The research landscape of tuberous sclerosis complex-associated neuropsychiatric disorders (TAND)-a comprehensive scoping review

Risk Factors for Psychiatric Disorders in Pediatric Patients with Tuberous Sclerosis Complex

To identify and evaluate risk factors for psychiatric disorders in pediatric patients with tuberous sclerosis complex (TSC).We recruited 121 children with TSC from the Hangzhou Children's Hospital between April 2021 and December 2023. Four clinical psychiatric scales were used to screen and diagnose the psychiatric comorbidities of TSC: the autism behavior checklist, the SNAP-IV scale, and the self-rating anxiety and depression scales. Risk factors related to each psychiatric disorder were analyzed using univariate and multivariate regression analyses.Comorbid psychiatric disorders were found in 70 (57.85%) children: 51 (42.15%) cases had autism spectrum disorder (ASD), 49 (40.50%) cases had attention-deficit hyperactivity disorder (ADHD), 17 (14.05%) cases had anxiety, and 14 (11.57%) cases had depression. Uni- and multivariate logistic regression analysis revealed that seizure frequency (>1/month; OR = 6.206, P = 0.021), use of anti-seizure medications (≥ 2 types; OR = 118.869, P = 0.003), infantile spasms (OR = 25.748, P = 0.000), ADHD (OR = 11.170, P = 0.001), and intellectual disability (OR = 32.131, P = 0.001) were risk factors for TSC children with ASD; ASD was the only risk factor for occurrence of ADHD (OR = 7.302, P = 0.022). Seizure duration (≥ 2 years; OR = 56.200, P = 0.036) and seizure frequency (>1/month; OR = 25.855, P = 0.027) were closely related to occurrence of anxiety and/or depression disorders in pediatric patients with TSC.The study results showed that psychiatric comorbidities of children with TSC had a high incidence and risk factors. The study provides new insights into the diagnosis and treatment of comorbid psychiatric disorders in pediatric patients with TSC.

Neuropsychiatric disorders in Chinese pediatric tuberous sclerosis complex patients associated with drug-resistant epilepsy: A TAND checklist-based survey

Tuberous sclerosis complex (TSC) is an autosomal-dominant genetic disorder frequently accompanied by neuropsychiatric disorders, especially in patients who have drug-resistant epilepsy (DRE). This study aimed to evaluate the distribution of neuropsychiatric disorders in Chinese children with TSC-related epilepsy using the TAND (Tuberous Sclerosis Complex Associated Neuropsychiatric Disorders) checklist, comparing those with DRE to those achieving seizure freedom. A total of 47 children, aged 6 to 18 years, diagnosed with TSC at Peking University People's Hospital, participated in this cross-sectional study. All participants met the latest diagnostic criteria for TSC. Based on the definition of drug-resistant epilepsy, participants were categorized into DRE group and seizure-free group. Neurodevelopmental disorders were evaluated using the TAND checklist. The study found that 66 % of participants exhibited varying degrees of intellectual disability, with the DRE group demonstrating significantly poorer performance in intelligence, behavior, neuropsychological, and learning skills compared to the seizure-free group. The DRE group also had higher rates of attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD), alongside greater impairments in psychosocial functioning. This study indicates that DRE is strongly associated with neuropsychiatric development in children with TSC, but also that all children with TSC are at increased risk of TAND. Our findings highlight the importance of regular assessment and intervention to support TAND and improve quality of life in this vulnerable group.

Cognitive and neuro-psychiatric profile in adult patients with epilepsy secondary to Tuberous Sclerosis Complex

INTRODUCTION

Tuberous Sclerosis Complex (TSC) is a neurocutaneous disorder associated with epilepsy (70-90% of cases) and neuropsychiatric symptoms (NPS). However, the influence of epilepsy on NPS remains unclear.

OBJECTIVES

This study aimed to describe the presence of NPS in our cohort and to establish their relationship with epilepsy severity and other clinical characteristics (genetic, neuroimaging, and EEG findings).

PATIENTS AND METHODS

Descriptive, cross-sectional, single-centre study of adults (18-65 years) with TSC, without significant intellectual disability. Patients underwent comprehensive neurological and neuropsychological assessment, which included cognitive, depression, and quality of life evaluations, alongside the TAND-checklist for NPS.

RESULTS

Twenty-eight patients with TSC were included (19 women, 44.7 ± 14.4 years). Seven patients had TSC1 variants and 11 had TSC2 variants. Nineteen (67.86 %) patients had epilepsy, 7(36.84 %) of them exhibiting drug-resistant epilepsy. Five (17.86 %) presented Infantile Spasms in the past. Regarding TAND-L, the most frequent NPS were: mood swings (80 %), excessive shyness (70 %), sleep/attention disorders (60 %) and low self-esteem (50 %). A longer duration of epilepsy and a higher number of anti-seizure medications (ASM) trials correlated with poorer total IQ -Intelligence Quotient- (Pearson correlation = -0.53, significant at 0.007 and -0.45, significant at 0.03, respectively). Patients carrying a TSC2 variant or with a history of Infantile Spasms had higher intellectual disability and worse TAND scores (p < 0.05). Despite the high prevalence of NPS, only 4(14.28 %) patients had received specific psychiatric care.

CONCLUSION

Patients with TSC and severe epilepsy showed worse neuropsychiatric outcomes. The high prevalence of NPS underscores the need for specific protocols for early detection and intervention.

Diagnostic Journey for Tuberous Sclerosis Complex-Interviews From a Clinical Trial

Tuberous sclerosis complex (TSC) is a genetic condition characterized by both medical and neuropsychiatric diagnoses that emerge across the lifespan. As part of a clinical trial, caregivers of children with TSC were interviewed about their experiences navigating medical, school, and social services. Semistructured interviews (N = 20) with caregivers of children with TSC (27-60 months) were conducted upon exit from the study. The interviews covered topics related to experiences following diagnosis, interactions with providers, sources of information, and access to services and treatment. The main themes from the caregiver interviews included: (1) sources of information about TSC and treatment; (2) access to high-quality and expert medical care; (3) perception and diagnosis of TAND; (4) impact of epilepsy on daily life, intervention, and schooling; and (5) access to therapeutic services, compatible providers, and evaluations. Additionally, parents provided recommendations for other caregivers navigating their child's early treatment following diagnosis. These results reflect the importance of current research priorities for TSC stakeholders, including implementation of existing clinical guidelines, improved access to TSC expertise, and coordinated and integrated health care.

The power of human stem cell-based systems in the study of neurodevelopmental disorders

Neurodevelopmental disorders (NDDs) affect 15% of children and are usually associated with intellectual disability, seizures, and autistic behaviors, among other neurological presentations. Mutations in a wide spectrum of gene families alter key stages of human brain development, leading to defects in neural circuits or brain architecture. Studies in animal systems have provided important insights into the pathobiology of several NDDs. Human stem cell technologies provide a complementary system that allows functional manipulation of human brain cells during developmental stages that would otherwise be inaccessible during human fetal brain development. Therefore, stem cell-based models advance our understanding of human brain development by revealing human-specific mechanisms contributing to the broad pathogenesis of NDDs. We provide a comprehensive overview of the latest research on two and three-dimensional human stem cell-based models. First, we discuss convergent cellular and molecular phenotypes across different NDDs that have been revealed by human iPSC systems. Next, we examine the contribution of in vitro human neural systems to the development of promising therapeutic strategies. Finally, we explore the potential of stem cell systems to draw mechanistic insight for the study of sex dimorphism within NDDs.

Impaired GABAergic regulation and developmental immaturity in interneurons derived from the medial ganglionic eminence in the tuberous sclerosis complex

GABAergic interneurons play a critical role in maintaining neural circuit balance, excitation-inhibition regulation, and cognitive function modulation. In tuberous sclerosis complex (TSC), GABAergic neuron dysfunction contributes to disrupted network activity and associated neurological symptoms, assumingly in a cell type-specific manner. This GABAergic centric study focuses on identifying specific interneuron subpopulations within TSC, emphasizing the unique characteristics of medial ganglionic eminence (MGE)- and caudal ganglionic eminence (CGE)-derived interneurons. Using single-nuclei RNA sequencing in TSC patient material, we identify somatostatin-expressing (SST+) interneurons as a unique and immature subpopulation in TSC. The disrupted maturation of SST+ interneurons may undergo an incomplete switch from excitatory to inhibitory GABAergic signaling during development, resulting in reduced inhibitory properties. Notably, this study reveals markers of immaturity specifically in SST+ interneurons, including an abnormal NKCC1/KCC2 ratio, indicating an imbalance in chloride homeostasis crucial for the postsynaptic consequences of GABAergic signaling as well as the downregulation of GABAA receptor subunits, GABRA1, and upregulation of GABRA2. Further exploration of SST+ interneurons revealed altered localization patterns of SST+ interneurons in TSC brain tissue, concentrated in deeper cortical layers, possibly linked to cortical dyslamination. In the epilepsy context, our research underscores the diverse cell type-specific roles of GABAergic interneurons in shaping seizures, advocating for precise therapeutic considerations. Moreover, this study illuminates the potential contribution of SST+ interneurons to TSC pathophysiology, offering insights for targeted therapeutic interventions.

Development and Pilot Validation of the DuMAND Checklist to Screen for Duchenne Muscular Dystrophy-Associated Neurobehavioral Difficulties (DuMAND)

Background

Patients with Duchenne muscular dystrophy (DMD) face a higher risk of neurobehavioral problems, yet an international consensus on screening, assessing, and managing these difficulties is lacking.

Objective

This report introduces the term Duchenne Muscular Dystrophy-Associated Neurobehavioral Difficulties (DuMAND) to comprehensively cover the spectrum of neurobehavioral issues in DMD patients, including behavior, psychiatric disorders, and various cognitive, academic, and psychosocial deficits. To facilitate screening, the DuMAND Checklist, a 43-item tool with five subscales, was developed.

Methods and results

DuMAND categories were derived through literature review, parent (48 mothers and 37 fathers), and expert (n = 28) input and feedback. The DuMAND Checklist subscales were developed iteratively, incorporating item selection, expert panel (n = 10) assessment for face validity, comprehensiveness, and a pilot validation study in a DMD sample (n = 20). DuMAND encompasses five categories: cognition and learning, social responsiveness, emotion regulation, externalizing behavior, and eating and sleeping. Preliminary validation of the DuMAND Checklist indicates acceptable-to-excellent internal consistency and construct validity.

Conclusion

By introducing the DuMAND concept, this study seeks to inspire a consensus approach for screening, assessing, and managing neurobehavioral issues in DMD. Incorporating screening, using the DuMAND Checklist, in addition to medical follow-up will facilitate early intervention, addressing a critical gap in identification of neurobehavioral disorders in DMD. Future research is needed to further evaluate psychometric properties of the DuMAND Checklist and investigate the natural course of DuMAND.

Development and Feasibility of the Self-Report Quantified Tuberous Sclerosis Complex-Associated Neuropsychiatric Disorders Checklist (TAND-SQ)

BACKGROUND

Tuberous sclerosis complex-associated neuropsychiatric disorders (TAND) are often present but underidentified and undertreated in individuals with tuberous sclerosis complex (TSC). The clinician-completed TAND-Lifetime Checklist (TAND-L) was developed to address this identification and treatment gap. Stakeholder engagement identified the need for a TAND Checklist that can (1) be completed by caregivers or individuals with TSC and (2) quantify TAND difficulties. The aim of this study was to develop a self-report quantified TAND Checklist (TAND-SQ) and conduct feasibility and acceptability testing.

METHODS

This aim was addressed in three phases: (1) development of the TAND-SQ Checklist, (2) feasibility and acceptability testing of the "near-final" TAND-SQ Checklist, and (3) preparation of the final TAND-SQ Checklist. Participants included 23 technical experts from the TAND consortium in all phases and 58 lived experts (caregivers and individuals with TSC) in phase 2. All participants completed a TAND-SQ Checklist and a checklist feedback form.

RESULTS

Phase 1 additions to the TAND-SQ, when compared with the TAND-L, included four new items and a quantification rating. Phase 2 showed high ratings for the "near-final" TAND-SQ Checklist on comprehensiveness, clarity, ease of use, and overall acceptability. In phase 3, questions on strengths, strategies, and a TAND Cluster Profile were added.

CONCLUSION

The TAND-SQ Checklist is presented here for use by individuals with TSC and their caregivers. The next steps as part of the TANDem project include internal and external validation of the checklist and linking of TAND Cluster Profiles generated from the checklist to evidence-informed consensus recommendations within a smartphone application.

International consensus recommendations for the identification and treatment of tuberous sclerosis complex-associated neuropsychiatric disorders (TAND)

BACKGROUND

Tuberous sclerosis complex (TSC) is associated with a wide range of physical manifestations for which international clinical recommendations for diagnosis and management have been established. TSC is, however, also associated with a wide range of TSC-Associated Neuropsychiatric Disorders (TAND) that are typically under-identified and under-treated yet associated with a profound burden of disease. The contemporary evidence base for the identification and treatment of TAND is much more limited and, to date, consensus recommendations for the diagnosis and management of TAND have also been limited and non-specific.

METHODS

The TANDem project was launched with an international, interdisciplinary, and participatory consortium of 24 individuals, including TSC family representatives, from all World Health Organization (WHO) regions but one. One of the aims of the TANDem project was to generate consensus recommendations for the identification and treatment of TAND. At the time of this project, no internationally adopted standard methodology and methodological checklists existed for the generation of clinical practice recommendations. We therefore developed our own systematic procedure for evidence review and consensus-building to generate evidence-informed consensus recommendations of relevance to the global TSC community.

RESULTS

At the heart of the consensus recommendations are ten core principles surrounded by cluster-specific recommendations for each of the seven natural TAND clusters identified in the literature (autism-like, dysregulated behavior, eat/sleep, mood/anxiety, neuropsychological, overactive/impulsive, and scholastic) and a set of wraparound psychosocial cluster recommendations. The overarching recommendation is to "screen" for TAND at least annually, to "act" using appropriate next steps for evaluation and treatment, and to "repeat" the process to ensure early identification and early intervention with the most appropriate biological, psychological, and social evidence-informed approaches to support individuals with TSC and their families.

CONCLUSIONS

The consensus recommendations should provide a systematic framework to approach the identification and treatment of TAND for health, educational, social care teams and families who live with TSC. To ensure global dissemination and implementation of these recommendations, partnerships with the international TSC community will be important. One of these steps will include the generation of a "TAND toolkit" of "what to seek" and "what to do" when difficulties are identified in TAND clusters.

Understanding the impact of tuberous sclerosis complex: development and validation of the TSC-PROM

BACKGROUND

Tuberous sclerosis complex (TSC) is a rare and complex genetic disorder, associated with tumor growth in various organ systems, epilepsy, and a range of neuropsychiatric manifestations including intellectual disability. With improving patient-centered care and targeted therapies, patient-reported outcome measures (PROMs) are needed to measure the impact of TSC manifestations on daily functioning. The aim of this study was to develop a TSC-specific PROM for adults that captures the impact of TSC on physical functions, mental functions, activity and participation, and the social support individuals with TSC receive, called the TSC-PROM.

METHODS

COSMIN methodology was used to develop a self-reported and proxy-reported version. Development and validation consisted of the following studies: PROM development, content validity, structural validity, internal consistency, and construct validity. The International Classification of Functioning and Disability was used as a framework. Content validity was examined by a multidisciplinary expert group and cognitive interview study. Structural and construct validity, and internal consistency were examined in a large cohort, using confirmatory factor analysis, hypotheses testing, and Cronbach's alpha.

RESULTS

The study resulted in an 82-item self version and 75-item proxy version of the TSC-PROM with four subscales (physical functions 18 and 19 items, mental functions 37 and 28 items, activities and participation 13 and 14 items, social support 13 items, for self version and proxy version respectively). Sufficient results were found for structural validity with sufficient unidimensionality for each subscale. With regard to construct validity, 82% of the hypotheses were met for the self version and 59% for the proxy version. The PROM showed good internal consistency (Cronbach's alpha 0.78-0.97).

CONCLUSIONS

We developed a PROM for adults with TSC, named TSC-PROM, showing sufficient evidence for reliability and validity that can be used in clinical and research settings to systematically gain insight into their experiences. It is the first PROM in TSC that addresses the impact of specific TSC manifestations on functioning, providing a valuable, patient-centered addition to the current clinical outcomes.

Childhood tuberous sclerosis complex in southern Sweden: a paradigm shift in diagnosis and treatment

AIM

To investigate the complete clinical spectrum of individuals with paediatric tuberous sclerosis complex in southern Sweden and explore changes over time.

METHODS

In this retrospective observational study, 52 individuals aged up to 18 years at the study start were followed-up at regional hospitals and centres for habilitation from 2000 to 2020.

RESULTS

Cardiac rhabdomyoma was detected prenatally/neonatally in 69.2% of the subjects born during the latest ten years of the study period. Epilepsy was diagnosed in 82.7% of subjects, and 10 (19%) were treated with everolimus, mainly (80%) for a neurological indication. Renal cysts were detected in 53%, angiomyolipomas in 47%, astrocytic hamartomas in 28% of the individuals. There was a paucity of standardized follow-up of cardiac, renal, and ophthalmological manifestations and no structured transition to adult care.

CONCLUSION

Our in-depth analysis shows a clear shift towards an earlier diagnosis of tuberous sclerosis complex in the latter part of the study period, where more than 60% of cases showed evidence of this condition already in utero due to the presence of a cardiac rhabdomyoma. This allows for preventive treatment of epilepsy with vigabatrin and early intervention with everolimus for potential mitigation of other symptoms of tuberous sclerosis complex.

Spine morphogenesis and synapse formation in tubular sclerosis complex models

Tuberous sclerosis complex (TSC) is caused by mutations in the Tsc1 or Tsc2 genes, whose products form a complex and inactivate the small G-protein Rheb1. The activation of Rheb1 may cause refractory epilepsy, intellectual disability, and autism, which are the major neuropsychiatric manifestations of TSC. Abnormalities in dendritic spines and altered synaptic structure are hallmarks of epilepsy, intellectual disability, and autism. In addition, spine dysmorphology and aberrant synapse formation are observed in TSC animal models. Therefore, it is important to investigate the molecular mechanism underlying the regulation of spine morphology and synapse formation in neurons to identify therapeutic targets for TSC. In this review, we focus on the representative proteins regulated by Rheb1 activity, mTORC1 and syntenin, which are pivotal downstream factors of Rheb1 in the alteration of spine formation and synapse function in TSC neurons.