High levels of heterogeneity were observed in the availability of treatment recommendations across indications, with 13 and 67 recommendations found for RTT and TSC, respectively. For RTT, all treatment recommendations were positive and sodium valproate had the highest number of positive recommendations (Khwaja, Sahin (2011) Curr Opin Pediatr 23(6):633-9). All TSC treatments (21 medications) received either exclusively negative (National Organization for Rare Disorders (2019)) or positive (Chu-Shore et al. (2010) Epilepsia 51(7):1236-41) recommendations; vigabatrin received the highest number of positive recommendations (Kaur, Christodoulou (2019)).

CONCLUSIONS

This review highlights the need for the development of international high-quality and comprehensive consensus-based guidance for the management of seizures with pharmacological therapy in RTT and TSC.

TRIAL REGISTRATION

Not applicable.

Neuropsychiatric manifestations of tuberous sclerosis in a young man in a psychiatric hospital in Botswana: a case report

Tuberous sclerosis complex (TSC), first described in 1880, is a disorder that affects multiple systems. Its symptoms include seizures, intellectual disability, and angiofibromas. TSC is caused by mutations in the TSC1 and TSC2 genes and is inherited in an autosomal dominant manner. The present report describes the case of a patient with an unusual psychological presentation who was evaluated in a psychiatric hospital. A man with poorly managed epilepsy was brought to Botswana's only psychiatric hospital. After clinical assessment, a diagnosis of tuberous sclerosis complex was made, which was later confirmed through neuroimaging and genetic tests. Some of the patient's relatives also showed similar neuropsychiatric symptoms. Given that psychiatry may be the first medical contact for TSC patients, especially in low-resource settings, clinicians need to be knowledgeable of various neuropsychiatric conditions and be aware of the possibility of TSC in patients that present with neurocutaneous manifestations. A multidisciplinary team approach is vital for the investigation and management of such cases.

Is tuberous sclerosis complex-associated autism a preventable and treatable disorder?

BACKGROUND

Tuberous sclerosis complex (TSC) is a genetic disorder caused by inactivating mutations in the TSC1 and TSC2 genes, causing overactivation of the mechanistic (previously referred to as mammalian) target of rapamycin (mTOR) signaling pathway in fetal life. The mTOR pathway plays a crucial role in several brain processes leading to TSC-related epilepsy, intellectual disability, and autism spectrum disorder (ASD). Pre-natal or early post-natal diagnosis of TSC is now possible in a growing number of pre-symptomatic infants.

DATA SOURCES

We searched PubMed for peer-reviewed publications published between January 2010 and April 2023 with the terms "tuberous sclerosis", "autism", or "autism spectrum disorder"," animal models", "preclinical studies", "neurobiology", and "treatment".

RESULTS

Prospective studies have highlighted that developmental trajectories in TSC infants who were later diagnosed with ASD already show motor, visual and social communication skills in the first year of life delays. Reliable genetic, cellular, electroencephalography and magnetic resonance imaging biomarkers can identify pre-symptomatic TSC infants at high risk for having autism and epilepsy.

CONCLUSIONS

Preventing epilepsy or improving therapy for seizures associated with prompt and tailored treatment strategies for autism in a sensitive developmental time window could have the potential to mitigate autistic symptoms in infants with TSC.

Tsc2 coordinates neuroprogenitor differentiation

Neural stem cells (NSCs) of the ventricular-subventricular zone (V-SVZ) generate numerous cell types. The uncoupling of mRNA transcript availability and translation occurs during the progression from stem to differentiated states. The mTORC1 kinase pathway acutely controls proteins that regulate mRNA translation. Inhibiting mTORC1 during differentiation is hypothesized to be critical for brain development since somatic mutations of mTORC1 regulators perturb brain architecture. Inactivating mutations of TSC1 or TSC2 genes cause tuberous sclerosis complex (TSC). TSC patients have growths near the striatum and ventricles. Here, it is demonstrated that V-SVZ NSC Tsc2 inactivation causes striatal hamartomas. Tsc2 removal altered translation factors, translatomes, and translational efficiency. Single nuclei RNA sequencing following in vivo loss of Tsc2 revealed changes in NSC activation states. The inability to decouple mRNA transcript availability and translation delayed differentiation leading to the retention of immature phenotypes in hamartomas. Taken together, Tsc2 is required for translational repression and differentiation.

Multifocal drug-resistant epilepsy in a patient with a newly discovered mutation in tuberous sclerosis complex 1 gene treated by deep brain stimulation in the anterior thalamic nucleus

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder caused by mutations in the tumor suppressor genes TSC1 or TSC2. TSC is characterized by the formation of multiple tumors in various organs. The most common neurological manifestation of the disorder is epilepsy present in 79-90% of cases. At least one-third of TSC patients develop drug-resistant epilepsy (DRE) which remains a great challenge for clinicians. Neuromodulation is an option in cases of multifocal epilepsy, epilepsy originating in eloquent areas, or the inability to identify the ictal onset zone. Deep brain stimulation of the anterior thalamic nucleus (ANT-DBS) may be used in the treatment of multifocal DRE. Here, we present a case of a patient with multifocal DRE caused by TSC, who was treated with ANT-DBS. A follow-up period of eight months showed that the patient's multifocal DRE was successfully treated by ANT-DBS.

MR-Guided Focused Ultrasound for Refractory Epilepsy: Where Are We Now?

Epilepsy is one of the most common neurological diseases in both adults and children. Despite improvements in medical care, 20 to 30% of patients are still resistant to the best medical treatment. The quality of life, neurologic morbidity, and even mortality of patients are significantly impacted by medically intractable epilepsy. Nowadays, conservative therapeutic approaches consist of increasing medication dosage, changing to a different anti-seizure drug as monotherapy, and combining different antiseizure drugs using an add-on strategy. However, such measures may not be sufficient to efficiently control seizure recurrence. Resective surgery, ablative procedures and non-resective neuromodulatory (deep-brain stimulation, vagus nerve stimulation) treatments are the available treatments for these kinds of patients. However, invasive procedures may involve lengthy inpatient stays for the patients, risks of long-term neurological impairment, general anesthesia, and other possible surgery-related complications (i.e., hemorrhage or infection). In the last few years, MR-guided focused ultrasound (MRgFUS) has been proposed as an emerging treatment for neurological diseases because of technological advancements and the goal of minimally invasive neurosurgery. By outlining the current knowledge obtained from both preclinical and clinical studies and discussing the technical opportunities of this therapy for particular epileptic phenotypes, in this perspective review, we explore the various mechanisms and potential applications (thermoablation, blood-brain barrier opening for drug delivery, neuromodulation) of high- and low-intensity ultrasound, highlighting possible novel strategies to treat drug-resistant epileptic patients who are not eligible or do not accept currently established surgical approaches. Taken together, the available studies support a possible role for lesional treatment over the anterior thalamus with high-intensity ultrasound and neuromodulation of the hippocampus via low-intensity ultrasound in refractory epilepsy. However, more studies, likely conceiving epilepsy as a network disorder and bridging together different scales and modalities, are required to make ultrasound delivery strategies meaningful, effective, and safe.

A single-center observational study on long-term neurodevelopmental outcomes in children with tuberous sclerosis complex

BACKGROUND

Tuberous sclerosis complex (TSC) is a rare multisystem disorder caused by mutations in the TSC1 or TSC2 gene. More than 90% of patients with TSC develop neurological and/or neuropsychiatric manifestations. The aim of the present study was to determine the developmental and cognitive long-term outcomes of pediatric TSC patients.

METHODS

This cross-sectional, monocenter study included pediatric TSC patients who received multidisciplinary long-term care with a last visit between 2005 and 2019. Neurological manifestations and cognitive development (BSID, K-ABC) were analyzed in relation to age and type of mutation.

RESULTS

Thirty-five patients aged 13.5 ± 7.8 years were included in the study. Diagnosis was confirmed genetically in 65.7% of patients (TSC1, 26.1%; TSC2, 65.2%; NMI, 8.7%). Mean age at diagnosis was 1.3 ± 3.5 years; 74.3% of the patients had been diagnosed within the first year of life due to seizures (62.9%) or/and cardiac rhabdomyomas (28.6%). The most common TSC manifestations included structural brain lesions (cortical tubers, 91.4%; subependymal nodules, 82.9%), epilepsy (85.7%), and cardiac rhabdomyomas (62.9%). Mean age at seizure onset was 1.5 ± 2.3 years, with onset in 80.0% of patients within the first two years of life. Infantile spasms, which were the first seizure type in 23.3% of the patients, developed earlier (0.6 ± 0.4 years) than focal seizures (1.8 ± 2.5 years). Refractory epilepsy was present in 21 (70.0%) patients, mild or severe intellectual impairment in 66.6%, and autism spectrum disorders in 11.4%. Severe cognitive impairment (33.3%) was significantly associated with epilepsy type and age at seizure onset (p < 0.05).

CONCLUSIONS

The results emphasized the phenotypic variability of pediatric-onset TSC and the high rate of neurological and neuropsychiatric morbidity. Early-onset refractory epilepsy was associated with impaired cognitive development. Children of all ages with TSC require multidisciplinary long-term care and individual early-intervention programs.

The evolution of epilepsy surgery in tuberous sclerosis in Sweden: A national registry study

PURPOSE

This study aimed to characterize the Swedish cohort of surgically treated patients with TSC and explore differences in preoperative investigation and outcome over time.

METHODS

Data on patient and seizure characteristics were retrieved from the Swedish National Epilepsy Surgery Register. Two-year follow-up results were compared between the years 1997-2010 and 2011-2018. Preoperative investigations were re-evaluated.

RESULTS

Eighteen tuberectomies and seven callosotomies were identified. Seizure freedom after tuberectomy was achieved in 11 % (1/9) 1997-2010 and 56 % (5/9) 2011-2018. The number of tuberectomies increased each decade. Patients operated on in 1997-2010 had higher seizure frequency (median 175 seizures/month vs. 102) and incidence of infantile spasms (4/9 vs. 1/9, none after 2011). There was a trend towards surgery at a younger age (median 86 months 1997-2010 vs. 48 months 2011-2018). None with >200 seizure/month, SEGA, or history of infantile spasms achieved seizure freedom. Two patients underwent anterior callosotomy (1992 and 1994) and became free of drop attacks. Five callosotomies were performed between 2011 and 2013, one patient became free of drop attacks. Two complications with new neurological deficits were reported. The median age at surgery was higher in the callosotomy group (14 years) than in the tuberectomy group (5 years).

CONCLUSION

Seizure freedom after tuberectomy in patients with TSC has increased over time in our cohort. Signs of a heavier disease burden were more frequently observed 1997-2010 and associated with worse outcomes. Callosotomy operations were prevalent at the beginning of the 2010s.

Updated clinical recommendations for the management of tuberous sclerosis complex associated epilepsy

Children with tuberous sclerosis complex (TSC), may experience a variety of seizure types in the first year of life, most often focal seizure sand epileptic spasms. Drug resistance is seen early in many patients, and the management of TSC associated epilepsy remain a major challenge for clinicians. In 2018 clinical recommendations for the management of TSC associated epilepsy were published by a panel of European experts. In the last five years considerable progress has been made in understanding the neurobiology of epileptogenesis and three interventional randomized controlled trials have changed the therapeutic approach for the management of TSC associated epilepsy. Pre-symptomatic treatment with vigabatrin may delay seizure onset, may reduce seizure severity and reduce the risk of epileptic encephalopathy. The efficacy of mTOR inhibition with adjunctive everolimus was documented in patients with TSC associated refractory seizures and cannabidiol could be another therapeutic option. Epilepsy surgery has significantly improved seizure outcome in selected patients and should be considered early in all patients with drug resistant epilepsy. There is a need to identify patients who may have a higher risk of developing epilepsy and autism spectrum disorder (ASD). In the recent years significant progress has been made owing to the early identification of risk factors for the development of drug-resistant epilepsy. Better understanding of the mechanism underlying epileptogenesis may improve the management for TSC-related epilepsy. Developmental neurobiology and neuropathology give opportunities for the implementation of concepts related to clinical findings, and an early genetic diagnosis and use of EEG and MRI biomarkers may improve the development of pre-symptomatic and disease-modifying strategies.

Neurological and Dermatological Manifestations of Tuberous Sclerosis Complex: Report from a Romanian Tertiary Hospital Cohort

Tuberous sclerosis complex is a rare multisystem genetic disorder characterized by multiorgan involvement, frequently associated with intellectual impairment and epilepsy. The aim of our study was to describe the neurological and dermatological manifestations of TSC in 32 adult patients (of whom 19 were females) who attended the Neurology and Nephrology Clinics of Fundeni Clinical Institute in Romania from 2015 to 2020. Seventeen patients were diagnosed with epilepsy, nine patients had intellectual impairment, and complete neuroimaging was available for twenty-two patients. As expected, the most frequent dermatological lesions were cutaneous angiofibromas in 20 patients, but with a lower frequency than described in the current literature. Statistical analysis was performed considering the small number of patients. Cortical tubers in neuroimaging seemed to be associated with the diagnosis of epilepsy, while subependymal nodules represented a risk factor for intellectual impairment. Males showed a larger number of dermatological types of lesions, especially café -au-lait patches. Interestingly, we found a statistically significant positive association between epilepsy and the presence of cutaneous angiofibromas, as well as total dermatological involvement. Females had significantly higher Charlson comorbidity index scores, indicating a higher burden of disease. Everolimus seemed to be a well-tolerated treatment and showed promising results in controlling epileptic seizures alone in two patients. More studies, with the inclusion of a larger number of patients, are needed to confirm these results.

Updated Genotype-Phenotype Correlations in TSC

GENOTYPE/PHENOTYPE CORRELATIONS IN TUBEROUS SCLEROSIS COMPLEX

Paolo Curatolo MD, Romina Moavero MD, Denis Roberto, Federica Graziola Seminars in Pediatric Neurology Volume 22, Issue 4, December 2015, Pages 259-273 Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by the development of widespread hamartomatous lesions in various organs, including brain, skin, kidneys, heart, and eyes. Central nervous system is almost invariably involved, with up to 85% of patients presenting with epilepsy, and at least half of patients having intellectual disability or other neuropsychiatric disorders including autism spectrum disorder. TSC is caused by the mutation in one of the 2 genes TSC1, at 9q34, and TSC2, at 16p13.3. They respectively encode for hamartin and tuberin, which form an intracellular complex inhibiting the mammalian target of rapamycin. Mammalian target of rapamycin overactivation following the genetic defect determines the cell growth and proliferation responsible for TSC-related lesions, as well as the alterations in neuronal excitability and synaptogenesis leading to epilepsy and neuropsychiatric disorders. A causative mutation for the disorder is identified in about 85% of patients with a clinical diagnosis of TSC. Mosaicism and technology limits likely explain most of the no mutation identified cases. This review confirms that patients with TSC2 mutations considered as a group usually present a more severe phenotype, characterized by higher number of tubers, earlier age at seizure onset and higher prevalence of intellectual disability. However, the clinical phenotype of the disease presents a high variability, thus making the prediction of the phenotype on an individual basis still challenging. The increasing application of new molecular techniques to subjects with TSC has the potential to significantly reduce the rate of patients with no mutation demonstrated and to identify an increasing higher number of mutations. This would hopefully allow a better characterization of higher risk mutations, which might help clinicians to plan individualized surveillance plans. Furthermore, the increasing availability of disease registries to collect clinical and genetics data of patients help to define more valid and clinically oriented genotype or phenotype correlations.

Suberoylanilide Hydroxamic Acid (SAHA) Is a Driver Molecule of Neuroplasticity: Implication for Neurological Diseases

Neuroplasticity is a crucial property of the central nervous system to change its activity in response to intrinsic or extrinsic stimuli. This is mainly achieved through the promotion of changes in the epigenome. One of the epi-drivers priming this process is suberoylanilide hydroxamic acid (SAHA or Vorinostat), a pan-histone deacetylase inhibitor that modulates and promotes neuroplasticity in healthy and disease conditions. Knowledge of the specific molecular changes induced by this epidrug is an important area of neuro-epigenetics for the identification of new compounds to treat cognition impairment and/or epilepsy. In this review, we summarize the findings obtained in cellular and animal models of various brain disorders, highlighting the multiple mechanisms activated by SAHA, such as improvement of memory, learning and behavior, and correction of faulty neuronal functioning. Supporting this evidence, in vitro and in vivo data underline how SAHA positively regulates the expression of neuronal genes and microtubule dynamics, induces neurite outgrowth and spine density, and enhances synaptic transmission and potentiation. In particular, we outline studies regarding neurodevelopmental disorders with pharmaco-resistant seizures and/or severe cognitive impairment that to date lack effective drug treatments in which SAHA could ameliorate defective neuroplasticity.

Efficacy and safety of vigabatrin in patients with tuberous sclerosis complex and infantile epileptic spasm syndrome: a systematic review

INTRODUCTION

Tuberous sclerosis complex (TSC) is a common genetic cause of epilepsy. Infantile epileptic spasm syndrome (IESS) is often the presenting neurologic feature, progressively evolving into refractory epilepsy. Vigabatrin (VGB) is often used in clinical practice as a first-line therapy in TSC with IESS. This systematic review aims to collect and analyze the efficacy data about VGB in TSC cases with IESS, in order to evaluate the strength of evidence in the literature.

METHODS

A systematic search of trials, observational studies, and case series involving patients with TSC and IESS treated with VGB was performed using MEDLINE, CENTRAL, and the US NIH Clinical Trials Registry. Single case studies, animal and non-English language studies were excluded. Seventeen studies were selected, of which 3 were RCTs and 14 were observational studies.

RESULTS

An overall response rate of 67% (231/343 responders) resulted from the analysis, with a spasm-free rate restricted to RCTs of 88% (29/33 subjects).

CONCLUSIONS

Although all the studies analyzed reported beneficial effects of VGB in TSC patients with IESS, with higher response rates in comparison to non-TSC subjects with IESS, a low level of evidence and high heterogeneity do not guarantee sufficient strength for therapeutic recommendations.