Alzheimer disease (AD) is a widespread neurodegenerative disorder. It is pathologically marked by the deposition of β-amyloid (Aβ) plaques and a high phosphorylation level of tau proteins, resulting in neurofibrillary tangle development, cognitive decline, and neuronal loss. Previous studies showed the correlation between AD and pyroptosis, an inflammasome-mediated programmed cell death. It was reported that Aβ and tau deposits may activate the NOD-like receptor pyrin domain-3 (NLRP3) and inflammasome-caspase-1-gasdermin D (GSDMD) pathway. This leads to cell membrane rupture and discharge of IL-1β and IL-18 cytokines that initiate neuroinflammation. However, there is still a lack of research on therapeutic approaches that target the pyroptotic pathway in AD. This review documents recent research on the regulatory function of miRNAs in regulating the NLRP3/caspase-1/GSDMD pathways and their potential to lessen pyroptosis-induced neuronal damage. We also address novel platforms for delivering antipyroptotic drugs and miRNA modulators across the blood-brain barrier using nanotechnology, such as engineered nanocarriers and exosome-like nanoparticles. These approaches have a promising therapeutic implication as potential treatment options for AD by combining molecular regulation and nanomedicine.
Hemangioblastomas (HB) are rare CNS neoplasms. Their main differential diagnosis includes meningioma, glioma, and metastatic clear cell renal carcinoma. However, the diagnostic immunoprofile of HBs is only imprecisely defined. We analyzed a multicentric cohort of HBs using tissue microarrays and whole sections to determine immunoreactivities of a range of selected meningothelial, glial and other markers used in diagnostic pathology. The clinical and pathological features were correlated. The cohort included 112 tumors from 104 patients (46.1% males, 53.9% females) with a mean age 50.1 years. The tumors occurred in cerebellum (72%), spine (18.9%) and medulla oblongata (5.4%). No HB expressed SSTR2A, MUC4 or STAT6. Expression of glial markers S100, GFAP, Olig2, and SOX10 was observed in 93.3%, 80.6%, 5.1%, and 8.1% of cases, respectively. Inhibin-α was positive in 84.5% and carbonic anhydrase IX (CAIX) in 100% of the cases. Negative PAX8 immunostaining was observed using specific C-terminus antibody whereas N-terminus anti-PAX8 staining yielded 63.2% positivity. T-brachyury, SATB2, and GPNMB were observed in 3.8%, 2.1%, and 20.8%, respectively. No expression of SOX17, CDX2, Sall4, GATA3, or INSM1 was observed. Thus, HBs show a consistent PAX8-negative/CAIX-positive immunoprofile while they lack meningothelial markers and occasionally may express SOX10 and Olig2.
Over 120 phytocannabinoids and 190 synthetic and semi-synthetic cannabinoids have been identified. Many of these currently circulate in recreational and illicit drug markets. Epidemiological evidence indicates a progressive increase in their use but long-term effects of cannabinoids on the CNS remain poorly understood. Exogenous cannabinoids can interact with cannabinoid receptor CB2, which is expressed on astrocytes and microglia, the key regulators of neuroinflammatory responses. Dysregulated or chronic microglial activation can sustain neuroinflammation, a central mechanism underlying neurodegenerative diseases. Clarifying cannabinoid-induced alterations in glia is therefore crucial both because their widespread consumption and the global burden of neurodegenerative disorders, for which cannabinoids might offer therapeutic potential. This review was conducted by a multidisciplinary team following JBI and PRISMA-ScR guidelines that systematically mapped available evidence across PubMed, Scopus and Web of Science. The findings are thematically organized and qualitatively summarized and indicate compound and time-dependent effects. Acute exposure appears to be neuroprotective whereas chronic effects remain unclear. Preliminary data suggest that some synthetic and semi-synthetic cannabinoids may retain protective actions while Δ9-tetrahydrocannabinol (THC) may promote glial activation and neuroinflammation, These results underscore the need for further in vivo and longitudinal studies to evaluate long-term impacts and inform safe therapeutic and regulatory strategies.
In adult-type diffuse gliomas CDKN2A and/or CDKN2B (CDKN2A/B) deletions often co-occur with deletion of MTAP, suggesting that MTAP immunohistochemistry (IHC) may be a surrogate marker of CDKN2A/B status. However, the association between CDKN2A/B and MTAP deletion at the genomic level remains unknown. We assessed CDKN2A/B and MTAP deletions by chromosomal microarray in 333 adult-type diffuse gliomas and performed MTAP IHC on a subset (n = 63). CDKN2A/B and MTAP deletions were detected in 216 and 215 cases, respectively, and were concurrent in 99.5% (215/216). While most tumors with CDKN2A/B homozygous deletion (n = 148) showed concurrent MTAP homozygous deletion (108/148; 73.0%), a subset harbored MTAP heterozygous deletion (39/148; 26.4%). By analyzing the size of the chromosomal alterations, we demonstrate that initial large chromosomal 9p losses result in concurrent heterozygous deletion of CDKN2A/B and MTAP whereas smaller "second hit" deletions leading to homozygous CDKN2A/B deletion do not always encompass the MTAP locus. Discordant CDKN2A/B and MTAP tumors affect the association between MTAP IHC and copy number status of MTAP and CDKN2A/B. These findings suggest that adult-type diffuse gliomas, regardless of IDH status, follow a stereotypic pathway involving concurrent CDKN2A/B and MTAP heterozygous deletion but may diverge for CDKN2A/B and MTAP homozygous deletion.
Extracorporeal shock wave therapy (ESWT) has emerged as a promising treatment for neurological disorders but optimal protocols regarding energy density and session frequency remain unclear. This study aimed to evaluate the effects of different ESWT energy levels and treatment sessions on peripheral nerve regeneration in rats with sciatic nerve injury. Fifty rats were randomized into five groups: four experimental groups received ESWT at low energy (0.098 mJ/mm2) or high energy (0.229 mJ/mm2), either once or three times, and one control group received no treatment. Assessments included protein expression analysis, histological examination, and functional recovery measured by sciatic functional index and compound muscle action potentials over 9 weeks. All ESWT-treated groups showed increased levels of regeneration-associated proteins and improved nerve structure compared to controls. The high-energy groups demonstrated more significant enhancements than low-energy groups, with the high-energy three-session group showing the greatest improvements in axonal growth, myelin thickness, and functional outcomes. These findings indicate that ESWT promotes peripheral nerve regeneration in a dose-dependent manner, with repeated high-energy sessions yielding superior recovery. Further research is necessary to optimize ESWT protocols for clinical applications and understand long-term effects on nerve repair.
Ferroptosis has a crucial role in cerebral ischemia-reperfusion injury (IRI) but its potential modulation is a key challenge in the treatment of ischemic stroke. The function and mechanism of the E3 ubiquitin ligase tripartite motif-containing protein 21 (TRIM21) in neurological diseases, particularly its regulatory role in ferroptosis are unclear. We used a mouse model of transient middle cerebral artery occlusion (tMCAO/R) and a PC12 cell model of oxygen-glucose deprivation/reperfusion (OGD/R) to investigate the effects of virus-mediated gene knockdown of TRIM21. Effects were assessed using Western blotting, immunoprecipitation, biochemical assays, and behavioral tests. TRIM21 expression was significantly increased after cerebral IRI. Knockdown of TRIM21 improved neurological deficits, reduced cerebral infarct size, and suppressed inflammation. Knockdown of TRIM21 also inhibited ferroptosis and improved mitochondrial function whereas TRIM21 negatively regulated the p62-Keap1-Nrf2 pathway through ubiquitination of p62. Salvage experiments confirmed that Nrf2 is a key downstream molecule for the neuroprotective effects of TRIM21. The data indicate that TRIM21 inhibition of the Keap1-Nrf2 pathway through p62 ubiquitination exacerbated ferroptosis after ischemic stroke in the tMCAO/R model and suggest that targeted inhibition of TRIM21 holds promise as a novel strategy for treating ischemic stroke.
Machine learning enables scalable quantification of neuropathology, offering deeper phenotyping of Alzheimer's disease (AD). In this validation study, we quantified amyloid-beta (Aβ) deposits, evaluating multiple brain regions across institutions, and evaluated associations with clinical, demographic, and genetic factors in persons pathologically diagnosed with AD. All linear models were adjusted for sex, age of death, ethnicity, and center. We analyzed densities (#/mm2) of cored plaques, diffuse plaques, and cerebral amyloid angiopathy (CAA) in 273 individuals from 3 Alzheimer's Disease Research Centers. Formalin-fixed paraffin-embedded sections of frontal, temporal, and parietal cortices were immunostained and digitized, generating 799 whole-slide images (WSIs). Following log transformation, mixed-effects modeling revealed the parietal cortex had the highest cored plaque densities (P < .001); the temporal cortex had the highest diffuse plaque (P < .001); CAA showed no regional differences. Wilcoxon rank-sum test, and covariates adjusted linear models showed ApoE ε4- status was associated with higher cored plaque densities in the temporal lobe (P = .04). ApoE ε4+ status was associated with diffuse plaques in the temporal lobe (P = .001), and CAA in the frontal lobe (P = .004). These findings provide further validation and provide exploratory associations advancing deeper phenotyping of AD.
Loss of upper and lower motor neurons (MNs) is a defining pathological feature underlying the clinical manifestations of amyotrophic lateral sclerosis (ALS). However, the differences in MN loss and TDP-43 pathology between these areas in ALS patients remain unclear. This study included 7 patients with ALS and 3 controls from consecutive autopsies. The cell density and regional density of TDP-43-positive inclusions in 4 upper MN areas and their anatomically corresponding lower MN areas were measured. The numbers of large cells with loss of nuclear TDP-43 and cytoplasmic delta-like-1 homolog (DLK1) were counted. The results showed severe MN loss in both upper and lower MN areas. However, TDP-43-positive inclusions differed markedly, that is they were rare in upper MNs but abundant in lower MN. In upper MN areas, TDP-43 density was not associated with the residual rate of MNs, whereas in lower MN areas, the density in MNs was associated with the cell residual rate. Significantly higher numbers of MNs lacking nuclear TDP-43 and cytoplasmic DLK1 were observed in the upper and lower MN regions in ALS vs controls. These findings suggest that these morphological changes may be closely related to motor neuron vulnerability and may be mechanistic contributors to ALS development.
Microglia and astrocytes are essential glial cells in the CNS that play key roles in brain development, homeostasis, and disease. While immortalized cell lines are convenient, they lack the physiological relevance of primary cells, highlighting the need for reliable human-based isolation protocols. This systematic review synthesizes 21 studies describing methods for isolating and culturing primary human microglia and astrocytes from adult surgical resections, postmortem tissues, and fetal brains. Using the Human Brain Cell Atlas v1.0 single-nuclei RNA-Seq dataset and voxel-wise mapping on the MNI152 template, we provide a spatial transcriptomic context for region-specific glial isolation. We critically assess tissue dissociation techniques, enrichment strategies, and culture conditions, including substrate coatings and growth factors. Additionally, we summarize phenotypic and functional assays used for characterization including surface marker expression, phagocytosis, and cytokine profiling. Despite variability across protocols, we propose an optimized, spatially informed workflow to reproducibly isolate viable, pure glial populations from human brain tissues. This approach supports New Approach Methodologies and the 3Rs-Replacement, Reduction, and Refinement by promoting ethical, human-relevant in vitro models. Our framework advances glial cell-based systems, improving the translational relevance of neurodegenerative and neuroinflammatory disease research and aligns with multiple United Nations Sustainable Development Goals through responsible scientific practices.
Leucine-rich pentatricopeptide repeat-containing protein (LRPPRC) is a recently identified N6-methyladenosine (m6A) reader protein involved in a myriad of biological processes in cancer. However, its roles in glioma have not been reported. Both in vitro and in vivo studies were performed to examine the anti-glioma activity of LRPPRC silencing. Chromatin immunoprecipitation assay and RNA immunoprecipitation assay were used for the analysis of interaction between upstream and downstream molecules. Methylated RNA immunoprecipitation assay was conducted to examine m6A modification. Our results showed that LRPPRC expression was dramatically upregulated in glioma tissues and cell lines. LRPPRC regulated the m6A modification of protocadherin-7 (PCDH7) and affected its expression in glioma cell lines; LRPPRC silencing significantly inhibited glycolysis and induced ferroptosis in glioma cell lines; this was reversed by PCDH7 overexpression. Furthermore, GATA-binding protein 3 (GATA3) directly bound to the LRPPRC promoter and transcriptionally regulated LRPPRC. LRPPRC mediated the regulatory effects of GATA3 on glycolysis and ferroptosis in glioma cell lines. In vivo studies showed that LRPPRC silencing suppressed tumor growth. Taken together, our data demonstrate that LRPPRC expression was dramatically upregulated in gliomas and that inhibition of the GATA3/LRPPRC/PCDH7 axis exerted an anti-glioma effect by regulating glycolysis and ferroptosis.
Primary intracranial sarcoma, DICER1-mutant, a novel, rare entity in the 2021 WHO classification of central nervous system tumors, is characterized by spindled to pleomorphic cells with eosinophilic cytoplasmic globules, immunophenotypic evidence of myogenic differentiation and DICER1 mutations. These tumors mainly occur in children and have a distinct methylation profile. We report 5 additional cases of primary intracranial sarcoma, DICER1-mutant (age range 6 to 40 years) identified by methylation profiling and/or sequencing, including 1 in an unusual infratentorial location, 1 in an adult patient and 1 in the setting of a germline DICER1 mutation. All tumors were surgically resected and demonstrated spindle cells with fascicular growth and variable pleomorphism; 3 showed variably prominent eosinophilic cytoplasmic globules and at least focal myogenic differentiation by immunohistochemistry. All cases had a hotspot DICER1 mutation; 2 had concurrent DICER1 loss; and 1 had a known germline truncating DICER1 mutation. Three cases also demonstrated a KRAS mutation, 1 of which had a TP53 mutation. Two patients were alive with no evidence of disease after 26.7 and 39.3 months; 1 patient died of disease after 20.1 months. We demonstrate the utility of methylation profiling in combination with next generation sequencing testing in the diagnosis of this rare entity.
Microglia-mediated neuroinflammation in the central nervous system is a hallmark of both multiple sclerosis (MS) and the animal model experimental autoimmune encephalomyelitis (EAE). Current immunosuppressive therapies for MS have limited efficacy and notable side effects. This study aimed to investigate mechanisms underlying anti-neuroinflammatory effects of morroniside, an iridoid glycoside derived from Cornus officinalis, which is used in Chinese herbal medicine. Morroniside treatment significantly attenuated lipopolysaccharide-induced alterations and mitochondrial dysfunction in BV2 microglia cells. In vivo, morroniside treatment improved clinical scores and ameliorated pathological findings and neurological deficits in a mouse EAE model. Mechanistic investigations revealed that morroniside activated the Nrf2/HO-1 signaling axis, promoted Nrf2 nuclear translocation and elevated HO-1 expression. This activation also upregulated p62, thereby enhancing LC3-II/PINK1/Parkin-mediated mitophagosome formation. The resultant mitophagy suppressed p65 phosphorylation leading to anti-inflammatory effects. Collectively, our findings suggest that morroniside ameliorates EAE by increasing anti-inflammatory microglial activation through upregulating the Nrf2/HO-1/p62 axis to mitigate mitochondrial oxidative stress and enhance mitophagy. These results identify morroniside as a promising therapeutic candidate for MS and emphasize the importance of the Nrf2-p62-mitophagy axis in resolving neuroinflammation and maintaining mitochondrial homeostasis.
Convincing evidence suggests that FoxO signaling (FS) dysfunction is associated with cancer progression and tumorigenesis but its effect on the tumor microenvironment (TME) and immunotherapy response remains unclear. Here, we retrieved FS-related genes from the KEGG database, first analyzing their differential expression in 31 TCGA cancer types with matched Genotype-Tissue Expression (GTEx) normal tissue data. We then calculated FS scores via ssGSEA for 33 TCGA cancer types, systematically exploring their prognostic value and correlations with TME characteristics and immunotherapy response. High FS scores were consistently associated with an immunosuppressive TME and poorer OS across multiple tumor types. Analysis of the IMvigor210 immunotherapy cohort further revealed elevated FS scores correlated with anti-PD-1 treatment resistance. Focusing on gliomas, we identified FS-based molecular subtypes and constructed a PCA score that robustly predicted glioma prognosis and immune checkpoint inhibitor response. External validation was achieved in independent CGGA and GEO cohorts. Our findings indicate that FS is a key modulator of the immunosuppressive TME and support FS and PCA scores as potential prognostic and immunotherapeutic biomarkers for gliomas with their clinical utility pending experimental validation.
Postacute sequelae of SARS-CoV-2 infection (PASC), or Long COVID, is estimated to affect over 60 million individuals globally, with almost half of COVID-19 survivors experiencing persistent symptoms such as neuropathic pain, fatigue, and autonomic dysfunction. Despite its prevalence, the pathophysiology of PASC remains poorly understood. This narrative review highlights activation of mast cells (MCs), the unique tissue immune cells as a central contributor to neuropathic manifestations in PASC. Mast cell locations near nerves and vessels allows them to regulate neuroimmune and neurovascular processes. Mast cell activation mirrors patterns seen in small-fiber neuropathy and myalgic encephalomyelitis/chronic fatigue syndrome, suggesting a shared immune-mediated etiology. The SARS-CoV-2 spike protein has been shown to activate MCs via angiotensin-converting enzyme 2 and toll-like receptor 4, triggering release of pro-inflammatory and neurotoxic mediators, including interleukin-1β, interleukin-6, tumor necrosis factor alpha, histamine, and tryptase. Such mediators sensitize peripheral nerves, disrupt the blood-brain barrier, and recruit microglia, ultimately contributing to small-fiber injury, neuroinflammation, and dysautonomia. Emerging reports suggest benefit from MC-directed treatments although responses remain variable. Understanding the role of MCs in PASC may offer a plausible mechanism of pathogenesis and guide targeted therapies. Future studies are needed to validate these findings and improve PASC patient outcomes.
Azetidine 2-carboxylic acid (Aze) is consumed by humans and can be misincorporated in place of proline (Pro) in myelin basic protein (MBP). In systemically treated mice Aze induced distinct oligodendroglial (OL) alterations mimicking those in multiple sclerosis (MS) patient normal-appearing white matter. Here, Aze induced an unfolded protein response (UPR), cytoplasmic MBP aggregation, apoptosis and tumor necrosis factor secretion in the human OL lineage MO13.3 cell line. These alterations were counteracted by equimolar Pro suggesting that they are due to Aze substitution for Pro in OL proteins. Gene set enrichment analysis demonstrated extensive Aze-induced alterations of cell cycle, cytoskeletal, organelle, transport, developmental, inflammation-associated and myelination pathways that are altered in OL in MS patients and in toxin and inflammatory MS animal models. These data provide mechanistic support for the hypothesis that Aze protein misincorporation during early life myelinogenesis might over time result in a progressive UPR culminating in a pro-inflammatory/immunomodulatory phenotype, intracytoplasmic MBP aggregation, accelerated senescence and apoptosis in OL. This could occur prior to and independent of an external immune stimulus such as a viral infection. Aze-induced pathological alterations might enhance subsequent antiviral and autoimmune responses and contribute to MS susceptibility, lesion pathogenesis, remyelination failure, neurodegeneration and clinical progression.
Accumulating evidence indicates that tripartite motif-containing protein 32 (TRIM32) has important functions in brain physiology and disease. This study investigated the role of TRIM32 in the development of epilepsy and its impact on synaptic remodeling. A rat model of epilepsy was established using pilocarpine with lithium chloride pretreatment and TRIM32 expression was examined by Western blotting and immunohistochemistry. The interaction between TRIM32 and BDNF was assessed by co-immunoprecipitation and immunofluorescence colocalization. TRIM32 knockdown in epileptic rats was achieved by shRNA transfection. Cognitive and anxiety-like behaviors were evaluated using the Y-maze and open-field tests; Western blotting was used to quantify the synaptic proteins PSD-95 and SYN and to assess activity of the BDNF/TrkB/CREB signaling pathway. TRIM32 expression was significantly reduced in epileptic rats. Moreover, TRIM32 knockdown aggravated epilepsy-associated cognitive deficits, impaired open-field performance, and exacerbated synaptic loss. Mechanistically, TRIM32 deficiency intensified these abnormalities through dysregulation of the BDNF/TrkB/CREB pathway. These data suggest that TRIM32 regulates synaptic protein expression in epilepsy and that its deficiency worsens anxiety-like behavior, cognitive impairment, and synaptic loss by perturbing BDNF/TrkB/CREB signaling, thereby providing insights that may inform future therapeutic strategies targeting this signaling pathway.
Cellular growth and homeostasis via amino acid-responsive pathways are mediated by the mTOR signaling pathway. Rag GTPases and Map4K3 modify mTOR signaling as amino acid sensors. Altered mTOR signaling in relation to amino acid sensors might represent factors that modify proliferation and treatment responses in astrocytic tumors. To investigate this hypothesis, RagC and Map4K3 expression was studied in human gliomas, glioma cells (U87MG/U138MG), and nonglial cells (MCF-7, IOMM-Lee). RagC and Map4K3 knockout in glioma cells was generated using CRISPR-Cas and shRNA. High-grade astrocytomas had significantly reduced immunoreactivity for RagC and Map4K3 compared to low-grade astrocytomas. RagC- and Map4K3-deficient glioma cells had significantly increased proliferation and showed altered morphology and motility. Induced amino acid deficiency (leucine deprivation) reduced proliferation in Map4K3- but not in RagC-deficient cells. mTOR signaling in RagC- and Map4K3-deficient U87 cells was altered with increased phosphorylation of p70S6K and increased expression of RagD and transcription factor EB. In this context, uncoupled, exaggerated autophagy occurred in Map4K3-deficient U87 cells. In contrast, RagC-deficient U87 cells showed increased senescence but no autophagy induction. These data show that losses of RagC and Map4K3 in malignant gliomas have proliferation-inducing effects and differentially modulate key mTOR signaling-dependent cellular mechanisms.
Repetitive low-level blast exposures in rats induce the development of a post-traumatic stress disorder (PTSD)-like phenotype and evolving chronic brain vascular alterations. These alterations included atherogenic-like lesions characterized by increased extravasation of blood elements into the arterial subendothelial layers, nuclear expression of c-Fos in endothelial and vascular smooth muscle cells, vascular hyperplasia, foam cell formation, and ultimately vascular rupture. Foam cells were mainly of macrophage/microglial or of vascular smooth muscle cell origin with upregulated expression of MHC II and of its co-stimulatory molecule CD86, which is characteristic of antigen-presenting cells. Foam cells also upregulated the lysosomal CD68 marker, indicating macrophage/microglial phagocytic and inflammatory activity. Foam cells of vascular smooth muscle cell origin were present at arteriolar bends, kinks, and bifurcations and were associated with a progressive arterial network degeneration in regions with enlarged perivascular spaces. Foam cell inclusions also contained the gelatinase MMP-9, which is involved in extracellular matrix degradation, and the pro-inflammatory cytokine TNF-α that further induces foam cell formation. These findings indicate that the chronic atherogenic lesions associated with blast-induced vascular degeneration may trigger a progressive pro-inflammatory state and expand the progressive vascular degeneration associated with the PTSD-like phenotype.
Alzheimer disease (AD) neuropathologic change (ADNPC), Parkinson disease (PD) α-synuclein (α-Syn), and TAR DNA-binding protein 43 (TDP-43) pathology overlap in a continuum in fine particulate matter (PM2.5)-exposed Metropolitan Mexico City (MMC) children and young adult forensic autopsy brains. This report focuses on a forensic targeted immunohistochemistry protocol to assess ADNPC, α-Syn and TDP-43 in ≤40y subjects, and to define their relationship with cumulative PM2.5 (CPM) exposures. We proposed an early measurement of abnormal protein expression to evaluate neurodegenerative disease prevalence in exposed PM2.5 urban young populations. We studied 189 autopsies average age 26±10y, including 179 MMC ≤40y olds and 10 low pollution controls. Among MMC adults 18-40y, 11.3% exhibited ADNPC alone; 50% had ADNPC + PD, 32.0% had ADNPC + PD + TDP-43 and 6.7% had ADNPC + TDP-43 pathology. In 37 children (13.0±4.8y), 24.3% had ADNPC, 37.8% had ADNPC + PD, 32.4% had ADNPC + PD + TDP-43; 5.4% had ADNPC + TDP-43 pathology. The overlapping children's neuropathology was documented under low CPM. We suggest that measurements of abnormal protein expression to evaluate neurodegenerative disease in young PM2.5-exposed young urban populations in US autopsies will define the prevalence and overlap of early neurodegenerative biological markers. This information guide preventive medicine, health services, environmental PM2.5 emission control and early neuroprotection from potentially preventable air pollution-associated neurodegenerative diseases.
Conventional CSF markers often fail to distinguish immune-mediated neurologic disorders (IMNDs) from non-immune-mediated neurologic disorders (N-IMNDs). We performed multiparametric flow cytometric profiling of CSF T-cell developmental subsets in 37 IMND patients and 10 N-IMND controls to identify IMND-associated T-cell signatures. CSF CD8+ T-cells were detectable in 86% (32/37) of IMND patients versus 0% (0/10) of N-IMND controls (Padj < .001). Among CD8+ T-cell-positive IMND cases, effector memory (CD45RA-CCR7-, median, 65.0%; IQR, 45.5%-73.5%) and terminally differentiated effector memory T-cells (TEMRA, CD45RA+CCR7-, median, 35.0%; IQR, 0%-49.5%) predominated. Hierarchical clustering demonstrated significant separation between IMND and N-IMND driven by CD8+ T-cell subset profiles (R2 = 0.165, P = .001), whereas CD4+ T-cell subsets showed no disease-associated clustering. Paired blood-CSF analysis in 6 treatment-naïve IMND patients revealed compartmentalized enrichment of CD8+ effector memory (blood median 19.2%; IQR, 6.4%-26.9%; CSF median 47.3%; IQR, 42.2%-53.7%; P = .031), confirming CNS-restricted CD8+ T-cell activation. These findings identify CSF CD8+ effector memory profiles as a potential biomarker distinguishing IMNDs from N-IMNDs that may complement conventional biomarkers for CNS autoimmunity.