Direct and indirect costs and cost-driving factors of Tuberous sclerosis complex in children, adolescents, and caregivers: a multicenter cohort study

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.

Kidney transplantation in patients with tuberous sclerosis complex

BACKGROUND

Tuberous sclerosis complex (TSC) is a disorder of the mammalian target of the rapamycin (mTOR) pathway associated with the development of multisystem tumors, including renal angiomyolipoma (AML). These renal tumors are benign by nature but locally invasive and carry a risk for the progression of chronic kidney disease (CKD) to end stage kidney disease (ESKD). The frequency of subsequent renal transplantation in this population is largely uncharacterized, although single-center data suggests that 5%-15% of adult TSC patients are kidney transplant recipients.

METHODS

This retrospective cohort study utilized United Network for Organ Sharing (UNOS) data. We included candidates waitlisted between 1987 and 2020 for a first kidney transplant with TSC-associated kidney failure. We utilized descriptive statistics to characterize the frequency of first-time kidney transplant waitlisting and transplantation among persons with TSC and the Fine-Gray subdistribution hazard model to evaluate characteristics associated with progression from waitlist.

RESULTS

We identified 200 TSC-associated kidney failure patients within the waitlist cohort. Of these, 12 were pediatric patients. Two-thirds (N = 134) of waitlisted persons were female. One hundred forty patients received a transplant with a median waitlist time of 2 years. Younger age at waitlisting was associated with a greater probability of progressing to transplant (HR 0.98 [95% CI: 0.96-0.99]). 91.8% of kidney transplant recipients survived 1-year post-transplant with a functioning allograft.

CONCLUSIONS

The majority of patients with TSC who are waitlisted for a kidney transplant progress onto transplantation with excellent 1-year post transplant patient and allograft survival.

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.

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.

Methods used to account for caregivers' sex and gender within studies examining the financial burden of caregivers of children and adolescents : Results from a scoping review

Background

Interest in the financial burden of informal caregivers has been growing. Unfortunately, it remains unclear which method(s) should be used when quantifying this burden.

Purpose

We conducted a scoping review aimed at identifying which methods have been used to conduct such work and quantified their performance. We were also interested in examining how sex and gender considerations were considered within selected studies.

Data Sources

Using a standardized approach, we identified studies published between 2012 and 2022 that aimed to document the financial burden of caregivers to child and adolescent patients. Our search strategy was applied to the MEDLINE, Embase, CINHAL, and Academic Search Premier databases.

Study Selection

Manuscript selection was performed by pairs of reviewers.

Data Extraction

Data extraction was performed by one reviewer with a second reviewer performing quality control. Results were reported using a narrative approach.

Data Synthesis

We identified 9801 unique citations, of which 200 were included in our review. Selected studies covered various disease area (eg, infection/parasitic diseases [n = 31, 16%]) and included quantitative (n = 180, 90%), qualitative (n = 4, 2%) and mixed study designs (n = 16, 8%). Most studies (n = 182, 91%) used questionnaires/surveys, either alone or in combination with other methods, to assess caregivers' financial burden. Less than half (n = 93, 47%) of studies reported on caregivers' sex and none reported on their gender.

Conclusion

We conducted an unrestricted review of published studies examining caregiver's financial burden which allowed us to identify general methodological trends observed in this literature. We believe this work may help improve future studies focusing on this important issue.

Australian children living with rare diseases: health service use and barriers to accessing care

BACKGROUND

Children with rare diseases experience challenges at home and school and frequently require multi-disciplinary healthcare. We aimed to determine health service utilization by Australian children with rare diseases and barriers to accessing healthcare.

METHODS

Parents completed an online survey on health professional and emergency department (ED) presentations, hospitalization, and barriers to accessing services. Potential barriers to service access included residential location (city, regional, remote) and child health-related functioning, determined using a validated, parent-completed measure-of-function tool.

RESULTS

Parents of 462 children with over 240 rare diseases completed the survey. Compared with the general population, these children were more likely to be hospitalized [odds ratio (OR) = 17.25, 95% confidence interval (CI) = 15.50-19.20] and present to the ED (OR = 4.15, 95% CI = 3.68-4.68) or a family physician (OR = 4.14, 95% CI = 3.72-4.60). Child functional impairment was nil/mild (31%), moderate (48%) or severe (22%). Compared to children with nil/mild impairment, those with severe impairment were more likely to be hospitalized (OR = 13.39, 95% CI = 7.65-23.44) and present to the ED (OR = 11.16, 95% CI = 6.46-19.27). Most children (75%) lived in major cities, but children from regional (OR = 2.78, 95% CI = 1.72-4.55) and remote areas (OR = 9.09, 95% CI = 3.03-25.00) experienced significantly more barriers to healthcare access than children from major cities. Barriers included distance to travel, out-of-pocket costs, and lack of specialist medical and other health services.

CONCLUSIONS

Children with rare diseases, especially those with severe functional impairment have an enormous impact on health services, and better integrated multidisciplinary services with patient-centered care are needed. Access must be improved for children living in rural and remote settings.

The Burden of Caring for Individuals with Tuberous Sclerosis Complex (TSC) Who Experience Epileptic Seizures: A Descriptive UK Survey

INTRODUCTION

Tuberous sclerosis complex (TSC) is a rare multisystem genetic condition characterised by benign tumours; prevalent manifestations include epilepsy and neuropsychiatric disorders. This study examined the burden of TSC for primary caregivers and families, exploring the impact of characteristics such as seizures.

METHODS

Primary caregivers of individuals with TSC in the United Kingdom participated in an online survey, comprising the Pediatric Quality of Life Inventory™ Family Impact Module, Hospital Anxiety and Depression Scale (HADS), and TSC-specific items. Responses were analysed using descriptive and regression analysis statistics (closed-ended) or qualitative content analysis (open-ended).

RESULTS

Seventy-three participants partially completed and 59 fully completed the survey; 95% were female, and 90% were parents of an individual with TSC. A median (range) of 2 (1-11) household members were carers. Primary caregivers spent a mean (standard deviation [SD]) of 104.3 (51.7) hours caring in the previous week, reporting high mean (SD) HADS scores of 11.2 (4.8) (anxiety) and 7.9 (4.4) (depression) and considerable family burden. Increased seizure frequency increased hours spent caring by primary caregivers (p = 0.01) and was associated with a decreased mean (SD) family functioning score of 46.2 (23.0) and parent health-related quality of life (HRQL) score of 45.4 (20.3) (both p = 0.03). Multivariable models predicted intellectual disability increased hours spent caring by primary caregivers (p = 0.01-0.04), and neuropsychiatric comorbidities decreased family functioning (p = 0.02) and caregiver HRQL (p < 0.01).

CONCLUSION

These findings highlight the role of epileptic seizures and neuropsychiatric disorders in the considerable burden of TSC on primary caregivers and families.

The burden of illness in Lennox-Gastaut syndrome: a systematic literature review

BACKGROUND

Lennox-Gastaut syndrome (LGS) is a severe developmental and epileptic encephalopathy characterized by drug-resistant epilepsy with multiple seizure types starting in childhood, a typical slow spike-wave pattern on electroencephalogram, and cognitive dysfunction.

METHODS

We performed a systematic literature review according to the PRISMA guidelines to identify, synthesize and appraise the burden of illness in LGS (including "probable" LGS). Studies were identified by searching MEDLINE, Embase and APA PsychInfo, Cochrane's database of systematic reviews, and Epistemonikos. The outcomes were epidemiology (incidence, prevalence or mortality), direct and indirect costs, healthcare resource utilization, and patient and caregiver health-related quality of life (HRQoL).

RESULTS

The search identified 22 publications evaluating the epidemiology (n = 10), direct costs and resource (n = 10) and/or HRQoL (n = 5). No studies reporting on indirect costs were identified. With no specific ICD code for LGS in many regions, several studies had to rely upon indirect methods to identify their patient populations (e.g., algorithms to search insurance claims databases to identify "probable" LGS). There was heterogeneity between studies in how LGS was defined, the size of the populations, ages of the patients and length of the follow-up period. The prevalence varied from 4.2 to 60.8 per 100,000 people across studies for probable LGS and 2.9-28 per 100,000 for a confirmed/narrow definition of LGS. LGS was associated with high mortality rates compared to the general population and epilepsy population. Healthcare resource utilization and direct costs were substantial across all studies. Mean annual direct costs per person varied from $24,048 to $80,545 across studies, and home-based care and inpatient care were significant cost drivers. Studies showed that the HRQoL of patients and caregivers was adversely affected, although only a few studies were identified. In addition, studies suggested that seizure events were associated with higher costs and worse HRQoL. The risk of bias was low or moderate in most studies.

CONCLUSIONS

LGS is associated with a significant burden of illness featuring resistant seizures associated with higher costs and worse HRQoL. More research is needed, especially in evaluating indirect costs and caregiver burden, where there is a notable lack of studies.

Use of mTOR inhibitors (rapalogs) for the treatment of skin changes in tuberous sclerosis complex

BACKGROUND

Skin manifestations of Tuberous Sclerosis Complex (TSC) are present in more than 90% of patients. Facial angiofibromas (AF) are considered a skin hallmark of TSC. They are responsible for esthetic impact in patients. We aimed at reviewing the data available on the use of rapamycin (sirolimus) and everolimus for the oral or topical treatment of AF and other TSC-related skin changes and reporting our preliminary experience at Angers University Hospital.

METHODS

The literature search has been performed in combining the terms "rapamycin", "sirolimus", "everolimus", "tuberous sclerosis complex", "skin" and "trial". We have splited the findings of the literature search into two parts: 1) the value of rapalogs used systemically for extracutaneous purposes and 2) the role of topical rapalogs used specifically for skin lesions.

RESULTS

Large clinical trials using rapamycin or everolimus for the treatment of brain, lung or kidney manifestations of TSC unfortunately poorly define the "skin lesion response rate" they report. Conversely, the trials with topical rapamycin demonstrate significant, albeit transient, efficacy on AF size and visibility and acceptable tolerance. Several trials suggest better efficacy in younger patients than in adults. Long-term evaluation (up to 136 weeks) point to sustained response and good local and systemic tolerance. However, maintenance therapy appears to be mandatory to preserve skin response. Other skin changes, especially shagreen fibrotic plaques, hypomelanotic macules and ungual tumors still need far more research. Our experience in 124 patients (children and adults) treated for facial AF at Angers University Hospital showed that about 80% of them had an impressive and sustained response.

CONCLUSION

The issues of cost and access to affordable topical rapamycin formulations are critical for the patients even if skin changes do not cause serious harm in the context of TSC. We strongly suggest to improve and standardize the formulation of topical rapamycin, to encourage the pharmaceutical industry for providing commercial products, and the Health systems (social welfare) to reimburse them. © 2022 French Society of Pediatrics. Published by Elsevier Masson SAS. All rights reserved.

Aspects of autism spectrum disorder and correlation with neuroimaging findings in tuberous sclerosis complex

BACKGROUND

Tuberous sclerosis complex (TSC) patients may have different specific neuropsychological deficits related to the location of the tubers. Autism spectrum disorders (ASD) are common in TSC patients but the relationship between these diagnoses has not been formally explored. In this study we sought to examine brain Magnetic Resonance Imaging (MRI) findings in TSC patients with ASD.

METHODS

We evaluated 34 TSC patients on the basis of DSM-V diagnostic criteria for ASD, Wechsler Intelligence Scale for Children (WISC-R), psychiatrist's examination and also structured parent interviews. The number and localization of the tubers, postcontrast signal characteristics of the tubers, SWI findings, DWI findings on brain MRI were recorded. Demographic features, epilepsy histories, number of antiseizure medications, cognitive status were eveluated also. Patients were divided into two groups: ASD group, which represented group 1 and group 2 consisting of patients without any ASD symptoms.

RESULTS

In our study, the mean number of tuber count was 21.8 in patients with ASD patients (Group 1, n = 13) and 12.4 in other TSC patients without ASD (Group 2, n = 21). Rate of tubers in prefrontal cortex/whole tubers (0.51) in patients with ASD was determined to be higher in group 1 (p = 0.003). Also a significant difference was detected between generalize epileptiform activities on EEG and the rate of DRE (p = 0.002; p = 0.001) between groups. Cognitive disturbances and infantile spasm history were similar between groups. TSC2 mutations have been identified in 29 (86%) patients.

CONCLUSION

The mean of total tuber count and the rate of the location in the prefrontal cortex were determined to be higher in TSC patients with ASD. Specific areas on brain MRI may help understanding the development of ASD in TSC patients.

Epidemiology and disease burden of tuberous sclerosis complex in France: A population-based study based on national health insurance data

OBJECTIVE

Tuberous sclerosis complex (TSC) is a rare multisystem disorder, often associated with epilepsy. This retrospective study aimed to identify patients with TSC, including those with epilepsy, from a French healthcare claims database, and to report incidence, prevalence, and healthcare costs and resource utilization.

METHODS

The anonymized French health insurance database (SNDS) covers almost the entire French population. Patients with TSC were identified as having ≥1 International Classification of Diseases, Tenth Revision (ICD-10) diagnosis code Q85.1 or a long-term disease (LTD) registration over the inclusion period (2006-2017). Patients with an ICD-10 epilepsy code or who were dispensed ≥1 antiseizure medication (ASM) in the same year or after their TSC diagnosis were identified as having TSC with epilepsy. Newly diagnosed patients over the inclusion period constituted the incident cohort. Healthcare costs (patients with recorded costs only), healthcare resource use, and ASM dispensation are reported for patients with 2018 data.

RESULTS

In 2018, 3139 prevalent patients with TSC were identified (crude prevalence, 4.69 per 100 000); the incident cohort comprised 2988 patients (crude incidence, 0.44 per 100 000). Among patients with TSC, 67% (2101/3139) had epilepsy (mean [standard deviation, SD] age: 28.8 [18.8] years; male: 48%). Among patients with epilepsy, total mean (SD) annual healthcare costs were €11 413 (27 620) per capita (outpatient, 63%; inpatient, 37%), 46% were hospitalized during 2018 (mean [SD]: 1.8 [10.9] acute care visits per patient), and 65% visited a hospital specialist. Among patients with epilepsy, medication (mean [SD]: €4518 [12 102] per capita) was the greatest contributor (63%) to outpatient costs, and in 2018, 74% were dispensed ≥1 different ASM and 9% were dispensed ≥4 ASMs.

SIGNIFICANCE

TSC with epilepsy was associated with substantial healthcare costs and resource utilization, particularly outpatient and medication costs. Many patients with TSC with epilepsy were prescribed multiple ASMs, suggesting refractory epilepsy.

Multicenter, cross-sectional study of the costs of illness and cost-driving factors in adult patients with epilepsy

OBJECTIVE

This study was undertaken to quantify epilepsy-related costs of illness (COI) in Germany and identify cost-driving factors.

METHODS

COI were calculated among adults with epilepsy of different etiologies and severities. Multiple regression analysis was applied to determine any epilepsy-related and sociodemographic factors that serve as cost-driving factors.

RESULTS

In total, 486 patients were included, with a mean age of 40.5 ± 15.5 years (range = 18-83 years, 58.2% women). Mean 3-month COI were estimated at €4911, €2782, and €2598 for focal, genetic generalized, and unclassified epilepsy, respectively. The mean COI for patients with drug-refractory epilepsy (DRE; €7850) were higher than those for patients with non-DRE (€4720), patients with occasional seizures (€3596), or patients with seizures in remission for >1 year (€2409). Identified cost-driving factors for total COI included relevant disability (unstandardized regression coefficient b = €2218), poorer education (b = €2114), living alone (b = €2612), DRE (b = €1831), and frequent seizures (b = €2385). Younger age groups of 18-24 years (b = -€2945) and 25-34 years (b = -€1418) were found to have lower overall expenditures. A relevant disability (b = €441), DRE (b = €1253), frequent seizures (b = €735), and the need for specialized daycare (b = €749) were associated with higher direct COI, and poorer education (b = €1969), living alone (b = €2612), the presence of a relevant disability (b = €1809), DRE (b = €1831), and frequent seizures (b = €2385) were associated with higher indirect COI.

SIGNIFICANCE

This analysis provides up-to-date COI data for use in further health economics analyses, highlighting the high economic impacts associated with disease severity, disability, and disease-related loss of productivity among adult patients with epilepsy. The identified cost drivers could be used as therapeutic and socioeconomic targets for future cost-containment strategies.

Health-related quality of life in children and adolescents with tuberous sclerosis complex and their caregivers: A multicentre cohort study from Germany

OBJECTIVE

This study aimed to measure health-related quality of life (HRQOL) in children and adolescents with tuberous sclerosis complex (TSC) and quality of life (QOL) and depressive symptoms among caregivers.

METHODS

Adequate metrics were used to assess HRQOL in children and adolescents with TSC (4-18 years, KINDL^R) as well as QOL (EQ-5D) and symptoms of depression (BDI-II) among caregivers. Predictors for reduced HRQOL and depressive symptoms were identified by variance analysis, ordinal regression, and bivariate correlation.

RESULTS

The mean HRQOL score was 67.9 ± 12.7, and significantly lower values were associated with increasing age, attending special needs education, TSC-associated psychiatric symptoms, and drug-related adverse events. The mean QOL of caregivers was 85.4 ± 15.7, and caregiver's sex, TSC mutation locus, familial TSC clustering, special needs education, degree of disability, care dependency, presence of TSC-associated psychiatric symptoms, and TSC severity were significant predictors of lower QOL. Depressive symptoms were identified in 45.7% of caregivers, associated with female sex of the caregiver, familial TSC clustering, special needs education, and presence of TSC-associated psychiatric symptoms of the child. Multivariate regression analysis revealed adolescence and drug-related adverse events as significant predictors for lower HRQOL in TSC children, and TSC2 variants predicted lower QOL and depressive symptoms in caregivers.

CONCLUSION

Compared with other chronic diseases, such as headache, diabetes or obesity, children with TSC have significantly lower HRQOL, which further decreases during adolescence. A decreased HRQOL of patients correlates with a lower QOL and increased symptoms of depression of their caregivers. These results may improve the comprehensive therapy and care of children and adolescents with TSC and their families and caregivers.

TRIAL REGISTRATION

DRKS, DRKS00016045. Registered 01 March 2019, http://www.drks.de/DRKS00016045.

Epilepsy associated with tuberous sclerosis complex in childhood: Long-term outcome in children after epilepsy surgery and children non-eligible for epilepsy surgery

OBJECTIVE

Drug-resistant epilepsy is one of the major disease burdens in patients with tuberous sclerosis complex (TSC). Epilepsy surgery has been shown to be effective in TSC, but making a decision for surgery is often more complex than in other surgically amenable epilepsy syndromes and not all patients with TSC are eligible. We investigated long-term outcomes (after ≥one year; median, 6.4 years) with a special interest in general developmental level, health-related quality of life, parental concerns due to epilepsy, impact on family, and social adaptation in children who underwent epilepsy surgery and in children who were not eligible for surgery.

METHODS

Eighty-five children (median age at intervention: 3.3 years, interquartile range [IQR]: 1.8-6.3 years) with TSC-related epilepsy had a presurgical investigation, and 34 of this group underwent epilepsy surgery. At follow-up (median age: 11.5 years, IQR: 7.8-15.5 years), we assessed seizure outcome, health-related quality of life, social adaptation, parental concerns due to epilepsy, and general developmental level based on established questionnaires and a standardized interview. Generalized linear models were performed for statistical evaluation.

RESULTS

At follow-up, 53% (18/34) of the operated patients were seizure free for ≥12 months and 30% (15/50) of the patients non-eligible for epilepsy surgery (p = 0.037). In the surgical group, developmental level was significantly higher in seizure-free patients, in comparison to non-seizure-free patients (p = 0.004); this was also observed in the non-surgical group, but less marked (p = 0.089). Furthermore, developmental level was significantly (p ≤ 0.001) related to quality of life, social adaptation, impact on family, and parental concerns. In both cohorts, parental concerns were less pronounced if children became seizure free (p < 0.001 and p = 0.018, respectively).

SIGNIFICANCE

In children with TSC-related epilepsy, quality of life, social adaptation, and impact on family were related to general developmental level, which in turn was significantly related to seizure freedom. Consequent epilepsy management aiming at seizure freedom, including presurgical evaluation and, if indicated, epilepsy surgery in a center specifically experienced with TSC-related epilepsy, is a worthwhile effort to improve quality of life in patients with TSC and their families.

Review of the treatment options for epilepsy in tuberous sclerosis complex: towards precision medicine

Tuberous sclerosis complex (TSC) is a rare genetic disorder caused by mutations in the TSC1 or TSC2 genes, which encode proteins that antagonise the mammalian isoform of the target of rapamycin complex 1 (mTORC1) - a key mediator of cell growth and metabolism. TSC is characterised by the development of benign tumours in multiple organs, together with neurological manifestations including epilepsy and TSC-associated neuropsychiatric disorders (TAND). Epilepsy occurs frequently and is associated with significant morbidity and mortality; however, the management is challenging due to the intractable nature of the seizures. Preventative epilepsy treatment is a key aim, especially as patients with epilepsy may be at a higher risk of developing severe cognitive and behavioural impairment. Vigabatrin given preventatively reduces the risk and severity of epilepsy although the benefits for TAND are inconclusive. These promising results could pave the way for evaluating other treatments in a preventative capacity, especially those that may address the underlying pathophysiology of TSC, including everolimus, cannabidiol and the ketogenic diet (KD). Everolimus is an mTOR inhibitor approved for the adjunctive treatment of refractory TSC-associated seizures that has demonstrated significant reductions in seizure frequency compared with placebo, improvements that were sustained after 2 years of treatment. Highly purified cannabidiol, recently approved in the US as Epidiolex® for TSC-associated seizures in patients ⩾1 years of age, and the KD, may also participate in the regulation of the mTOR pathway. This review focusses on the pivotal clinical evidence surrounding these potential targeted therapies that may form the foundation of precision medicine for TSC-associated epilepsy, as well as other current treatments including anti-seizure drugs, vagus nerve stimulation and surgery. New future therapies are also discussed, together with the potential for preventative treatment with targeted therapies. Due to advances in understanding the molecular genetics and pathophysiology, TSC represents a prototypic clinical syndrome for studying epileptogenesis and the impact of precision medicine.