Search Results (322)

Background: Neurocutaneous syndromes (NCS), including neurofibromatosis type 1 (NF1), tuberous sclerosis complex (TSC), and Sturge–Weber syndrome (SWS), are rare neurodevelopmental disorders frequently associated with epilepsy, cognitive impairment, and behavioural difficulties. Although caused by different genetic alterations, these disorders share biological mechanisms that influence brain development, neuronal connectivity, and network excitability. Beyond being a common neurological manifestation, epilepsy is increasingly recognized as an important factor influencing cognitive and behavioural outcomes in neurocutaneous syndromes. Methods: This narrative review summarizes current evidence on the relationship between epilepsy, cognitive dysfunction, and behavioural manifestations in major neurocutaneous syndromes. Attention is given to epileptogenic mechanisms, shared molecular pathways, and factors influencing long-term neurodevelopmental outcomes. Results: Epilepsy is consistently associated with cognitive and behavioural outcomes in neurocutaneous syndromes, particularly in disorders characterized by early-onset and treatment-resistant seizures. Early seizure onset, poor seizure control, and persistent network dysfunction have been associated with intellectual disability, executive dysfunction, attention deficits, autism spectrum features, and impaired adaptive functioning. In TSC and SWS, epilepsy burden is strongly associated with cognitive outcome, particularly in interaction with underlying structural, vascular, and molecular abnormalities. In neurofibromatosis type 1, cognitive and behavioural difficulties are more often related to altered neuronal connectivity and dysregulated signalling pathways, although epilepsy may further contribute to neurodevelopmental impairment in a subset of patients. Despite their distinct genetic origins, these disorders converge on dysregulated RAS/MAPK, PI3K/AKT/mTOR, and Gαq-mediated signalling pathways that influence both epileptogenesis and brain development. Conclusions: Despite their distinct genetic origins, major neurocutaneous syndromes converge on common pathways linking epilepsy, network dysfunction, and neurodevelopmental impairment. Understanding how these processes interact may facilitate earlier intervention and more accurate prognostic assessment, ultimately improving long-term outcomes for affected children. Full article

Neurofibromatosis type 1 (NF1) is a genetic tumor predisposition syndrome characterized by a substantial risk of developing peripheral nerve sheath tumors, including malignant peripheral nerve sheath tumors (MPNSTs), which occur in 8–13% of patients. Approximately 50% arise from plexiform neurofibromas (PNs) and 40% develop de novo, making them a major cause of premature mortality. Current clinical management is limited by the intrinsic shortcomings of standard imaging modalities: magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT), and tissue biopsy in distinguishing benign PNs from early malignant transformation, which remains a major clinical challenge. This progression follows a stepwise molecular continuum marked by cumulative genetic alterations and widespread epigenetic dysregulation. In this setting, liquid biopsy has emerged as a promising non-invasive approach to help fill these diagnostic gaps by enabling real-time molecular monitoring through the analysis of circulating tumor DNA (ctDNA) and other blood-based biomarkers. This review examines the current evidence supporting liquid biopsy applications in NF1 management, including early detection of MPNST, discrimination between benign and malignant lesions, mutational profiling for therapeutic targeting, and disease monitoring before and during treatment. We also discuss the current evidence on fragmentomics, methylomics and driver mutation profiling as tools to distinguish PNs from MPNSTs. Recent evidence suggests that liquid biopsy may help detect molecular changes associated with malignant transformation before clear clinical signs emerge, potentially opening an important window for intervention and supporting a shift towards a more molecularly informed surveillance model. Finally, this review considers the possible extension of liquid biopsy to other tumor types, including NF1-deficient breast cancer, and outlines a future management framework aimed at improving early diagnosis and personalized therapeutic intervention in this high-risk population. Full article

Background/Objectives: For patients with profound deafness resulting from auditory nerve pathology, as in Neurofibromatosis type 2, auditory brainstem implantation (ABI) can restore meaningful acoustic input. The literature reporting real-world results for ABI users is limited, especially regarding patients with bilateral implants. Here, we provide an updated report on the audiologic outcomes among all ABI patients treated at a tertiary institution, including high-performing bilateral ABI users. Methods: In this updated and expanded retrospective case series, audiologic outcomes were reviewed in sixteen consecutive patients who underwent ABI placement by a single neurosurgeon-neurotologist team at our center since 2018. Implantation in four of these patients was on their second side after having undergone first side implantation prior to receiving care at our hospital. Main outcome measures were sound awareness (sound-field threshold testing) and speech understanding (pattern perception, spondee, open-set speech testing). Results: Sound awareness was achieved in 100% of patients (16/16) using an average of 12 electrodes (range 7–20). Persistent non-auditory sensations were reported by 12.5% (2/16). Postoperative speech differentiation (with or without lip-reading) was experienced in 87.5% (14/16). Two second-sided ABI recipients experienced exceptional outcomes as high-performing outliers: one achieved 57% audio only and 86% audio + visual hearing in noise test (HINT) sentence scores; the second bilateral user scored 92% with auditory-only input. Conclusions: ABI represents a viable option for patients who are at risk of developing bilateral profound deafness resulting from auditory nerve disruption. Second sided device implantation is safe and has the potential to significantly improve auditory outcomes. Full article

Background/Objectives: Scoliosis is a three-dimensional deformity involving coronal curvature, axial rotation, and sagittal imbalance, which may alter thoracic geometry and reduce ventilatory capacity. Traditional two-dimensional radiographic measures incompletely represent the complexity of axial rotation, and the apical vertebra is not always the most rotated vertebra. We aimed to determine whether computed tomography (CT)-derived three-dimensional vertebral rotation indices, particularly global rotational asymmetry between main and compensatory curves, are associated with pulmonary function impairment in a large heterogeneous scoliosis cohort. Methods: We retrospectively reviewed 250 patients with scoliosis who underwent full-spine CT and spirometry within a 1-year interval (2013–2023). Vertebral rotation was measured using the Aaro–Dahlborn method. Rotation indices included apical rotation (R(Apex)), averaged apical rotation across the apical vertebra and adjacent levels (R(Avg)), and rotational asymmetry defined as the absolute difference between rotation in the main and compensatory curves (ΔR(M–C)). Pulmonary function outcomes were FVC (L), FEV1 (L), FVC% and FEV1%. Pearson correlation and multivariate linear regression, adjusted for age, sex, height, and weight, were performed; sensitivity analyses, additionally adjusted for upright Cobb angle and thoracic kyphosis (TK) to evaluate whether ΔR(M–C) provided independent explanatory information, and subgroup analyses by etiology were performed. Results: The cohort had a mean age of 15.6 ± 5.7 years; 49.6% were female. All rotation indices showed significant negative correlations with pulmonary function in the overall cohort. ΔR(M–C) showed the strongest associations with FVC% (r = −0.66) and FEV1% (r = −0.64), as well as with absolute volumes (FVC, r = −0.59; FEV1, r = −0.58). In adjusted multivariate analyses, models incorporating ΔR(M–C) consistently demonstrated the highest explanatory performance compared with models based on R(Apex) or R(Avg). Subgroup analysis revealed the strongest associations in neurofibromatosis-related scoliosis (r = −0.87) and congenital scoliosis (r = −0.71). Associations were attenuated in neuromuscular subtypes and did not reach statistical significance in SMA. In sensitivity analyses adjusting for Cobb angle and thoracic kyphosis, ΔR(M–C) retained a robust independent association with FVC% (unstandardized B = −0.82 percentage points per 1°, 95% CI −0.98 to −0.66; p < 0.001; partial F = 103, p < 0.001), while neither Cobb angle nor TK remained statistically significant after adjustment for ΔR(M–C); comparable patterns were observed across FEV1%, FVC, and FEV1. Conclusions: CT-derived global rotational asymmetry between the main and compensatory curves is strongly associated with pulmonary function impairment in scoliosis and demonstrates superior explanatory performance to single-level rotation indices and retains independent explanatory value after adjustment for conventional 2D radiographic parameters (Cobb angle and thoracic kyphosis). Incorporating a CT-derived metric may complement traditional two-dimensional assessments for functional risk stratification. Full article

Ultrasonography can assist in the preoperative evaluation and postoperative surveillance of superficial soft tissue tumors of the hand. We present an ultrasound-based identification of a neurofibroma in a patient with neurofibromatosis type 1 (NF1). A 45-year-old male presented with a slowly enlarging subcutaneous mass over the dorsal aspect of the hand associated with localized paresthesia. Physical examination revealed characteristic NF1 stigmata, including café-au-lait macules, axillary freckling, and craniofacial asymmetry suggestive of sphenoid wing dysplasia. High-resolution ultrasonography demonstrated a well-defined hypoechoic fusiform lesion along the course of a digital nerve, suggestive of a peripheral nerve sheath tumor. Magnetic resonance imaging showed a T2-hyperintense lesion compatible with a nerve sheath tumor. Surgical excision was subsequently performed, and histopathological examination confirmed a localized neurofibroma with incorporation of native nerve fascicles within a myxoid spindle cell matrix. Serial postoperative ultrasonography at 3 and 12 months demonstrated no evidence of local recurrence. This case highlights ultrasonography as a practical, radiation-free, and cost-effective modality for both preoperative assessment and longitudinal follow-up of superficial NF1-associated neurofibromas. Full article

Juvenile myelomonocytic leukemia (JMML) is a rare, aggressive myeloproliferative neoplasm of early childhood characterized by constitutive activation of the RAS-MAPK signaling pathway. RASopathies are a heterogeneous group of complex genetic disorders arising from germline mutations that dysregulate RAS-MAPK signaling. Noonan syndrome, CBL syndrome, and neurofibromatosis type 1 (NF1) are the three major RASopathies predisposing to JMML. More than 90% of JMML cases harbor germline or somatic mutations in one of five canonical driver genes—PTPN11, NRAS, KRAS, NF1, or CBL—establishing JMML as the prototypical malignant manifestation of RASopathy biology. The fifth edition of the World Health Organization Classification of Tumours reclassified JMML as a myeloproliferative neoplasm while the International Consensus Classification adopted JMML under pediatric and/or germline mutation-associated disorders, introducing a JMML-like category for cases lacking five canonical mutations but harboring emerging drivers such as SH2B3::LNK alterations and ALK::ROS1 fusions. The distinction between germline and somatic mutations profoundly influences prognosis: e.g., germline PTPN11-associated myeloproliferations and many germline CBL cases undergo spontaneous resolution, whereas somatic PTPN11- and NF1-mutated JMML is more aggressive and requires prompt allogeneic hematopoietic stem cell transplantation. DNA methylation profiling has emerged as the most robust prognostic framework, with consensus defining high-, intermediate-, and low-methylation subgroups that independently predict outcome. Both genotype and DNA methylation subclassification have been integrated into clinical decision-making, incorporating pretransplant azacitidine, watch-and-wait approaches for favorable-risk patients, and emerging targeted therapies including MEK inhibitors. This review synthesizes recent advances in understanding JMML as a bona fide RASopathy; provides a diagnostic algorithm, molecular landscapes, and prognostic models; and highlights opportunities for molecularly targeted therapeutic intervention. Full article

Moyamoya angiopathy (MMA) is a rare, chronic progressive cerebrovascular condition characterized by bilateral stenosis or occlusion of the terminal internal carotid arteries and their major branches. This progressive occlusion triggers the development of telangiectatic and fragile vessels at the base of the brain, creating the characteristic angiographic appearance of a “puff of smoke.” Depending on the etiology, MMA is classified as Moyamoya Disease (MMD) when idiopathic and primary or Moyamoya Syndrome (MMS) when associated with underlying systemic conditions. While the RNF213 gene, particularly the p.R4810K variant, is recognized as the major susceptibility locus for MMD in East Asian populations, it does not fully account for the global genetic landscape or the phenotypic diversity of the disease. This review provides a comprehensive overview of the genetic architecture of the entire MMA spectrum, exploring loci beyond RNF213. We analyze the role of genes involved in vascular smooth muscle cell contractility (ACTA2, MYH11), TGF-β signaling, and DNA repair mechanisms that drive MMS, alongside the genetic basis of syndromic forms associated with neurofibromatosis type 1, trisomy 21, and RASopathies. Understanding these diverse genetic drivers is crucial for early diagnosis, risk stratification, and the development of targeted molecular therapies. Full article

Plexiform neurofibromas (pNF1s) are benign peripheral nerve sheath tumors caused by NF1 loss, leading to dysregulated RAS/mitogen-activated protein kinase (MAPK) signaling. While the mitogen-activated protein kinase kinase (MEK) inhibitors, selumetinib and mirdametinib, can reduce tumor volume, surgical resection remains the primary treatment for immediate debulking and symptom relief. Complete removal is often limited by tumor infiltration along nerve plexuses, and residual tumors may undergo postsurgical tissue remodeling, producing localized regions of stiffened extracellular matrix (ECM). The impact of ECM stiffness on pNF1 growth and drug responses remains unclear. Using immortalized patient-derived pNF1 tumor cell lines cultured in 3D hydrogels with defined stiffness (1.5 kPa, soft; 7 kPa, stiff), we found that stiff ECM promoted spread morphology, increased growth, and progressive intracellular softening. Stiff ECM also reduced lysyl oxidase (LOX) expression, suggesting mechanoadaptive ECM remodeling, and increased P-glycoprotein expression. Under the same conditions, stiff ECM was associated with reduced sensitivity to selumetinib. These results provide the first evidence that ECM stiffening, including that plausibly associated with postsurgical remodeling, may contribute to pNF1 growth and reduced sensitivity to selumetinib in this 3D pNF1 culture model. Our findings highlight mechanobiology as a key regulator of tumor behavior and support further investigation of ECM-targeted strategies to improve outcomes in neurofibromatosis type 1 (NF1). Full article

Background: To investigate the risk factors for and prognostic implications of massive blood loss during posterior spinal instrumentation and fusion (PSIF) in pediatric patients with scoliosis. Methods: We retrospectively analyzed the electronic medical records of 460 children who underwent scheduled PSIF under general anesthesia between June 2021 and January 2024. Patients were grouped based on intraoperative blood loss: massive (estimated blood loss [EBL]/estimated blood volume [EBV] ≥ 30%) and nonmassive (EBL/EBV < 30%). Perioperative parameters were compared. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors for massive intraoperative blood loss. Results: Among the 460 patients with scoliosis who underwent PSIF, 188 were male and 272 were female (mean age 9.4 ± 4.1 years). Massive intraoperative blood loss occurred in 126 (27%) patients. Factors associated with massive blood loss included age, preoperative Cobb angle, history of heart disease or neurofibromatosis, number of previous scoliosis surgeries, operative time, number of fused levels, number of pedicle screws inserted, and whether osteotomy was performed. Multivariate analysis identified younger age (odds ratios [OR] = 0.829, 95% confidence interval [CI], 0.751–0.914, p < 0.001), history of heart disease (OR = 4.338, 95% CI: 1.637–11.498, p = 0.003), greater number of fused levels (OR = 1.118, 95% CI: 1.014–1.233, p = 0.025), and longer operative time (OR = 1.008, 95% CI: 1.005–1.012, p < 0.001) as independent risk factors. Additionally, the massive blood loss group had a longer postoperative hospital stay (p = 0.008) and a higher rate of postoperative allogeneic blood transfusion (7.1% vs. 1.2%, p = 0.002) than the nonmassive blood loss group. Conclusions: Younger age, preexisting heart disease, a greater number of fused levels, and longer operation duration are independent risk factors for massive intraoperative blood loss in children undergoing PSIF for scoliosis. Full article

Neurofibromatosis type 1 (NF1) patients are predisposed to develop plexiform neurofibromas (PNFs). By cross-comparison of RNA sequencing and RUNX1-CHIP sequencing data on mouse PNFs, we found that transcripts encoding the NF1-interacting p97/valosin-containing protein (VCP) gene are overexpressed in PNFs. Co-immunoprecipitation confirmed that VCP bounded to neurofibromin. Western blot and immunostaining confirmed VCP overexpression in both mouse and human PNFs. Treatment of primary mouse PNF Schwann cells with CB-5083, a p97/VCP inhibitor, led to accumulation of poly-ubiquitinated proteins and generation of irresolvable proteotoxic stress. Pharmacological or genetic inhibition of VCP reduced mouse PNF cell-derived sphere number, and genetic inhibition of Vcp in Schwann cell precursors decreased tumor-like lesion numbers in a cell transplantation model. In vivo treatment with CB-5083 in Nf1^fl/fl;DhhCre PNF mice significantly inhibited cell proliferation, increased cell apoptosis and reduced PNF volume. The combination with a MEK inhibitor did not increase efficacy compared to the single agent, supporting the hypothesis that VCP functions in parallel to, and may be modulated by, RAS–MAPK signaling under stress or oncogenic conditions. The significant effects of VCP inhibition in this pre-clinical study suggest a potential novel therapy for patients with PNFs. Full article

We describe a case of a 3-year-old girl with neurofibromatosis type 1 presenting with arterial hypertension, in whom multimodal vascular imaging identified significant right renal artery stenosis. The patient was successfully treated with percutaneous transluminal renal angioplasty; however, post-procedural Doppler ultrasound revealed a transient vascular fistula. Changes in renal arterial inflow during the procedure may have temporarily altered pressure gradients, facilitating the opening of communication involving pre-existing compensatory collateral vessels. This case illustrates the diagnostic value of multimodal vascular imaging in pediatric hypertension and highlights a rare, self-limiting post-interventional vascular phenomenon. Full article

Neurofibromatosis type 1 (NF1) and NF2-related schwannomatosis (NF2-SWN) are major genetic tumor predisposition syndromes characterized by progressive, often debilitating neoplasms of the peripheral and central nervous systems. Over the past five years, substantial advances in molecular genetics, signaling biology, and targeted therapeutic development have reshaped diagnostic and management paradigms for both disorders. This Perspective synthesizes recent developments, including gene-based reclassification, emergence of MEK inhibitor therapy in NF1, renewed evaluation of bevacizumab and kinase-pathway inhibitor brigatinib, the discovery of a novel TβR1-RKIP pathogenic axis, and a brain-penetrant HDAC inhibitor in NF2-SWN. These insights highlight a shift toward precision-medicine strategies and mechanistically driven therapies poised to redefine future clinical care. Full article

Background: Difficult benign intracranial tumors (including meningiomas, schwannomas, neurofibromatosis-related tumors, and pituitary neuroendocrine tumors) have substantial morbidity in patients. Due to their limited treatment options, there is a need for individualized treatment beyond histological and surgical approaches. Objective: To summarize how novel treatment innovations have been implemented for these tumors, meningiomas and schwannomas are prioritized, followed by NF-associated neoplasms, and then pituitary neuroendocrine tumors in comparison to low-grade gliomas. Methods: We summarize the current knowledge relating to targeted therapies for gliomas, meningiomas, schwannomas, neurofibromatosis (NF) tumors, and pituitary neuroendocrine tumors to investigate an individual’s treatment options for difficult benign brain tumors. This review synthesizes evidence on tumor genomics and molecular markers, supported by methylation-based classification, immunohistochemistry, and functional assays, emphasizing current clinical applications. Evidence Synthesis: The recent data show that DNA methylation-based models can predict post-surgical outcomes and radiotherapy responses, enabling risk stratification and radiotherapy benefit prediction. Early signals support target-directed treatment, including cMET blockade that radiosensitizes NF2 schwannoma models, brigatinib-associated tumor shrinkage in NF2-deficient models, and PitNET organoid data. Conclusions: We support clinical decision-making that utilizes molecular profiling with functional testing to guide targeted treatment. We also identify evidence gaps such as biomarker-defined prospective trials that are needed for broader clinical implementation. Full article

There is no approved drug therapy for schwannomas associated with NF2-related schwannomatosis (NF2-SWN). Neither life-saving surgical resection or radiation are curative and can compound the debilitating neurological effects of the schwannomas. We previously identified fimepinostat, a dual histone deacetylase (HDAC)/phosphoinositide-3 kinase (PI3K) inhibitor, as a promising drug candidate with pro-apoptotic effects on NF2-related schwannomas. This preclinical study used the pharmaceutical formulation of fimepinostat to confirm its efficacy in schwannomas and identify pro-apoptotic signaling pathways. Fimepinostat was tested in human schwannoma model cells, patient-derived primary vestibular and non-vestibular schwannoma cells, and in a sciatic nerve allograft model. The signaling pathways leading to caspase-3-dependent apoptosis were elucidated using immune assays, flow cytometry, imaging, proteome, and acetylome analysis. Acute exposure to fimepinostat led to p21-dependent cell cycle inhibition, upregulation of tumor necrosis factor-related apoptosis-inducing ligand receptor 2 (TRAIL R2), and downregulation of tumor necrosis factor receptor 1 (TNFR1), Yes-associated protein (YAP), and inhibitors of apoptosis. Moreover, fimepinostat downregulated cytokine and chemokine secretion increased by merlin loss in schwannoma cells. Fimepinostat is a promising new drug intervention for NF2-SWN patients with the potential to promote tumor regression. Full article

Background: Vestibular schwannomas (VSs) are benign tumors that can cause significant morbidity, particularly in neurofibromatosis 2 (NF2) patients, in whom conventional treatments have important limitations. Merlin is a tumor suppressor protein encoded by the Neurofibromin 2 (NF2) gene, and the loss of its function leads to the activation of multiple signaling pathways, providing a rationale for targeted pharmacological therapies. Agents such as bevacizumab and other receptor tyrosine kinase inhibitors (TKIs) have shown variable efficacy but remain limited by toxicity and inconsistent responses. This review aims to evaluate the efficacy and safety of targeted therapies for VSs. Methods: This study was conducted according to PRISMA 2020 guidelines, using a PICO-based search of PubMed, EMBASE, and Scopus to identify studies on pharmacological therapies for VSs published between 2000 and 2025. Eligible human studies included clinical trials and observational studies reporting efficacy, safety, neuroimaging and audiological outcomes. Results: In total, 23 studies were analyzed, predominantly involving NF2-associated VSs. Treatment with bevacizumab was the most frequently investigated medical therapy and yielded the most consistent tumor control along with occasional hearing improvement, albeit with frequent but mostly manageable adverse events. Other targeted agents, including everolimus and TKIs, demonstrated limited or variable efficacy with acceptable toxicity profiles. Conclusions: VSs, particularly in NF2 patients, can cause significant morbidity and are often poorly managed by surgery or radiotherapy. Consequently, targeted medical therapies, especially anti-angiogenic agents, have emerged as valuable alternatives. Bevacizumab shows the most consistent benefits in tumor control, hearing stabilization, and quality of life, despite heterogeneous responses and notable toxicity. Evidence suggests that treatment discontinuation may lead to rapid tumor rebound, highlighting the need for long-term or maintenance strategies and careful monitoring. Future studies are needed to evaluate medical therapy integration with conventional treatments. Full article