Neuroimaging in tuberous sclerosis complex

Predicting Antiseizure Medication Treatment in Children with Rare Tuberous Sclerosis Complex-Related Epilepsy Using Deep Learning

BACKGROUND AND PURPOSE

Tuberous sclerosis complex disease is a rare, multisystem genetic disease, but appropriate drug treatment allows many pediatric patients to have positive outcomes. The purpose of this study was to predict the effectiveness of antiseizure medication treatment in children with tuberous sclerosis complex-related epilepsy.

MATERIALS AND METHODS

We conducted a retrospective study involving 300 children with tuberous sclerosis complex-related epilepsy. The study included the analysis of clinical data and T2WI and FLAIR images. The clinical data consisted of sex, age of onset, age at imaging, infantile spasms, and antiseizure medication numbers. To forecast antiseizure medication treatment, we developed a multitechnique deep learning method called WAE-Net. This method used multicontrast MR imaging and clinical data. The T2WI and FLAIR images were combined as FLAIR3 to enhance the contrast between tuberous sclerosis complex lesions and normal brain tissues. We trained a clinical data-based model using a fully connected network with the above-mentioned variables. After that, a weighted-average ensemble network built from the ResNet3D architecture was created as the final model.

RESULTS

The experiments had shown that age of onset, age at imaging, infantile spasms, and antiseizure medication numbers were significantly different between the 2 drug-treatment outcomes (P < .05). The hybrid technique of FLAIR3 could accurately localize tuberous sclerosis complex lesions, and the proposed method achieved the best performance (area under the curve = 0.908 and accuracy of 0.847) in the testing cohort among the compared methods.

CONCLUSIONS

The proposed method could predict antiseizure medication treatment of children with rare tuberous sclerosis complex-related epilepsy and could be a strong baseline for future studies.

Effects of Walnut and Pumpkin on Selective Neurophenotypes of Autism Spectrum Disorders: A Case Study

Special diets or nutritional supplements are regularly given to treat children with autism spectrum disorder (ASD). The increased consumption of particular foods has been demonstrated in numerous trials to lessen autism-related symptoms and comorbidities. A case study on a boy with moderate autism who significantly improved after three years of following a healthy diet consisting of pumpkin and walnuts was examined in this review in connection to a few different neurophenotypes of ASD. We are able to suggest that a diet high in pumpkin and walnuts was useful in improving the clinical presentation of the ASD case evaluated by reducing oxidative stress, neuroinflammation, glutamate excitotoxicity, mitochondrial dysfunction, and altered gut microbiota, all of which are etiological variables. Using illustrated figures, a full description of the ways by which a diet high in pumpkin and nuts could assist the included case is offered.

Fetal neurosonography as accurate tool for diagnosis of brain involvement in tuberous sclerosis

OBJECTIVE

To demonstrate the potential utility of dedicated neurosonography for the diagnosis of fetal brain involvement in tuberous sclerosis complex.

METHODS

This was a multicenter retrospective study of fetuses at high risk for tuberous sclerosis complex. Dedicated neurosonographic, fetal magnetic resonance imaging (MRI) and postnatal reports were reviewed. Data collected included reason for referral, gestational age at which cardiac rhabdomyoma was first suspected and final number of cardiac rhabdomyomas detected on dedicated imaging. We searched for tuberous sclerosis complex-related brain involvement, defined as the presence of one or more of the following findings: white-matter lesions; subependymal nodules; cortical/subcortical tubers; and subependymal giant-cell astrocytoma.

RESULTS

We included 20 patients at high risk of tuberous sclerosis complex, of whom 19 were referred for the presence of cardiac rhabdomyomas and one for a deletion in chromosome 16 involving the tuberous sclerosis complex gene locus. Cardiac rhabdomyomas were diagnosed at a mean gestational age of 27 + 2 weeks (range, 16 + 0 to 36 + 3 weeks) and the mean number of cardiac rhabdomyomas per patient was 4 (range, 1-10). Brain involvement was present in 15 fetuses, in 13 of which the disease was confirmed in one or more of the following ways: chromosomal microarray analysis (n = 1), exome sequencing (n = 7), autopsy (n = 4), clinical tuberous sclerosis complex in the newborn (n = 4) and a sibling diagnosed with clinical tuberous sclerosis complex (n = 1). In two cases, the disease could not be confirmed: one was lost to follow-up and autopsy, following termination of pregnancy, was not performed in the other. Among the five cases without brain findings, tuberous sclerosis complex was confirmed in three by exome sequencing (n = 2) and/or autopsy findings (n = 2). The two remaining cases had normal exome sequencing; one case had five cardiac rhabdomyomas, which was a highly suggestive finding, while in the final case, the autopsy was considered normal, representing the only false-positive case in our cohort.

CONCLUSIONS

Contrary to current literature, dedicated neurosonography appears to be effective in the diagnosis of brain involvement in fetuses at risk of tuberous sclerosis complex and should be used as the first-line approach. Although the number of cases in which MRI was performed was small, it seems that, in the presence of ultrasound findings, the added value of MRI is low. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Recognizing Pediatric Tuberous Sclerosis Complex Based on Multi-Contrast MRI and Deep Weighted Fusion Network

Multi-contrast magnetic resonance imaging (MRI) is wildly applied to identify tuberous sclerosis complex (TSC) children in a clinic. In this work, a deep convolutional neural network with multi-contrast MRI is proposed to diagnose pediatric TSC. Firstly, by combining T2W and FLAIR images, a new synthesis modality named FLAIR3 was created to enhance the contrast between TSC lesions and normal brain tissues. After that, a deep weighted fusion network (DWF-net) using a late fusion strategy is proposed to diagnose TSC children. In experiments, a total of 680 children were enrolled, including 331 healthy children and 349 TSC children. The experimental results indicate that FLAIR3 successfully enhances the visibility of TSC lesions and improves the classification performance. Additionally, the proposed DWF-net delivers a superior classification performance compared to previous methods, achieving an AUC of 0.998 and an accuracy of 0.985. The proposed method has the potential to be a reliable computer-aided diagnostic tool for assisting radiologists in diagnosing TSC children.

Specific Features of Focal Cortical Dysplasia in Tuberous Sclerosis Complex

Patients with tuberous sclerosis complex present with cognitive, behavioral, and psychiatric impairments, such as intellectual disabilities, autism spectrum disorders, and drug-resistant epilepsy. It has been shown that these disorders are associated with the presence of cortical tubers. Tuberous sclerosis complex results from inactivating mutations in the TSC1 or TSC2 genes, resulting in hyperactivation of the mTOR signaling pathway, which regulates cell growth, proliferation, survival, and autophagy. TSC1 and TSC2 are classified as tumor suppressor genes and function according to Knudson's two-hit hypothesis, which requires both alleles to be damaged for tumor formation. However, a second-hit mutation is a rare event in cortical tubers. This suggests that the molecular mechanism of cortical tuber formation may be more complicated and requires further research. This review highlights the issues of molecular genetics and genotype-phenotype correlations, considers histopathological characteristics and the mechanism of morphogenesis of cortical tubers, and also presents data on the relationship between these formations and the development of neurological manifestations, as well as treatment options.

Microtubule Cytoskeletal Network Alterations in a Transgenic Model of Tuberous Sclerosis Complex: Relevance to Autism Spectrum Disorders

Tuberous sclerosis complex (TSC) is a rare genetic multisystem disorder caused by loss-of-function mutations in the tumour suppressors TSC1/TSC2, both of which are negative regulators of the mammalian target of rapamycin (mTOR) kinase. Importantly, mTOR hyperactivity seems to be linked with the pathobiology of autism spectrum disorders (ASD). Recent studies suggest the potential involvement of microtubule (MT) network dysfunction in the neuropathology of "mTORopathies", including ASD. Cytoskeletal reorganization could be responsible for neuroplasticity disturbances in ASD individuals. Thus, the aim of this work was to study the effect of Tsc2 haploinsufficiency on the cytoskeletal pathology and disturbances in the proteostasis of the key cytoskeletal proteins in the brain of a TSC mouse model of ASD. Western-blot analysis indicated significant brain-structure-dependent abnormalities in the microtubule-associated protein Tau (MAP-Tau), and reduced MAP1B and neurofilament light (NF-L) protein level in 2-month-old male B6;129S4-Tsc2^tm1Djk/J mice. Alongside, pathological irregularities in the ultrastructure of both MT and neurofilament (NFL) networks as well as swelling of the nerve endings were demonstrated. These changes in the level of key cytoskeletal proteins in the brain of the autistic-like TSC mice suggest the possible molecular mechanisms responsible for neuroplasticity alterations in the ASD brain.

eTSC-Net: A Parameter-efficient Convolutional Neural Network for Drug Treatment Outcome Studies of Pediatric Epilepsy.. [DOI: 10.21203/rs.3.rs-2024294/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background: Ability to predict the outcomes of pharmacological treatment of epilepsy in pediatric patients with tuberous sclerosis complex (TSC) can confer a distinct leverage and guide therapeutic decision-making. Multi-contrast magnetic resonance imaging (MRI) is routinely used for diagnosis of TSC by pediatricians. We propose a parameter-efficient convolutional neural network with multi-contrast images to predict the drug treatment outcomes of pediatric epilepsy in TSC. Methods: Image-based models were generated using the EfficientNet3D-B0 network architecture. A weighted average ensemble network with multi-contrast images was created as the final model. The proposed neural network is named as Efficient Tuberous sclerosis complex-Net (eTSC-Net).We compared our methods with a Residual Network 3D（ResNet3D) model. We trained a 3D-ResNet on our T2FLAIR data. Binary classification models were trained to distinguish non-controlled group patients from controlled group patients on T2W and T2FLAIR images. We trained all the models using an Nvidia RTX A6000 Graphical Processing Unit (GPU) card. Area under curve(AUC), accuracy (ACC), sensitivity (SEN), and specificity (SPE) were calculated to assess the classification performance for each model in each cohort. The differences between subgroups were assessed using independent samples t test and pvalues < 0.05 were considered indicative of statistical significance. Results: The proposed neural network (eTSC-Net) achieved the best performance with an AUC value of 0.833 and 90.0% accuracy in the testing cohort, which was better than other models. Conclusions: The results demonstrated the ability of the proposed method for predicting drug treatment outcomes in pediatric TSC-related epilepsy. eTSC-Net can serve as a useful computer-aided diagnostic tool to help clinical radiologists formulate more targeted treatment.

Identification of Children's Tuberous Sclerosis Complex with Multiple-contrast MRI and 3D Convolutional Network

Identifying rare tuberous sclerosis complex (TSC) children is valuable and crucial. Magnetic resonance imaging (MRI) is used for rare TSC diagnoses. In this work, T2w and FLAIR were combined as a new modality named FLAIR3 to maximize the contrast between TSC lesions and normal-appearing brain tissues. After that, for the first time, we propose to use two different 3D CNN combined with late fusion strategies to diagnose TSC. A total of 520 children were enrolled in the study, including 260 health and 260 TSC children. The experiments had shown that the FLAIR3 could effectively improve the conspicuity of TSC lesions and classification performance. And the results showed the proposed late fusion method can improve the classification performance and achieve the state-of-the-art performance of the AUC of 0.994 and the accuracy of 0.971, which could be treated as an effective computer-aided diagnostic tool to help clinical radiologists diagnose TSC children. Clinical Relevance- Our deep learning method can be a non-invasive, efficient, and reliable way to help clinical radiologists to identify TSC patients. FLAIR3 can provide clinicians with a new modality to accurately localize TSC lesions in TSC patients.

Giant cyst-like cortical tubers in an adult with tuberous sclerosis presenting as spastic tetraplegia

Introduction and importance

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder caused by inactivating mutations in TSC1 or TSC2 genes, resulting in benign lesions that involve multiple organs including the central nerves system.

Case presentation

A 39-year-old male of known TSC presented with inability to walk for two months. On physical examination, he was consciously oriented and cooperative, but he had spastic tetraparesis in the muscle-motor examination. On brain imaging, cystic lesions of various sizes in the supra and infratentorial regions were observed, consistent with giant cyst-like tubers. However, they could not differentiate from TSC related brain tumors based on the imaging findings. He underwent surgical intervention to resect/evacuate the large cystic lesion, which had the mass effects on the brain stem. The pathologic examinations revealed no malignant changes.

Clinical discussion

Although the cyst-like lesions in the cortex and white matter have been reported in several previous studies of TSC, they usually had a small size and similar intensity to CSF on T2- weighted MRI and low intensity on FLAIR images.

Conclusion

Giant cyst-like cortical tubers are exceedingly rare and atypical findings of tuberous sclerosis complex, which are usually associated with epilepsy and neurological deficits. Though many authors recommend the brain MRI as a screening tool for patients with TSC once every 1–3 years until the age of 25, our report showed that the brain lesions may develop in patients with TSC even after the age of 25. Thus, the MRI should be used periodically in all patients with TSC to timely detect the brain lesions and prevent the patient's disability. Surgical resection is the mainstay of treatment for the symptomatic cystic-like cortical tuber; however, it may recur after resection.

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Giant cyst-like cortical tubers are rare and atypical findings of tuberous sclerosis complex.

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They are usually associated with epilepsy and neurological deficits.

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MRI should be used periodically in all patients with tuberous sclerosis complex to timely detect the brain lesions.

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Surgical resection is the mainstay of treatment. However, these lesions may recur after resection.

Altered transcallosal fiber count and volume in high-functioning adults with autism spectrum disorder

An altered pattern of information processing has been hypothesized in autism spectrum disorder (ASD), characterized by enhanced local network connectivity and reduced long-distance communication. Previous findings of impaired white matter integrity in the genu and the body of the corpus callosum already indicated reduced long-distance connectivity in patients with ASD. However, it remained unclear how this reduced white matter integrity affects the structural connectivity of the corresponding brain areas. To this end, we analyzed magnetic resonance images (MRI) from 30 participants with high-functioning ASD and 30 typically developed individuals using a global tracking approach to estimate the fiber count and volume of the transcallosal fiber tracts of the five corpus callosum subsections. A reduced fiber count and fiber volume in the anterior subsection of the corpus callosum was detected, supporting the hypothesis of reduced long-distance connectivity in ASD.

Managing Headache Disorders Associated with Tuberous Sclerosis and Neurofibromatosis

PURPOSE OF REVIEW

Tuberous sclerosis complex (TSC) and neurofibromatosis (NF) are neurocutaneous disorders often encountered by neurologists in clinical practice. This article aims to familiarize adult and pediatric neurologists with common features of these disorders and headache specific evaluation and management.

RECENT FINDINGS

Non-malignant intracranial tumors in TSC include cortical tubers (glioneuronal hamartomas), subependymal nodules or subependymal giant-cell astrocytomas (SEGA). Headache disorders in TSC are largely secondary and can cause headaches due to increased intracranial pressure, mass effect, obstructive hydrocephalus, or hemorrhage. Neurosurgical intervention is typically required for management of large SEGAs; however, in patients with increased surgical risk, newer treatment modalities may be offered such as neoadjuvant therapy with an mTOR inhibitor (mTORi). Newer studies indicate headache disorders are more prevalent in neurofibromatosis type 1 (NF1). Primary headache disorders can include migraine and tension-type headache, while secondary headache disorders can be due to associated neoplasms such as optic pathway gliomas or brainstem gliomas, or less commonly vasculopathies such as moyamoya syndrome. Selumetinib is an oral, small molecule mitogen-activated protein kinase (MEK) agent with antineoplastic activity which is in ongoing trials for treatment of NF1-associated pediatric low-grade gliomas. NF1 stands out as having a higher association with primary headache disorders such as migraine. This association may be related to effects of mutation of the neurofibromin gene on pathways involved in pain and migraine genesis, however, warrants future study. Care should be taken when formulating a headache treatment plan to address comorbidities and avoid medications that may be contraindicated.

Neurosurgical Considerations of Neurocutaneous Syndromes

The phakomatoses are a group of genetic and acquired disorders characterized by neurologic, cutaneous, and often ocular manifestations, thus commonly referred to as neurocutaneous syndromes. In several of these conditions the underlying genetic pathophysiology has been elucidated, which will continue to play an important role in advancing therapeutic techniques. This article focuses on several examples of such neurocutaneous syndromes, with special attention to the relevant neurosurgical considerations of these patients.

mTOR-related synaptic pathology causes autism spectrum disorder-associated functional hyperconnectivity

Postmortem studies have revealed increased density of excitatory synapses in the brains of individuals with autism spectrum disorder (ASD), with a putative link to aberrant mTOR-dependent synaptic pruning. ASD is also characterized by atypical macroscale functional connectivity as measured with resting-state fMRI (rsfMRI). These observations raise the question of whether excess of synapses causes aberrant functional connectivity in ASD. Using rsfMRI, electrophysiology and in silico modelling in Tsc2 haploinsufficient mice, we show that mTOR-dependent increased spine density is associated with ASD -like stereotypies and cortico-striatal hyperconnectivity. These deficits are completely rescued by pharmacological inhibition of mTOR. Notably, we further demonstrate that children with idiopathic ASD exhibit analogous cortical-striatal hyperconnectivity, and document that this connectivity fingerprint is enriched for ASD-dysregulated genes interacting with mTOR or Tsc2. Finally, we show that the identified transcriptomic signature is predominantly expressed in a subset of children with autism, thereby defining a segregable autism subtype. Our findings causally link mTOR-related synaptic pathology to large-scale network aberrations, revealing a unifying multi-scale framework that mechanistically reconciles developmental synaptopathy and functional hyperconnectivity in autism.

Sclerosi tuberosa ed everolimus: una nuova storia

Tuberous sclerosis complex (TSC) is a rare autosomal dominant disorder, due to inactivating muta-tions of TSC1 or TSC2 mTOR pathway genes and is characterized by variable multisystem manifestations ranging from hamartomas to malignant neoplasms. It frequently associated to seizures, intellectual disability and behavioural disorders. Surgical treatment has traditionally been used to manage subependymal giant cells astrocytomas (SEGA). The introduction of mTOR inhibitor rapamycin, with its definite role both as primary and as adjuvant treatment, has significantly modified the management opportunities in the clinical practice. It is important to consider both treatment options in a balanced way and not only the SEGA, but also the individual patient and their associated comorbidities. The pros and the cons of both options should be discussed by a multidisciplinary team before establishing an individualized treatment recommendation. The paper reports the case of a patient with an asymptomatic SEGA who was treated with everolimus. The treatment was effective in reducing the size of the tumour, it was safe and well tolerated.

Experience using mTOR inhibitors for subependymal giant cell astrocytoma in tuberous sclerosis complex at a single facility

BACKGROUND

Subependymal giant cell astrocytoma (SEGA) is occasionally seen in tuberous sclerosis complex (TSC). Two main options are currently available for treating SEGA: surgical resection or pharmacotherapy using mammalian target of rapamycin inhibitors (mTORi). We hypothesized that opportunities for surgical resection of SEGA would have reduced with the advent of mTORi.

METHODS

We retrospectively reviewed the charts of patients treated between August 1979 and July 2020, divided into a pre-mTORi era group (Pre-group) of patients treated before November 2012, and a post-mTORi era group (Post-group) comprising patients treated from November 2012, when mTORi became available in Japan for SEGA. We compared groups in terms of treatment with surgery or mTORi. We also reviewed SEGA size, rate of acute hydrocephalus, recurrence of SEGA, malignant transformation and adverse effects of mTORi.

RESULTS

In total, 120 patients with TSC visited our facility, including 24 patients with SEGA. Surgical resection was significantly more frequent in the Pre-group (6 of 7 patients, 86 %) than in the Post-group (2 of 17 patients, 12 %; p = 0.001). Acute hydrocephalus was seen in 1 patient (4 %), and no patients showed malignant transformation of SEGA. The group treated using mTORi showed significantly smaller SEGA compared with the group treated under a wait-and-see policy (p = 0.012). Adverse effects of pharmacotherapy were identified in seven (64 %; 6 oral ulcers, 1 irregular menstruation) of the 11 patients receiving mTORi.

CONCLUSIONS

The Post-group underwent surgery significantly less often than the Pre-group. Since the treatment option to use mTORi in the treatment of SEGA in TSC became available, opportunities for surgical resection have decreased in our facility.

Neuroimaging and genetic characteristics of malformation of cortical development due to mTOR pathway dysregulation: clues for the epileptogenic lesions and indications for epilepsy surgery

Introduction: Malformation of cortical development (MCD) is strongly associated with drug-resistant epilepsies for which surgery to remove epileptogenic lesions is common. Two notable technological advances in this field are identification of the underlying genetic cause and techniques in neuroimaging. These now question how presurgical evaluation ought to be approached for 'mTORpathies.'Area covered: From review of published primary and secondary articles, the authors summarize evidence to consider focal cortical dysplasia (FCD), tuber sclerosis complex (TSC), and hemimegalencephaly (HME) collectively as MCD mTORpathies. The authors also consider the unique features of these related conditions with particular focus on the practicalities of using neuroimaging techniques currently available to define surgical targets and predict post-surgical outcome. Ultimately, the authors consider the surgical dilemmas faced for each condition.Expert opinion: Considering FCD, TSC, and HME collectively as mTORpathies has some merit; however, a unified approach to presurgical evaluation would seem unachievable. Nevertheless, the authors believe combining genetic-centered classification and morphologic findings using advanced imaging techniques will eventually form the basis of a paradigm when considering candidacy for early surgery.

The Most Common Lesions Detected by Neuroimaging as Causes of Epilepsy

Epilepsy is a common neurological disorder characterized by chronic, unprovoked and recurrent seizures, which are the result of rapid and excessive bioelectric discharges in nerve cells. Neuroimaging is used to detect underlying structural abnormalities which may be associated with epilepsy. This paper reviews the most common abnormalities, such as hippocampal sclerosis, malformations of cortical development and vascular malformation, detected by neuroimaging in patients with epilepsy to help understand the correlation between these changes and the course, treatment and prognosis of epilepsy. Magnetic resonance imaging (MRI) reveals structural changes in the brain which are described in this review. Recent studies indicate the usefulness of additional imaging techniques. The use of fluorodeoxyglucose positron emission tomography (FDG-PET) improves surgical outcomes in MRI-negative cases of focal cortical dysplasia. Some techniques, such as quantitative image analysis, magnetic resonance spectroscopy (MRS), functional MRI (fMRI), diffusion tensor imaging (DTI) and fibre tract reconstruction, can detect small malformations—which means that some of the epilepsies can be treated surgically. Quantitative susceptibility mapping may become the method of choice in vascular malformations. Neuroimaging determines appropriate diagnosis and treatment and helps to predict prognosis.