BACKGROUND AND OBJECTIVES:Chronic active lesions (CALs) reflect chronic inflammation in multiple sclerosis (MS). Slowly expanding lesions (SELs) are CALs identified on conventional MRI by linear, concentric expansion over time, while paramagnetic rim lesions (PRLs) are CALs characterized by a paramagnetic rim on susceptibility-sensitive MRI. However, the prevalence of SELs and their overlap with PRLs remain unclear. The aims of this study were to (1) estimate the proportion of SELs among all T2 lesions and the proportion of patients with at least 1 SEL and (2) assess the proportion of SELs overlapping with PRLs. METHODS:We systematically searched PubMed, Scopus, Web of Science, and Embase on February 1, 2026, for studies evaluating SELs in MS. At least 2 authors independently assessed study eligibility. Primary outcomes were the pooled proportion of SELs among T2 lesions and the proportion of patients with at least 1 SEL. We estimated mean per-patient volumes of SELs and total T2 lesions and the proportion of SELs overlapping with PRLs. Random-effects generalized linear mixed-effects models and inverse-variance methods were used, with between-study heterogeneity assessed using τ2 and I2 and robustness using sensitivity analyses. Univariable meta-regression explored heterogeneity. PROSPERO: CRD42024603778. RESULTS:Of 5,980 records, 20 studies comprising 4,786 patients with MS were included (mean age: 43.6 ± 6.3 years; 63.7% female). Sample sizes varied by outcome. SELs accounted for 14% (95% CI 10-21) of all T2 lesions, and 78% (67-85) of patients had at least 1 SEL. After sensitivity analysis, per-patient mean volumes were 1.42 mL (0.79-2.06) for SELs and 10.6 mL (8.53-12.67) for total T2 lesions. In total, 11% (6-20) of SELs overlapped with PRLs. In subgroup analyses, proportions of SELs were similar in relapsing-remitting and progressive MS (15%), but the proportion of patients with at least 1 SEL was higher in progressive MS. Between-study heterogeneity was high across analyses with no significant sources identified. DISCUSSION:Although SELs represent a minority of T2 lesions, most patients have at least 1 SEL and a subset overlaps with PRLs, suggesting a partial correspondence between these 2 imaging markers of chronic inflammatory activity. Limitations include possible publication bias, high unexplained heterogeneity, differences in SEL identification methods, and differences in MRI time point number/timing.
Repulsive guidance molecule-a (RGMa) has emerged as a significant therapeutic target in a variety of neurological disorders, including neurodegenerative diseases and acute conditions. This review comprehensively examines the multifaceted role of RGMa in central nervous system (CNS) pathologies such as Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, multiple sclerosis, neuromyelitis optica spectrum disorder, spinal cord injury, stroke, vascular dementia, auditory neuropathy, and epilepsy. The mechanisms through which RGMa contributes to neuroinflammation, neuronal degeneration, and impaired axonal regeneration are herein discussed. Evidence from preclinical studies associate RGMa overexpression with negative outcomes, such as increased neuroinflammation and synaptic loss, while RGMa inhibition, particularly the use of agents like elezanumab, has shown promise in enhancing neuronal survival and functional recovery. RGMa’s responses concerning immunomodulation and neurogenesis highlight its potential as a therapeutic avenue. We emphasize RGMa’s critical role in CNS pathology and its potential to pave the way for innovative treatment strategies in neurological disorders. While preclinical findings are encouraging so far, further clinical trials are needed to validate the safety and efficacy of RGMa-targeted therapies.
ObjectivesApproximately 25% of individuals experience various symptoms months after the COVID-19 infection and are referred to as having Long-COVID syndrome. The primary objective of this study was to identify the pattern of neuropsychiatric symptoms and their influence on psychological health, sleep quality, and overall well-being.MethodsIn this cross-sectional study, Long-COVID patients reported on their symptoms by using a predefined list. The symptom patterns were examined using cluster analysis. The clustering groups were compared based on psychological health, sleep, and well-being scores obtained from structured questionnaires.ResultsThere were 40 females and 13 males, with a mean age of 54.1 +/- 12.2 years. The most frequently reported symptoms were fatigue (94.3%), followed by anxiety (79.2%), myalgias (75.5%), and concentration difficulties (71.7%). Clustering analysis revealed two clusters separated by the number of cognitive, psychiatric, general neurologic, and somatic symptoms (i.e. high and low number). Patients within the high number cluster reported significantly more symptoms of depression, anxiety and stress, and worse quality of sleep than the low number cluster. Overall, 32 patients (60.4%) were found to have poor well-being. Reporting more than 17 symptoms (58.6% of patients) predicted poor well-being with a sensitivity of 37.5% and specificity of 95.2% (p = 0.011).DiscussionIn this study, Long-COVID patients presenting at the outpatient neurologic clinic were clustered based on the number of symptoms instead of the nature of these symptoms. A higher number of symptoms were associated with poorer psychological health, sleep quality, and overall well-being.
Approximately 10% of patients experience persistent symptoms following COVID-19, known as long-COVID syndrome. This cross-sectional study explored factors of quality of life (QoL) in 53 long-COVID patients. QoL was measured using the World Health Organization-Five Well-Being Index, fatigue with the Fatigue Visual Analogue Scale, and psychological health with the Depression-Anxiety-Stress-21 questionnaire. Six neuropsychological tests assessed information processing speed, verbal memory, visual memory, working memory, attention, language, fluency, recall, and visuospatial function with a composite score calculated by averaging z scores. Patients (76% female, mean age: 54.1 years) were assessed 8.7 months postinfection. Cognitive impairment, present in 49% of the sample, was not associated with QoL. In multiple linear regression, gender, fatigue, and psychological distress accounted for 42% of QoL variance, with fatigue and distress contributing 7% and 11%, respectively. Further studies are needed to determine if fatigue and psychological distress are causally related to QoL in long-COVID and could be treatment targets.
COVID-19’s effects on the human brain reveal a multifactorial impact on cognition and the potential to inflict lasting neuronal damage. Type I interferon signaling, a pathway that represents our defense against pathogens, is primarily affected by COVID-19. Type I interferon signaling, however, is known to mediate cognitive dysfunction upon its dysregulation following synaptopathy, microgliosis and neuronal damage. In previous studies, we proposed a model of outside-in dysregulation of tonic IFN-I signaling in the brain following a COVID-19. This disruption would be mediated by the crosstalk between central and peripheral immunity, and could potentially establish feed-forward IFN-I dysregulation leading to neuroinflammation and potentially, neurodegeneration. We proposed that for the CNS, the second-order mediators would be intrinsic disease-associated molecular patterns (DAMPs) such as proteopathic seeds, without the requirement of neuroinvasion to sustain inflammation. Selective vulnerability of neurogenesis sites to IFN-I dysregulation would then lead to clinical manifestations such as anosmia and cognitive impairment. Since the inception of our model at the beginning of the pandemic, a growing body of studies has provided further evidence for the effects of SARS-CoV-2 infection on the human CNS and cognition. Several preclinical and clinical studies have displayed IFN-I dysregulation and tauopathy in gene expression and neuropathological data in new cases, correspondingly. Furthermore, neurodegeneration identified with a predilection for the extended olfactory network furthermore supports the neuroanatomical concept of our model, and its independence from fulminant neuroinvasion and encephalitis as a cause of CNS damage. In this perspective, we summarize the data on IFN-I as a plausible mechanism of cognitive impairment in this setting, and its potential contribution to Alzheimer’s disease and its interplay with COVID-19.
Oligoclonal bands (OCBs) in cerebrospinal fluid (CSF) are utilized for diagnosing multiple sclerosis (MS), as they are found in 95
Introduction: The subventricular zone promotes remyelination through activation differentiation of oligodendroglial precursor cells (OPCs) and neural stem cells (NSCs) into mature oligodendrocytes and thus in the adult brain. In multiple sclerosis (MS) this regenerative capability is halted resulting in neurodegeneration. We aimed to systematically search and synthesize evidence on mechanisms and phenomena associated with subventricular zone (SVZ) dysfunction in MS.Materials and Methods: Our systematic review was reported according to the PRISMA-ScR statement. MEDLINE, SCOPUS, ProQuest, and Google Scholar were searched using the terms "subventricular zone" and "multiple sclerosis," including English-written in vivo and postmortem studies.Results: Twenty studies were included. Thirteen studies on models of experimental autoimmune encephalomyelitis (EAE) reported among others strong stathmin immunoreactivity in the SVZ of EAE models, the role of MOG immunization in neurogenesis impairment, the effect of parenchymal OPCs and NSCs in myelin repair, and the importance of ependymal cells (E1/E2) and ciliated B1 cells in SVZ stem cell signaling. CXCR4 signaling and transcriptional profiles of SVZ microglia, Gli1 pathway, and galactin-3 were also explored. Studies in humans demonstrated microstructural SVZ damage in progressive MS and the persistence of black holes near the SVZ, whereas postmortem confirmed the generation of polysialic acid-neural cell adhesion molecule and NG2-positive progenitors through SVZ activation, SVZ stathmin immunoreactivity, Shh pathway, and Gal-3 upregulation.Discussion: Oligodendrogenesis defects translate to reduced remyelination, a hallmark of MS that determines its end-phenotype and disease course.Conclusion: The role of inflammation and subsequent SVZ microenvironment disruption is evident in MS pathology. Impact Statement In this work, the role of impaired adult neurogenesis and oligodendrogenesis in the pathophysiology of multiple sclerosis is explored. We herein synthesize the state of the art on human studies and animal models that involve the subventricular zone (SVZ), a hub critical for both neoneurogenesis and oligodendrogenesis. Our findings highlight defects that may affect both processes in the long term and synergistically shape the pathophysiology of multiple sclerosis. Furthermore, the exposure of this delicate system and oligodendroglia progenitors to peripheral inflammation may be a plausible mechanism of myelin restorative failure following demyelination, and of impaired olfactory neurogenesis in multiple sclerosis.
Boucher Neuhäuser Syndrome (BNS) is a rare disease with autosomal recessive inheritance defined by the classical triad; early-onset ataxia, hypogonadism and chorioretinal dystrophy. We present two siblings diagnosed with BNS at midlife, identified with homozygous state of a novel PNPLA6 missense mutation. One healthy sibling and the mother were heterozygous carriers of the mutation. The proband presented with the classical triad and the other sibling presented with visual problems at first. The proband was referred to our department by a private Neurologist, in early adulthood, because of hypogonadism, cerebellar ataxia, axonal neuropathy, and chorioretinal dystrophy for further evaluation. The sibling was referred to our department for evaluation, at childhood, due to visual problems. Later, the patient displayed the triad of ataxia, hypogonadotropic hypogonadism, and chorioretinal dystrophy. The unusual medical history of the two siblings led to further examinations and eventually the diagnosis of the first BNS cases in Cyprus. WES-based ataxia in silico gene panel analysis revealed 15 genetic variants and further filtering analysis revealed the PNPLA6 c.3323G > A variant. Segregation analysis in the family with Sanger sequencing confirmed the PNPLA6 homozygous variant c.3323G > A, p.Arg1108Gln in exon 29. This highlights the importance of considering rare inherited causes of visual loss, spinocerebellar ataxia, or/and HH in a neurology clinic and the significant role of genetic sequencing in the diagnostic process.
Stroke is currently the second most common cause of death worldwide and a major cause of serious long-term morbidity. Selenium is a trace element with pleotropic effects on human health. Selenium deficiency has been associated with a prothrombotic state and poor immune response, particularly during infection. Our aim was to synthesize current evidence on the tripartite interrelationship between selenium levels, stroke, and infection. Although evidence is contradictory, most studies support the association between lower serum selenium levels and stroke risk and outcomes. Conversely, limited evidence on the role of selenium supplementation in stroke indicates a potentially beneficial effect of selenium. Notably, the relationship between stroke risk and selenium levels is bimodal rather than linear, with higher levels of serum selenium linked to disturbances of glucose metabolism and high blood pressure, morbidities which are, in turn, substrates for stroke. Another such substrate is an infection, albeit forming a bidirectional relationship with both stroke and the consequences of impaired selenium metabolism. Perturbed selenium homeostasis leads to impaired immune fitness and antioxidant capacity, which both favor infection and inflammation; specific pathogens may also contend with the host for transcriptional control of the selenoproteome, adding a feed-forward loop to this described process. Broader consequences of infection such as endothelial dysfunction, hypercoagulation, and emergent cardiac dysfunction both provide stroke substrates and further feed-forward feedback to the consequences of deficient selenium metabolism. In this review, we provide a synthesis and interpretation of these outlined complex interrelationships that link selenium, stroke, and infection and attempt to decipher their potential impact on human health and disease. Selenium and the unique properties of its proteome could provide both biomarkers and treatment options in patients with stroke, infection, or both.
Both peripheral neuropathy and autonomic dysfunction are known consequences of chronic and excessive alcohol consumption. The prevalence of peripheral neuropathy among chronic alcohol abusers is 46.3% (CI 35.7%–57.3%) when confirmed via nerve conduction studies. Alcohol-related peripheral neuropathy is generally described as a progressive, predominantly sensory axonal length-dependent neuropathy. Based on cardiovascular reflex tests, 16%–73% of the chronic alcohol abusers suffer from autonomic dysfunction. Erectile dysfunction is the most commonly reported feature. The most important risk factor for both conditions is total lifetime dose of ethanol. There is also evidence that other risk factors have been identified in the pathogenesis of peripheral neuropathy due to alcohol abuse including genetic factors, male gender, and type of alcohol consumed. There is limited evidence for other environmental risk factors in the pathogenesis of alcohol-induced autonomic dysfunction. Currently, there is limited evidence regarding the management for both conditions, but sparse data support abstinence to lead to a significant improvement in autonomic dysfunction and the use of B-vitamin supplementation including thiamine to be promising in the management of alcohol-induced peripheral neuropathy.
INTRODUCTION:The universality and complexity of pain, which is highly prevalent, yield its significance to both patients and researchers. Developing a non-invasive tool that can objectively measure pain is of the utmost importance for clinical and research purposes. Traditionally electroencephalography (EEG) has been mostly used in epilepsy; however, over the recent years EEG has become an important non-invasive clinical tool that has helped increase our understanding of brain network complexities and for the identification of areas of dysfunction. This review aimed to investigate the role of EEG recordings as potential biomarkers of pain perception.METHODS:A systematic search of the PubMed database led to the identification of 938 papers, of which 919 were excluded as a result of not meeting the eligibility criteria, and one article was identified through screening of the reference lists of the 19 eligible studies. Ultimately, 20 papers were included in this systematic review.RESULTS:Changes of the cortical activation have potential, though the described changes are not always consistent. The most consistent finding is the increase in the delta and gamma power activity. Only a limited number of studies have looked into brain networks encoding pain perception.CONCLUSION:Although no robust EEG biomarkers of pain perception have been identified yet, EEG has potential and future research should be attempted. Designing strong research protocols, controlling for potential risk of biases, as well as investigating brain networks rather than isolated cortical changes will be crucial in this attempt.
Immunoglobulins (IG) are widely used for the treatment of a variety of immune-mediated diseases. The exact mechanism of action remains unknown, but IG modulate the expression and function of Fc receptors, interfere with complement activation and production of cytokines, neutralize pathogenic autoantibodies, and affect the activation and effector functions of B and T lymphocytes. Immunoglobulins are usually delivered intravenously, and are effective in ameliorating motor symptoms, and/or preventing disease progression in immune-mediated neuropathies, including Guillain–Barré syndrome and chronic inflammatory demyelinating polyneuropathy. The aim of this systematic review and meta-analysis was to study the potential of IG for the treatment of painful peripheral neuropathy (PPN). The outcome of interest was the percentage of patients with PPN who achieved pain relief following IG administration. We performed a systematic literature search on March 17, 2022, in the PubMed database without any publication date restrictions. We also looked for unpublished or ongoing trials in clinicaltrials.org. Pain reduction following IG treatment had to be within the aims (primary or secondary). The aforementioned literature search strategy revealed five studies (two open-label, three randomized placebo-controlled) eligible to be included. The pooled estimate of the percentage of patients with PPN who received immunoglobulins and reported pain relief was found to be 65% (95% CI 58–71%). The likelihood of achieving pain relief with immunoglobulin treatment was 2.9 times higher (95% CI 1.6–5.2) compared to placebo (p = 0.0003). The use of IG for the treatment of pain due to peripheral neuropathy has a potential therapeutic benefit. Further studies across patients with different types of painful peripheral neuropathy are needed to better characterize this effect. Registration number on PROSPERO: CRD42022319614.
Introduction Physical exercise appeared to be effective, when implemented as an adjuvant to the pharmacotherapy option, in a variety of painful conditions. Peripheral neuropathic pain (PNP) is very prevalent and affects up to two-thirds of individuals with polyneuropathy (PN), regardless of etiology. The aim of this systematic review was to evaluate the currently available studies that assess adjuvant physical exercise for the management of PNP. Methods A systematic literature search was conducted in the PubMed international database. For the systematic search, three medical subject headings (MeSH) were used. Term A was 'physical exercise' OR 'exercise' OR 'activity' OR 'workout' OR 'training'; term B was 'pain' OR 'painful'; term C was 'neuropathy' OR 'polyneuropathy.' Additionally, three filters were used: human subjects, English language, and full text. The reference lists of eligible papers and relevant reviews were also meticulously searched in order to include further relevant studies. Six papers eligible to be included were identified. Results Physical exercise in various forms can be of benefit in the management of PNP when used as an adjuvant to the standard care. Overall, using the American Society of Interventional Pain Physicians (ASIPP) criteria, the current best available evidence exists for both aerobic and muscle strengthening exercise programs (level II evidence). The intensity of the exercise seems to play a significant role, with higher intensity interval training programs being more promising, though this remains to be confirmed in future studies. Conclusions Physical exercise is a promising non-pharmacological intervention for the management of PNP. Future RCTs should be conducted to make a face-to-face comparison of the available exercise treatments with the aim to design specific exercise programs for patients with PNP.