Current management of tuberous sclerosis complex

Calvarial Thickening in Tuberous Sclerosis Complex

BACKGROUND

Tuberous sclerosis complex (TSC)-related skeletal abnormalities are understudied. Awareness of skull thickening in patients with TSC is important from the surgical standpoint because a thick skull might complicate craniotomy. This study aimed to discover if patients with TSC are generally prone to skull thickening by retrospectively investigating the frequency and characteristics of skull thickening in these patients.

METHODS

Patients with TSC ages 10 to 60 years who underwent magnetic resonance imaging in the neurosurgery, dermatology, or pediatrics clinic between 2010 and 2021 were identified. Two control groups were used for comparison: one with patients with unruptured intracranial aneurysms to serve as control without antiseizure medication exposure and one with non-TSC epilepsy as control with antiseizure medication exposure. In all patients, thickness of frontal, parietal, temporal, and occipital bones was measured at a fixed location of each bone on T2-weighted axial images.

RESULTS

Inclusion criteria were fulfilled by 29 patients. Frontal and temporal bones of the TSC group were significantly thicker than those of either control group. Skull thickening was significantly associated with intracerebral calcification, but not with age, sex, or antiseizure medication exposure. Focal skull thickening was associated with the presence of a subcortical calcification.

CONCLUSIONS

Patients with TSC have skull thickening, which is often linked to intracerebral calcification. The presence of skull thickening may require modification of surgical approach during craniotomy. Skull thickening and the underlying intracerebral calcification likely share a common precipitating factor given their relationship. Future studies are warranted to clarify the genetic underpinnings of this relationship and even broader skeletal abnormalities in TSC.

Neoadjuvant Therapy with Everolimus for Subependymal Giant Cell Astrocytoma: A Case Report

Direct surgical resection remains to be the standard treatment for tuberous sclerosis complex (TSC) with subependymal giant cell astrocytoma (SEGA). Medical therapy with everolimus (mammalian target of rapamycin inhibitor or mTOR) serves as a second-line treatment for patients with SEGA who are determined to be ineligible for surgical resection. Some recent studies have reported that neoadjuvant therapy for SEGA may be a useful, novel treatment. In this study, we herein present a case of SEGA and demonstrate the efficacy of preoperative everolimus therapy. We have also examined the utility and safety of neoadjuvant therapy for SEGA and investigated four previously reported cases of preoperative administration of mTOR inhibitors. In these cases, everolimus was administered preoperatively to shrink the tumor although the duration of treatment varied. Afterward, gross total tumor removal was conducted in all the cases. No postoperative complications were reported during the follow-up period. These findings indicate that neoadjuvant therapy with an mTOR inhibitor can be a potential treatment for SEGA. The findings of this present study also suggested that a short administration period of about 2 months may be sufficient to achieve preoperative tumor reduction.

Analysis of serum lipid parameters predicting lipid metabolic disorders in TSC-AML patients with treatment of mTOR inhibitors

WHAT IS KNOWN AND OBJECTIVE

Patients with tuberous sclerosis complex (TSC) demonstrate disrupted lipid homeostasis before and during treatment with mammalian target of rapamycin (mTOR) inhibitor. However, few previous reports focused on if the serum lipid status at baseline would influence lipid metabolic side-effects of mTOR inhibitors for TSC associated renal angiomyolipomas (TSC-AML). The present study was designed to evaluate the predictive function of serum lipid status at baseline for hyperlipidaemia by mTOR inhibitor treatment in TSC-AML patients.

METHODS

The clinical data of TSC-AML patients who took mTOR inhibitors in Department of Urology of Peking Union Medical College Hospital (PUMCH) from 1 January 2014 to 1 January 2021, were retrospectively analysed. The record of lipid parameters at baseline and the highest levels of total cholesterol (TC) and triglyceride (TG) after treatment at least ≥3 months were collected. The correlation of serum lipid parameters at baseline with incidence of hyperlipidaemia during mTOR inhibitor treatment was analysed. Receiver operating characteristic (ROC) curve analysis was conducted to evaluate the ability of the serum lipid parameters in predicting hyperlipidaemia.

RESULTS AND DISCUSSION

19 patients experienced hyperlipidaemia and 13 patients still had normal TC and TG levels during mTOR inhibitor treatment. The levels of high-density lipoprotein cholesterol (HDL-C) (0.98 ± 0.30 mmol/L vs. 1.23 ± 0.31 mmol/L, p = 0.030), low-density lipoprotein cholesterol (LDL-C) (2.47 ± 0.69 mmol/L vs. 1.95 ± 0.53 mmol/L, p = 0.029) and apolipoprotein B (ApoB) (0.82 ± 0.21 g/L vs. 0.65 ± 0.16 g/L, p = 0.019) are higher in the patients who experienced hyperlipidaemia during mTOR inhibition therapy. TC, TG, LDL-C, ApoB and high-sensitivity C-reactive protein (hsCRP) at baseline had positive correlation with TC after treatment; ApoB at baseline had positive correlation, while HDL-C and free fat acid (FFA) at baseline had negative correlation with TG after treatment. Therefore, ApoB concentration at baseline has statistically significant correlation with both TC (p < 0.001) and TG (p = 0.012) levels after mTOR inhibitor treatment. ROC curve and AUC revealed that ApoB with a cut-off value of 0.640g/L may be the best parameter for predicting hyperlipidaemia during mTOR inhibitor treatment in TSC-AML patients. The incidence rates of hyperlipidaemia were 27.3% and 76.2% among the patients with ApoB level ≤0.640 g/L and >0.640 g/L respectively.

WHAT IS NEW AND CONCLUSION

Some baseline serum lipid parameters could be used for predicting incidence of hyperlipidaemia during mTOR inhibition therapy in TSC-AML patients, and ApoB with 0.640 g/L as a cut-off value may be a potentially optimal indicator, which could help for diagnosis and treatment decision-making.

The UK guidelines for management and surveillance of Tuberous Sclerosis Complex

BACKGROUND

The severity of Tuberous Sclerosis Complex (TSC) can vary among affected individuals. Complications of TSC can be life threatening, with significant impact on patients' quality of life. Management may vary dependent on treating physician, local and national policies, and funding. There are no current UK guidelines. We conducted a Delphi consensus process to reach agreed guidance for the management of patients with TSC in the UK.

METHODS

We performed a literature search and reviewed the 2012/13 international guideline for TSC management. Based on these, a Delphi questionnaire was formed. We invited 86 clinicians and medical researchers to complete an online survey in two rounds. All the people surveyed were based in the UK. Clinicians were identified through the regional TSC clinics, and researchers were identified through publications. In round one, 55 questions were asked. In round two, 18 questions were asked in order to obtain consensus on the outstanding points that had been contentious in round one. The data was analysed by a core committee and subcommittees, which consisted of UK experts in different aspects of TSC. The Tuberous Sclerosis Association was consulted.

RESULTS

About 51 TSC experts took part in this survey. Two rounds were required to achieve consensus. The responders were neurologists, nephrologists, psychiatrist, psychologists, oncologists, general paediatricians, dermatologist, urologists, radiologists, clinical geneticists, neurosurgeons, respiratory and neurodisability clinicians.

CONCLUSIONS

These new UK guidelines for the management and surveillance of TSC patients provide consensus guidance for delivery of best clinical care to individuals with TSC in the UK.

Economic burden, work, and school productivity in individuals with tuberous sclerosis and their families

AIMS

Tuberous sclerosis complex (TSC) is a multi-organ autosomal-dominant, genetic disorder with incomplete penetrance. The multiple manifestations of TSC and impacts to numerous organ systems represent significant disease, healthcare, and treatment burden. The economic and employment burden of the disease on individuals and their families is poorly understood. This study assessed the cost of illness and work and school productivity burden associated with TSC in a cross-sectional web-survey sample.

MATERIALS AND METHODS

Eligible TSC individuals and caregivers were invited through the Tuberous Sclerosis Alliance advocacy group to complete a web-based survey about illness characteristics, treatment, disease burden, direct and indirect healthcare costs, work and school impairment.

RESULTS

Data from 609 TSC adults or caregiver respondents with no cognitive impairments were analyzed. TSC adults (>18 years of age) had significantly higher direct out-of-pocket costs for ER visits, expenses for medical tests and procedures, alternative treatments, medications and lifetime cost of surgeries compared to TSC pediatric individuals. Both TSC adults and TSC caregivers reported work and school absenteeism and presenteeism; however, adults reported significantly higher absenteeism and presenteeism and overall activity impairment due to TSC, as might be expected, compared to TSC caregivers. TSC adults had significantly higher absenteeism and presenteeism rates compared to adults with moderate-to-severe plaque psoriasis and muscular sclerosis.

CONCLUSIONS

TSC results in considerable direct out-of-pocket medical costs and impairment to work productivity, especially for adults. Future studies should include the comparator group and examine direct cost burden in the US using electronic medical records and insurance databases.

Expert Opinion on the Management of Lennox-Gastaut Syndrome: Treatment Algorithms and Practical Considerations

Lennox–Gastaut syndrome (LGS) is a severe epileptic and developmental encephalopathy that is associated with a high rate of morbidity and mortality. It is characterized by multiple seizure types, abnormal electroencephalographic features, and intellectual disability. Although intellectual disability and associated behavioral problems are characteristic of LGS, they are not necessarily present at its outset and are therefore not part of its diagnostic criteria. LGS is typically treated with a variety of pharmacological and non-pharmacological therapies, often in combination. Management and treatment decisions can be challenging, due to the multiple seizure types and comorbidities associated with the condition. A panel of five epileptologists met to discuss consensus recommendations for LGS management, based on the latest available evidence from literature review and clinical experience. Treatment algorithms were formulated. Current evidence favors the continued use of sodium valproate (VPA) as the first-line treatment for patients with newly diagnosed de novo LGS. If VPA is ineffective alone, evidence supports lamotrigine, or subsequently rufinamide, as adjunctive therapy. If seizure control remains inadequate, the choice of next adjunctive antiepileptic drug (AED) should be discussed with the patient/parent/caregiver/clinical team, as current evidence is limited. Non-pharmacological therapies, including resective surgery, the ketogenic diet, vagus nerve stimulation, and callosotomy, should be considered for use alongside AED therapy from the outset of treatment. For patients with LGS that has evolved from another type of epilepsy who are already being treated with an AED other than VPA, VPA therapy should be considered if not trialed previously. Thereafter, the approach for a de novo patient should be followed. Where possible, no more than two AEDs should be used concomitantly. Patients with established LGS should undergo review by a neurologist specialized in epilepsy on at least an annual basis, including a thorough reassessment of their diagnosis and treatment plan. Clinicians should always be vigilant to the possibility of treatable etiologies and alert to the possibility that a patient’s diagnosis may change, since the seizure types and electroencephalographic features that characterize LGS evolve over time. To date, available treatments are unlikely to lead to seizure remission in the majority of patients and therefore the primary focus of treatment should always be optimization of learning, behavioral management, and overall quality of life.

Clinical patterns and outcomes of status epilepticus in patients with tuberous sclerosis complex

INTRODUCTION

Refractory epilepsy is a common clinical manifestation in patients with tuberous sclerosis complex (TSC), which can be complicated by many life-threatening conditions, such as status epilepticus (SE). However, very few reports mention the patterns and semiology of SE in those patients.

OBJECTIVE

To study the clinical characteristics and outcomes of SE in TSC patients.

MATERIALS AND METHODS

This observational, prospective study was carried out on 36 Egyptian children with definite TSC. Clinical history, general and neurological examination and psychometric evaluation by standard questionnaires were used to explore characteristics of epileptic manifestations and clinical patterns of SE. All included patients were required to have long-term video electroencephalograms (EEGs) and brain MRI performed.

RESULTS

A total of 32 attacks of SE were recorded in 21 patients (58.3%) in our cohort during a follow-up period of 2.8±1.1 years; of those patients, 15 had convulsive status, 7 had non-convulsive SE, 6 had refractory/super-refractory SE and 14 patients had a history of infantile spasms (epileptic spasms). The duration of status ranged from 40 to 150 min (mean ± standard deviation: 90±15). Fourteen patients with SE had severe mental retardation, 9 had autistic spectrum disorder and 22 had severe epileptogenic EEG findings. Patients with SE had higher tuber numbers (mean: 9.6), 5 patients had subependymal giant cell astrocytomas and 2 patients had their SE after receiving everolimus.

CONCLUSIONS

The incidence of SE in our patient sample is high (>50%); severe mental retardation, autistic features, history of infantile spasm (epileptic spasms) and high tuber burden are risk factors for developing SE.

Recent Advances and Challenges of mTOR Inhibitors Use in the Treatment of Patients with Tuberous Sclerosis Complex

Tuberous sclerosis complex (TSC) is a genetic condition characterized by the presence of benign, noninvasive, and tumor-like lesions called hamartomas that can affect multiple organ systems and are responsible for the clinical features of the disease. In the majority of cases, TSC results from mutations in the TSC1 and TSC2 genes, leading to the overactivation of the mammalian target of rapamycin (mTOR) signalling pathway, which controls several cell functions, including cell growth, proliferation, and survival. The establishment of a connection between TSC and mTOR led to the clinical use of drugs known as mTOR inhibitors (like rapamycin, also known as sirolimus and everolimus), which are becoming an increasingly interesting tool in the management of TSC-associated features, such as subependymal giant cell astrocytomas, renal angiomyolipomas, and also epilepsy. However, the intrinsic characteristics of these drugs and their systemic effects in such a heterogeneous condition pose many challenges in clinical practice, so that some questions remain unanswered. This article provides an overview of the pharmacological aspects of mTOR inhibitors about the clinical trials leading to their approval in TSC-related conditions and exposes current challenges and future directions associated with this promising therapeutic line.

Long-term treatment of epilepsy with everolimus in tuberous sclerosis

OBJECTIVE

To evaluate the long-term benefit and safety of everolimus for the treatment of medically refractory epilepsy in patients with tuberous sclerosis complex (TSC).

METHODS

Everolimus was titrated over 4 weeks and continued an additional 8 weeks in a prospective, open-label, phase I/II clinical trial design. Participants demonstrating initial benefit continued treatment until study completion (48 months). The primary endpoint was percentage of patients with a ≥50% reduction in seizure frequency compared to baseline. Secondary endpoints assessed absolute seizure frequency, adverse events (AEs), behavior, and quality of life.

RESULTS

Of the 20 participants who completed the initial study phase, 18 continued extended treatment. Fourteen of 18 (78%) participants completed the study, all but 1 of whom reported ≥50% reduction in seizure frequency at 48 months. All participants reported at least 1 AE, the vast majority (94%) of which were graded mild or moderate severity. Improvements in behavior and quality of life were also observed, but failed to achieve statistical significance at 48 months.

CONCLUSIONS

Improved seizure control was maintained for 4 years in the majority of patients with TSC with medically refractory epilepsy treated with everolimus. Long-term treatment with everolimus is safe and well-tolerated in this population. Everolimus may be a therapeutic option for refractory epilepsy in TSC.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that for patients with TSC with medically refractory epilepsy everolimus improves seizure control.

PEComa: morphology and genetics of a complex tumor family

Perivascular epithelioid cell tumors, or PEComas, are mesenchymal neoplasms composed of histologically and immunohistochemically distinctive epithelioid or spindle cells, which are immunoreactive for both smooth muscle and melanocytic markers. The cells in PEComas are typically arranged around blood vessels and appear to form the vessel wall, often infiltrating the smooth muscle of small- to medium-sized vessels. Periluminal cells are usually epithelioid and the more peripheral cells are spindle shaped. The cells have small, round to oval nuclei, sometimes with focal nuclear atypia, and clear to eosinophilic cytoplasm, and no counterpart normal cell has been identified. The PEComa "family" now includes angiomyolipoma, pulmonary clear cell "sugar" tumor and lymphangioleiomyomatosis, primary extrapulmonary sugar tumor, clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres, abdominopelvic sarcoma of perivascular epithelioid cells, and other tumors with similar features at various sites that are simply termed PEComa. Some PEComas occur in patients with tuberous sclerosis complex and share the genetic abnormalities. There is a behavioral spectrum from benign to frankly malignant, and histologic criteria have been proposed for assessing malignant potential. The differential diagnosis can include carcinomas, smooth muscle tumors, other clear cell neoplasms, and adipocytic tumors. PEComas constitute a genetically diverse group that includes neoplasms harboring TFE3 gene rearrangements and those with TSC2 mutations, indicating alternative tumorigenic pathways. Recent advances in therapy of malignant PEComas relate to increased knowledge of specific genetic changes and their effects on metabolic pathways that are susceptible to specific interventions. We review PEComas, emphasizing the diagnostic spectrum and recent immunohistochemical and genetic findings.

Response of subependymal giant cell astrocytoma with spinal cord metastasis to everolimus

BACKGROUND

Brain subependymal giant cell astrocytomas (SEGAs) in patients with tuberous sclerosis have been reported to respond to everolimus.

METHODS

A 15-year-old male patient with intractable seizures and multiple SEGAs of the brain developed leptomeningeal enhancement and multiple metastatic, histologically confirmed SEGAs of the spinal cord. He received daily everolimus at a dose of 3 mg/m for 6 weeks, which was then increased to 6 mg/m.

RESULTS

Magnetic resonance image of the brain and spine showed significant reduction in the size of SEGAs after 6 weeks of treatment. The patient has remained free of progression for 24 months. Additional benefits included: excellent seizure control, decrease in the size of cardiac rhabdomyomas, and improved quality of life.

CONCLUSIONS

We describe a rare case of metastatic SEGA, which was successfully treated with everolimus.

Recommendations for the radiological diagnosis and follow-up of neuropathological abnormalities associated with tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is a genetic condition with multisystem involvement, characterized by the development of tumors and other abnormalities in organs such as the brain, retina, skin, heart, kidneys, and lungs. Most patients have neuropathological abnormalities such as cortical tubers, white matter radial migration lines, subependymal nodules, and subependymal giant cell astrocytomas (SEGAs). These lesions are associated with different neurological manifestations that are frequently associated with TSC. These manifestations consist of epilepsy, intellectual disability, and neurobehavioral and psychiatric problems, including autism spectrum disorder. Hydrocephalus may also develop in patients with SEGAs due to ventricular obstruction, when this usually slow-growing tumor reaches sufficient size. Surgery has been the classical approach to treat SEGAs, although this treatment is associated with substantial morbidity and does not completely prevent tumor recurrence. Recently, the mammalian target of rapamycin (mTOR) inhibitor, everolimus, has been approved by the Food and Drug Administration and the European Medicines Agency for the treatment of patients with SEGAs associated with TSC. However, the treatment of SEGAs with these agents requires the development of guidelines that establish a differential diagnosis between SENs and SEGAs, in which neuroradiological examinations play an essential role. With the aim of improving the neuroradiological diagnosis and follow-up of the neuropathological abnormalities associated with TSC, a group of experts in this field has reviewed different aspects related to these issues and put together, a series of statements and recommendations intended to provide guidance to specialists involved in the management of TSC.

Mechanisms regulating neuronal excitability and seizure development following mTOR pathway hyperactivation

The phosphatidylinositol-3-kinase/phosphatase and tensin homolog (PTEN)-mammalian target of rapamycin (mTOR) pathway regulates a variety of neuronal functions, including cell proliferation, survival, growth, and plasticity. Dysregulation of the pathway is implicated in the development of both genetic and acquired epilepsies. Indeed, several causal mutations have been identified in patients with epilepsy, the most prominent of these being mutations in PTEN and tuberous sclerosis complexes 1 and 2 (TSC1, TSC2). These genes act as negative regulators of mTOR signaling, and mutations lead to hyperactivation of the pathway. Animal models deleting PTEN, TSC1, and TSC2 consistently produce epilepsy phenotypes, demonstrating that increased mTOR signaling can provoke neuronal hyperexcitability. Given the broad range of changes induced by altered mTOR signaling, however, the mechanisms underlying seizure development in these animals remain uncertain. In transgenic mice, cell populations with hyperactive mTOR have many structural abnormalities that support recurrent circuit formation, including somatic and dendritic hypertrophy, aberrant basal dendrites, and enlargement of axon tracts. At the functional level, mTOR hyperactivation is commonly, but not always, associated with enhanced synaptic transmission and plasticity. Moreover, these populations of abnormal neurons can affect the larger network, inducing secondary changes that may explain paradoxical findings reported between cell and network functioning in different models or at different developmental time points. Here, we review the animal literature examining the link between mTOR hyperactivation and epileptogenesis, emphasizing the impact of enhanced mTOR signaling on neuronal form and function.

The ominous sequence in patients with tuberous sclerosis complex

BACKGROUND

The clinical phenotypes and their severity in patients with tuberous sclerosis complex can be quite variable and are sometimes never determined simply by the primary mutation. These make clinically selecting appropriate treatments and predicting disease outcome difficult. In this report, the prognostic ominous sequence was evaluated in association with clinical manifestations and gene mutations.

METHODS

The patients were classified by each renal lesion of angiomyolipomas and polycystic disease. The other clinical manifestations and outcomes of epilepsy, mental retardation, facial angiofibromas, subependymal giant cell astrocytoma, cortical tubers were reviewed and each gene mutations were analyzed in seven unrelated patients.

RESULTS

Two patients with multiple and large proliferative renal angiomyolipoma showed poor clinical outcome than the patients with other renal lesions. These patients presented with progressively proliferative facial angiofibroma, West syndrome, Lennox-Gastaut syndrome, severe mental retardation, subependymal giant cell astrocytoma and they were affected by TSC2 gene mutations.

CONCLUSION

The sequence of progressively proliferative renal angiomyolipoma, facial angiofibroma, West syndrome and TSC2 gene mutations might be prognostic ominous factors.

Association of oestrogen-containing contraceptives with pulmonary lymphangioleiomyomatosis in women with tuberous sclerosis complex--findings from a survey

OBJECTIVES About 30-40% of women with tuberous sclerosis complex (TSC) develop pulmonary lymphangioleiomyomatosis (LAM). Oestrogen seems to be involved in LAM pathogenesis and oestrogen-containing contraception should be avoided in women with known LAM. However, there is very little data on the use of contraceptives in TSC patients. METHODS We conducted a survey on the use of contraception and disease characteristics. The questionnaire was forwarded to all adult female TSC patients listed in the database of a German patient organisation. RESULTS Data from 39 such patients could be analysed. Of these, 15 were diagnosed with LAM. Twenty-five patients (65%) confirmed current or past use of oestrogen-containing contraceptives. We found a suggestive correlation between the history of oestrogen-containing contraception, and LAM (Odds ratio: 6.500; 95% confidence interval: 1.199-35.230). However, oestrogen use was not associated with LAM complications. CONCLUSIONS Based on our findings, oestrogen-containing contraceptives should be resorted to by these patients only with great caution, and avoided whenever possible.

Assisting a child with tuberous sclerosis complex (TSC): a qualitative deep analysis of parents' experience and caring needs

OBJECTIVE

This study was aimed to explore parents' experience of assisting children affected by tuberous sclerosis complex (TSC) with subependymal giant-cell astrocytoma (SEGA) manifestation, in order to understand their caring needs and expectation of support.

SETTING AND PROCEDURE

The study was designed according to the qualitative method of interpretative description and implied two sequential phases of data collection. The first phase was based on in-depth interviews with 18 Italian caregivers of children living with TSC. The second phase of the research was based on an online forum with 30 caregivers of children living with TSC.

PARTICIPANTS

48 Italian caregivers, assisting patients with TSC with SEGA manifestation have been involved in the study.

RESULTS

When a TSC diagnosis is made, the whole family is affected psychologically. TSC has a great impact on families' quality of life and on their ability to cope with the disease and support the child's ability to recover and reach an acceptable level of well-being. Caregivers report the experience of losing control and the feeling of loneliness and abandon from the healthcare system.

CONCLUSION AND PRACTICE IMPLICATIONS

Families of children affected by TSC need targeted psychosocial assistance in order to support patients and caregivers and facilitate their social integration.

Tuberous sclerosis complex surveillance and management: recommendations of the 2012 International Tuberous Sclerosis Complex Consensus Conference

BACKGROUND

Tuberous sclerosis complex is a genetic disorder affecting every organ system, but disease manifestations vary significantly among affected individuals. The diverse and varied presentations and progression can be life-threatening with significant impact on cost and quality of life. Current surveillance and management practices are highly variable among region and country, reflective of the fact that last consensus recommendations occurred in 1998 and an updated, comprehensive standard is lacking that incorporates the latest scientific evidence and current best clinical practices.

METHODS

The 2012 International Tuberous Sclerosis Complex Consensus Group, comprising 79 specialists from 14 countries, was organized into 12 separate subcommittees, each led by a clinician with advanced expertise in tuberous sclerosis complex and the relevant medical subspecialty. Each subcommittee focused on a specific disease area with important clinical management implications and was charged with formulating key clinical questions to address within its focus area, reviewing relevant literature, evaluating the strength of data, and providing a recommendation accordingly.

RESULTS

The updated consensus recommendations for clinical surveillance and management in tuberous sclerosis complex are summarized here. The recommendations are relevant to the entire lifespan of the patient, from infancy to adulthood, including both individuals where the diagnosis is newly made as well as individuals where the diagnosis already is established.

CONCLUSIONS

The 2012 International Tuberous Sclerosis Complex Consensus Recommendations provide an evidence-based, standardized approach for optimal clinical care provided for individuals with tuberous sclerosis complex.

Everolimus treatment of refractory epilepsy in tuberous sclerosis complex

OBJECTIVE

Epilepsy is a major manifestation of tuberous sclerosis complex (TSC). Everolimus is an mammalian target of rapamycin complex 1 inhibitor with demonstrated benefit in several aspects of TSC. We report the first prospective human clinical trial to directly assess whether everolimus will also benefit epilepsy in TSC patients.

METHODS

The effect of everolimus on seizure control was assessed using a prospective, multicenter, open-label, phase I/II clinical trial. Patients≥2 years of age with confirmed diagnosis of TSC and medically refractory epilepsy were treated for a total of 12 weeks. The primary endpoint was percentage of patients with a ≥50% reduction in seizure frequency over a 4-week period before and after treatment. Secondary endpoints assessed impact on electroencephalography (EEG), behavior, and quality of life.

RESULTS

Twenty-three patients were enrolled, and 20 patients were treated with everolimus. Seizure frequency was reduced by ≥50% in 12 of 20 subjects. Overall, seizures were reduced in 17 of the 20 by a median reduction of 73% (p<0.001). Seizure frequency was also reduced during 23-hour EEG monitoring (p=0.007). Significant reductions in seizure duration and improvement in parent-reported behavior and quality of life were also observed. There were 83 reported adverse events that were thought to be treatment-related, all of which were mild or moderate in severity.

INTERPRETATION

Seizure control improved in the majority of TSC patients with medically refractory epilepsy following treatment with everolimus. Everolimus demonstrated additional benefits on behavior and quality of life. Treatment was safe and well tolerated. Everolimus may be a therapeutic option for refractory epilepsy in this population.

Resource utilization in children with tuberous sclerosis complex and associated seizures: a retrospective chart review study

Seizures are a hallmark manifestation of tuberous sclerosis complex, yet data characterizing resource utilization are lacking. This retrospective chart review was performed to assess the economic burden of tuberous sclerosis complex with neurologic manifestations. Demographic and resource utilization data were collected for 95 patients for up to 5 years after tuberous sclerosis complex diagnosis. Mean age at diagnosis was 3.1 years, with complex partial and infantile spasms as the most common seizure types. In the first 5 years post-diagnosis, 83.2% required hospitalization, 30.5% underwent surgery, and the majority of patients (90.5%) underwent ≥3 testing procedures. In 79 patients with a full 5 years of data, hospitalizations, intensive care unit stays, diagnostic testing, and rehabilitation services decreased over the 5-year period. Resource utilization is cost-intensive in children with tuberous sclerosis complex and associated seizures during the first few years following diagnosis. Improving seizure control and reducing health care costs in this population remain unmet needs.

Unusual myoid, perivascular, and postradiation lesions, with emphasis on atypical vascular lesion, postradiation cutaneous angiosarcoma, myoepithelial tumors, myopericytoma, and perivascular epithelioid cell tumor

In recent years, a number of new soft tissue tumor entities have been described that occur in the skin only, or that also occur in other sites but form clinically and pathologically distinct subsets when arising in the skin and subcutaneous tissue. These include a variety of mesenchymal lineages and have variable malignant potential, although superficial malignant soft tissue tumors generally have a more favorable outcome than their more deeply located counterparts. This article reviews the clinical and pathologic features and differential diagnoses of atypical vascular lesion, postradiation cutaneous angiosarcoma, myoepithelioma, myopericytoma, and perivascular epithelioid cell tumor.

An epigenetic framework for neurodevelopmental disorders: from pathogenesis to potential therapy

Neurodevelopmental disorders (NDDs) are characterized by aberrant and delayed early-life development of the brain, leading to deficits in language, cognition, motor behaviour and other functional domains, often accompanied by somatic symptoms. Environmental factors like perinatal infection, malnutrition and trauma can increase the risk of the heterogeneous, multifactorial and polygenic disorders, autism and schizophrenia. Conversely, discrete genetic anomalies are involved in Down, Rett and Fragile X syndromes, tuberous sclerosis and neurofibromatosis, the less familiar Phelan-McDermid, Sotos, Kleefstra, Coffin-Lowry and "ATRX" syndromes, and the disorders of imprinting, Angelman and Prader-Willi syndromes. NDDs have been termed "synaptopathies" in reference to structural and functional disturbance of synaptic plasticity, several involve abnormal Ras-Kinase signalling ("rasopathies"), and many are characterized by disrupted cerebral connectivity and an imbalance between excitatory and inhibitory transmission. However, at a different level of integration, NDDs are accompanied by aberrant "epigenetic" regulation of processes critical for normal and orderly development of the brain. Epigenetics refers to potentially-heritable (by mitosis and/or meiosis) mechanisms controlling gene expression without changes in DNA sequence. In certain NDDs, prototypical epigenetic processes of DNA methylation and covalent histone marking are impacted. Conversely, others involve anomalies in chromatin-modelling, mRNA splicing/editing, mRNA translation, ribosome biogenesis and/or the regulatory actions of small nucleolar RNAs and micro-RNAs. Since epigenetic mechanisms are modifiable, this raises the hope of novel therapy, though questions remain concerning efficacy and safety. The above issues are critically surveyed in this review, which advocates a broad-based epigenetic framework for understanding and ultimately treating a diverse assemblage of NDDs ("epigenopathies") lying at the interface of genetic, developmental and environmental processes. This article is part of the Special Issue entitled 'Neurodevelopmental Disorders'.

mTOR Inhibitors in Tuberous Sclerosis Complex

Tuberous sclerosis complex (TSC) is a genetic multiple organ system disorder that is characterized by the development of tumor-like lesions (hamartomas) and neurodevelopmental disorders. Mutations in the TSC1 and TSC2 tumor suppressor genes occur in the majority of patients with TSC, resulting in hyperactivation of the mammalian target of rapamycin (mTOR) signaling pathway and subsequent abnormalities in numerous cell processes. As a result, mTOR inhibitors such as sirolimus and everolimus have the potential to provide targeted therapy for patients with TSC. Everolimus is the first mTOR inhibitor approved as a treatment option in the USA and in Europe for patients with subependymal giant-cell astrocytomas (SEGAs) associated with TSC. The clinical evidence to date supports the use of mTOR inhibitors in a variety of TSC-associated disease manifestations, including SEGAs, renal angiomyolipoma, skin manifestations, and epilepsy. Furthermore, ongoing clinical trials evaluating mTOR inhibitors in TSC are underway, and the results of these studies are expected to provide further evidence that will firmly establish their role in this setting. This article will discuss the role of the mTOR pathway in TSC and review the pharmacokinetics, pharmacodynamics, clinical efficacy, and tolerability of mTOR inhibitors, along with their current place in clinical practice.

Molecular therapies for tuberous sclerosis and neurofibromatosis

Neurofibromatosis type 1 (NF1) and tuberous sclerosis complex (TSC) are autosomal-dominant genetic disorders that result from dysregulation of the PI3K/AKT/mammalian target of rapamycin (mTOR) pathway. NF1 is caused by mutations in the NF1 gene on chromosome 17q11.2. Its protein product, neurofibromin, functions as a tumor suppressor and ultimately produces constitutive upregulation of mTOR. TSC is caused by mutations in either the TSC1 (chromosome 9q34) or TSC2 (chromosome 16p.13.3) genes. Their protein products, hamartin and tuberin, respectively, form a dimer that acts via the GAP protein Rheb (Ras homolog enhanced in brain) to directly inhibit mTOR, again resulting in upregulation. Specific inhibitors of mTOR are in clinical use, including sirolimus, everolimus, temsirolimus, and deforolimus. Everolimus has been shown to reduce the volume and appearance of subependymal giant cell astrocytomas (SEGA), facial angiofibromas, and renal angiomyolipomas associated with TSC, with a recent FDA approval for SEGA not suitable for surgical resection. This article reviews the use of mTOR inhibitors in these diseases, which have the potential to be a disease-modifying therapy in these and other conditions.

Primary care management of tuberous sclerosis complex in children

PURPOSE

To provide primary care providers with a general overview of the genetic disorder tuberous sclerosis complex (TSC). By understanding the disease mechanism for this genetic condition, providers can effectively care for TSC patients and properly educate families who are affected by TSC. The article also describes the multi-system clinical presentation of the disease to assist primary care providers with an early diagnosis.

DATA RESOURCES

Research articles and evidence-based guidelines found through MEDLINE and the World Wide Web.

CONCLUSIONS

Using various diagnostic tools and treatment options, providers can offer the multidisciplinary approach needed to manage this disease appropriately. New treatment options, such as rapamycin, may be the future drug of choice in treating TSC.

IMPLICATIONS FOR PRACTICE

By following evidence-based clinical practice guidelines, providers can hope to reduce TSC-related morbidity and mortality.

Vigabatrin for childhood partial-onset epilepsies

To determine vigabatrin's effectiveness and the prevalence of symptomatic visual impairment (i.e., impairment affecting the ability to perform everyday activities) associated with its therapy in pediatric epilepsy, we retrospectively reviewed medical records of 156 patients receiving vigabatrin at Cincinnati Children's Medical Center from 1998-2010. In addition to demographics and vigabatrin dosing information, data included seizure type/frequency at presentation and subsequent follow-up. Of 156 patients, we excluded 35 because their medical records were insufficient to permit verification of the exact duration or timing of vigabatrin treatment. To evaluate efficacy (n = 121/135), we used a 5-point scale (0-4) to compare seizure frequency at several time points. To evaluate visual impairment (n = 63), we reviewed serial ophthalmologic evaluations at baseline and during treatment for patients in whom they were clinically indicated. Mean age at treatment initiation was 1.8 years (range, 0.1-29.2 years). Treatment duration ranged from 0.7-101.0 months, with an estimated average daily dose of 79 mg/kg/day. Tuberous sclerosis complex was the commonest seizure etiology (83%). Partial-onset seizure, alone or with infantile spasms, was the commonest seizure type (84%). Seizure frequency decreased from 3.7 ± 0.6 S.D. at baseline to 1.8 ± 1.7 S.D. at 6 months (P < 0.001). Responses to vigabatrin did not differ by tuberous sclerosis complex or nontuberous sclerosis complex etiology, and were sustained for 5 years. Sixty-three patients (∼50% of all patients evaluated) underwent clinically indicated ophthalmologic assessments during the review period. In our clinical judgment, no cases of clinically relevant vigabatrin-associated visual impairment occurred. Vigabatrin was effective for refractory childhood partial-onset epilepsy, and was not associated with symptomatic vision loss.

Everolimus: in patients with subependymal giant cell astrocytoma associated with tuberous sclerosis complex

Everolimus is an orally administered inhibitor of the mammalian target of rapamycin (mTOR). Everolimus (starting dosage 3.0 mg/m(2)) was associated with a significant reduction in the volume of the largest subependymal giant cell astrocytoma (SEGA) in 28 patients aged ≥3 years with tuberous sclerosis complex (TSC) in a phase II trial (C2485). At 6 months, 32% of patients treated with everolimus had a ≥50% reduction in the volume of their largest SEGA lesion (assessed via an independent central radiology review); 75% had a ≥30% reduction. No patients developed new lesions. During the extension phase of this trial (median duration 34 months), the reduction in SEGA volume was maintained, with no everolimus recipient requiring surgery or other therapy for SEGA or hydrocephalus. In a phase III trial (EXIST-1) in 117 patients with SEGA associated with TSC, 35% of everolimus recipients (starting dosage 4.5 mg/m(2)) versus none of the placebo recipients (p < 0.0001) had an overall response (a reduction in the sum of all target SEGA volumes of ≥50% relative to baseline, nonworsening of non-target SEGA lesions, no new SEGA lesions, and no new/worsening hydrocephalus). Everolimus was generally well tolerated in patients with SEGA associated with TSC; most drug-related adverse reactions were mild to moderate in severity.

Everolimus: an mTOR inhibitor for the treatment of tuberous sclerosis

Tuberous sclerosis complex (TSC) is a devastating disease affecting virtually all organ systems of the body and is characterized by multiple hamartomas and neurodevelopmental disorders. The majority of patients with TSC have mutations in TSC1 or TSC2, resulting in constitutive activation of mTOR. Because the pathogenesis of the disease is mTOR hyperactivity, mTOR inhibitors have the potential to treat the underlying cause in TSC patients. Everolimus is the first mTOR inhibitor approved in the USA for the treatment of patients with subependymal giant-cell astrocytomas (SEGAs) associated with TSC. Evidence supports and ongoing studies are evaluating the role of mTOR inhibitors in the treatment of a wide spectrum of disease manifestations, including reduction in tumor volume (SEGAs, renal angiomyolipoma) and improvement in epilepsy, lung function and skin manifestations, including facial angiofibromas. In time, the use of mTOR inhibitors in patients with TSC will likely be very well established.

Burden of disease and unmet needs in tuberous sclerosis complex with neurological manifestations: systematic review

OBJECTIVES

Tuberous sclerosis complex (TSC) is a progressive genetic disorder characterized by pervasive benign tumor growth. We sought to assess the current understanding of burden of TSC-related neurological manifestations.

METHODS

We systematically searched MEDLINE- and EMBASE-indexed, English-language literature (5/2000-5/2010) and non-indexed materials.

RESULTS

In total, 119 articles were included, 115 on epidemiology and treatment. Recent prevalence estimates from Ireland and Taiwan report TSC in 1:14,000-25,000 individuals, below older estimates of 1:10,000. While neurological manifestations are common, treatment is largely unaddressed by guidelines and focuses on symptoms, with resection standard for subependymal giant cell astrocytomas (SEGAs) and common practice for refractory epilepsy. Antiepileptic drugs and mammalian target of rapamycin inhibitors safely, effectively minimize the need for surgery for severe epilepsy and SEGAs.

CONCLUSION

Morbidity and treatment burden of prevalent neurological manifestations is significant, suggesting substantial economic and humanistic burden; however, these areas are poorly studied, indicating total disease burden is unknown. Future research should assess quality of life, caregiver burden, and costs.

Neurosurgical treatment of tuberous sclerosis complex lesions

BACKGROUND

Tuberous sclerosis complex (TSC) is an autosomal dominantly inherited syndrome. Renal disease is the main cause of death. Brain disorders are the origin of more frequent and severe problems, such as tumors, epilepsy, and mental retardation. Participation of neurosurgeons in the study and especially in the treatment of TSC patients is often required.

MATERIALS AND METHODS

Two types of pathological conditions mainly require neurosurgical interventions in TSC: subependymal giant cell astrocytomas (SGCA) and cortical tubers. SGCA are located in the cerebral region close to the foramina of Monroe, uni- or bilaterally, and originate in hamartomas that can grow slowly as well as rapidly, even suddenly, especially in cases with intratumoral cyst, causing increased intracranial pressure (ICP) with severe risk for visual loss and life. Neurosurgeons have to participate in the follow-up of the patients as soon as the risk of ICP exists to remove the tumor when the criteria of SGCA growth are present. The other intracranial lesions that require neurosurgical intervention by are the cortical tubers.

CONCLUSION

These dysplastic lesions are associated with TSC in almost the 100% of affected persons and are the cause of epilepsy in most patients. The seizures can be resistant to antiepileptic medication in many cases in which a tuber is identified as the origin of the focal seizures after functional studies, such as EEG, MR, PET, etc. In these cases, only surgical removal of the tuber and the perituberal epileptogenic foci can cure the epilepsy. Large tubers are more epileptogenic than smaller ones.

Everolimus tablets for patients with subependymal giant cell astrocytoma

INTRODUCTION

Better understanding of aberrantly active molecular pathways in tumors offers potential to develop more specific and less toxic therapies. Abnormal mammalian target of rapamycin (mTOR) complex signaling and defects in TSC1 and TSC2 have been associated with the development of subependymal giant cell astrocytomas (SEGAs) in tuberous sclerosis complex (TSC) patients. Recently, mTOR inhibitors such as everolimus have shown encouraging benefit for patients with SEGAs.

AREAS COVERED

The authors discuss a molecular genetic pathway linked with TSC, specifically the role of two proteins whose functional absence is responsible for most SEGA tumors that arise in TSC patients. The authors also examine the rationale for targeted agents against this pathway therapeutically and describe the clinical evidence underlying the FDA approval of everolimus for patients with inoperable SEGAs.

EXPERT OPINION

Everolimus (Afinitor) selectively targets a molecular defect of SEGAs in TSC patients. Although surgery is effective, most SEGAs recur. An agent that inhibits an underlying molecular abnormality represents a particularly attractive therapeutic option for patients with inoperable or recurrent tumors. Studies are also underway to assess everolimus in treating other sequelae of TSC, and other gliomas. Finally, additional research aimed at better understanding aberrant cell signaling pathways may lead to the development of more effective therapeutics.

Targeting mTOR complex 1 to treat neurological and psychiatric manifestations of tuberous sclerosis complex

While tuberous sclerosis complex is a genetic disorder with multiorgan involvement, it is the cerebral lesions and abnormal brain function that are responsible for the highest morbidity in affected individuals and for negatively impacting overall quality of life. Identification and effective treatment of the resultant neurological and psychiatric symptoms can be challenging, and evidence-based management techniques are often lacking to help the clinician provide optimal care for these patients. This article identifies the most significant neurological and psychiatric disorders associated with tuberous sclerosis complex and their current management, as well as exploring recent advances in the use of mTOR complex 1 inhibitors, such as sirolimus or everolimus, to treat these disorders.

Everolimus for subependymal giant-cell astrocytomas in tuberous sclerosis

BACKGROUND

Neurosurgical resection is the standard treatment for subependymal giant-cell astrocytomas in patients with the tuberous sclerosis complex. An alternative may be the use of everolimus, which inhibits the mammalian target of rapamycin, a protein regulated by gene products involved in the tuberous sclerosis complex.

METHODS

Patients 3 years of age or older with serial growth of subependymal giant-cell astrocytomas were eligible for this open-label study. The primary efficacy end point was the change in volume of subependymal giant-cell astrocytomas between baseline and 6 months. We gave everolimus orally, at a dose of 3.0 mg per square meter of body-surface area, to achieve a trough concentration of 5 to 15 ng per milliliter.

RESULTS

We enrolled 28 patients. Everolimus therapy was associated with a clinically meaningful reduction in volume of the primary subependymal giant-cell astrocytoma, as assessed on independent central review (P<0.001 for baseline vs. 6 months), with a reduction of at least 30% in 21 patients (75%) and at least 50% in 9 patients (32%). Marked reductions were seen within 3 months and were sustained. There were no new lesions, worsening hydrocephalus, evidence of increased intracranial pressure, or necessity for surgical resection or other therapy for subependymal giant-cell astrocytoma. Of the 16 patients for whom 24-hour video electroencephalography data were available, seizure frequency for the 6-month study period (vs. the previous 6-month period) decreased in 9, did not change in 6, and increased in 1 (median change, -1 seizure; P=0.02). The mean (±SD) score on the validated Quality-of-Life in Childhood Epilepsy questionnaire (on which scores can range from 0 to 100, with higher scores indicating a better quality of life) was improved at 3 months (63.4±12.4) and 6 months (62.1±14.2) over the baseline score (57.8±14.0). Single cases of grade 3 treatment-related sinusitis, pneumonia, viral bronchitis, tooth infection, stomatitis, and leukopenia were reported.

CONCLUSIONS

Everolimus therapy was associated with marked reduction in the volume of subependymal giant-cell astrocytomas and seizure frequency and may be a potential alternative to neurosurgical resection in some cases, though long-term studies are needed. (Funded by Novartis; ClinicalTrials.gov number, NCT00411619.).