Ophthalmic manifestations of tuberous sclerosis: a review

A case of tuberous sclerosis complex revealed by epilepsy

Tuberous sclerosis complex is a multisystem genetic disease with autosomal dominant inheritance, characterized by the development of benign tumors known as hamartomas that affect multiple organs. It is a condition with a wide phenotypic spectrum, and its clinical presentation varies over time within the same individual. Hence, the importance of early screening and rigorous monitoring of evolving clinical manifestations. Diagnosis can occur at any age. These tumors are generally benign, but their size and location can have a significant impact on the prognosis and, in some cases, even on life expectancy. Cardiac, neurological, and cutaneous manifestations are most common in childhood. The onset of early and severe epilepsy within the first year of life is associated with neurodevelopmental disorders that impact the quality of life for affected individuals and their families. We present a case of a 22-year-old female patient experiencing inaugural epileptic seizures in adulthood, with magnetic resonance imaging revealing subependymal hamartomas, cortical tubers and radial migration bands accompanied by polycystic kidney disease; the diagnosis of tuberous sclerosis complex was established based on the association of these lesions, which constitute major and minor criteria.

Multimodal Analysis of the Retinal Manifestations of Tuberous Sclerosis Complex: A Case Series

BACKGROUND AND OBJECTIVE

We used a multi-modal imaging approach including fundus fluorescein angiography (FFA) to assess the retinal lesions in tuberous sclerosis complex (TSC) and evaluate their correlation with intracranial tuber burden on magnetic resonance imaging (MRI).

PATIENTS AND METHODS

Participants with TSC underwent bilateral fundus photography, optical coherence tomography (OCT), infrared (IR) imaging, and FFA. Participants' most recent MRI brain scans were analyzed to determine intracranial tuber load.

RESULTS

Nine participants were included. OCT identified all retinal astrocytic hamartoma (RAH) lesions, IR identified 75%, fundus photography identified 63%, and FFA detected just 57%. On FFA, 20% of flat-type hamartomas and all multi-nodular and transitional types were hyperfluorescent. There were significant positive correlations between the quantities of intracranial tubers and all TSC-retinal lesions (r = 0.8, P < 0.01) and all RAH lesions (r = 0.8, P = 0.01).

CONCLUSIONS

A multimodal imaging-based approach with fundal photography, IR imaging, and OCT should be used to assess the retina in TSC as it may indicate the intracranial tuber burden. [Ophthalmic Surg Lasers Imaging Retina 2024;55:XX-XX.].

Ocular manifestations of renal ciliopathies

Renal ciliopathies are a common cause of kidney failure in children and adults, and this study reviewed their ocular associations. Genes affected in renal ciliopathies were identified from the Genomics England Panels. Ocular associations were identified from Medline and OMIM, and the genes additionally examined for expression in the human retina ( https://www.proteinatlas.org/humanproteome/tissue ) and for an ocular phenotype in mouse models ( http://www.informatics.jax.org/ ). Eighty-two of the 86 pediatric-onset renal ciliopathies (95%) have an ocular phenotype, including inherited retinal degeneration, oculomotor disorders, and coloboma. Diseases associated with pathogenic variants in ANK6, MAPKBP1, NEK8, and TCTN1 have no reported ocular manifestations, as well as low retinal expression and no ocular features in mouse models. Ocular abnormalities are not associated with the most common adult-onset "cystic" kidney diseases, namely, autosomal dominant (AD) polycystic kidney disease and the AD tubulointerstitial kidney diseases (ADTKD). However, other kidney syndromes with cysts have ocular features including papillorenal syndrome (optic disc dysplasia), Hereditary Angiopathy Nephropathy, Aneurysms and muscle Cramps (HANAC) (tortuous retinal vessels), tuberous sclerosis (retinal hamartomas), von Hippel-Lindau syndrome (retinal hemangiomas), and Alport syndrome (lenticonus, fleck retinopathy). Ocular abnormalities are associated with many pediatric-onset renal ciliopathies but are uncommon in adult-onset cystic kidney disease. However the demonstration of ocular manifestations may be helpful diagnostically and the features may require monitoring or treatment.

Optical coherence tomography detection of retinal neural loss in patients with tuberous sclerosis

PURPOSE

Tuberous Sclerosis (TS) is a rare, multisystem genetic disease caused by mutations in the TSC1 and TSC2 genes, leading to abnormalities in cell differentiation and proliferation. This study aimed to evaluate the neural integrity of individuals with TS by using Optical Coherence Tomography (OCT) to examine the peripapillary retinal nerve fiber layer (RNFL) thickness and the macular thickness in patients with TS and to compare with healthy controls.

METHODS

Peripapillary and macular OCT scans (Optopol Revo NX SD OCT) were performed on 41 eyes from 22 TS patients, divided into two groups based on the presence of retinal hamartomas, and compared to 20 eyes from a control group. The average peripapillary RNFL thickness was measured for each quadrant. The macular total thickness and ganglion cell layer (GCL) + inner plexiform layer (IPL) thickness were measured based on the Early Treatment Diabetic Retinopathy Study (ETDRS) map. All measurements were then compared between the groups and controls.

RESULTS

The TS group showed significantly reduced RNFL thickness and macular thickness when compared to the control group. Specifically, patients with retinal hamartomas exhibited an even more pronounced thinning of both RNFL and macular thickness.

CONCLUSIONS

These findings suggest that TS patients undergo significant changes in retinal neurodevelopment and experience axonal loss. This finding may have significant prognostic utility regarding central nervous system degeneration in TS, particularly among patients with retinal hamartomas. OCT may serve as a valuable tool for assessing axonal structural abnormalities in TS patients.

TRIAL REGISTRATION NUMBER

Not applicable.

Retinal hamartomas at different stages in a patient with tuberous sclerosis: A OCT-SS description

Retinal astrocytic hamartoma (RAH) is a benign glial tumor that may be present in patients with tuberous sclerosis (TS), contributing to the diagnosis of this syndrome. While hamartomas identified through indirect ophthalmoscopy are often large enough to affect vessels and optic disc anatomy, RAH not detected in previous fundoscopies may become apparent in optical coherence tomography (OCT). The purpose of this report was to describe and characterize RAH with OCT with swept-source technology (OCT-SS), aiming to establish a more comprehensive classification for these hamartomas due to their diverse presentations. Fundus examination of a 11-year-old girl revealed retinal tumors in both eyes. OCT-SS confirmed the diagnosis of TS, revealing dome-shaped hyperreflective masses at different stages of evolution. Lesion 1: maximum thickness (MT) of 336 μm and ganglion cell layer disorganization. Lesion 2: MT of 438 μm and preserved outer plexiform layer. Lesion 3: posterior shadow, MT of 1478 μm and complete rupture of retinal anatomy. Lesion 4: MT of 342 μm and preserved retinal anatomy. OCT is a noninvasive method which assists the diagnosis of subclinical lesions and clinical characterization of TS patients.

Paradigm shift in the treatment of tuberous sclerosis: Effectiveness of everolimus

Tuberous sclerosis complex (TSC) is an autosomal dominant disease characterised by abnormal cell proliferation and differentiation that affects multiple organs and can lead to the growth of hamartomas. Tuberous sclerosis complex is caused by the disinhibition of the protein mTOR (mammalian target of rapamycin). In the past, various therapeutic approaches, even if only symptomatic, have been attempted to improve the clinical effects of this disease. While all of these therapeutic strategies are useful and are still used and indicated, they are symptomatic therapies based on the individual symptoms of the disease and therefore not fully effective in modifying long-term outcomes. A new therapeutic approach is the introduction of allosteric inhibitors of mTORC1, which allow restoration of metabolic homeostasis in mutant cells, potentially eliminating most of the clinical manifestations associated with Tuberous sclerosis complex. Everolimus, a mammalian target of the rapamycin inhibitor, is able to reduce hamartomas, correcting the specific molecular defect that causes Tuberous sclerosis complex. In this review, we report the findings from the literature on the use of everolimus as an effective and safe drug in the treatment of TSC manifestations affecting various organs, from the central nervous system to the heart.

Refractive Errors, Retinal Findings, and Genotype of Tuberous Sclerosis Complex: A Retrospective Cohort Study

PURPOSE

To examine the refractive errors, retinal manifestations, and genotype in tuberous sclerosis complex (TSC) patients in a Korean population.

MATERIALS AND METHODS

A total of 98 patients with TSC were enrolled in Severance Hospital for a retrospective cohort study. The number of retinal astrocytic hamartoma and retinal achromic patch within a patient, as well as the size, bilaterality, and morphological type were studied. In addition, the refractive status of patients and the comorbidity of intellectual disability and epilepsy were also examined.

RESULTS

Retinal astrocytic hamartoma was found in 37 patients, and bilateral invasion was observed in 20 patients (54%). TSC1 mutation was associated with myopia (p=0.01), while TSC2 mutation was associated with emmetropia (p=0.01). Retinal astrocytic hamartoma was categorized into three morphological types and examined as follows: type I (87%), type II (35%), and type III (14%). Single invasion of retinal astrocytic hamartoma was identified in 32% of the patients, and multiple invasions in 68%. The TSC1/TSC2 detection rate was 91% (41/45). Among them, TSC1 variant was detected in 23 patients (54%), whereas TSC2 variant was detected in 18 patients (40%). The results showed that TSC2 mutations are correlated with a higher rate of retinal astrocytic hamartoma involvement (all p<0.05), and multiple and bilateral involvement of retinal hamartomas (all p<0.05). However, the size of retinal astrocytic hamartomas, comorbidity of epilepsy, or intellectual disability did not show correlation with the genetic variant.

CONCLUSION

TSC1 variant patients were more myopic, while TSC2 variant patients showed association with more extensive involvement of retinal astrocytic hamartoma.

Case report: tuberous sclerosis and persistent hyperplastic primary vitreous

BACKGROUND

Persistent hyperplastic primary vitreous (PHPV) in a patient with tuberous sclerosis (TS) has been described in one previous case report in 1999. Otherwise, there is no literature around this potential association. We describe a case of an infant with TS and PHPV.

CASE PRESENTATION

An 11-month old male was under investigation for leukocoria, microphthalmia and suspected PHPV after being seen in ophthalmology clinic. He presented to hospital with seizures and was diagnosed with TS on imaging. Imaging also showed the known microphthalmia and a mass associated with the lens. Subsequent paediatric ophthalmology review and examination under anaesthesia confirmed microphthalmia, PHPV and a retrolental mass which was thought to represent total retinal detachment or a retinal hamartoma within a retinal detachment.

CONCLUSIONS

This is the second case report of PHPV in a patient with TS. The previous case report postulated that the atypical location of the retinal hamartoma was secondary to the abnormal globe development in PHPV.

Analysis of Clinical Features and Next-Generation Sequencing of 12 Tuberous Sclerosis Families in China

Background

Tuberous sclerosis complex (TSC) is a rare autosomal dominant genetic disease with systemic organ involvement. So far, only a few TSC families in China have been reported. Therefore, more data on the clinical and genetic features of TSC families are required.

Materials and Methods

We retrospectively analyzed 12 TSC family probands and their family members. Next-generation sequencing (NGS) has been applied to confirm the type of TSC mutation along with a detailed physical examination.

Results

In this study, twenty-seven patients in 12 TSC families were reported, including 12 male and 15 female patients, aged 8-67 years. Skin lesions were detected among all patients with TSC, including 25 cases of facial angiofibromas, 18 cases of hypomelanotic macules, 15 cases of ungual fibromas, and 13 cases of shagreen patch. Other clinical features were also revealed: 14 cases of renal angiomyolipoma, 6 cases of subependymal nodules (SENs), and 3 cases of lymphangioleiomyomatosis. All twenty-seven patients with TSC were tested by NGS. Totally, TSC2 mutations were reported in 19 cases (7 frameshift mutations, 10 nonsense mutations, and 2 missense mutations), TSC1 mutations were reported in 4 cases (4 nonsense mutations), and 4 cases were genetically negative. The novel causal mutations (TSC2: c.208dup, c.1874C > G, c.1852del) identified in three families were first reported in TSC.

Conclusion

Our findings expand the mutation spectrum of patients with TSC in China. The clinical characteristics can vary among patients with TSC with the same pathogenic mutation. The genetic results and summary of clinical features of 12 TSC families contribute to a more accurate diagnosis and further genetic counseling.

The clinical and paraclinical manifestations of tuberous sclerosis complex in children

Tuberous sclerosis complex (TSC) is an autosomal-dominant, multi-system, neurocutaneous disorder characterized by hamartomas in multiple organs. This study aimed to evaluate the clinical and paraclinical manifestations of children with TSC. The clinical and paraclinical characteristics of 79 children with TSC were evaluated and the possible correlations between the factors were calculated. Among the studied children which composed of 41 females (51.9%) and 38 males (48.1%), skin manifestations as hypopigmented macules as well as the brain involvement as cortical tubers in all (100%) cases, seizure in 74 (93.7%), and sub-ependymal nodules in 73 (92.4%) patients were the most common findings. The renal angiomyolipoma was diagnosed in 36 (70.6%) out of 51 patients. Subependymal giant cell astrocytoma in 25 (3/54%) out of 46 patients, retinal hamartoma in 15 (42.9%) out of 35 patients, and cardiac rhabdomyoma in 17 (41.3%) out of 46 patients were diagnosed. Furthermore, 50 (63.3%) out of 79 patients had psychological disorders that had a significant correlation with the prevalence of seizures (p = 0.002). Given the multi-systemic involvement of TSC, it is necessary that all organs of the patients even without any related clinical symptom or sign be examined regularly for proper therapeutic intervention and prevent disease progression. The growth of hamartomas in the brain and kidneys can be life-threatening; therefore, these organs have more importance to be regularly followed up and examined.

Mammalian target of rapamycin inhibitors for the treatment of astrocytic hamartoma in tuberous sclerosis complex (TSC)

PURPOSE

Tuberous sclerosis complex (TSC) is an inherited neurocutaneous disorder. Fifty percent of patients with TSC will develop retinal astrocytic hamartoma (RAH). The mammalian target of rapamycin (mTOR) inhibitors interferes with the pathological mechanisms of TSC. Treatment of RAH with mTOR inhibitors has been described in only a few isolated case reports. The purpose of this study was to assess the effect of mTOR inhibitors on RAH in a small cohort of patients.

METHODS

The medical records of all consecutive patients with ocular manifestations of TSC that were treated with mTOR inhibitors at the Sheba Medical Center from January 2014 to December 2018 were retrospectively reviewed. Data collection included demographics, medical history, ocular presentation, ocular treatment, and treatment outcome. Tumor size was assessed by a masked observer, before and after treatment. Lesion measurements were made with Heidelberg SD-OCT (HRA + OCT SPECTRALIS), and fundus photos were taken with RetCam3® (Natus, USA) and analyzed by "ImageJ" software.

RESULTS

Eleven patients with tuberous sclerosis and astrocytic hamartoma were treated with mTOR inhibitors in the study period. Of them, 6 children (11 eyes, 20 tumors) had proper imaging of tumor size before and after treatment. The analysis included these 11 eyes. All six patients had non-ocular manifestations of TSC, including dermatologic (n = 5), neurologic (n = 5), and renal (n = 3) involvement. Ocular involvement included in five eyes (45%) tumors near the optic disc and in four eyes (37%) foveal tumors. The mean follow-up duration was 2.15 ± 1.4 years (range 10 months to 4.5 years). The average tumor base reduction in the treated group was 17.8% ± 15.9. The average maximal thickness at baseline was 414 ± 174 μm (range 152-686 μm). There was a 14% ± 7.1 reduction after treatment. None of the tumors showed evidence of growth at the final follow-up.

CONCLUSION

The findings of this study suggest that mTOR inhibitors can reduce tumor size and that they can be considered as an optional treatment in certain conditions. This preliminary report is the first to quantitatively assess pre- and posttreatment tumor size, in young patients.

Current concepts on ocular vascular abnormalities in the phakomatoses

BACKGROUND

Neurofibromatosis, Von Hippel Lindau disease, and tuberous sclerosis complex are classified under the term phakomatoses. They are characterized by ocular vascular abnormalities such as vascular tortuosity, corkscrew retinal vessel configuration, moyamoya-like aspect, microaneurysms, hemangioblastomas, and focal sheathing of retinal arteries, possibly due to abnormal formation, migration, and differentiation of neural crest cells. These alterations can be the first sign or the hallmark of disease and can be related to vasoproliferative tumors.

PURPOSE

Novel imaging technologies in ophthalmology, such as near-infrared reflectances and spectral domain optical coherence tomography, have improved our knowledge in the diagnosis of these pathologies. Previously undetected macular vascular alterations have been reported in phakomatoses using optical coherence tomography angiography. This review will summarize the ophthalmic vascular abnormalities and novel imaging methods in the phakomatoses.

CONCLUSION

Active research is being led into the ophthalmic management of these conditions and their complications, and owing to elevated vascular endothelial growth factor production from hemangioblastoma, hamartoma, and retinal vascular proliferative tumors, increasing interest in this line of therapy has been conducted although research is still ongoing in this area.

Retinal manifestations of the neurocutaneous disorders

PURPOSE OF REVIEW

The neurocutaneous disorders are a genetically and phenotypically diverse group of congenital syndromes characterized by cutaneous, ocular, and central nervous system manifestations. This review provides an overview of the clinical features and retinal findings in selected neurocutaneous disorders.

RECENT FINDINGS

Advances in genetics and diagnostic retinal and neuroimaging allow for the recognition of retinal features of common neurocutaneous syndromes and for improved characterization of rarer entities based on previously underdiagnosed or unrecognized retinal findings.

SUMMARY

Better characterization of the neurocutaneous disorders allows for earlier recognition and the potential for expeditious vision-saving and life-saving treatment.

Intracranial calcifications in childhood: Part 1

This article is the first of a two-part series on intracranial calcification in childhood. Intracranial calcification can be either physiological or pathological. Physiological intracranial calcification is not an expected neuroimaging finding in the neonatal or infantile period but occurs, as children grow older, in the pineal gland, habenula, choroid plexus and occasionally the dura mater. Pathological intracranial calcification can be broadly divided into infectious, congenital, endocrine/metabolic, vascular and neoplastic. The main goals in Part 1 are to discuss the chief differences between physiological and pathological intracranial calcification, to discuss the histological characteristics of intracranial calcification and how intracranial calcification can be detected across neuroimaging modalities, to emphasize the importance of age at presentation and intracranial calcification location, and to propose a comprehensive neuroimaging approach toward the differential diagnosis of the causes of intracranial calcification. Finally, in Part 1 the authors discuss the most common causes of infectious intracranial calcification, especially in the neonatal period, and congenital causes of intracranial calcification. Various neuroimaging modalities have distinct utilities and sensitivities in the depiction of intracranial calcification. Age at presentation, intracranial calcification location, and associated neuroimaging findings are useful information to help narrow the differential diagnosis of intracranial calcification. Intracranial calcification can occur in isolation or in association with other neuroimaging features. Intracranial calcification in congenital infections has been associated with clastic changes, hydrocephalus, chorioretinitis, white matter abnormalities, skull changes and malformations of cortical development. Infections are common causes of intracranial calcification, especially neonatal TORCH (toxoplasmosis, other [syphilis, varicella-zoster, parvovirus B19], rubella, cytomegalovirus and herpes) infections.

Clinical features and optical coherence tomography findings of retinal astrocytic hamartomas in Chinese patients with tuberous sclerosis complex

PURPOSE

To investigate the clinical features and spectral-domain optical coherence tomography (SD-OCT) findings of retinal astrocytic hamartoma (RAH) in Chinese patients with tuberous sclerosis complex (TSC).

METHODS

The medical records of 91 consecutive patients with established TSC diagnosis were retrospectively reviewed. Fundus findings regarding RAH documented by fundus photography and SD-OCT at presentation were collected and analyzed.

RESULTS

RAHs were seen in 69 of the 91 patients (75.8%); 50.7% of these patients showed bilateral retinal involvement. Type 1 RAH was found the most common type with a prevalence of 94.2%, while type 2 and type 3 RAH with 7.2% and 18.8% respectively. A significant correlation between age and RAH types was shown by Fisher's exact test (p < 0.001). By SD-OCT, non-calcified RAHs featured in hyperreflective thickening of the retinal nerve fiber layer with some degree of retinal disorganization, while multinodular calcified RAHs characterized with moth-eaten appearances representing intraretinal calcification with posterior dense optical shadowing.

CONCLUSION

A higher prevalence of TSC-associated RAH but an unexpected lower prevalence of calcified RAHs was shown in Chinese compared with that of Caucasians. SD-OCT can be used to facilitate the detection and follow-up of RAHs.

Neuro-ophthalmological manifestations of tuberous sclerosis: current perspectives

Tuberous sclerosis complex (TSC) is a complex, multi-system disorder with a well-described underlying genetic etiology. While retinal findings are common in TSC and important in establishing the diagnosis, TSC also has many potential neuro-ophthalmology manifestations. The neuro-ophthalmology manifestations of TSC can have a significant impact on visual function and are sometimes a sign of serious neurological disease. The purpose of this review is to describe the neuro-ophthalmological manifestations of TSC. These manifestations include optic nerve hamartomas, elevated intracranial pressure, cranial nerve palsies, cortical visual impairment, visual field deficits, and ocular toxicity from vigabatrin treatment of infantile spasms. It is important to be aware of potential neuro-ophthalmological manifestations in these patients in order to detect signs of vision- or life-threatening disease and to optimize visual function and quality-of-life.

Subthreshold micropulse laser photocoagulation therapy in a case of bilateral retinal astrocytic hamartomas with tuberous sclerosis complex: A case report

RATIONALE

Report a case of bilateral multiple retinal hamartomas (RAHs) in a patient with tuberous sclerosis complex (TSC) and introduced a new method (subthreshold micropulse laser photocoagulation) for the treatment of RAHs.

PATIENT CONCERNS

A 20-year-old man with TSC complained of decreased vision and metamorphosia in both eyes for 2 months. At presentation, visual acuity (VA) was 20/32 in the right eye and 20/40 in the left eye. Fundus photographs, optical coherence tomography, fundus fluorescein angiography (FFA), and indocyanine green angiography indicated multiple RAHs in both eyes.

DIAGNOSES

Bilateral retinal astrocytic hamartomas.

INTERVENTIONS

In the right eye, 577 nm photocoagulation was adopted to treat the RAHs with obvious fluorescein leakage in FFA. The paramacular RAHs were treated by subthreshold micropulse mode to minimize the damage to macula. Photocoagulation therapy was administrated in the left eye after 1 dose of intravitreal ranibizumab treatment.

OUTCOMES

After photocoagulation therapy (including subthreshold micropulse laser photocoagulation for the paramacular RAHs in both eyes), the VA improved to 20/25 OD and 20/32 OS with no recurrence of exudation.

LESSONS

About 577 nm photocoagulation for the peripheral RAHs in combination with subthreshold micropulse laser photocoagulation for RAHs in the macular zone is a good option for multiple RAHs in patients with TSC.

Tuberous sclerosis complex: a clinical case with multiple ophthalmological manifestations

The tuberous sclerosis complex is a rare disease, with autosomal dominant transmission, with multisystemic involvement including ophthalmologic. Retinal hamartomas and retinal achromic patch are the most frequent ocular findings. Other ophthalmic signs and symptoms are relatively rare in this disease.We describe the case of a young woman with tuberous sclerosis who presented with horizontal binocular diplopia and decreased visual acuity without complaints of nausea, vomiting or headache. She had right abducens nerve palsy, pale oedema of both optic discs and retinal hamartomas. An obstructive hydrocephalus caused by an intraventricular expansive lesion was identified in brain CT.Observation by the ophthalmologist is indicated in all confirmed or suspected cases of tuberous sclerosis to aid in clinical diagnosis, monitoring of retinal hamartomas or identification of poorly symptomatic papilloedema.

Role of mTORC1 Controlling Proteostasis after Brain Ischemia

Intense efforts are being undertaken to understand the pathophysiological mechanisms triggered after brain ischemia and to develop effective pharmacological treatments. However, the underlying molecular mechanisms are complex and not completely understood. One of the main problems is the fact that the ischemic damage is time-dependent and ranges from negligible to massive, involving different cell types such as neurons, astrocytes, microglia, endothelial cells, and some blood-derived cells (neutrophils, lymphocytes, etc.). Thus, approaching such a complicated cellular response generates a more complex combination of molecular mechanisms, in which cell death, cellular damage, stress and repair are intermixed. For this reason, animal and cellular model systems are needed in order to dissect and clarify which molecular mechanisms have to be promoted and/or blocked. Brain ischemia may be analyzed from two different perspectives: that of oxygen deprivation (hypoxic damage per se) and that of deprivation of glucose/serum factors. For investigations of ischemic stroke, middle cerebral artery occlusion (MCAO) is the preferred in vivo model, and uses two different approaches: transient (tMCAO), where reperfusion is permitted; or permanent (pMCAO). As a complement to this model, many laboratories expose different primary cortical neuron or neuronal cell lines to oxygen-glucose deprivation (OGD). This ex vivo model permits the analysis of the impact of hypoxic damage and the specific response of different cell types implicated in vivo, such as neurons, glia or endothelial cells. Using in vivo and neuronal OGD models, it was recently established that mTORC1 (mammalian Target of Rapamycin Complex-1), a protein complex downstream of PI3K-Akt pathway, is one of the players deregulated after ischemia and OGD. In addition, neuroprotective intervention either by estradiol or by specific AT2R agonists shows an important regulatory role for the mTORC1 activity, for instance regulating vascular endothelial growth factor (VEGF) levels. This evidence highlights the importance of understanding the role of mTORC1 in neuronal death/survival processes, as it could be a potential therapeutic target. This review summarizes the state-of-the-art of the complex kinase mTORC1 focusing in upstream and downstream pathways, their role in central nervous system and their relationship with autophagy, apoptosis and neuroprotection/neurodegeneration after ischemia/hypoxia.

Tuberous Sclerosis Complex: A Review

Tuberous sclerosis complex (TSC) is a neurocutaneous syndrome that can present at any age and can affect multiple organ systems. This disorder is usually identified in infants and children based on characteristic skin lesions, seizures, and cellular overgrowth or hamartomas in the heart, brain, and kidneys. Tuberous sclerosis complex is a genetic disorder caused by a mutation in either the TSC1 or TSC2 gene leading to dysfunction of hamartin or tuberin, respectively. Hamartin and tuberin form a protein complex that helps regulate cellular hyperplasia. Accurate diagnosis is essential in implementing appropriate surveillance and treatment to patients with this disorder. Specific guidelines for diagnosis, surveillance, and management have been proposed by the International Tuberous Sclerosis Complex Consensus Group. Treatment of tuberous sclerosis complex is in part symptomatic; however, for certain clinical manifestations, specific treatments may be indicated. [Pediatr Ann. 2017;46(4):e166-e171.].