The pathogenesis and imaging of the tuberous sclerosis complex

Incidence and Characteristics of Cerebellar Atrophy/Volume Loss in Children with Confirmed Diagnosis of Tuberous Sclerosis Complex

Objectives: The goal of our study was to determine the incidence of cerebellar atrophy, assess the imaging findings in the posterior fossa and determine the incidence of hippocampal sclerosis in a cohort of pediatric patients with confirmed tuberous sclerosis complex (TSC). Material and methods: MRI studies of 98 TSC pediatric patients (mean age 7.67 years) were evaluated for cerebellar atrophy, cerebral/cerebellar tubers, white matter lesions, subependymal nodules, subependymal giant cell astrocytomas, ventriculomegaly, and hippocampal sclerosis. Clinical charts were revisited for clinical symptoms suggesting cerebellar involvement, for seizures and treatment for seizures, behavioral disorders and autism. Results: Cerebral tubers were present in 97/98 cases. In total, 97/98 had subependymal nodules, 15/98 had SEGA, 8/98 had ventriculomegaly and 4/98 had hippocampal sclerosis. Cerebellar tubers were found in 8/98 patients (8.2%), whereas cerebellar atrophy was described in 38/98 cases (38.8%). In 37/38 patients, cerebellar volume loss was mild and diffuse, and only one case presented with left hemi-atrophy. Briefly, 32/38 presented with seizures and were treated with anti-seizure drugs. In total, 8/38 (21%) presented with behavioral disorders, 10/38 had autism and 2/38 presented with seizures and behavioral disorders and autism. Conclusions: Several studies have demonstrated cerebellar involvement in patients with TSC. Cerebellar tubers differ in shape compared with cerebral tubers and are associated with cerebellar volume loss. Cerebellar atrophy may be focal and diffuse and one of the primary cerebellar manifestations of TSC, especially if a TSC2 mutation is present. Cerebellar degeneration may, however, also be secondary/acquired due to cellular damage resulting from seizure activity, the effects of anti-seizure drugs and anoxic-ischemic injury from severe seizure activity/status epilepticus. Further, prospective studies are required to identify and establish the pathogenic mechanism of cerebellar atrophy in patients with TSC.

Early Diagnosis of Tuberous Sclerosis Complex: Prenatal Diagnosis

BACKGROUND AND PURPOSE

Strong emphasis has been placed recently on early (4 postnatal months) detection of tuberous sclerosis complex and the introduction of antiepileptic treatment before seizure onset. This objective can be achieved prenatally: Cardiac rhabdomyomas and the major diagnostic tuberous sclerosis complex sign are detected during fetal ultrasound, and prenatal MR imaging allows detection of cerebral major manifestations: cortical tubers, subependymal nodules, and subependymal giant cell astrocytomas.

MATERIALS AND METHODS

We retrospectively reviewed 50 fetuses with ultrasound-detected cardiac tumors at 19-36 gestational weeks (median, 31 weeks). MR imaging with the use of 1.5T scanners was performed at 24-37 gestational weeks (median, 34 weeks).

RESULTS

In 11 fetuses (22%), cardiac tumors remained the only criterion. In remaining 39 fetuses (78%), MR imaging revealed a prenatal diagnosis of tuberous sclerosis complex, having shown an additional 1-3 major criteria: subependymal nodules in all cases (39/39 = 100.0%), subependymal giant cell astrocytomas in 6 (6/39 = 15.4%), and cortical tubers in 24 (24/39 = 61.5%). Radial migration lines and cerebellar tuber, not published so far, were shown in 1 case each.

CONCLUSIONS

A schedule of proper care of children with tuberous sclerosis complex can be established during the perinatal period due to education of women to report for mandatory ultrasound examinations during pregnancy, the good quality of ultrasound, and referral to MR imaging if a cardiac tumor is depicted on ultrasound. Gynecologists and pediatric cardiologists performing fetal ultrasound and radiologists performing prenatal MR imaging are a key to early diagnosis of tuberous sclerosis complex in many cases.

Morphological Features of Language Regions in Individuals with Tuberous Sclerosis Complex

A significant number of individuals with tuberous sclerosis complex (TSC) exhibit language difficulties. Here, we examined the language-related brain morphometry in 59 participants (7 participants with TSC and comorbid autism spectrum disorder (ASD) (TSC + ASD), 13 with TSC but no ASD (TSC-ASD), 10 with ASD-only (ASD), and 29 typically developing (TD) controls). A hemispheric asymmetry was noted in surface area and gray matter volume of several cortical language areas in TD, ASD, and TSC-ASD groups, but not in TSC + ASD group. TSC + ASD group demonstrated increased cortical thickness and curvature values in multiple language regions for both hemispheres, compared to other groups. After controlling for tuber load in the TSC groups, within-group differences stayed the same but the differences between TSC-ASD and TSC + ASD were no longer statistically significant. These preliminary findings suggest that comorbid ASD in TSC as well as tuber load in TSC is associated with changes in the morphometry of language regions. Future studies with larger sample sizes will be needed to confirm these findings.

Extension of microglial activation is associated with epilepsy and cognitive dysfunction in Tuberous sclerosis complex: A TSPO-PET study

BACKGROUND AND OBJECTIVES

Neuroinflammation contributes to the severity of various neurological disorders, including epilepsy. Tuberous sclerosis complex (TSC) is a condition that results in the overactivation of the mammalian target of rapamycin (mTOR) pathway, which has been linked to the activation of microglia responsible for neuroinflammation. To clarify the involvement of neuroinflammation in the neuropathophysiology of TSC, we performed a positron emission tomography (PET) study using the translocator protein (TSPO) radioligand, [¹¹C] DPA713, and investigated microglial activation in relation to neurological manifestations, especially epilepsy and cognitive function.

METHODS

This cross-sectional study included 18 patients with TSC (6 in the no-seizure group, 6 in the refractory seizure group, and 6 in the mTOR-inhibitor [mTOR-i] group). All participants underwent [¹¹C] DPA713-PET. PET results were superimposed with a 3D T2-weighted fluid-attenuated inversion-recovery (FLAIR) and T1-weighted image (T1WI) to evaluate the location of cortical tubers. Microglial activation was assessed using the standardized uptake value ratio (SUVr) of DPA713 binding. The volume ratio of the DPA713-positive area to the intracranial volume (volume ratio of DPA713/ICV) was calculated to evaluate the extent of microglial activation. A correlation analysis was performed to examine the relationship between volume ratio of DPA713/ICV and severity of epilepsy and cognitive function.

RESULTS

Most cortical tubers with hyperintensity on FLAIR and hypo- or isointensity on T1WI showed microglial activation. The extent of microglial activation was significantly greater in the refractory seizure group than in the no-seizure or mTOR-i groups (p < 0.001). The extent of microglial activation in subjects without mTOR-i treatment correlated positively with epilepsy severity (r = 0.822, P = 0.001) and negatively with cognitive function (r = -0.846, p = 0.001), but these correlations were not present in the mTOR-i group (r = 0.232, P = 0.658, r = 0.371, P = 0.469, respectively).

CONCLUSION

Neuroinflammation is associated with the severity of epilepsy and cognitive dysfunction in brains with TSC. mTOR-i may suppress the extent of neuroinflammation in TSC. Investigating the spread of microglial activation using TSPO-PET in these patients may help to predict the progression of neuropathy by assessing the degree of neuroinflammation and therefore be useful for determining how aggressive the treatment should be and in assessing the effectiveness of such treatment in patients with TSC.

Clinical profile of tuberous sclerosis complex patients with and without epilepsy: a need for awareness for early diagnosis

BACKGROUND

Tuberous sclerosis complex (TSC) is a multisystemic disorder. Its clinical features manifest differently in several organs, prompting the need for better knowledge.

OBJECTIVE

The goal of the present study is to evaluate the neurological findings of TSC, such as cerebral lesions and epilepsy, and to raise awareness of non-neurological findings that could contribute to an earlier diagnosis and treatment.

METHODS

This was a natural history study of patients with a definitive diagnosis of TSC who were referred to a specialized outpatient clinic and followed-up for 2 years with clinical and radiological exams.

RESULTS

A total of 130 TSC patients (59 males [45.4%], mean age 20.4 years old [1 to 56 years old]); 107 patients (82.3%) were diagnosed with epilepsy. Seizures predominantly began at < 1 year old (72.8%); focal seizures predominated (86.9%); epileptic spasms occurred in 34.5% of patients, and refractory epilepsy was present in 55.1%. Neuropsychiatric disorders, cortical tubers and cerebellar tubers were significantly more frequent in the epilepsy group. Moreover, rhabdomyomas were significantly more frequent in the epilepsy group (p = 0.044), while lymphangioleiomyomatosis was significantly less frequent in the epilepsy group (p = 0.009). Other non-neurological findings did not differ significantly between the groups with and without epilepsy.

CONCLUSIONS

The present study of TSC patients demonstrated the predominantly neurological involvement and significantly higher proportion of TSC-associated neuropsychiatric disorders in the epilepsy group. Higher proportions of cortical and cerebellar tubers may be a risk factor for epilepsy and neurodevelopmental disorders.

Cancer and Radiosensitivity Syndromes: Is Impaired Nuclear ATM Kinase Activity the Primum Movens?

There are a number of genetic syndromes associated with both high cancer risk and clinical radiosensitivity. However, the link between these two notions remains unknown. Particularly, some cancer syndromes are caused by mutations in genes involved in DNA damage signaling and repair. How are the DNA sequence errors propagated and amplified to cause cell transformation? Conversely, some cancer syndromes are caused by mutations in genes involved in cell cycle checkpoint control. How is misrepaired DNA damage produced? Lastly, certain genes, considered as tumor suppressors, are not involved in DNA damage signaling and repair or in cell cycle checkpoint control. The mechanistic model based on radiation-induced nucleoshuttling of the ATM kinase (RIANS), a major actor of the response to ionizing radiation, may help in providing a unified explanation of the link between cancer proneness and radiosensitivity. In the frame of this model, a given protein may ensure its own specific function but may also play additional biological role(s) as an ATM phosphorylation substrate in cytoplasm. It appears that the mutated proteins that cause the major cancer and radiosensitivity syndromes are all ATM phosphorylation substrates, and they generally localize in the cytoplasm when mutated. The relevance of the RIANS model is discussed by considering different categories of the cancer syndromes.

Tuberöse-Sklerose-Komplex

CLINICAL BACKGROUND

Tuberous sclerosis complex (TSC) is a phakomatosis and is a tumor predisposition syndrome. As a genetic multisystem disease, patients present with a broad range of changes in the brain, heart, skin, kidneys, and lungs.

OBJECTIVES

Which imaging modalities are required to monitor TSC patients according to current international recommendations?

MATERIALS AND METHODS

Common findings in TSC are cortical tubers, subependymal nodules, and giant cell astrocytomas in the central nervous system (CNS), rhabdomyomas in the heart, and cysts and angiomyolipomas in the kidneys. Magnetic resonance imaging (MRI) of the brain and kidneys and abdominal ultrasound are the imaging modalities of choice, due to the very good soft tissue contrast and lack of X‑ray radiation.

RESULTS

Using standard and functional MRI sequences in a multimodal approach, the type, malignancy, size, and morphology of changes in TSC can be reliably determined. Abdominal ultrasound using high-resolution transducers can be used to rapidly and reliably detect even the smallest changes in the kidneys.

CONCLUSION

Regular follow-up of patients with TSC using MRI and ultrasound is necessary for early detection of complications, for planning individualized therapy, and for optimal lifelong care.

Association of Early MRI Characteristics With Subsequent Epilepsy and Neurodevelopmental Outcomes in Children With Tuberous Sclerosis Complex

BACKGROUND AND OBJECTIVE

Multiple factors have been found to contribute to the high risk of epilepsy in infants with Tuberous Sclerosis Complex (TSC), including evolution of EEG abnormalities, TSC gene mutation and MRI characteristics. The aim of the present prospective multi-center study was to: 1) identify early MRI biomarkers of epilepsy in infants with TSC aged < 6 months and before seizure onset, and 2) associate these MRI biomarkers with neurodevelopmental outcomes at 2 years of age. The study was part of the EPISTOP project.

METHODS

We evaluated brain MRIs performed in infants with TSC younger than 6 months of age. We used harmonized MRI-protocols across centers and children were monitored closely with neuropsychological evaluation, and serial video EEG. MRI characteristics defined as tubers, radial migration lines, white matter abnormalities, cysts, calcifications, subependymal nodules (SEN) and subependymal giant cell astrocytoma (SEGA) were visually evaluated and lesions were detected semi-automatically. Lesion to brain volume ratios were calculated and associated with epilepsy and neurodevelopmental outcomes at two years.

RESULTS

Lesions were assessed on MRIs from 77 TSC infants, 62 MRIs were sufficient for volume analysis. The presence of tubers and higher tuber-brain ratios were associated with the development of clinical seizures, independently of TSC gene mutation and preventive treatment. Furthermore, higher tuber-brain ratios were associated with lower cognitive and motor development quotients at two years, independently of TSC gene mutation and presence of epilepsy.

DISCUSSION

In infants with TSC, there is a significant association between characteristic TSC lesions detected on early brain MRI and development of clinical seizures, as well as neurodevelopmental outcomes in the first two years of life. According to our results, early brain MRI findings may guide clinical care for young children with TSC.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that in infants with TSC, there is a significant association between characteristic TSC lesions on early brain MRI and the development of clinical seizures and neurodevelopmental outcomes in the first two years of life.

Neuropsychological and ASD phenotypes in rare genetic syndromes: A critical review of the literature

OBJECTIVE

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by core deficits in social communication and restricted and repetitive behaviors and interests. Recent advances in clinical genetics have improved our understanding of genetic syndromes associated with ASD, which has helped clarify distinct etiologies of ASD and document syndrome-specific profiles of neurocognitive strengths and weaknesses. Pediatric neuropsychologists have the potential to be impactful members of the care team for children with genetic syndromes and their families.

METHOD

We provide a critical review of the current literature related to the neuropsychological profiles of children with four genetic syndromes associated with ASD, including Tuberous Sclerosis Complex (TSC), fragile X syndrome (FXS), 22q11.2 deletion syndrome, and Angelman syndrome. Recommendations for assessment, intervention, and future directions are provided.

RESULTS

There is vast heterogeneity in terms of the cognitive, language, and developmental abilities of these populations. The within- and across-syndrome variability characteristic of genetic syndromes should be carefully considered during clinical evaluations, including possible measurement limitations, presence of intellectual disability, and important qualitative differences in the ASD-phenotypes across groups.

CONCLUSIONS

Individuals with genetic disorders pose challenging diagnostic and assessment questions. Pediatric neuropsychologists with expertise in neurodevelopmental processes are well suited to address these questions and identify profiles of neurocognitive strengths and weaknesses, tailor individualized recommendations, and provide diagnostic clarification.

Tuberous Sclerosis: Current Update

Tuberous sclerosis complex (TSC) is a relatively rare autosomal dominant neurocutaneous disorder secondary to mutations in the TSC1 or TSC2 tumor suppressor genes. Although manifestation of the classic triad of seizures, intellectual disability, and facial angiofibromas may facilitate timely diagnosis of TSC, the multisystem features that may indicate TSC in the absence of these manifestations remain highly variable. In addition, patients with TSC are at risk of developing multiple benign and malignant tumors in various organ systems, resulting in increased morbidity and mortality. Thus, imaging plays a critical role in diagnosis, surveillance, and management of patients with TSC. It is crucial that radiologists be familiar with TSC and the various associated imaging features to avoid a delayed or incorrect diagnosis. Key manifestations include cortical dysplasias, subependymal nodules, subependymal giant cell astrocytomas, cardiac rhabdomyomas, lymphangioleiomyomatosis, and angiomyolipomas. Renal angiomyolipomas in particular can manifest with imaging features that mimic renal malignancy and pose a diagnostic dilemma. Other manifestations include dermatologic and ophthalmic manifestations, renal cysts, renal cell carcinomas, multifocal micronodular pneumocyte hyperplasia, splenic hamartomas, and other rare tumors such as perivascular epithelioid tumors. In addition to using imaging and clinical features to confirm the diagnosis, genetic testing can be performed. In this article, the molecular pathogenesis, clinical manifestations, and imaging features of TSC are reviewed. Current recommendations for management and surveillance of TSC are discussed as well. ^©RSNA, 2021.

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.

Sequential everolimus for angiomyolipoma associated with tuberous sclerosis complex: a prospective cohort study

Background

To evaluate the efficacy, safety and health economics of sequential everolimus in treating angiomyolipoma (AML) associated with tuberous sclerosis complex (TSC).

Methods

In this prospective cohort study, patients met the inclusion criteria received standard or sequential treatment according to their willingness. All patients received an initial dose of everolimus (10 mg oral, once a day) for 3 months. The standard treatment group maintained 10 mg QD for 12 months, while the sequential treatment group reduced the dose to 5 mg QD from the 4th month. The efficacy, serum everolimus concentration and safety were evaluated at 1, 3, 6, 9 and 12 months after treatment. The primary efficacy endpoint was the proportion of patients with confirmed angiomyolipoma response of at least a 50% reduction in the total volume of target AML relative to baseline.

Results

Between June 1, 2016 and June 1, 2017, a total of 53 patients were included. Twenty-three patients received standard treatment, 30 patients received sequential treatment. At 1, 3, 6, 9 and 12 months after treatment, the proportion of patients whose total target tumor volume decreased by ≥ 50% from baseline was 39.1% versus 36.7%, 43.5% versus 56.7%, 47.8% versus 50%, 47.8% versus 60% and 47.8% versus 23.3% respectively (P > 0.05 for all). The overall response rate of skin lesions in the two groups was 40.4%, and the response rates of skin lesions at different times were similar for two groups (P > 0.05 for all). Major adverse effects (AEs) included mouth ulceration, hypertriglyceridemia, hypercholesterolemia, menstrual disorders. There was no significant difference between the two groups in the incidence of AEs at 3 months after treatment. The incidence of overall and grade 3/4 AEs at 12 months after treatment were significantly lower in the sequential treatment group. The average direct cost of the two groups in 12 months was $15,466 and $11,120, respectively.

Conclusions

Compared to standard treatment, sequential treatment was equally effective, with a lower incidence of adverse events and a lower direct cost, suggesting that it may be an alternative treatment for AML associated with TSC.

All tubers are not created equal: Cerebellar tubers in a pediatric patient with tuberous sclerosis

Tuberous sclerosis complex (TSC) is a rare autosomal dominant disease characterized by multiple tumors throughout the body. Supratentorial hamartomas (or tubers), are a very common CNS feature of TSC. Cerebellar tubers are much less common in TSC. We present an interesting case of cerebellar tuber in a 14-year-old patient with TSC, highlighting clinical and diagnostic criteria for TSC and review the unique features of cerebellar tubers, differentiating these lesions from their more common supratentorial counterparts. This case serves as an educational tool to improve awareness of cerebellar tubers in patients with tuberous sclerosis.

Epilepsy, impaired functioning, and quality of life in patients with tuberous sclerosis complex

OBJECTIVE

To estimate health-related quality of life (HRQoL) in patients with tuberous sclerosis complex (TSC) and associated manifestations and to identify potential factors associated with HRQoL in this population of patients.

METHODS

We performed a retrospective chart review of adults with TSC who attended the outpatient clinic of the University Medical Center Utrecht in the Netherlands from 1990 to 2015 (N = 363; on average 33.6 years of follow-up). HRQoL data were assessed in 2012 using the Health Utility Index version 3 (HUI-3) questionnaire completed by patients or caregivers (N = 214 with HUI score and ≥1 TSC manifestation, including renal angiomyolipomas [rAMLs], subependymal giant cell astrocytoma [SEGA], or epilepsy).

RESULTS

Of 214 patients in the study sample, 171 had TSC-associated epilepsy (with or without rAML/SEGA), 37 had TSC and rAML (without epilepsy or SEGA), and 6 had other combinations of manifestations. The median HUI score for the 214 patients with ≥1 TSC manifestation was 0.51 (-0.371 to 1 scale, 1 = perfect health, 0 = death, <0 = worse than death). Among all components used to build the overall HUI score, the cognition component had the lowest score (mean = 0.47; 0-1 scale). Patients with TSC-epilepsy had significantly lower overall HUI than patients with TSC and rAML only (median HUI = 0.31 vs 0.95, P < .05), especially those who were in refractory state for prolonged periods of time (median HUI = -0.11 among patients with seizures during the entire duration of their follow-up time). In multivariate analyses, severe impairment of daily functioning was the strongest predictor of HRQoL decrement (adjusted HUI difference between patients with severe vs. no impairment = -0.55, P < .05).

SIGNIFICANCE

This study showed that TSC-related epilepsy is associated with lower HUI, especially for patients who have refractory seizures for prolonged periods of time. Early and effective interventions to control or reduce seizures and preserve patients' cognitive functions may help to improve patients' quality of life.

Treatment Patterns and Use of Resources in Patients With Tuberous Sclerosis Complex: Insights From the TOSCA Registry

Tuberous Sclerosis Complex (TSC) is a rare autosomal-dominant disorder caused by mutations in the TSC1 or TSC2 genes. Patients with TSC may suffer from a wide range of clinical manifestations; however, the burden of TSC and its impact on healthcare resources needed for its management remain unknown. Besides, the use of resources might vary across countries depending on the country-specific clinical practice. The aim of this paper is to describe the use of TSC-related resources and treatment patterns within the TOSCA registry. A total of 2,214 patients with TSC from 31 countries were enrolled and had a follow-up of up to 5 years. A search was conducted to identify the variables containing both medical and non-medical resource use information within TOSCA. This search was performed both at the level of the core project as well as at the level of the research projects on epilepsy, subependymal giant cell astrocytoma (SEGA), lymphangioleiomyomatosis (LAM), and renal angiomyolipoma (rAML) taking into account the timepoints of the study, age groups, and countries. Data from the quality of life (QoL) research project were analyzed by type of visit and age at enrollment. Treatments varied greatly depending on the clinical manifestation, timepoint in the study, and age groups. GAB Aergics were the most prescribed drugs for epilepsy, and mTOR inhibitors are dramatically replacing surgery in patients with SEGA, despite current recommendations proposing both treatment options. mTOR inhibitors are also becoming common treatments in rAML and LAM patients. Forty-two out of the 143 patients (29.4%) who participated in the QoL research project reported inpatient stays over the last year. Data from non-medical resource use showed the critical impact of TSC on job status and capacity. Disability allowances were more common in children than adults (51.1% vs 38.2%). Psychological counseling, social services and social worker services were needed by <15% of the patients, regardless of age. The long-term nature, together with the variability in its clinical manifestations, makes TSC a complex and resource-demanding disease. The present study shows a comprehensive picture of the resource use implications of TSC.

[CNS manifestations of neurocutaneous syndromes]

CLINICAL/METHODICAL ISSUE

Phakomatoses refer to a heterogeneous and inconsistently defined group of neurocutaneous disorders. Tuberous sclerosis, neurofibromatosis types 1 and 2, Sturge-Weber syndrome and von Hippel-Lindau disease are entities with typical findings in neuroimaging studies STANDARD RADIOLOGICAL METHODS: These findings are usually easily depicted on magnetic resonance imaging (MRI) studies, thus, making diagnosis easier.

Everolimus compliance and persistence among tuberous sclerosis complex patients with renal angiomyolipoma or subependymal giant cell astrocytoma

OBJECTIVE

Everolimus is the only FDA approved drug to treat renal angiomyolipoma or subependymal giant-cell astrocytoma (SEGA) in tuberous sclerosis complex (TSC). Potential differences exist between patients with commercial and Medicaid insurance on everolimus use; however, there is limited information from the real world. This study compared compliance and persistence of everolimus between commercial and Medicaid patients using US claims data.

METHODS

Patients with ≥1 claim of TSC with renal angiomyolipoma or SEGA were selected from the MarketScan commercial (1 January 2009-31 August 2016) and Medicaid (1 January 2009-30 June 2015) databases. Patients were followed from index date (the earliest date of TSC, renal angiomyolipoma or SEGA diagnosis) to death or end of data. Non-persistence, defined as ≥60 day gap without everolimus, and medication possession ratio (MPR) were assessed among the subset of patients with ≥1 year of follow-up from the first everolimus claim.

RESULTS

A total of 1497 TSC patients met the study criteria (896 renal angiomyolipoma only, 411 SEGA only and 190 both). Compared to Medicaid patients (N = 513), commercial patients (N = 984) had the same ages (22 years) but a shorter length of follow-up (38 vs. 48 months, p < .001). Medicaid and commercial patients had similar rates of being treated with everolimus (14.4% vs. 13.6%, p = .668), but it took Medicaid patients a longer time to start everolimus (871 vs. 704 days, p < .001). Although the non-persistence rate was not significantly different between commercial and Medicaid patients (42.5% vs. 35.1%, p = .561), the number of days from everolimus initiation to non-persistence was significantly lower for commercial patients (945 vs. 1132, p < .001). During the 1 year post everolimus initiation, commercial patients had a significantly higher MPR (0.81 vs. 0.74, p < .001) and higher percentage of patients with MPR ≥0.80 (67.8% vs. 58.1%, p < .001).

CONCLUSIONS

Among TSC patients with renal angiomyolipoma or SEGA and treated with everolimus, everolimus MPR was between 0.74 and 0.81. Medicaid patients had lower MPR than commercial patients but better persistence.

Dysplasia and overgrowth: magnetic resonance imaging of pediatric brain abnormalities secondary to alterations in the mechanistic target of rapamycin pathway

The current classification of malformations of cortical development is based on the type of disrupted embryological process (cell proliferation, migration, or cortical organization/post-migrational development) and the resulting morphological anomalous pattern of findings. An ideal classification would include knowledge of biological pathways. It has recently been demonstrated that alterations affecting the mechanistic target of rapamycin (mTOR) signaling pathway result in diverse abnormalities such as dysplastic megalencephaly, hemimegalencephaly, ganglioglioma, dysplastic cerebellar gangliocytoma, focal cortical dysplasia type IIb, and brain lesions associated with tuberous sclerosis. We review the neuroimaging findings in brain abnormalities related to alterations in the mTOR pathway, following the emerging trend from morphology towards genetics in the classification of malformations of cortical development. This approach improves the understanding of anomalous brain development and allows precise diagnosis and potentially targeted therapies that may regulate mTOR pathway function.

Radiobiological Characterization of Tuberous Sclerosis: a Delay in the Nucleo-Shuttling of ATM May Be Responsible for Radiosensitivity

The tuberous sclerosis complex (TSC) syndrome is associated with numerous cutaneous pathologies (notably on the face), epilepsy, intellectual disability and developmental retardation and, overall, high occurrence of benign tumors in several organs, like angiofibromas, giant cell astrocytomas, renal angiomyolipomas, and pulmonary lymphangioleiomyomatosis. TSC is caused by mutations of either of the hamartin or tuberin proteins that are mainly cytoplasmic. Some studies published in the 1980s reported that TSC is associated with radiosensitivity. However, its molecular basis in TSC cells is not documented enough. Here, we examined the functionality of the repair and signaling of radiation-induced DNA double-strand breaks (DSB) in fibroblasts derived from TSC patients. Quiescent TSC fibroblast cells elicited abnormally low rate of recognized DSB reflected by a low yield of nuclear foci formed by phosphorylated H2AX histones. Irradiated TSC cells also presented a delay in the nucleo-shuttling of the ATM kinase, potentially due to a specific binding of ATM to mutated TSC protein in cytoplasm. Lastly, TSC fibroblasts showed abnormally high MRE11 nuclease activity suggesting genomic instability. A combination of biphosphonates and statins complemented these impairments by facilitating the nucleoshuttling of ATM and increasing the yield of recognized DSB. Our results showed that TSC belongs to the group of syndromes associated with low but significant defect of DSB signaling and delay in the ATM nucleo-shuttling associated with radiosensitivity.

mTOR inhibitors in the pharmacologic management of tuberous sclerosis complex and their potential role in other rare neurodevelopmental disorders

Tuberous sclerosis complex (TSC) is a rare autosomal dominant genetic disorder that affects multiple organ systems throughout the body. Dysregulation of the mammalian target of rapamycin (mTOR) pathway is implicated in the disease pathology, and evidence exists to support the use of mTOR inhibitors in treatment. The mTOR pathway has also been investigated as a potential treatment target for several other rare diseases. TSC research has highlighted the value of pursuing targeted therapies based on underlying molecular pathophysiology. One goal of current research is to identify the role of mTOR inhibition in neurologic and developmental disorders apart from TSC. There is also particular interest in the potential role of mTOR inhibitors in preventing seizures, neurodevelopmental disabilities, renal tumors, cutaneous tumors, and other manifestations typically seen in TSC. It is foreseeable that use of mTOR inhibition to prevent long-term morbidity in TSC will become mainstream therapeutic practice. This review will provide an overview of the relationship between the mTOR pathway and TSC disease pathology, summarize the clinical evidence supporting the use of mTOR inhibitors for treatment of the various manifestations of TSC, and discuss the potential therapeutic role of mTOR inhibitors in several rare diseases.

Fetal and Postnatal Magnetic Resonance Imaging of Unilateral Cystic Renal Dysplasia in a Neonate with Tuberous Sclerosis

Tuberous sclerosis (TS) is an autosomal dominant condition associated with mutations in the TSC1 and/or TSC2 genes. Clinical manifestations are multisystemic, and they often include lesions in the brain, skin, heart, kidneys, and bones. TSC2 gene mutations can be seen concomitantly with autosomal dominant polycystic kidney disease gene mutations. We present a case of a fetus with prenatal diagnosis of TS that had unique asymmetrical distribution of renal cystic disease. We describe the extensive work up with both fetal and neonatal magnetic resonance imaging with correlating images of the unilateral polycystic renal disease in addition to typical TS brain findings.

Tuberous Sclerosis Complex Associated with Vascular Anomalies or Overgrowth

BACKGROUND

Dysregulation of the mammalian target of rapamycin pathway is the underlying pathogenic mechanism in tuberous sclerosis complex (TSC). Other syndromes caused by genetic alterations in this pathway frequently manifest as vascular anomalies or asymmetric overgrowth. Rarely, these features have been documented in TSC.

OBJECTIVE

To collate cases of TSC with vascular anomaly or overgrowth that have been published and to assemble additional recent cases, as this finding has been underreported.

METHODS

TSC cases from three pediatric dermatology referral centers on two continents were reviewed to identify individuals noted to have hemihypertrophy or vascular anomalies.

RESULTS

We report five additional cases of TSC associated with vascular anomalies or overgrowth that contribute to our understanding of some of the pathways and treatments involved in vascular anomalies.

CONCLUSION

Hemihypertrophy and vascular anomalies may be more frequent in the setting of TSC than previously appreciated. A common pathogenetic mechanism may tie these manifestations together.

Review of the Tuberous Sclerosis Renal Guidelines from the 2012 Consensus Conference: Current Data and Future Study

Renal-related disease is the most common cause of tuberous sclerosis complex (TSC)-related death in adults, and renal angiomyolipomas can lead to complications that include chronic kidney disease (CKD) and hemorrhage. International TSC guidelines recommend mammalian target of rapamycin (mTOR) inhibitors as first-line therapy for management of asymptomatic, growing angiomyolipomas >3 cm in diameter. This review discusses data regarding patient outcomes that were used to develop current guidelines for embolization of renal angiomyolipomas and presents recent data on 2 available mTOR inhibitors - sirolimus and everolimus - in the treatment of angiomyolipoma. TSC-associated renal angiomyolipomas can recur after embolization. Both sirolimus and everolimus have shown effectiveness in reduction of angiomyolipoma volume, with an acceptable safety profile that includes preservation of renal function with long-term therapy. The authors propose a hypothesis for mTORC1 haploinsufficiency as an additional mechanism for CKD and propose that preventive therapy with mTOR inhibitors might have a role in reducing the number of angiomyolipoma-related deaths. Because mTOR inhibitors target the underlying pathophysiology of TSC, patients might benefit from treatment of multiple manifestations with one systemic therapy. Based on recent evidence, new guidelines should be considered that support the earlier initiation of mTOR inhibitor therapy for the management of renal angiomyolipomas to prevent future serious complications, rather than try to rescue patients after the complications have occurred.

Tuberous sclerosis complex: Imaging characteristics in 11 cases and review of the literature

Tuberous sclerosis complex (TSC) is an uncommon multiorgan disorder that may present many and different manifestations on imaging. Radiology plays an important role in diagnosis and management, and can substantially improve the clinical outcome of TSC. Therefore, a comprehensive understanding of this disease is essential for the radiologist. The manifestations of TSC on computer tomography (CT) and magnetic resonance (MR) images were analyzed. Eleven patients with a clinical diagnosis of TSC were retrospectively reviewed. Central nervous system lesions included subependymal nodules (SENs) (11/11), subependymal giant cell astrocytomas (SEGAs) (2/11), cortical and subcortical tuber lesions (5/11), and white matter lesions (4/11). Of the 6 patients with abdominal scans, there were 6 cases of renal angiomyolipomas (AMLs), and one case of hepatic AMLs. Of the 4 patients undergoing chest CT, lung lymhangioleiomyomatosis (LAM) (2/4), and multiple small sclerotic bone lesions (2/4) were observed. Different modalities show different sensitivity to the lesion. Analysis of images should be integrated with patients' history in order to diagnose TSC.

Cross-sectional Imaging Review of Tuberous Sclerosis

Tuberous sclerosis complex (TSC) is a multisystem, genetic disorder characterized by development of hamartomas in the brain, abdomen, and thorax. It results from a mutation in one of 2 tumor suppressor genes that activates the mammalian target of rapamycin pathway. This article discusses the origins of the disorder, the recently updated criteria for the diagnosis of TSC, and the cross-sectional imaging findings and recommendations for surveillance. Familiarity with the diverse radiological features facilitates diagnosis and helps in treatment planning and monitoring response to treatment of this multisystem disorder.

Pulmonary choriostoma in a case of tuberous sclerosis complex

A 52 years old lady was diagnosed to have Tuberous Sclerosis Complex (TSC) on the basis of 2 major and one minor criterion. She had family history of similar complaints in her sister and two sons. There was involvement of kidney in the form of angiomyolipoma, skin in the form of facial angiofibroma and teeth with a dental pit. She had an unusual lung involvement in the form of multiple small choristomas. Choristoma was diagnosed on transbronchial lung biopsy and was present in the form of disorganised striated muscles. The reported pulmonary manifestations of TCS i.e. lymphangioleiomyomatosis (LAM) and multifocal micronodular pneumocyte hyperplasia (MMPH) are types of hamartomas. Hamartomas and choristomas are both types of disorganized tissue. ‘Choristoma’of lung in TSC however is not reported. Clinopathological correlation of pulmonary hamartoma and choristoma, and treatment in TSC has been discussed.

CT and MR imaging for evaluation of cystic renal lesions and diseases

Cystic renal lesions are commonly encountered in abdominal imaging. Although most cystic renal lesions are benign simple cysts, complex renal cysts, infectious cystic renal disease, and multifocal cystic renal disease are also common phenomena. The Bosniak classification system provides a useful means of categorizing cystic renal lesions but places less emphasis on their underlying pathophysiology. Cystic renal diseases can be categorized as focal, multifocal, or infectious lesions. Diseases that manifest with focal lesions, such as cystic renal cell carcinoma, mixed epithelial and stromal tumor, and cystic nephroma, are often difficult to differentiate but have differing implications for follow-up after resection. Multifocal cystic renal lesions can be categorized as acquired or heritable. Acquired entities, such as glomerulocystic kidney disease, lithium-induced nephrotoxicity, acquired cystic kidney disease, multicystic dysplastic kidney, and localized cystic renal disease, often have distinct imaging and clinical features that allow definitive diagnosis. Heritable diseases, such as autosomal dominant polycystic kidney disease, von Hippel-Lindau disease, and tuberous sclerosis, are usually easily identified and have various implications for patient management. Infectious diseases have varied imaging appearances, and the possibility of infection must not be overlooked when assessing a cystic renal lesion. A thorough understanding of the spectrum of cystic renal disease will allow the radiologist to make a more specific diagnosis and provide the clinician with optimal recommendations for further diagnostic testing and follow-up imaging.

Everolimus for subependymal giant cell astrocytoma: 5-year final analysis

Objective

To analyze the cumulative efficacy and safety of everolimus in treating subependymal giant cell astrocytomas (SEGA) associated with tuberous sclerosis complex (TSC) from an open‐label phase II study (NCT00411619). Updated data became available from the conclusion of the extension phase and are presented in this ≥5‐year analysis.

Methods

Patients aged ≥ 3 years with a definite diagnosis of TSC and increasing SEGA lesion size (≥2 magnetic resonance imaging scans) received everolimus starting at 3mg/m²/day (titrated to target blood trough levels of 5–15ng/ml). The primary efficacy endpoint was reduction from baseline in primary SEGA volume.

Results

As of the study completion date (January 28, 2014), 22 of 28 (78.6%) initially enrolled patients finished the study per protocol. Median (range) duration of exposure to everolimus was 67.8 (4.7–83.2) months; 12 (52.2%) and 14 (60.9%) of 23 patients experienced SEGA volume reductions of ≥50% and ≥30% relative to baseline, respectively, after 60 months of treatment. The proportion of patients experiencing daily seizures was reduced from 7 of 26 (26.9%) patients at baseline to 2 of 18 (11.1%) patients at month 60. Most commonly reported adverse events (AEs) were upper respiratory tract infection and stomatitis of mostly grade 1 or 2 severity. No patient discontinued treatment due to AEs. The frequency of emergence of most AEs decreased over the course of the study.

Interpretation

Everolimus continues to demonstrate a sustained effect on SEGA tumor reduction over ≥5 years of treatment. Everolimus remained well‐tolerated, and no new safety concerns were noted. Ann Neurol 2015;78:929–938

Differentiation of Sporadic Versus Tuberous Sclerosis Complex-Associated Angiomyolipoma

OBJECTIVE

We review the imaging of renal angiomyolipomas, including differentiation of tuberous sclerosis complex (TSC)-associated and sporadic renal angiomyolipomas and other solid renal tumors. We also focus on radiologic interventions and molecular targeting of the TSC genetic pathway.

CONCLUSION

Imaging plays a central role in the diagnosis and management of renal angiomyolipomas. It provides essential information to make the best therapeutic decisions about the interventional and pharmacologic options to help prevent bleeding and preserve functional parenchyma.

Clinical management of tuberous sclerosis complex over the lifetime of a patient

Tuberous sclerosis complex (TSC) is a genetic disorder characterized by nonmalignant tumors (hamartomas) that can occur in various organ systems, including the brain, kidneys, lungs, skin, eyes, and heart. Clinical manifestations of TSC can occur at any age, thereby making the diagnosis difficult. No typical disease presentation is known, and the clinical presentation usually differs between pediatric and adult patients. Furthermore, variable penetrance of the genetic mutation causes a range of disease severity from very mild to severe, and affected individuals can go undetected for years because many of the clinical manifestations of TSC lack specificity. Once a diagnosis is made, TSC management strategies should be tailored to address the symptoms and risks most relevant to the age of the patient. Improved understanding of the genetic basis of TSC and of the central issue of mTOR overactivation has led to use of pharmacotherapies such as the mTOR inhibitors everolimus and sirolimus in the treatment of TSC disease. In Phase II and III studies, everolimus has demonstrated efficacy and safety in the treatment of both brain (subependymal giant cell astrocytoma) and renal (angiomyolipoma) manifestations associated with TSC. It is important to bear in mind that TSC is a lifelong condition, and for those diagnosed as children, a continuum of care will be needed as they transition from pediatric to adult health services. Clearly identifying the likely differences among diagnosis, monitoring, and management of pediatric and adult patients with TSC is an important step in enabling efficiencies to be maximized without compromising the care provided to patients.

Rapamycin and its analogues (rapalogs) for Tuberous Sclerosis Complex-associated tumors: a systematic review on non-randomized studies using meta-analysis

Background

Rapamycin has gained significant attention for its potential activity in reducing the size of TSC-associated tumors, thus providing alternative to surgery. This study aimed at determining the efficacy of rapamycin and rapalogs for reducing the size of TSC-associated solid tumors in patients with Tuberous Sclerosis Complex (TSC).

Methods

Our data sources included electronic searches of the PubMed. We included into our meta-analysis any type of non-randomized study that reported the use of rapamycin and rapalogs for reducing the size of TSC-associated solid tumors in patients with TSC. Data was entered into Cochrane Review Manager Version 5.3 and analyzed.

Results

Four case reports and 4 clinical trials were included. Five patients from the case reports (all with SEGA) and 91 patients from the clinical trials (41 with SEGA, 63 with kidney angiomyolipoma and 5 with liver angiomyolipoma) were included into the analysis. Volume and diameter of SEGAs were significantly reduced by mean difference of 1.23 cc (95 % CI −2.32 to −0.13; p = 0.03) and 7.91 mm (95 % CI −11.82 to −4.01; p < 0.0001), respectively. Volume and mean of sum of longest diameter of kidney angiomyolipomas were significantly reduced by mean difference of 39.5 cc (95 % CI −48.85 to −30.15; p <0.00001) and 69.03 mm (95 % CI −158.05 to 12.65; p = 0.008), respectively. In liver angiomyolipomas, however, reduction in tumor size was not evident. Sum of longest diameter of liver angiomyolipomas in 4 patients were enlarged by 2.7 mm (95 % CI 28.42 to −23.02) by the end of treatment, though not significant (p = 0.84).

Conclusions

Rapamycin and rapalogs showed efficacy towards reducing the size of SEGA and kidney angiomyolipoma but not liver angiomyolipomas. This finding is strengthening the conclusion of our Cochrane systematic review on the randomized trials.

Everolimus for renal angiomyolipoma in patients with tuberous sclerosis complex or sporadic lymphangioleiomyomatosis: extension of a randomized controlled trial

BACKGROUND

Mammalian target of rapamycin (mTOR) inhibitors are recommended as first-line treatment of renal angiomyolipoma associated with tuberous sclerosis complex (TSC) or sporadic lymphangioleiomyomatosis (sporadic LAM), but follow-up is limited. Longer term efficacy and tolerability data from a Phase 3, double-blind, placebo-controlled trial are presented.

METHODS

Following favorable results from the primary analysis (data cutoff 30 June 2011) of the EXIST-2 trial, patients still receiving study treatment were allowed to enter an open-label extension. Everolimus was initiated at 10 mg once daily and titrated based on tolerability. The primary outcome was angiomyolipoma response rate (≥ 50% reduction from baseline in target lesion volumes). Safety was a secondary endpoint.

RESULTS

As of the cutoff date (1 May 2013), 112 patients had received everolimus, and the response rate in 107 patients with angiomyolipoma (median duration of medication exposure of 28.9 months) was 54%. The proportion of patients achieving angiomyolipoma reductions of ≥ 30% and ≥ 50% increased over time, reaching 81.6% (62/76) and 64.5% (49/76), respectively, by Week 96. No everolimus-treated patients experienced renal bleeding. The long-term safety profile was consistent with previous reports; adverse events (AEs) were mostly Grade 1/2, and there were no new safety issues. The frequency of emerging AEs and severe AEs lessened over time.

CONCLUSIONS

Longer term everolimus treatment appeared safe and effective in patients with TSC- or sporadic LAM-associated renal angiomyolipoma not requiring surgical intervention. Continued reduction in angiomyolipoma volume was demonstrated, and there was no angiomyolipoma-related bleeding; AEs were predictable and generally manageable.

TRIAL REGISTRATION

clinicaltrialsgov identifier: NCT00790400 (http://clinicaltrials.gov/ct2/show/NCT00790400).

Accurate Characterization of Skeletal Lesions in Tuberous Sclerosis Complex Using 99mTc MDP SPECT/CT

We report a 15-year-old patient with tuberous sclerosis complex or Bourneville's disease with history of generalized tonic-clonic seizure for last 2 years and was currently on antiepileptic medication. He also had a history of left nephrectomy for renal cell carcinoma clear cell type. The patient had multiple adenoma sebaceum over the nasolabial region, ash leaf spots over the lower limbs, a Shagreen patch over the back, and multiple calcified tubers in the subependymal region. He was then referred for the skeletal scintigraphy to look for skeletal lesions, which revealed involvement of bilateral humeri, tibiae, and iliac bones accurately characterized on SPECT/CT.

Altered Structural Brain Networks in Tuberous Sclerosis Complex

Tuberous sclerosis complex (TSC) is characterized by benign hamartomas in multiple organs including the brain and its clinical phenotypes may be associated with abnormal neural connections. We aimed to provide the first detailed findings on disrupted structural brain networks in TSC patients. Structural whole-brain connectivity maps were constructed using structural and diffusion MRI in 20 TSC (age range: 3-24 years) and 20 typically developing (TD; 3-23 years) subjects. We assessed global (short- and long-association and interhemispheric fibers) and regional white matter connectivity, and performed graph theoretical analysis using gyral pattern- and atlas-based node parcellations. Significantly higher mean diffusivity (MD) was shown in TSC patients than in TD controls throughout the whole brain and positively correlated with tuber load severity. A significant increase in MD was mainly influenced by an increase in radial diffusivity. Furthermore, interhemispheric connectivity was particularly reduced in TSC, which leads to increased network segregation within hemispheres. TSC patients with developmental delay (DD) showed significantly higher MD than those without DD primarily in intrahemispheric connections. Our analysis allows non-biased determination of differential white matter involvement, which may provide better measures of "lesion load" and lead to a better understanding of disease mechanisms.

[Tuberous sclerosis complex]

Tuberous sclerosis complex is an autosomal dominant disorder with variable affection of the central nervous system (CNS) and many other organ systems. Radiological features include various lesions of the brain as well as lesions of the lungs, kidneys and the heart. Imaging is important for the early detection of complications. This article provides an overview of the clinical features and therapy as well as the specific imaging of tuberous sclerosis complex.

Emergency embolization of actively bleeding renal angiomyolipoma in a patient of tuberous sclerosis

Renal angiomyolipoma is a benign hamartomatous lesion which contains varying proportions of abnormal blood vessels along with muscle and fat component. Tuberous sclerosis predisposes to angiomyolipoma, and when associated, the lesion is often large with increased risk of hemorrhage and complications. When this occurs, transarterial embolization and surgery are the treatment options. Such a patient presented to us with acute onset of symptoms, and on account of severe anemia with active bleeding, transarterial embolization was performed. This was followed by elective nephrectomy without any complications. We present the imaging aspects of tuberous sclerosis and emphasize role of interventional radiology in this case.

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.

Subependymal giant cell astrocytoma: current concepts, management, and future directions

BACKGROUND

Subependymal giant cell astrocytoma (SEGA) is the most common central nervous system tumor in patients with tuberous sclerosis complex (TSC). SEGAs are generally benign, non-infiltrative lesions, but they can lead to intracranial hypertension, obstructive hydrocephalus, focal neurologic deficits, and even sudden death.

DISCUSSION

Surgical resection has been the standard treatment for SEGAs, and it is generally curative with complete resection. However, not all SEGAs are amenable to safe and complete resection. Gamma Knife stereotactic radiosurgery provides another treatment option as a primary or adjuvant treatment for SEGAs, but it has highly variable response effects with sporadic cases demonstrating its efficacy. Recently, biologically targeted pharmacotherapy with mammalian target of rapamycin (mTOR) inhibitors such as sirolimus and everolimus has provided a safe and efficacious treatment option for patients with SEGAs. However, SEGAs can recur few months after drug discontinuation, indicating that mTOR inhibitors may need to be continued to avoid recurrence. Further studies are needed to evaluate the advantages and adverse effects of long-term treatment with mTOR inhibitors. This review presents an overview of the current knowledge and particularly highlights the surgical and medical options of SEGAs in patients with TSC.

Rapamycin has a beneficial effect on controlling epilepsy in children with tuberous sclerosis complex: results of 7 children from a cohort of 86

PURPOSE

Tuberous sclerosis complex (TSC) is a genetic disorder characterized by the formation of hamartomas in various organ systems. We would like share our experience from 86 patients and the results of rapamycin treatment in seven children with TSC.

METHODS

Eighty-six children with TSC were enrolled into this retrospective study. The clinical features of seven children treated with oral rapamycin were presented in detail.

RESULTS

The most common complaint of administration was convulsion in 77 children (89.5%). Hypopigmented skin lesions, adenoma sebaceum, resistant epilepsy, intracardiac mass, renal angiomyolipomas, and West syndrome were detected (n = 83, 96.5%; n = 47, 54.7%; n = 36, 41.9%; n = 27, 31.4%; n = 18, 20.9%; and n = 13, 15.1%, respectively). Subependymal nodules were the most frequent finding in cranial imaging followed by cortical tubers and subependymal giant cell astrocytomas (n = 75, 87.2%; n = 71, 82.6%; and n = 8, 9.3%, respectively). Of the seven patients treated with rapamycin, the lesions of six children with facial adenoma sebaceum showed regression in various degrees. The frequency of convulsions decreased in five patients with resistant epilepsy within the first 6 months of the treatment, and complete control of convulsion for all patients was achieved in the second 6 months.

CONCLUSION

This is the first study that showed that rapamycin is an effective agent for controlling epilepsy without any significant side effect in children with TSC. Rapamycin seems to be effective after 6 months of therapy, and we recommend tapering the dosage after successful management of epilepsy.