Choroid plexus enlargement in paediatric multiple sclerosis: clinical relevance and effect of sex

Subventricular Zone Microstructure in Pediatric-Onset Multiple Sclerosis

OBJECTIVE

The aim of this study was to explore the microstructural dynamics of the subventricular zone (SVZ) with aging and their associations with clinical disability and brain structural damage in pediatric-onset multiple sclerosis (MS) patients.

METHODS

One-hundred and forty-one pediatric-onset MS patients (67 pediatric and 74 adults with pediatric-onset) and 233 healthy controls (HC) underwent neurological and 3.0 T MRI assessment. Fractional anisotropy (FA) and mean diffusivity (MD) were extracted from the SVZ and the thalamus (as control region).

RESULTS

In HC, SVZ FA was higher until age 40 then declined, whereas MD was lower until age 35 before rising (false discovery rate p value [pFDR] ≤ 0.008). Thalamic FA was higher until age 30 and then declined, whereas MD was higher until age 50 (pFDR ≤ 0.007). Pediatric MS patients showed significantly higher SVZ FA than pediatric HC (pFDR < 0.001), while adult patients showed no differences compared to adult HC (pFDR ≤ 0.724). Adult patients had lower thalamic FA and higher MD (pFDR < 0.001). Adults had lower SVZ FA and MD, but higher thalamic MD compared to pediatric patients (pFDR < 0.001). In pediatric MS, higher SVZ FA and MD were associated with higher white matter (WM) lesion volume (LV) and choroid plexus volume and lower brain and thalamic volumes (pFDR ≤ 0.047). In adult patients, higher SVZ MD associated with higher WM LV, lower brain volumes, and lower z-SDMT (pFDR≤0.019). Thalamic microstructural abnormalities were associated with more severe disability and brain damage in both groups (pFDR ≤ 0.018).

INTERPRETATION

Our findings suggest that microstructural changes in the SVZ occur early in pediatric MS and are associated with brain structural damage but not with clinical impairment. ANN NEUROL 2025;97:979-992.

Associations of choroid plexus volume with white matter hyperintensity volume and susceptibility and plasma amyloid markers in cerebral small vessel disease

BACKGROUND

White matter hyperintensity (WMH) is a key feature of cerebral small vessel disease (CSVD). The impact of the choroid plexus (CP) volume on disease progression remains largely unexplored. This study evaluated the relationship between CP volume and CSVD severity via WMH volume and susceptibility values. Additionally, we explored whether Alzheimer's disease (AD)-related plasma proteins influence the volume of the CP.

METHODS AND MATERIALS

Our study included 291 CSVD individuals, with 84 participants completing subsequent brain MRI at a mean follow-up of 20 months. To explore the potential CP-associated pathways, we assessed the relationships between AD-related plasma biomarkers and CP volume via multiple linear regression analysis. The longitudinal associations between CP volume and WMH characteristics (WMH volume and susceptibility) were analyzed via linear mixed-effects models. Finally, we employed random forest analysis with the Boruta algorithm to identify key predictors of CSVD severity.

RESULTS

Plasma Aβ1‒40 levels were positively correlated with CP volume (β = 0.115, P = 0.009), whereas Aβ42‒40 ratio were negatively associated with CP volume (β = -0.135, P = 0.03). Notably, increased CP volume was associated with both greater WMH burden (β = 0.191, P = 0.011) and decreased WMH susceptibility (β = -0.192, P = 0.012). Furthermore, random forest modeling identified CP volume and WMH susceptibility as the strongest predictors of CSVD severity.

CONCLUSIONS

CP volume changes were significantly correlated with both WMH volume and WMH susceptibility in CSVD patients. These findings suggest that CP-mediated pathways may link amyloid metabolism to CSVD progression.

Radiomics-based analysis of choroid plexus abnormalities in neuromyelitis optica spectrum disorders and multiple sclerosis and their clinical implications

BACKGROUND

The choroid plexus (CP) is closely linked to inflammation in multiple sclerosis (MS). While the CP volume is enlarged in MS compared with healthy controls (HC), no such changes are observed in neuromyelitis optica spectrum disorder (NMOSD), a disease with similar clinical and imaging features to MS. It remains unclear whether the CP plays a similar role in NMOSD as in MS.

PURPOSE

To investigate the abnormal CP radiomics in NMOSD and MS and explore their clinical implications.

METHODS

This retrospective study included 111 MS, 69 Aquaporin-4 (AQP4)-IgG positive NMOSD, and 82 HC, with age and sex matching. Radiomics features of the CP were extracted from T1-weighted images after automated segmentation, including shape, first order statistics (intensity), and texture features (N=1051). Analysis of covariance was used to assess group differences in these features, and 11 classic machine learning algorithms were employed to construct disease classification models. Moreover, partial correlation analysis was performed to further explore the relationships between differential radiomics features and clinical measures, such as Expanded Disability Status Scale (EDSS) and Symbol Digit Modalities Test (SDMT).

RESULTS

Compared with HC, MS exhibited significant differences in 453 features, including shape, intensity, and texture, while NMOSD displayed differences in 102 intensity and texture features, with no differences in shape. NMOSD and MS differed in 178 features, primarily texture (P < 0.05, Bonferroni correction). In the classification models based on CP radiomics features, the best AUC for MS vs HC was 0.935 (95% CI: 0.830 - 0.997) with the Partial Least Squares Regression Generalized Linear Model (plsRglm), while for NMOSD vs HC, it was 0.822 (95% CI: 0.629 - 0.962) with the Light Gradient Boosting Machine (LightGBM). Meanwhile, the best AUC for NMOSD vs MS was 0.832 (95% CI: 0.667 - 0.960) with the Quadratic Discriminant Analysis (QDA). Furthermore, of the 453 abnormal radiomics features of MS patients, 120 were significantly correlated with EDSS and 234 with SDMT scores (P < 0.05, FDR correction), while no radiomics features in NMOSD were significantly correlated with clinical scores (P > 0.05, FDR correction).

CONCLUSION

Radiomics can detect varying degrees of CP abnormalities in NMOSD and MS, suggesting CP involvement in the pathophysiology of NMOSD, albeit to a lesser extent than in MS. It may help understand the potential pathophysiological differences between the two diseases and their impact on clinical monitoring.

Dynamics of choroid plexus volume is associated with the presence and development of fatigue in multiple sclerosis

BACKGROUND

Immune-mediated processes are implicated in the pathogenesis of fatigue, a common symptom in multiple sclerosis (MS). The choroid plexus (CP) regulates central nervous system (CNS) immune homeostasis and undergoes volumetric modifications possibly contributing to MS-related fatigue. We explored the association between MS-related CP volume changes and fatigue dynamics.

METHOD

Eighty-five patients with MS and 68 healthy controls (HC) underwent brain 3T MRI, neurological evaluation and Modified Fatigue Impact Scale (MFIS) at two timepoints (median follow-up=1.4 years). Normalised brain and regional grey matter (GM) volumes were obtained using FSL-SIENAx, FIRST, SIENA and tensor-based morphometry. CP volumes were quantified with in-house methods, and longitudinal changes were analysed using linear mixed models.

RESULTS

At baseline, 25 (29%) patients with MS had fatigue (f-MS) (MFIS ≥38). Compared with HC, patients with MS had significantly higher brain T2-lesion volume, lower brain, deep GM, cortical volumes and higher CP volume (false discovery rate (FDR)-p ≤0.024). Compared with non-fatigued (nf-MS) patients, f-MS were older, more disabled (FDR-p ≤0.002) and showed numerically higher CP volume (FDR-p=0.076). At follow-up, 41 (68%) nf-MS remained non-fatigued (nf-FU-MS) and 19 (32%) developed fatigue (f-FU-MS). Patients with MS showed higher brain and deep GM atrophy rates versus HC (FDR-p ≤0.048), whereas clinical, lesional and brain volumetric changes were not significantly different among MS groups (FDR-p ≥0.287). CP volume significantly increased in all MS groups compared with HC (FDR-p ≤0.043), with greater enlargement in f-FU-MS versus nf-FU-MS (FDR-p=0.048).

CONCLUSIONS

Larger CP and greater enlargement are associated with the presence and development of fatigue in MS, likely reflecting dynamic inflammatory states within the CNS, supporting the immunological contribution to MS-related fatigue.

Choroid Plexus Enlargement in Secondary Progressive MS: phenotype comparison

Background

The choroid plexus (CP) is increasingly recognised as a contributor to chronic inflammation in multiple sclerosis (MS). While CP enlargement is reported in early MS, its role in secondary progressive MS (SPMS) is poorly understood.

Objective

We aimed to quantify CP volume in SPMS and compare it to relapsing-remitting MS (RRMS) and clinically isolated syndrome (CIS), and to assess associations with disease severity and progression.

Methods

CP volumes were manually segmented and normalised to intracranial volume. Age correction was applied using a healthy control cohort. Cross-sectional and longitudinal analyses evaluated relationships with ventricular volume, lesion burden, and brain atrophy.

Results

CP volume increased significantly across MS phenotypes: SPMS patients showed 26% higher CP volume than CIS (p=0.010) and 17% higher than RRMS (p=0.034). CP enlargement in SPMS was independent of ventricular size, indicating distinct underlying mechanisms. While lesion burden was the primary determinant of brain atrophy in SPMS, longitudinal data revealed significant associations between CP volume, chronic lesion expansion (r 2 =0.31), and brain volume loss (r 2 =0.52).

Conclusion

CP enlargement is a progressive feature of MS, not driven by ventricular expansion. In SPMS, it may reflect ongoing inflammation contributing to tissue damage, supporting its role as a biomarker.

Advances in neuroimaging of multiple sclerosis

PURPOSE OF REVIEW

To summarize recent advancements in understanding multiple sclerosis (MS) pathophysiology, predicting disease course, and monitoring treatment responses using MRI.

RECENT FINDINGS

Paramagnetic rim lesions (PRLs) are highly specific to MS and clinically relevant. Detected from the earliest disease phases, PRLs aid in distinguishing MS from other conditions, improving diagnostic accuracy. Moreover, PRLs are associated with more severe disability and measures of brain damage and may predict disease progression. Similarly, slowly expanding lesions (SELs) are associated with more severe disability and predict a more severe disease course. Disease-modifying therapies have limited effectiveness in reducing PRLs or SELs. Choroid plexus (CP) enlargement is associated with structural brain damage and clinical disability and predicts disease evolution. Enlarged perivascular spaces (ePVS) suggest microangiopathic changes rather than direct MS-related inflammation. Glymphatic dysfunction, evaluated using diffusion tensor image analysis along the perivascular space, emerges early in MS and correlates with disability, cognitive impairment, and structural brain damage. Aging and comorbidities exacerbate MS-related damage, complicating diagnosis and treatment. Emerging technologies, such as brain-age paradigms, aim to disentangle aging from MS-specific neurodegeneration.

SUMMARY

Advances in MRI have highlighted the clinical significance of chronic inflammation and glymphatic dysfunction as early contributors to MS progression as well as the interplay between aging, comorbidities and MS.

The impact of white matter brain lesions on processing speed deficits in systemic lupus erythematosus patients

BackgroundThe mechanism of cognitive dysfunction in systemic lupus erythematosus (SLE) is still not fully understood. Even though many SLE patients present some neurological dysfunction, including various cognitive deficits, neither a specific pattern of cognitive dysfunction nor specific structural changes associated with cognitive impairment in SLE patients have been established. Moreover, although prevalent and bothersome, cognitive deficits have not been included in the most recent SLE diagnostic criteria.PurposeThe aim of this study was to determine the relationship between the presence of white matter lesions (WMLs) and cognitive dysfunction in patients diagnosed with SLE.Research Design33 SLE patients underwent 3 T brain magnetic resonance imagining (MRI) and an extensive battery of psychological tests, including Automated Neuropsychological Assessment Metrics (ANAM) and the standard pen and paper neuropsychological tests. Patients were stratified into two groups based on the presence (N = 15) or absence (N = 18) of WMLs. Psychometric scores were compared between the two groups.Results and conclusionsSignificant deficits in cognitive functions were observed. Patients with WMLs showed deficits in attention and executive functions, as well as memory deficits in comparison to the group without WMLs. As measured with: STROOP Test (executive function), Color Trail Test (CTT) (attention), Californian Verbal Learning Test (CVLT) (memory), and from ANAM tests with: Procedural Reaction Time (PRT) (attention), Code Substitution Delayed (CS_D) (memory), Spatial Processing (SP) (visuospatial functions), Tower Puzzle (TP) (executive functions), 2 Choice Reaction Time (2CHRT) (attention), Running Memory CPT (RM CPT) (memory), Matching Grids (Mat GR) (visuospatial functions), Go/No _Go inhibition (Go/No_Go Go) (executive functions). Additionally, we analyzed structural volumetric measures derived from a comprehensive segmentation pipeline recon-all using Freesurfer 5.3. Significant differences were identified for the following structures' volumes: right choroid plexus, left choroid plexus, right lateral ventricle. All these structures had a greater volume in patients with WMLs.

Distinguishing Transient From Persistent Brain Structural Changes in Pediatric Patients With Acute Disseminated Encephalomyelitis

BACKGROUND AND OBJECTIVES

Pediatric patients with acute disseminated encephalomyelitis (ADEM) are at risk of impaired brain growth, with long-term neuropsychiatric consequences. We previously reported transient expansions of cerebral ventricle volume (VV) in experimental autoimmune encephalomyelitis, which subsequently normalized. In this study, we investigated changes in VV in ADEM in relation to other brain structures and clinical outcomes.

METHODS

We investigated brain MRI scans acquired in routine clinical practice from a multicenter cohort of 61 pediatric patients with ADEM, of whom 39 were myelin oligodendrocyte glycoprotein (MOG) antibody-positive. Patients were compared with 1,219 pediatric healthy controls (HCs). Volumes of multiple brain structures were computed using a contrast-agnostic machine learning-based tool and analyzed with mixed-effect models regarding other clinical parameters.

RESULTS

Patients with ADEM had larger VV than HCs at initial clinical presentation, before immune therapy. Most of the patients showed further VV increases within 2 months after disease onset. Patients had smaller brain volumes than HCs, with specific reductions in deep gray matter structures. These changes were more pronounced in MOG antibody-negative patients.Of the patients with more than 2 MRI scans, 12 of 22 resolved their VV expansion back to within 15% of baseline values while 10 of 22 had persistently increased VV at the last available MRI within 1 year from onset. Patients with persistent VV expansion had greater reductions in volumes of other brain structures at the last MRI than patients whose VV resolved and were more likely to have residual neurologic signs. The VV resolving and nonresolving patients did not differ regarding age, sex, elevated CSF cell counts at baseline, or occurrence of relapses. However, patients with a larger magnitude of VV expansion-≥90% of baseline volume-were more likely to be in the nonresolving group.

DISCUSSION

We could distinguish between 2 outcomes of VV changes in ADEM: one in which the VV expanded but ultimately returned to normal and one in which the expansions continued after disease onset and treatment but failed to resolve. The latter was associated with reduced brain volume, particularly in deep gray matter structures. This highlights the necessity for patients with ADEM to undergo regular MRI scans to assess whether developing VV expansions indicate a greater risk of permanent brain atrophy.

Choroid Plexus Volume in Pediatric-Onset Multiple Sclerosis

BACKGROUND AND OBJECTIVES

Recent studies suggest that the choroid plexus (CP) may function as a site of access of inflammatory cells into the CNS in multiple sclerosis (MS). Pediatric-onset MS (POMS) is characterized by a high inflammatory burden, as evidenced by a high relapse rate and volume of T2 lesions, making patients with POMS an informative population to evaluate choroid plexus volume (CPV). The objectives of the study were (1) to evaluate CPV at symptom onset in participants with POMS compared with healthy controls (HCs); (2) to evaluate changes in CPV in the first year of disease in participants with POMS; and (3) to evaluate associations between CPV, brain volumes, relapse activity, and disability in participants with POMS.

METHODS

Baseline 1.5T MRI scans were acquired from 23 participants with POMS and 23 age-matched and sex-matched HCs; 18 participants with POMS also had 12-month follow-up MRI scans. The CP of the lateral ventricles was segmented manually. CP and brain structure volumes were normalized for total intracranial volume. The number of relapses, T2 and gadolinium-enhancing T1 lesion counts, and Expanded Disability Status Scale (EDSS) scores at 12 months were also analyzed. Baseline CPVs were compared between groups using the Wilcoxon exact test, and CPV change from baseline to 12 months in participants with POMS was compared using the Wilcoxon signed-rank test. The relationship between CPV and brain volumetric measures, T2 lesion volumes, lesion count, number of relapses, and EDSS scores was assessed through Spearman correlation.

RESULTS

The median normalized CPV was 1.51 × 10-3 (interquartile range [IQR]: 1.32-1.76) in POMS baseline scans and 1.21 × 10-3 (IQR: 1.1-1.47) in HC scans (p = 0.001). CPV did not significantly change at 12 months in the 18 participants with POMS with follow-up scans (p = 0.352). CPV in participants with POMS and HCs correlated with lateral ventricular volume (p = 0.012 for both groups) but did not correlate with brain and T2 lesion volumes or lesion count at baseline, nor with relapse activity or EDSS scores at 12 months in participants with POMS.

DISCUSSION

CPV measured at baseline is greater in participants with POMS than in HCs. Baseline CPV did not predict higher disease activity or worse neurologic outcomes over 1 year. While higher CPV may be an early feature of inflammation in MS, its strong correlation with ventricular volumes could also reflect enlargement secondary to the mechanical attachment of CP to the ventricular wall.

Choroid plexus volume changes in multiple sclerosis: insights from a systematic review and meta-analysis of magnetic resonance imaging studies

PURPOSE

Multiple sclerosis (MS) is a chronic autoimmune disease characterized by the destruction of the myelin sheath within the central nervous system. The etiology of MS involves a complex interplay of genetic, environmental, and immunological factors. Recent studies indicated the potential role of the choroid plexus (CP) in the pathogenesis and progression of MS. This systematic review aims to assess existing research on the volume alterations of the CP in MS patients compared to the normal population.

METHODS

A comprehensive search was conducted across databases including PubMed, Embase, Scopus, and Web of Science up to June 2024. Data from the included studies were synthesized using a meta-analytical approach with a random-effects model, assessing heterogeneity with the I2 and Tau-squared indices.

RESULTS

We included 17 studies in this systematic review. The meta-analysis, which included data from eight studies reporting CP volume relative to TIV, found a statistically significant increase in CP volume in MS patients compared to healthy controls (HCs). The SMD was 0.77 (95% CI: 0.61 to 0.93), indicating a large effect size. This analysis showed no heterogeneity (I² = 0%). A separate meta-analysis was conducted using five studies that reported CP volume as normalized volume, resulting in an SMD of 0.63 (95% CI: 0.2-1.06).

CONCLUSION

This study demonstrates an increase in CP volume among MS patients compared to HCs, implying the potential involvement of CP in MS pathogenesis and/or progression. These results show that CP might serve as a radiological indicator in the diagnosis and prognosis of MS.

Elevated peripheral inflammation is associated with choroid plexus enlargement in independent sporadic amyotrophic lateral sclerosis cohorts

BACKGROUND

Using neuroimaging techniques, growing evidence has suggested that the choroid plexus (CP) volume is enlarged in multiple neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). Notably, the CP has been suggested to play an important role in inflammation-induced CNS damage under disease conditions. However, to our knowledge, no study has investigated the relationships between peripheral inflammation and CP volume in sporadic ALS patients. Thus, in this study, we aimed to verify CP enlargement and explore its association with peripheral inflammation in vivo in independent ALS cohorts.

METHODS

Based on structural MRI data, CP volume was measured using Gaussian mixture models and further manually corrected in two independent cohorts of sporadic ALS patients and healthy controls (HCs). Serum inflammatory protein levels were measured using a novel high-sensitivity Olink proximity extension assay (PEA) technique. Xtreme gradient boosting (XGBoost) was used to explore the contribution of peripheral inflammatory factors to CP enlargement. Then, partial correlation analyses were performed.

RESULTS

CP volumes were significantly higher in ALS patients than in HCs in the independent cohorts. Compared with HCs, serum levels of CRP, IL-6, CXCL10, and 35 other inflammatory factors were significantly increased in ALS patients. Using the XGBoost approach, we established a model-based importance of features, and the top three predictors of CP volume in ALS patients were CRP, IL-6, and CXCL10 (with gains of 0.24, 0.18, and 0.15, respectively). Correlation analyses revealed that CRP, IL-6, and CXCL10 were significantly associated with CP volume in ALS patients (r = 0.462 ∼ 0.636, p < 0.001).

CONCLUSION

Our study is the first to reveal a consistent and replicable contribution of peripheral inflammation to CP enlargement in vivo in sporadic ALS patients. Given that CP enlargement has been recently detected in other brain diseases, these findings should consider extending to other disease conditions with a peripheral inflammatory component.

Inflammation-Triggered Enlargement of Choroid Plexus in Subacute COVID-19 Patients with Neurological Symptoms

OBJECTIVE

To investigate whether choroid plexus volumes in subacute coronavirus disease 2019 (COVID-19) patients with neurological symptoms could indicate inflammatory activation or barrier dysfunction and assess their association with clinical data.

METHODS

Choroid plexus volumes were measured in 28 subacute COVID-19 patients via cerebral magnetic resonance imaging (MRI), compared with those in infection-triggered non-COVID-19 encephalopathy patients (n = 25), asymptomatic individuals after COVID-19 (n = 21), and healthy controls (n = 21). Associations with inflammatory serum markers (peak counts of leukocytes, C-reactive protein [CRP], interleukin 6), an MRI-based marker of barrier dysfunction (CSF volume fraction [V-CSF]), and clinical parameters like olfactory performance and cognitive scores (Montreal Cognitive Assessment) were investigated.

RESULTS

COVID-19 patients showed significantly larger choroid plexus volumes than control groups (p < 0.001, η2 = 0.172). These volumes correlated significantly with peak leukocyte levels (p = 0.001, Pearson's r = 0.621) and V-CSF (p = 0.009, Spearman's rho = 0.534), but neither with CRP nor interleukin 6. No significant correlations were found with clinical parameters.

INTERPRETATION

In patients with subacute COVID-19, choroid plexus volume is a marker of central nervous system inflammation and barrier dysfunction in the presence of neurologic symptoms. The absence of plexus enlargement in infection-triggered non-COVID-19 encephalopathy suggests a specific severe acute respiratory syndrome coronavirus 2 effect. This study also documents an increase in choroid plexus volume for the first time as a parainfectious event. ANN NEUROL 2024;96:715-725.

Choroid plexus enlargement correlates with periventricular pathology but not with disease activity in radiologically isolated syndrome

BACKGROUND

Choroid plexus (ChP) enlargement is an emerging radiological biomarker in multiple sclerosis (MS).

OBJECTIVES

This study aims to assess ChP volume in a large cohort of patients with radiologically isolated syndrome (RIS) versus healthy controls (HC) and explore its relationship with other brain volumes, disease activity, and biological markers.

METHODS

RIS individuals were included retrospectively and compared with HC. ChPs were automatically segmented using an in-house automated algorithm and manually corrected.

RESULTS

A total of 124 patients fulfilled the 2023 RIS criteria, and 55 HCs were included. We confirmed that ChPs are enlarged in RIS versus HC (mean (±SD) normalized ChP volume: 17.24 (±4.95) and 11.61 (±3.58), respectively, p < 0.001). Larger ChPs were associated with more periventricular lesions (ρ = 0.26; r2 = 0.27; p = 0.005 for the correlation with lesion volume, and ρ = 0.2; r2 = 0.21; p = 0.002 for the correlation with lesion number) and lower thalamic volume (ρ = -0.38; r2 = 0.44; p < 0.001), but not with lesions in other brain regions. Conversely, ChP volume did not correlate with biological markers. No significant difference in ChP volume was observed between subjects who presented or did not have a clinical event or between those with or without imaging disease activity.

CONCLUSIONS

This study provides evidence that ChP volume is higher in RIS and is associated with measures reflecting periventricular pathology but does not correlate with biological, radiological, or clinical markers of disease activity.

Enhanced choroid plexus segmentation with 3D UX-Net and its association with disease progression in multiple sclerosis

BACKGROUND

The choroid plexus (CP) is suggested to be closely associated with the neuroinflammation of multiple sclerosis (MS). Segmentation based on deep learning (DL) could facilitate rapid and reproducible volume assessment of the CP, which is crucial for elucidating its role in MS.

PURPOSE

To develop a reliable DL model for the automatic segmentation of CP, and further validate its clinical significance in MS.

METHODS

The 3D UX-Net model (3D U-Net used for comparison) was trained and validated on T1-weighted MRI from a cohort of 216 relapsing-remitting MS (RRMS) patients and 75 healthy subjects. Among these, 53 RRMS with baseline and 2-year follow-up scans formed an internal test set (dataset1b). Another 58 RRMS from multi-center data served as an external test set (dataset2). Dice coefficient was computed to assess segmentation performance. Compare the correlation of CP volume obtained through automatic and manual segmentation with clinical outcomes in MS. Disability and cognitive function of patients were assessed using the Expanded Disability Status Scale (EDSS) and Symbol Digit Modalities Test (SDMT).

RESULTS

The 3D UX-Net model achieved Dice coefficients of 0.875 ± 0.030 and 0.870 ± 0.044 for CP segmentation on dataset1b and dataset2, respectively, outperforming 3D U-Net's scores of 0.809 ± 0.098 and 0.601 ± 0.226. Furthermore, CP volumes segmented by the 3D UX-Net model aligned consistently with clinical outcomes compared to manual segmentation. In dataset1b, both manual and automatic segmentation revealed a significant positive correlation between normalized CP volume (nCPV) and EDSS scores at baseline (manual: r = 0.285, p = 0.045; automatic: r = 0.287, p = 0.044) and a negative correlation with SDMT scores (manual: r = -0.331, p = 0.020; automatic: r = -0.329, p = 0.021). In dataset2, similar correlations were found with EDSS scores (manual: r = 0.337, p = 0.021; automatic: r = 0.346, p = 0.017). Meanwhile, in dataset1b, both manual and automatic segmentation revealed a significant increase in nCPV from baseline to follow-up (p < 0.05). The increase of nCPV was more pronounced in patients with disability worsened than stable patients (manual: p = 0.023; automatic: p = 0.018). Patients receiving disease-modifying therapy (DMT) exhibited a significantly lower nCPV increase than untreated patients (manual: p = 0.004; automatic: p = 0.004).

CONCLUSION

The 3D UX-Net model demonstrated strong segmentation performance for the CP, and the automatic segmented CP can be directly used in MS clinical practice. CP volume can serve as a surrogate imaging biomarker for monitoring disease progression and DMT response in MS patients.

Choroid plexus volume differentiates MS from its mimics

This study aimed to determine whether choroid plexus volume (CPV) could differentiate multiple sclerosis (MS) from its mimics. A secondary analysis of two previously enrolled studies, 50 participants with MS and 64 with alternative diagnoses were included. CPV was automatically segmented from 3T magnetic resonance imaging (MRI), followed by manual review to remove misclassified tissue. Mean normalized choroid plexus volume (nCPV) to intracranial volume demonstrated relatively high specificity for MS participants in each cohort (0.80 and 0.76) with an area under the receiver-operator characteristic curve of 0.71 (95% confidence interval (CI) = 0.55-0.87) and 0.65 (95% CI = 0.52-0.77). In this preliminary study, nCPV differentiated MS from its mimics.

Enlargement of the choroid plexus in pediatric multiple sclerosis

Some studies have suggested an inflammatory role of the choroid plexus (CP) in the pathophysiology of multiple sclerosis (MS), but mainly in adult patients. We aimed to evaluate clinical and MRI parameters in patients with pediatric-onset multiple sclerosis (POMS). We included 10 patients with POMS and 16 healthy controls (HC), evaluating clinical and neuroimaging variables (cerebral cortex, CP, deep gray matter structures, and demyelinating lesions). Most patients were girls (80%), with a mean age of 15.3 years. POMS individuals had a higher CP volume (p = 0.012) and lower thalamic volume (p = 0.038) compared to HC. This study shows an enlargement of the CP and lower thalamic volume in POMS patients compared to HC.

Cognitive Impairment Is Related to Glymphatic System Dysfunction in Pediatric Multiple Sclerosis

OBJECTIVE

The aim of this study was to investigate whether, compared to pediatric healthy controls (HCs), the glymphatic system is impaired in pediatric multiple sclerosis (MS) patients according to their cognitive status, and to assess its association with clinical disability and MRI measures of brain structural damage.

METHODS

Sixty-five pediatric MS patients (females = 62%; median age = 15.5 [interquartile range, IQR = 14.5;17.0] years) and 23 age- and sex-matched HCs (females = 44%; median age = 14.1 [IQR = 11.8;16.2] years) underwent neurological, neuropsychological and 3.0 Tesla MRI assessment, including conventional and diffusion tensor imaging (DTI). We calculated the diffusion along the perivascular space (DTI-ALPS) index, a proxy of glymphatic function. Cognitive impairment (Co-I) was defined as impairment in at least 2 cognitive domains.

RESULTS

No significant differences in DTI-ALPS index were found between HCs and cognitively preserved (Co-P) pediatric MS patients (estimated mean difference [EMD] = -0.002 [95% confidence interval = -0.069; 0.065], FDR-p = 0.956). Compared to HCs and Co-P patients, Co-I pediatric MS patients (n = 20) showed significantly lower DTI-ALPS index (EMD = -0.136 [95% confidence interval = -0.214; -0.058], FDR-p ≤ 0.004). In HCs, no associations were observed between DTI-ALPS index and normalized brain, cortical and thalamic volumes, and normal-appearing white matter (NAWM) fractional anisotropy (FA) and mean diffusivity (MD) (FDR-p ≥ 0.348). In pediatric MS patients, higher brain WM lesion volume (LV), higher NAWM MD, lower normalized thalamic volume, and lower NAWM FA were associated with lower DTI-ALPS index (FDR-p ≤ 0.016). Random Forest selected lower DTI-ALPS index (relative importance [RI] = 100%), higher brain WM LV (RI = 59.5%) NAWM MD (RI = 57.1%) and intelligence quotient (RI = 51.3%) as informative predictors of cognitive impairment (out-of-bag area under the curve = 0.762).

INTERPRETATION

Glymphatic system dysfunction occurs in pediatric MS, is associated with brain focal lesions, irreversible tissue loss accumulation and cognitive impairment. ANN NEUROL 2024;95:1080-1092.

A Fully Automatic Method to Segment Choroid Plexuses in Multiple Sclerosis Using Conventional MRI Sequences

BACKGROUND

Choroid plexus (CP) volume has been recently proposed as a proxy for brain neuroinflammation in multiple sclerosis (MS).

PURPOSE

To develop and validate a fast automatic method to segment CP using routinely acquired brain T1-weighted and FLAIR MRI.

STUDY TYPE

Retrospective.

POPULATION

Fifty-five MS patients (33 relapsing-remitting, 22 progressive; mean age = 46.8 ± 10.2 years; 31 women) and 60 healthy controls (HC; mean age = 36.1 ± 12.6 years, 33 women).

FIELD STRENGTH/SEQUENCE

3D T2-weighted FLAIR and 3D T1-weighted gradient echo sequences at 3.0 T.

ASSESSMENT

Brain tissues were segmented on T1-weighted sequences and a Gaussian Mixture Model (GMM) was fitted to FLAIR image intensities obtained from the ventricle masks of the SIENAX. A second GMM was then applied on the thresholded and filtered ventricle mask. CP volumes were automatically determined and compared with those from manual segmentation by two raters (with 3 and 10 years' experience; reference standard). CP volumes from previously published automatic segmentation methods (freely available Freesurfer [FS] and FS-GMM) were also compared with reference standard. Expanded Disability Status Scale (EDSS) score was assessed within 3 days of MRI. Computational time was assessed for each automatic technique and manual segmentation.

STATISTICAL TESTS

Comparisons of CP volumes with reference standard were evaluated with Bland Altman analysis. Dice similarity coefficients (DSC) were computed to assess automatic CP segmentations. Volume differences between MS and HC for each method were assessed with t-tests and correlations of CP volumes with EDSS were assessed with Pearson's correlation coefficients (R). A P value <0.05 was considered statistically significant.

RESULTS

Compared to manual segmentation, the proposed method had the highest segmentation accuracy (mean DSC = 0.65 ± 0.06) compared to FS (mean DSC = 0.37 ± 0.08) and FS-GMM (0.58 ± 0.06). The percentage CP volume differences relative to manual segmentation were -0.1% ± 0.23, 4.6% ± 2.5, and -0.48% ± 2 for the proposed method, FS, and FS-GMM, respectively. The Pearson's correlations between automatically obtained CP volumes and the manually obtained volumes were 0.70, 0.54, and 0.56 for the proposed method, FS, and FS-GMM, respectively. A significant correlation between CP volume and EDSS was found for the proposed automatic pipeline (R = 0.2), for FS-GMM (R = 0.3) and for manual segmentation (R = 0.4). Computational time for the proposed method (32 ± 2 minutes) was similar to the manual segmentation (20 ± 5 minutes) but <25% of the FS (120 ± 15 minutes) and FS-GMM (125 ± 15 minutes) methods.

DATA CONCLUSION

This study developed an accurate and easily implementable method for automatic CP segmentation in MS using T1-weighted and FLAIR MRI.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 4.

Choroid plexus enlargement in amyotrophic lateral sclerosis patients and its correlation with clinical disability and blood-CSF barrier permeability

BACKGROUND

Using in vivo neuroimaging techniques, growing evidence has demonstrated that the choroid plexus (CP) volume is enlarged in patients with several neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. However, although animal and postmortem findings suggest that CP abnormalities are likely important pathological mechanisms underlying amyotrophic lateral sclerosis (ALS), the third most common neurodegenerative disease, no available study has been conducted to thoroughly assess CP abnormalities and their clinical relevance in vivo in ALS patients to date. Thus, we aimed to determine whether in vivo CP enlargement may occur in ALS patients. We also aimed to identify the relationships of CP volume with clinical disabilities and blood-CSF barrier (BCSFB) permeability in ALS patients.

METHODS

In this retrospective study, based on structural MRI data, CP volume was assessed using a Gaussian mixture model and underwent further manual correction in 155 ALS patients and 105 age- and sex-matched HCs from October 2021 to April 2023. The ALS Functional Rating Scale-Revised (ALSFRS-R) was used to assess clinical disability. The CSF/serum albumin quotient (Qalb) was used to assess BCSFB permeability. Moreover, all the ALS patients completed genetic testing, and according to genetic testing, the ALS patients were further divided into genetic ALS subgroup and sporadic ALS subgroup.

RESULTS

We found that compared with HCs, ALS patients had a significantly higher CP volume (p < 0.001). Moreover, compared with HCs, CP volume was significantly increased in both ALS patients with and without known genetic mutations after family-wise error correction (p = 0.006 and p < 0.001, respectively), while there were no significant differences between the two ALS groups. Furthermore, the CP volume was significantly correlated with the ALSFRS-r score (r = -0.226; p = 0.005) and the Qalb (r = 0.479; p < 0.001) in ALS patients.

CONCLUSION

Our study first demonstrates CP enlargement in vivo in ALS patients, and continues to suggest an important pathogenetic role for CP abnormalities in ALS. Moreover, assessing CP volume is likely a noninvasive and easy-to-implement approach for screening BCSFB dysfunction in ALS patients.

The Time Trajectory of Choroid Plexus Enlargement in Multiple Sclerosis

Choroid plexus (CP) can be seen as a watchtower of the central nervous system (CNS) that actively regulates CNS homeostasis. A growing body of literature suggests that CP alterations are involved in the pathogenesis of multiple sclerosis (MS) but the underlying mechanisms remain elusive. CPs are enlarged and inflamed in relapsing-remitting (RRMS) but also in clinically isolated syndrome (CIS) and radiologically isolated syndrome (RIS) stages, far beyond MS diagnosis. Increases in the choroid plexus/total intracranial volume (CP/TIV) ratio have been robustly associated with increased lesion load, higher translocator protein (TSPO) uptake in normal-appearing white matter (NAWM) and thalami, as well as with higher annual relapse rate and disability progression in highly active RRMS individuals, but not in progressive MS. The CP/TIV ratio has only slightly been correlated with magnetic resonance imaging (MRI) findings (cortical or whole brain atrophy) and clinical outcomes (EDSS score) in progressive MS. Therefore, we suggest that plexus volumetric assessments should be mainly applied to the early disease stages of MS, whereas it should be taken into consideration with caution in progressive MS. In this review, we attempt to clarify the pathological significance of the temporal CP volume (CPV) changes in MS and highlight the pitfalls and limitations of CP volumetric analysis.

Chronic Active Lesions and Larger Choroid Plexus Explain Cognition and Fatigue in Multiple Sclerosis

BACKGROUND AND OBJECTIVES

Chronic inflammation may contribute to cognitive dysfunction and fatigue in patients with multiple sclerosis (MS). Paramagnetic rim lesions (PRLs) and choroid plexus (CP) enlargement have been proposed as markers of chronic inflammation in MS being associated with a more severe disease course. However, their relation with cognitive impairment and fatigue has not been fully explored yet. Here, we investigated the contribution of PRL number and volume and CP enlargement to cognitive impairment and fatigue in patients with MS.

METHODS

Brain 3T MRI, neurologic evaluation, and neuropsychological assessment, including the Brief Repeatable Battery of Neuropsychological Tests and Modified Fatigue Impact Scale, were obtained from 129 patients with MS and 73 age-matched and sex-matched healthy controls (HC). PRLs were identified on phase images of susceptibility-weighted imaging, whereas CP volume was quantified using a fully automatic method on brain three-dimensional T1-weighted and fluid-attenuated inversion recovery MRI sequences. Predictors of cognitive impairment and fatigue were identified using random forest.

RESULTS

Thirty-six (27.9%) patients with MS were cognitively impaired, and 31/113 (27.4%) patients had fatigue. Fifty-nine (45.7%) patients with MS had ≥1 PRLs (median = 0, interquartile range = 0;2). Compared with HC, patients with MS showed significantly higher T2-hyperintense white matter lesion (WM) volume; lower normalized brain, thalamic, hippocampal, caudate, cortical, and WM volumes; and higher normalized CP volume (p from <0.001 to 0.040). The predictors of cognitive impairment (relative importance) (out-of-bag area under the curve [OOB-AUC] = 0.707) were normalized brain volume (100%), normalized caudate volume (89.1%), normalized CP volume (80.3%), normalized cortical volume (70.3%), number (67.3%) and volume (66.7%) of PRLs, and T2-hyperintense WM lesion volume (64.0%). Normalized CP volume was the only predictor of the presence of fatigue (OOB-AUC = 0.563).

DISCUSSION

Chronic inflammation, with higher number and volume of PRLs and enlarged CP, may contribute to cognitive impairment in MS in addition to gray matter atrophy. The contribution of enlarged CP in explaining fatigue supports the relevance of immune-related processes in determining this manifestation independently of disease severity. PRLs and CP enlargement may contribute to the pathophysiology of cognitive impairment and fatigue in MS, and they may represent clinically relevant therapeutic targets to limit the impact of these clinical manifestations in MS.

Enlarged choroid plexus in multiple sclerosis is associated with increased lesion load and atrophy in white matter but not gray matter atrophy

BACKGROUND

Enlargement of the choroid plexus (CP) is reported to associate with inflammatory activity and contribute to brain atrophy in patients with multiple sclerosis (pwMS). However, a recent study in healthy volunteers (HVTs) has suggested that CP enlargement can be attributed to ventriculomegaly.

OBJECTIVES

To clarify the pathological significance of the enlargement of CP in multiple sclerosis (MS).

METHODS

A total of 102 pwMS (89 with relapsing-remitting MS and 13 with secondary progressive MS) and 41 HVTs were cross-sectionally evaluated using brain volumetry. The CP volume was compared between disease groups and investigated for the relationships with other brain regional volumes.

RESULTS

CP volume was significantly larger in pwMS than in HVTs in the univariate analysis, but not in multivariable analysis. Meanwhile, the CP and lateral ventricle (LV) volumes were significantly correlated. CP enlargement was significantly associated with increased lesion load and cerebral white matter (WM) atrophy, even after adjusting for LV volume. In contrast, multivariable analyses revealed that LV enlargement, but not CP enlargement, was associated with total gray matter (GM) atrophy.

CONCLUSION

CP enlargement was closely associated with LV enlargement. After adjusting for LV volume, CP enlargement in pwMS was associated with increased lesion load and WM atrophy but not GM atrophy.

Choroid plexus and perivascular space enlargement in neuropsychiatric systemic lupus erythematosus

Choroid plexus (CP) enlargement is proposed as a marker of neuroinflammation in immune-mediated conditions. CP involvement has also been hypothesized in the immunopathology of systemic lupus erythematosus (SLE). We investigated whether CP enlargement occurs in SLE patients and its association with neuropsychiatric involvement. Additionally, we explored abnormalities along the glymphatic system in SLE patients through enlarged perivascular space (PVS) quantification. Clinical assessment and 3 Tesla brain dual-echo and T1-weighted MRI scans were obtained from 32 SLE patients and 32 sex and age-matched healthy controls (HC). CPs were manually segmented on 3D T1-weighted sequence and enlarged PVS (ePVS) were assessed through Potter's score. Compared to HC, SLE patients showed higher normalized CP volume (nCPV) (p = 0.023), with higher CP enlargement in neuropsychiatric SLE (NPSLE) (n = 12) vs. non-NPSLE (p = 0.027) patients. SLE patients with antiphospholipid antibodies (APA) positivity (n = 18) had higher nCPV compared to HC (p = 0.012), while APA negative ones did not. SLE patients also had higher Potter's score than HC (p < 0.001), with a tendency towards a higher number of basal ganglia ePVS in NPSLE vs. non-NPSLE patients. Using a random forest analysis, nCPV emerged as a significant predictor of NPSLE, together with T2-hyperintense white matter (WM) lesion volume (LV) and APA positivity (out-of-bag AUC 0.81). Our findings support the hypothesis of a role exerted by the CP in SLE physiopathology, especially in patients with neuropsychiatric involvement. The higher prevalence of ePVS in SLE patients, compared to HC, suggests the presence of glymphatic system impairment in this population.

Choroid plexus volume enlargement in first-episode antipsychotic-naïve schizophrenia

Investigation of the choroid plexus in schizophrenia has seen growing interest due to its role in the interaction between neuroinflammation and brain dysfunction. Most previous studies included treated and long-term ill patients, while antipsychotics and illness course might both affect the choroid plexus. Here, we recruited first-episode antipsychotic-naïve schizophrenia patients, performed high-resolution structural brain scan and manually extracted choroid plexus volume. Choroid plexus volume was compared between patients and healthy controls after controlling for age, sex and intracranial volume. Age and sex effects were examined on choroid plexus volume in patient and healthy control groups respectively. In patients, we also examined the correlation of choroid plexus volume with volume measures of cortical and subcortical gray matter, white matter, lateral ventricular as well as symptom severity and cognitive function. Schizophrenia patients showed significantly enlarged choroid plexus volume compared with healthy controls. Choroid plexus volume was positively correlated with age in only patient group and we found significantly larger choroid plexus volumes in males than females in both patient and healthy control groups, while the sex effects did not differ between groups. Choroid plexus volume was only found correlated with lateral ventricular volume among the brain volume measures. No significant correlation between choroid plexus volume and clinical ratings or cognitive performance was observed. Without potential confounding effects of pharmacotherapy or illness course, our findings indicated the enlargement of choroid plexus in schizophrenia might be an enduring trait for schizophrenia.

Understanding the Pathophysiology and Magnetic Resonance Imaging of Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorders

Magnetic resonance imaging (MRI) has been extensively applied in the study of multiple sclerosis (MS), substantially contributing to diagnosis, differential diagnosis, and disease monitoring. MRI studies have significantly contributed to the understanding of MS through the characterization of typical radiological features and their clinical or prognostic implications using conventional MRI pulse sequences and further with the application of advanced imaging techniques sensitive to microstructural damage. Interpretation of results has often been validated by MRI-pathology studies. However, the application of MRI techniques in the study of neuromyelitis optica spectrum disorders (NMOSD) remains an emerging field, and MRI studies have focused on radiological correlates of NMOSD and its pathophysiology to aid in diagnosis, improve monitoring, and identify relevant prognostic factors. In this review, we discuss the main contributions of MRI to the understanding of MS and NMOSD, focusing on the most novel discoveries to clarify differences in the pathophysiology of focal inflammation initiation and perpetuation, involvement of normal-appearing tissue, potential entry routes of pathogenic elements into the CNS, and existence of primary or secondary mechanisms of neurodegeneration.

Choroid plexuses at the interface of peripheral immunity and tissue repair in multiple sclerosis

PURPOSE OF REVIEW

Choroid plexuses (ChPs) are key actors of the blood-to-cerebrospinal-fluid barrier and serve as brain immune checkpoint. The past years have seen a regain of interest about their potential involvement in the physiopathology of neuroinflammatory disorders like multiple sclerosis (MS). This article offers an overview of the recent findings on ChP alterations in MS, with a focus on the imaging tools able to detect these abnormalities and on their involvement in inflammation, tissue damage and repair.

RECENT FINDINGS

On MRI, ChPs are enlarged in people with MS (PwMS) versus healthy individuals. This size increase is an early event, already detected in presymptomatic and pediatric MS. Enlargement of ChPs is linked to local inflammatory infiltrates, and their dysfunction selectively impacts periventricular damage, larger ChPs predicting the expansion of chronic active lesions, smoldering inflammation and remyelination failure in tissues surrounding the ventricles. ChP volumetry may add value for the prediction of disease activity and disability worsening.

SUMMARY

ChP imaging metrics are emerging as possible biomarkers of neuroinflammation and repair failure in MS. Future works combining multimodal imaging techniques should provide a more refined characterization of ChP functional changes, their link with tissue damage, blood to cerebrospinal-fluid barrier dysfunction and fluid trafficking in MS.

A review on multiple sclerosis prognostic findings from imaging, inflammation, and mental health studies

Magnetic resonance imaging (MRI) of the brain is commonly used to detect where chronic and active lesions are in multiple sclerosis (MS). MRI is also extensively used as a tool to calculate and extrapolate brain health by way of volumetric analysis or advanced imaging techniques. In MS patients, psychiatric symptoms are common comorbidities, with depression being the main one. Even though these symptoms are a major determinant of quality of life in MS, they are often overlooked and undertreated. There has been evidence of bidirectional interactions between the course of MS and comorbid psychiatric symptoms. In order to mitigate disability progression in MS, treating psychiatric comorbidities should be investigated and optimized. New research for the prediction of disease states or phenotypes of disability have advanced, primarily due to new technologies and a better understanding of the aging brain.

Unraveling the heterogeneous pathological substrates of relapse-onset multiple sclerosis: a multiparametric voxel-wise 3 T MRI study

BACKGROUND

In multiple sclerosis (MS), pathological processes affecting brain gray (GM) and white matter (WM) are heterogeneous.

OBJECTIVE

To apply a multimodal MRI approach to investigate the regional distribution of the different pathological processes occurring in the brain WM and GM of relapse-onset MS patients.

METHODS

Fifty-seven MS patients (forty-two relapsing remitting [RR], fifteen secondary progressive [SP]) and forty-seven age- and sex-matched healthy controls (HC) underwent a multimodal 3 T MRI acquisition. Between-group voxel-wise differences of brain WM and GM volumes, magnetization transfer ratio (MTR), T₁-weighted(w)/T₂w ratio, intracellular volume fraction (ICV_f), and quantitative susceptibility mapping (QSM) maps were investigated.

RESULTS

Compared to HC, RRMS showed significant WM, deep GM and cortical atrophy, significantly lower MTR and T₁w/T₂w ratio of periventricular and infratentorial WM, deep GM and several cortical areas, lower ICV_f in supratentorial and cerebellar WM and in some cortical areas, and lower QSM values in bilateral periventricular WM (p < 0.001). Compared to RRMS, SPMS patients showed significant deep GM and widespread cortical atrophy, significantly lower MTR of periventricular WM, deep GM and cerebellum, lower T₁w/T₂w ratio of fronto-temporal WM regions, lower ICV_f of some fronto-tempo-occipital WM and cortical areas. They also had increased QSM and T₁w/T₂w ratio in the pallidum, bilaterally (p < 0.001).

CONCLUSION

A periventricular pattern of demyelination and widespread GM and WM neuro-axonal loss are detectable in RRMS and are more severe in SPMS. Higher T₁w/T₂w ratio and QSM in the pallidum, possibly reflecting iron accumulation and neurodegeneration, may represent a relevant MRI marker to differentiate SPMS from RRMS.