Search Results (1,090)

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is characterized by the predominance of optic neuritis, myelitis, acute disseminated encephalomyelitis (ADEM), and cortical encephalitis, and can be diagnosed by the presence of pathogenic immunoglobulin G (IgG) antibodies targeting the extracellular domain of MOG in the serum and cerebrospinal fluid (CSF). Initially considered a variant of multiple sclerosis (MS) or neuromyelitis optica spectrum disorder (NMOSD), it is now widely recognized as a separate entity, supported by converging evidence from serological, pathological, and clinical studies. Patients with MOGAD often exhibit better recovery from acute attacks; however, their clinical and pathological features vary based on the immunological role of MOG-IgG via antibody- or complement-mediated perivenous demyelinating pathology, in addition to MOG-specific cellular immunity, resulting in heterogeneous demyelinated lesions from vanishing benign forms to tissue necrosis, even though MOGAD is not a mild disease. The key is the immunological mechanism of devastating lesion coalescence and long-term degenerating mechanisms, which may still accrue, particularly in the relapsing, progressing, and aggressive clinical course of encephalomyelitis. The warning features of the severe clinical forms are: (1) fulminant acute multifocal lesions or multiphasic ADEM transitioning to diffuse (Schilder-type) or tumefactive lesions; (2) cortical or subcortical lesions related to brain atrophy and/or refractory epilepsy (Rasmussen-type); (3) longitudinally extended spinal cord lesions severely affected with residual symptoms. In addition, it is cautious for patients refractory to acute stage early 1st treatment including intravenous methylprednisolone treatment and apheresis with residual symptoms and relapse activity with immunoglobulin and other 2nd line treatments including B cell depletion therapy. Persistent MOG-IgG high titration, intrathecal production of MOG-IgG, and suggestive markers of higher disease activity, such as cerebrospinal fluid interleukin-6 and complement C5b-9, could be identified as promising markers of higher disease activity, worsening of disability, and poor prognosis, and used to identify signs of escalating treatment strategies. It is promising of currently ongoing investigational antibodies against anti-interleukin-6 receptor and the neonatal Fc receptor. Moreover, due to possible refractory issues such as the intrathecal production of autoantibody and the involvement of complement in the worsening of the lesion, further developments of other mechanisms of action such as chimeric antigen receptor T-cell (CAR-T) and anti-complement therapies are warranted in the future. Full article

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an autoimmune disorder characterized by inflammation and neurodegeneration, yet current therapies lack direct neuroprotective effects. We investigated the therapeutic potential of 5-aminolevulinic acid (5-ALA), a key precursor for mitochondrial heme synthesis, in a chronic experimental autoimmune neuritis (EAN) rat model of CIDP. Rats with established EAN received daily oral 5-ALA (100 mg/kg) or vehicle. Treatment efficacy was assessed by clinical scoring, nerve histopathology, and biochemical analyses of sciatic nerves. 5-ALA administration significantly ameliorated clinical disease severity. This was associated with local immunomodulation in the sciatic nerve, marked by reduced pro-inflammatory IFN-γ and increased anti-inflammatory IL-10 levels. Concurrently, 5-ALA exerted direct neuroprotective effects, evidenced by restored mitochondrial ATP production, decreased oxidative DNA damage, upregulated antioxidant heme oxygenase-1 (HO-1), and improved myelin sheath integrity. These findings suggest that 5-ALA may offer a dual therapeutic benefit by targeting both local inflammation and mitochondrial-mediated neuroprotection. By addressing key pathological mechanisms currently unmet by standard therapies, 5-ALA emerges as a promising disease-modifying candidate for CIDP. Full article

Background/Objectives: Co-culture models of neurons and Schwann cells have been used to explore the mechanisms of myelination during development, axonal regeneration after injury, and the pathogenesis of various demyelinating neuropathies. A spontaneously immortalized Fischer rat Schwann cell line 1 (IFRS1), established from the primary culture of adult Fischer344 rat peripheral nerves, can myelinate neurites in co-cultures with primary cultured dorsal root ganglion neurons and neuronal cell lines, such as nerve growth factor (NGF)-primed PC12 cells and NSC-34 motor neuron-like cells. In this study, we aimed to establish a stable co-culture system using IFRS1 cells and ND7/23 sensory neuron-like cells. Methods: ND7/23 cells were seeded at a low density (2 × 10³/cm²) and maintained for 7 days in serum-containing medium supplemented with NGF (10 ng/mL) and the Rho kinase inhibitor Y27632 (5 μM) to promote neurite elongation. The cells were then treated with the anti-mitotic agent mitomycin C (1 μg/mL) for 12–16 h to suppress proliferative activity. Following this, the cells were co-cultured with IFRS1 cells (2 × 10⁴/cm²) and maintained at 37 °C in serum-containing medium supplemented with ascorbic acid (50 μg/mL), NGF (10 ng/mL), and ciliary neurotrophic factor (10 ng/mL). Results: Double-immunofluorescence staining performed on day 21 of the co-culture revealed myelin protein 22- or myelin basic protein-immunoreactive IFRS1 cells surrounding βIII tubulin-immunoreactive neurites emerging from ND7/23 cells. Myelin formation was further confirmed via Sudan Black B staining and electron microscopy. Conclusions: This co-culture system may provide a valuable tool for studying the processes of myelination in the peripheral nervous system, as well as the pathogenesis of various sensory neuropathies and potential novel therapeutic approaches for these conditions. Full article

Background: Hyponatremia, defined as a serum sodium concentration below 135 mmol/L, is a common and serious electrolyte disturbance in patients with traumatic brain injury (TBI), and may be treated with vaptans—vasopressin receptor antagonists that promote water excretion. This study evaluates the safety and efficacy of tolvaptan, a vaptan, in correcting hyponatremia in TBI patients compared to a non-trauma cohort. Methods: We conducted a single-center retrospective analysis of 126 adult patients in the intensive care unit who received tolvaptan. The study included 73 TBI patients and 53 non-trauma patients with chronic medical conditions. Serum sodium levels were assessed 48 h after tolvaptan administration and compared between the two groups. Results: At baseline, the mean sodium level was higher in the TBI group compared to the non-trauma group (128.3 ± 4 mmol/L vs. 125.3 ± 5 mmol/L, p = 0.003). Both groups showed a significant increase in sodium levels after 48 h of tolvaptan therapy, and while the post-treatment sodium level was higher in the TBI group, the absolute change was not significantly different between the two groups (132.3 ± 5 mmol/L vs. 130.9 ± 7 mmol/L, p = 0.18). Sodium normalization (135–145 mmol/L) occurred in 48% of TBI patients versus 30% of non-trauma patients (p = 0.045), though this difference was not statistically significant after adjusting for baseline sodium levels. No cases of osmotic demyelination syndrome were observed. Conclusions: Our preliminary analysis suggests that tolvaptan effectively increases sodium levels in both TBI and non-trauma patients with hyponatremia. Further research is needed to fully characterize this response and determine the optimal use of tolvaptan for managing hyponatremia in the TBI population. Full article

Background: Optic neuritis (ON) is a common manifestation of multiple sclerosis (MS), serving as a clinical window into central nervous system demyelination. Optical coherence tomography (OCT) and visual evoked potentials (VEPs) are complementary non-invasive tools for assessing structural and functional damage to the visual pathway. The objective of this paper is to evaluate correlations between OCT and VEP parameters in MS patients with and without a history of ON and assess their relationship with disease duration and disability (EDSS). Methods: This cross-sectional study included 54 eyes from 27 relapsing–remitting MS patients. OCT was used to measure circumpapillary and the temporal peripapillary retinal nerve fiber layer (pRNFL) and the foveal/parafoveal ganglion cell-inner plexiform layer (GCIPL) thickness. VEPs assessed P100 latency and amplitude. Patients were grouped by ON history. Results: Eyes without ON showed a significantly greater circumpapillary pRNFL thickness (mean difference: 18.27 ± 5.33 µm, p = 0.001), temporal pRNFL thickness (15.71 ± 5.49 µm, p = 0.006), and parafoveal GCIPL thickness (12.85 ± 5.3 µm, p = 0.019) compared to ON eyes. p100 latency was shorter and the amplitude was higher in NON eyes, but without statistical significance. Strong negative correlations were found between OCT thickness and EDSS and disease duration. p100 latency correlated negatively with OCT parameters, while amplitude showed a positive correlation with pRNFL thickness in ON eyes. Conclusions: OCT parameters, particularly pRNFL and GCIPL thickness, correlate with functional and clinical markers of MS. Combined OCT–VEP evaluation enhances the assessment of neurodegeneration and disease progression. Full article

Lipids, together with water and proteins, constitute the essential structure of cell membranes, and in the CNS, critically contribute to the production, function, and maintenance of the myelin sheath. Myelin produced by oligodendrocytes (OLs) acts as an electric insulator and assures proper conduction of information. Three major fractions of myelin lipids are cholesterol, phospholipids, and glycolipids. These lipids not only sculpt the myelin landscape as a structural support for proteins, but they also play a crucial role in molecular interactions underlying processes of protein trafficking and signal transductions. The high lipid content of myelin makes it susceptible to lipid metabolism disorders. Disorders in systemic and local lipid metabolism may lead to loss of myelin integrity and stability, and potentially to CNS demyelination seen in neurodegenerative diseases, notably progressive multiple sclerosis, for which there are few effective therapies. Precise interactions among disorders in lipid metabolism, function of oligodendrocytes, and demyelination/remyelination events, including de novo myelin formation and myelin remodeling processes, may lay the foundation for novel therapeutics for progressive MS and other demyelinating CNS conditions. Full article

Background/Objectives: Multifocal Motor Neuropathy (MMN) and Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) are immune-mediated polyneuropathies often treated with immunoglobulin therapy. They were prioritized for COVID-19 vaccination during the pandemic. However, their immune response following COVID-19 vaccination remains unclear. We investigated short- and long-term immune responses to COVID-19 vaccination in patients with MMN and CIDP compared to controls. Methods: In a prospective observational study, patients with CIDP or MMN and matched controls were followed over 24 months. Controls were age- and sex-matched 1:9. Participants received COVID-19 vaccines in accordance with the Danish vaccination program. Primary outcomes were levels of SARS-CoV-2 IgG antibodies and virus-neutralizing capacity. A positive vaccine response was defined as IgG > 225 AU/mL and neutralizing capacity ≥ 25%. Results: We included 34 patients and 306 matched controls. While baseline SARS-CoV-2 IgG levels were similar, controls exhibited higher IgG levels at 6- (mean difference, 88%; p = 0.008), 18- (91%; p = 0.023), and 24 months (160%; p < 0.001). Neutralization capacity was also higher in controls at 6 (10%, p = 0.004), 18 (7%, p < 0.001), and 24 months (9%, p = 0.002). Despite this, the proportion of vaccine responders did not differ between the two groups after 24 months (p = 0.196). In patients receiving immunoglobulin therapy, IgG levels were lower than in controls at 24-month follow-up alone (56%, p < 0.001); all demonstrated a positive vaccine response. Conclusions: Patients with CIDP and MMN demonstrated a positive humoral response to COVID-19 vaccination. Although IgG and neutralization levels were lower than in controls, all patients receiving immunoglobulin therapy were vaccine responders. Full article

Intercellular communication in the central nervous system (CNS) is essential for maintaining neural function and coordinating responses to injury or disease. With recent advances in single-cell and spatial transcriptomics, a growing body of research has revealed that this communication is highly dynamic, shifting across states of health, aging, demyelination, and neurodegeneration. In this review, we synthesize the current findings on intercellular communication networks involving neurons, astrocytes, microglia, oligodendrocytes, and other glial populations in the CNS across four major states: healthy homeostasis, aging, demyelinating diseases, and Alzheimer’s disease (AD). We focus on how changes in intercellular communication contribute to the maintenance or disruption of CNS integrity and function. Mechanistic insights into these signaling networks have revealed new molecular targets and pathways that may be exploited for therapeutic intervention. By comparing the intercellular signaling mechanisms across different disease contexts, we underscore the importance of CNS crosstalk not only as a hallmark of disease progression, but also as a potential gateway for precision therapy. Full article

Blood–brain barrier (BBB) deterioration with increasing age is an important factor contributing to vascular dementia. Previous studies show that endothelial nitric oxide synthase (eNOS) facilitates vascular endothelial growth factor-mediated angiogenesis and increased vascular permeability. In contrast, recent work has shown that aged hemi-deficient hemizygous eNOS^+/− mice manifest BBB disruption in association with increased incidence of thromboembolic events in the brain. To unravel whether eNOS contributes to or protects against hypoxia-induced cerebrovascular damage, we compared chronic mild hypoxia (CMH)-induced cerebrovascular angiogenic remodeling and BBB breakdown in aged (20 months old) eNOS^+/− and wild-type (WT) mice. This revealed that CMH strongly enhanced eNOS expression in cerebral blood vessels with much lower levels in eNOS^+/− mice. eNOS hemi-deficiency resulted in greater CMH-induced BBB disruption, but unexpectedly, had no effect on endothelial proliferation. eNOS^+/− mice also displayed enhanced endothelial expression of the endothelial activation markers MECA-32, VCAM-1, and β3 integrin in cerebral blood vessels, indicating greater vascular inflammation, and this correlated with increased levels of microglial activation and demyelination. Taken together, our results support the concept that eNOS plays an important protective function in the aged brain by suppressing endothelial activation and maintaining cerebrovascular health. Full article

Cathepsins, a family of lysosomal proteases, play critical roles in maintaining cellular homeostasis through protein degradation and modulation of immune responses. In the central nervous system (CNS), their functions extend beyond classical proteolysis, influencing neuroinflammation, synaptic remodeling, and neurodegeneration. Emerging evidence underscores the crucial role of microglial cathepsins in the pathophysiology of several neurological disorders. This review synthesizes current knowledge on the involvement of cathepsins in a spectrum of CNS diseases, including Parkinson’s disease, Alzheimer’s disease, multiple sclerosis, amyotrophic lateral sclerosis, epilepsy, Huntington’s disease, and ischemic stroke. We highlight how specific cathepsins contribute to disease progression by modulating key pathological processes such as α-synuclein and amyloid-β clearance, tau degradation, lysosomal dysfunction, neuroinflammation, and demyelination. Notably, several cathepsins demonstrate both neuroprotective and pathogenic roles depending on disease context and expression levels. Additionally, the balance between cathepsins and their endogenous inhibitors, such as cystatins, emerges as a critical factor in CNS pathology. While cathepsins represent promising biomarkers and therapeutic targets, significant gaps remain in our understanding of their mechanistic roles across diseases. Future studies focusing on their regulation, substrate specificity, and interplay with genetic and epigenetic factors may yield novel strategies for early diagnosis and disease-modifying treatments in neurology. Full article

Introduction: Hypertrophic olivary degeneration (HOD) is a rare form of trans-synaptic degeneration involving the Guillain–Mollaret triangle, characterized by enlargement of the inferior olivary nucleus—unlike the atrophy typical of most neurodegenerative processes. It is usually associated with stroke, surgical injury, or demyelination, but rarely follows hemorrhage from a cavernous malformation (CM). This report presents a case of HOD secondary to a mesencephalic CM hemorrhage, with emphasis on imaging findings and diagnostic considerations. Case Description: A 55-year-old woman presented with acute-onset, right-sided facial, torso, and limb hypoesthesia, along with gait instability. Neurological examination revealed sensory impairment in the right maxillary (V2) and mandibular (V3) trigeminal territories, as well as diminished pain and temperature sensation throughout the right hemibody. MRI revealed a hemorrhage in the posterior mesencephalon near the left red nucleus, leading to the diagnosis of a CM with an associated venous angioma. She was managed conservatively and improved clinically. Six months later, MRI showed hypertrophy and T2/FLAIR hyperintensity of the left inferior olive, consistent with developing HOD. At 1.5 years follow-up, olivary enlargement had progressed—now consistent with stage 2 HOD—and a bilateral palatal tremor was observed, more pronounced on the right side. DTI revealed asymmetric volume loss in the left brainstem fiber pathways at the level of the medulla oblongata, confirming trans-synaptic degeneration. Conclusions: This case highlights HOD as a rare but important complication of mesencephalic CM hemorrhage. Recognition of its characteristic imaging features—olivary hypertrophy with persistent T2/FLAIR hyperintensity—is essential for accurate diagnosis. DTI supports the trans-synaptic mechanism, helping distinguish HOD from other pathologies and preventing unnecessary investigations. Full article

Fatty-acid-hydroxylase-associated neurodegeneration (FAHN) is a rare neurodegenerative disorder caused by loss-of-function mutations in the FA2H gene, leading to impaired enzymatic activity and resulting in myelin sheath instability, demyelination, and axonal degeneration. In this study, we established a human in vitro model using neurons and oligodendrocytes derived from induced pluripotent stem cells (hiPSCs) of a FAHN patient. This coculture system enabled the investigation of myelination processes and myelin integrity in a disease-relevant context. Analyses using immunofluorescence and Western blot revealed impaired expression and localisation of key myelin proteins in oligodendrocytes and cocultures. FA2H-deficient cells showed reduced myelination, shortened internodes, and disrupted formation of the nodes of Ranvier. Additionally, we identified autophagy defects—a hallmark of many neurodegenerative diseases—including reduced p62 expression, elevated LC3B levels, and impaired fusion of autophagosomes with lysosomes. This study presents a robust hiPSC-based model to study FAHN, offering new insights into the molecular pathology of the disease. Our findings suggest that FA2H mutations compromise both the structural integrity of myelin and the efficiency of the autophagic machinery, highlighting potential targets for future therapeutic interventions. Full article

The three pathological hallmarks of multiple sclerosis (MS) are inflammation, demyelination, and progressive neurodegeneration. None of the approved disease-modifying therapies for MS counters all three pathologies, and, more specifically, none is approved for neuroprotection. Axonal loss is the most significant contributor to chronic and irreversible disability in MS. A tantalizing molecular target has emerged to uniquely counter all three MS pathologies: tumor necrosis factor receptor 2 (TNFR2). Agonism or activation of TNFR2 has been shown in MS models to induce immunosuppression, oligodendrocyte precursor differentiation, and neuroprotection. Further, in basic science studies stemming from the past 15 years, TNFR2 agonism is known to be a strong inducer of T-regulatory cells (Tregs). Treg cells, and especially those expressing TNFR2, are known to confer the strongest suppression per cell type. TNFR2 is even more attractive as a therapeutic target because of its restricted expression by only a handful of CNS and immune cell subsets, thereby minimizing the likelihood of systemic and other adverse effects. Recent antibody design work suggests many of the hurdles of Treg agonism may have been overcome. This review covers the current treatment landscape for MS, the basic science of TNFR2, the rationale for and evidence behind TNFR2 agonism to treat multiple sclerosis, the design of potent TNFR2 agonist antibodies, and the treatment applications for other neurological, autoimmune, or inflammatory diseases. Full article

Multiple sclerosis (MS) is a chronic autoimmune disease characterized by the immune system attacking the central nervous system, leading to demyelination and neurodegeneration. This work investigates the relationship between specific human leukocyte antigen (HLA) polymorphisms and MS, aiming to reveal the immunogenetic background of this disease for more individualized management approaches. This study employed a case–control design, analyzing HLA allele frequencies in 179 MS patients and 200 control subjects using next-generation sequencing, The key findings indicate significant associations between several HLA Class I and II alleles and MS, including HLA-B*35:03:01:03, HLA-C*04:01:01:14, HLA-DRB1*15:01:01:26, and HLA-DQA1*05:05:01:02. These findings emphasize the critical role of HLA molecules in MS Romanian patients. Full article

Multiple sclerosis (MS) is a chronic, immune-mediated disorder of the central nervous system (CNS) characterized by inflammation, demyelination, axonal degeneration, and gliosis. Its pathophysiology involves a complex interplay of genetic susceptibility, environmental triggers, and immune dysregulation, ultimately leading to progressive neurodegeneration and functional decline. Although significant advances have been made in disease-modifying therapies (DMTs), many patients continue to experience disease progression and unmet therapeutic needs. Drug repurposing—the identification of new indications for existing drugs—has emerged as a promising strategy in MS research, offering a cost-effective and time-efficient alternative to traditional drug development. Several compounds originally developed for other diseases, including immunomodulatory, anti-inflammatory, and neuroprotective agents, are currently under investigation for their efficacy in MS. Repurposed agents, such as selective sphingosine-1-phosphate (S1P) receptor modulators, kinase inhibitors, and metabolic regulators, have demonstrated potential in promoting neuroprotection, modulating immune responses, and supporting remyelination in both preclinical and clinical settings. Simultaneously, artificial intelligence (AI) is transforming drug discovery and precision medicine in MS. Machine learning and deep learning models are being employed to analyze high-dimensional biomedical data, predict drug–target interactions, streamline drug repurposing workflows, and enhance therapeutic candidate selection. By integrating multiomics and neuroimaging data, AI tools facilitate the identification of novel targets and support patient stratification for individualized treatment. This review highlights recent advances in drug repurposing and discovery for MS, with a particular emphasis on the emerging role of AI in accelerating therapeutic innovation and optimizing treatment strategies. Full article