CSF sphingolipids are correlated with neuroinflammatory cytokines and differentiate neuromyelitis optica spectrum disorder from multiple sclerosis.

BACKGROUND: There is a need for biomarkers of disease progression and therapeutic response in multiple sclerosis (MS). This study aimed to identify cerebrospinal fluid (CSF) lipids that differentiate MS from other neuroinflammatory conditions and correlate with Expanded Disability Status Scale (EDSS) scores, gadolinium-enhancing lesions or inflammatory mediators. METHODS: Lipids and inflammatory cytokines/chemokines were quantified with liquid chromatography-tandem mass spectrometry and multiplex ELISA, respectively, in CSF from people with untreated MS, neuromyelitis optica spectrum disorder (NMOSD), other inflammatory neurological diseases and non-inflammatory neurological diseases (NIND). Analytes were compared between groups using analysis of variance, and correlations were assessed with Pearson's analysis. RESULTS: Twenty-five sphingolipids and four lysophosphatidylcholines were significantly higher in NMOSD compared with MS and NIND cases, whereas no lipids differed significantly between MS and NIND. A combination of three sphingolipids differentiated NMOSD from MS with the area under the curve of 0.92 in random forest models. Ninety-four lipids, including those that differentiated NMOSD from MS, were positively correlated with macrophage migration inhibitory factor (MIF) and 37 lipids were positively correlated with CSF protein in two independent MS cohorts. EDSS was inversely correlated with cholesterol ester CE(16:0) in both MS cohorts. In contrast, MIF and soluble triggering receptor expressed on myeloid cells 2 were positively associated with EDSS. CONCLUSIONS: CSF sphingolipids are positively correlated with markers of neuroinflammation and differentiate NMOSD from MS. The inverse correlation between EDSS and CE(16:0) levels may reflect poor clearance of cholesterol released during myelin break-down and warrants further investigation as a biomarker of therapeutic response.

Predominant right temporal lobe atrophy: Clinical, neuropsychological and structural differences based on amyloid status.

BACKGROUND: Predominant right temporal atrophy is a radiological sign usually associated with frontotemporal dementia but this sign can also be present in Alzheimer's disease. Given the overlap of clinical symptoms between the two conditions, it is important to know which characteristics allow them to be differentiated. OBJECTIVES: To compare clinical, neuropsychological and structural magnetic resonance imaging (MRI) data of subjects with prominent right anterior temporal atrophy, depending on the status of amyloid biomarkers. METHODS: Among patients followed in the dementia center of Ospedale Maggiore Policlinico, subjects with right anterior temporal atrophy, defined as grade 3 or 4 on the corresponding visual rating scale, were identified. Only subjects with both an MRI scan and amyloid status available were considered. For selected subjects, data were extracted from clinical and neuropsychological records at initial presentation and at last available follow-up. Two raters applied a protocol of eight visual rating scales to compare brain atrophy and white matter hyperintensities. RESULTS: Of 497 subjects, 17 fulfilled the inclusion criteria: 7 amyloid-positive and 10 amyloid-negative. At initial presentation, executive dysfunction and topographical disorientation were more common in amyloid-positive patients. At follow-up, behavioral symptoms, such as social awkwardness and compulsive attitude, were more frequent in the amyloid-negative patients. Amyloid-positive patients presented an overall worse neuropsychological performance, especially in the language and visuospatial domain, and had higher scores on the right anterior cingulate visual rating scale. CONCLUSION: Patients with predominant right temporal atrophy showed clinical, neuropsychological and radiological differences, depending on the status of amyloid biomarkers.

Quantitative susceptibility mapping of the normal-appearing white matter as a potential new marker of disability progression in multiple sclerosis.

OBJECTIVES: To investigate the normal-appearing white matter (NAWM) susceptibility in a cohort of newly diagnosed multiple sclerosis (MS) patients and to evaluate possible correlations between NAWM susceptibility and disability progression. METHODS: Fifty-nine patients with a diagnosis of MS (n = 53) or clinically isolated syndrome (CIS) (n = 6) were recruited and followed up. All participants underwent neurological examination, blood sampling for serum neurofilament light chain (sNfL) level assessment, lumbar puncture for the quantification of cerebrospinal fluid (CSF) ß-amyloid1-42 (Aß) levels, and brain MRI. T2-weighted scans were used to quantify white matter (WM) lesion loads. For each scan, we derived the NAWM volume fraction and the WM lesion volume fraction. Quantitative susceptibility mapping (QSM) of the NAWM was calculated using the susceptibility tensor imaging (STI) suite. Susceptibility maps were computed with the STAR algorithm. RESULTS: Primary progressive patients (n = 9) showed a higher mean susceptibility value in the NAWM than relapsing-remitting (n = 44) and CIS (n = 6) (p = 0.01 and p = 0.02). Patients with a higher susceptibility in the NAWM showed increased sNfL concentration (ρ = 0.38, p = 0.004) and lower CSF Aß levels (ρ = -0.34, p = 0.009). Mean NAWM susceptibility turned out to be a predictor of the expanded disability status scale (EDSS) worsening at follow-up (ß = 0.41, t = 2.66, p = 0.01) and of the MS severity scale (MSSS) (ß = 0.38, t = 2.43, p = 0.019). CONCLUSIONS: QSM in the NAWM seems to predict the EDSS increment over time. This finding might provide evidence on the role of QSM in identifying patients with an increased risk of early disability progression. KEY POINTS: • NAWM-QSM is higher in PPMS patients than in RRMS. • NAWM-QSM seems to be a predictor of EDSS worsening over time. • Patients with higher NAWM-QSM show increased sNfL concentration and lower CSF Aß levels.

Telemedicine for cognitive impairment: a telephone survey of patients' experiences with neurological video consultation.

OBJECTIVE: This study aimed to evaluate the experience with telemedicine in patients with cognitive impairments and their caregivers. METHODS: We conducted a survey-based study of patients who completed neurological consultation via video link between January and April 2022. RESULTS: A total of 62 eligible neurological video consultations were conducted for the following categories of patients: Alzheimer's disease (33.87%), amnesic mild cognitive impairment (24.19%), frontotemporal dementia (17.74%), Lewy body dementia (4.84%), mixed dementia (3.23%), subjective memory disorders (12.90%), non-amnesic mild cognitive impairment (1.61%), and multiple system atrophy (1.61%). The survey was successfully completed by 87.10% of the caregivers and directly by the patients in 12.90% of cases. Our data showed positive feedback regarding the telemedicine experience; both caregivers and patients reported that they found neurological video consultation useful (caregivers: 87.04%, 'very useful'; patients: 87.50%, 'very useful') and were satisfied overall (caregivers: 90.74%, 'very satisfied'; patients: 100%, 'very satisfied'). Finally, all caregivers (100%) agreed that neurological video consultation was a useful tool to reduce their burden (Visual Analogue Scale mean ± SD: 8.56 ± 0.69). CONCLUSIONS: Telemedicine is well received by patients and their caregivers. However, successful delivery incorporates support from staff and care partners to navigate technologies. The exclusion of older adults with cognitive impairment in developing telemedicine systems may further exacerbate access to care in this population. Adapting technologies to the needs of patients and their caregivers is critical for the advancement of accessible dementia care through telemedicine.

Facing the digital divide into a dementia clinic during COVID-19 pandemic: caregiver age matters.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has dramatically stressed the health care system and has provoked changes in population use of digital technologies. Digital divide is any uneven distribution in Information and Communications Technologies between people. AIMS: The purpose of this work was to describe the digital divide of a population of patients with dementia contacted by telemedicine during Italian lockdown for COVID-19 pandemic. METHOD: One hundred eight patients with cognitive impairment were contacted by video call to perform a telemedicine neurological evaluation. Information on patients and caregivers attending the televisit were recorded. RESULTS: Seventy-four patients connected with neurologist (successful televisit, 68.5%) and 34 patients were not able to perform televisit and were contacted by phone (failed televisit, 31.5%). No significant differences were observed among the two groups concerning age, gender, and education, but the prevalence of successful televisit was higher in the presence of younger caregivers: televisits performed in the presence of subjects of younger generation (sons and grandsons) had a successful rate higher (86% successful, 14% failed) than the group without younger generation caregiver (49% successful, 51% failed). This difference is mainly due to the ability of technological use among younger people. DISCUSSION: The most impacting factors on digital divide in our population are the social support networks and the experience with the technology: the presence of a digital native caregiver. The COVID-19 pandemic is unmasking an emerging form of technology-related social inequalities: political and community interventions are needed to support the most socially vulnerable population and prevent social health inequalities.

Evidence of retinal anterograde neurodegeneration in the very early stages of multiple sclerosis: a longitudinal OCT study.

BACKGROUND: Neurodegenerative processes are present since the early stages of multiple sclerosis (MS), constituting the primary substrate of disability. As part of the CNS, retinal damage could be considered a reliable prognostic biomarker of neurodegeneration in MS. OBJECTIVES: To characterize longitudinal changes in the retinal layers' thickness and to investigate correlations between retinal atrophy and other prognostic biomarkers, i.e., cerebrospinal fluid (CSF) ß-amyloid1-42 (Aß) levels. METHODS: Forty-two eyes without a history of optic neuritis of 23 MS patients were recruited. All patients underwent spectral-domain-OCT scans (SD-OCT), brain magnetic resonance imaging (MRI), and lumbar puncture at baseline. SD-OCT and brain MRI were repeated after 12 months. Ten controls underwent the same OCT procedure. RESULTS: At baseline, macular ganglion cell/inner plexiform layer (mGCIPL) thickness was reduced in patients compared to controls (p = 0.008), without retinal nerve fiber layer (RNFL) thinning, that was revealed only at follow-up (p = 0.005). Patients with lower CSF Aß levels displayed reduced RNFL thickness values, both at baseline and follow-up. CONCLUSIONS: At very early clinical stages, mGCIPL thickness values were reduced without a concomitant peripapillary RNFL thinning. The longitudinal assessment demonstrated a RNFL loss in patients compared to HC, together with a plateau of mGCIPL thinning. Aßlow subgroup of patients showed a reduction of retinal nerve fiber layer thickness.

Amyloid PET as a marker of normal-appearing white matter early damage in multiple sclerosis: correlation with CSF ß-amyloid levels and brain volumes.

PURPOSE: The disease course of multiple sclerosis (MS) is unpredictable, and reliable prognostic biomarkers are needed. Positron emission tomography (PET) with ß-amyloid tracers is a promising tool for evaluating white matter (WM) damage and repair. Our aim was to investigate amyloid uptake in damaged (DWM) and normal-appearing WM (NAWM) of MS patients, and to evaluate possible correlations between cerebrospinal fluid (CSF) ß-amyloid1-42 (Aß) levels, amyloid tracer uptake, and brain volumes. METHODS: Twelve MS patients were recruited and divided according to their disease activity into active and non-active groups. All participants underwent neurological examination, neuropsychological testing, lumbar puncture, brain magnetic resonance (MRI) imaging, and 18F-florbetapir PET. Aß levels were determined in CSF samples from all patients. MRI and PET images were co-registered, and mean standardized uptake values (SUV) were calculated for each patient in the NAWM and in the DWM. To calculate brain volumes, brain segmentation was performed using statistical parametric mapping software. Nonparametric statistical analyses for between-group comparisons and regression analyses were conducted. RESULTS: We found a lower SUV in DWM compared to NAWM (p < 0.001) in all patients. Decreased NAWM-SUV was observed in the active compared to non-active group (p < 0.05). Considering only active patients, NAWM volume correlated with NAWM-SUV (p = 0.01). Interestingly, CSF Aß concentration was a predictor of both NAWM-SUV (r = 0.79; p = 0.01) and NAWM volume (r = 0.81, p = 0.01). CONCLUSIONS: The correlation between CSF Aß levels and NAWM-SUV suggests that the predictive role of ß-amyloid may be linked to early myelin damage and may reflect disease activity and clinical progression.

The loss of macular ganglion cells begins from the early stages of disease and correlates with brain atrophy in multiple sclerosis patients.

BACKGROUND: The importance of neurodegeneration in multiple sclerosis (MS) is increasingly well recognized. OBJECTIVES: To evaluate retinal pathology using optical coherence tomography (OCT) and to investigate possible associations between retinal layers' thickness and specific patterns of gray matter volume in patients with a new diagnosis of MS. METHODS: A total of 31 patients underwent OCT scans and brain magnetic resonance imaging. In total, 30 controls underwent the same OCT procedure. The association between focal cortical volume and OCT measurements was investigated with voxel-based morphometry (VBM). RESULTS: Compared to controls, patients' macular retinal nerve fiber layer (mRNFL), macular ganglion cell layer (mGCL), macular inner plexiform layer (mIPL), and macular ganglion cell-inner plexiform layer (mGCIPL) thickness were significantly reduced ( p = 0.0009, p = 0.0003, p = 0.0049, and p = 0.0007, respectively). Peripapillary RNFL (pRNFL) and temporal sector pRNFL (T-pRNFL) did not show any significant changes, although there was a trend toward T-pRNFL thinning ( p = 0.0254). VBM analysis showed that mGCIPL and pRNFL were significantly correlated with the volume reduction of occipital-parietal cortex ( p < 0.005). CONCLUSION: mRNFL, mGCL, and mIPL are significantly reduced in MS patients without concomitant pRNFL thinning. These retinal changes show a significant association with cortical regions that are known to be important for visuospatial performance.

CSF ß-amyloid predicts prognosis in patients with multiple sclerosis.

BACKGROUND: The importance of predicting disease progression in multiple sclerosis (MS) has increasingly been recognized, and hence reliable biomarkers are needed. OBJECTIVES: To investigate the prognostic role of cerebrospinal fluid (CSF) amyloid beta1-42 (Aß) levels by the determination of a cut-off value to classify patients in slow and fast progressors. To evaluate possible association with white matter (WM) and grey matter (GM) damage at early disease stages. METHODS: Sixty patients were recruited and followed up for 3-5 years. Patients underwent clinical assessment, brain magnetic resonance imaging (MRI; at baseline and after 1 year), and CSF analysis to determine Aß levels. T1-weighted volumes were calculated. T2-weighted scans were used to quantify WM lesion loads. RESULTS: Lower CSF Aß levels were observed in patients with a worse follow-up Expanded Disability Status Scale (EDSS; r = -0.65, p < 0.001). The multiple regression analysis confirmed CSF Aß concentration as a predictor of patients' EDSS increase (r = -0.59, p < 0.0001). Generating a receiver operating characteristic curve, a cut-off value of 813 pg/mL was determined as the threshold able to identify patients with worse prognosis (95% confidence interval (CI): 0.690-0.933, p = 0.0001). No differences in CSF tau and neurofilament light chain (NfL) levels were observed (p > 0.05). CONCLUSION: Low CSF Aß levels may represent a predictive biomarker of disease progression in MS.

Structural and metabolic cerebral alterations between elderly bipolar disorder and behavioural variant frontotemporal dementia: A combined MRI-PET study.

BACKGROUND: Elderly bipolar disorder (BD) and behavioural variant of frontotemporal dementia (bvFTD) may exhibit similar symptoms and both disorders are characterized by selective abnormalities in cortical and subcortical regions that are associated with cognitive and emotional impairments. We aimed to investigate common and distinct neural substrates of BD and bvFTD by coupling, for the first time, magnetic resonance imaging (MRI) and positron emission tomography (PET) techniques. METHODS: 3-Tesla MRI and 18 fluorodeoxyglucose-PET scans were acquired for 16 elderly BD patients, 23 bvFTD patients with mild cognitive impairments and 68 healthy controls (48 for PET and 20 for MRI analyses). RESULTS: BD and bvFTD patients exhibit a different localization of grey matter reductions in the lateral prefrontal cortex, with the first group showing grey matter decrease in the ventrolateral prefrontal cortex and the latter group showing grey matter reductions in the dorsolateral prefrontal cortex as well as unique grey matter and metabolic alterations within the orbitofrontal cortex. The bvFTD group also displayed unique volumetric shrinkage in regions within the temporo-parietal network together with greater metabolic impairments within the temporal cortex and more extensive volumetric and metabolic abnormalities within the limbic lobe. Finally, while the BD group showed greater grey matter volumes in caudate nucleus, bvFTD subjects displayed lower metabolism. CONCLUSION: This MRI-PET study explored, for the first time to the best of our knowledge, structural and functional abnormalities in bvFTD and elderly BD patients, with the final aim of identifying the specific biological signature of these disorders, which might have important implications not only in prevention but also in differential diagnosis and treatment.

CSF ß-amyloid and white matter damage: a new perspective on Alzheimer's disease.

OBJECTIVE: To assess the connection between amyloid pathology and white matter (WM) macrostructural and microstructural damage in demented patients compared with controls. METHODS: Eighty-five participants were recruited: 65 with newly diagnosed Alzheimer's disease (AD), non-AD dementia or mild cognitive impairment and 20 age-matched and sex-matched healthy controls. ß-amyloid1-42 (Aß) levels were determined in cerebrospinal fluid (CSF) samples from all patients and five controls. Among patients, 42 had pathological CSF Aß levels (Aß(+)), while 23 had normal CSF Aß levels (Aß(-)). All participants underwent neurological examination, neuropsychological testing and brain MRI. We used T2-weighted scans to quantify WM lesion loads (LLs) and diffusion-weighted images to assess their microstructural substrate. Non-parametric statistical tests were used for between-group comparisons and multiple regression analyses. RESULTS: We found an increased WM-LL in Aß(+) compared with both, healthy controls (p=0.003) and Aß(-) patients (p=0.02). Interestingly, CSF Aß concentration was the best predictor of patients' WM-LL (r=-0.30, p<0.05) when using age as a covariate. Lesion apparent diffusion coefficient value was higher in all patients than in controls (p=0.0001) and correlated with WM-LL (r=0.41, p=0.001). In Aß(+), WM-LL correlated with WM microstructural damage in the left peritrigonal WM (p<0.0001). CONCLUSIONS: WM damage is crucial in AD pathogenesis. The correlation between CSF Aß levels and WM-LL suggests a direct link between amyloid pathology and WM macrostructural and microstructural damage.

Recognition of viral and self-antigens by TH1 and TH1/TH17 central memory cells in patients with multiple sclerosis reveals distinct roles in immune surveillance and relapses.

BACKGROUND: Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS) that is caused by autoreactive T cells and associated with viral infections. However, the phenotype of pathogenic T cells in peripheral blood remains to be defined, and how viruses promote MS is debated. OBJECTIVE: We aimed to identify and characterize potentially pathogenic autoreactive T cells, as well as protective antiviral T cells, in patients with MS. METHODS: We analyzed CD4+ helper T-cell subsets from peripheral blood or cerebrospinal fluid for cytokine production, gene expression, plasticity, homing potentials, and their reactivity to self-antigens and viral antigens in healthy subjects and patients with MS. Moreover, we monitored their frequencies in untreated and fingolimod- or natalizumab-treated patients with MS. RESULTS: TH1/TH17 central memory (TH1/TH17CM) cells were selectively increased in peripheral blood of patients with relapsing-remitting MS with a high disease score. TH1/TH17CM cells were closely related to conventional TH17 cells but had more pathogenic features. In particular, they could shuttle between lymph nodes and the CNS and produced encephalitogenic cytokines. The cerebrospinal fluid of patients with active MS was enriched for CXCL10 and contained mainly CXCR3-expressing TH1 and TH1/TH17 subsets. However, while TH1 cells responded consistently to viruses, TH1/TH17CM cells reacted strongly with John Cunningham virus in healthy subjects but responded instead to myelin-derived self-antigens in patients with MS. Fingolimod and natalizumab therapies efficiently targeted autoreactive TH1/TH17CM cells but also blocked virus-specific TH1 cells. CONCLUSIONS: We propose that autoreactive TH1/TH17CM cells expand in patients with MS and promote relapses after bystander recruitment to the CNS, whereas TH1 cells perform immune surveillance. Thus the selective targeting of TH1/TH17 cells could inhibit relapses without causing John Cunningham virus-dependent progressive multifocal encephalomyelitis.

CSF ß-amyloid as a putative biomarker of disease progression in multiple sclerosis.

BACKGROUND: Neurodegeneration plays a major role in determining disability in multiple sclerosis (MS) patients. Hence, there is increasing need to identify reliable biomarkers, which could serve as prognostic measure of disease progression. OBJECTIVES: To assess whether cerebrospinal fluid (CSF) tau and ß-amyloid (Aß) levels were altered in newly diagnosed MS patients and correlated with disability. Moreover, we investigated whether these CSF biomarkers associate with macroscopic brain tissue damage measures. METHODS: CSF Aß and tau levels were determined by enzyme-linked immunosorbent assay in CSF samples from 48 newly diagnosed MS patients, followed-up clinically for 3 years by recording their Expanded Disability Status Scale score at 6-month intervals, and 45 controls. All patients underwent magnetic resonance imaging at baseline and at the end of follow-up to quantify their lesion load (LL). RESULTS: CSF Aß levels were significantly reduced in patients compared to controls ( p < 0.001). Lower CSF Aß levels at baseline were a disability predictor at 3-year follow-up ( p = 0.009). CSF tau levels correlated with T2- and T1-LL ( p < 0.001). CONCLUSION: CSF Aß reduction is a promising biomarker of neurodegeneration and may predict patients' clinical outcome. Therefore, CSF Aß should be considered as a potential biomarker of prognostic value.

Balò's concentric sclerosis: still to be considered as a variant of multiple sclerosis?

Balò's concentric sclerosis (BCS) is considered a rare demyelinating disease and regarded as an aggressive variant of multiple sclerosis (MS). We describe three cases (one male and two females) with neuroimaging features suggestive of BCS and heterogeneous symptoms, with benign long-term clinical course upon treatment with natalizumab and fingolimod. Neurological examination, blood and cerebrospinal fluid analyses, brain and spinal cord magnetic resonance imaging (MRI) and brain proton magnetic resonance spectroscopy were performed. At onset, patient #1 showed predominant cognitive impairment with consciousness disturbances; patient #2 presented with left hemiparesis; patient #3 demonstrated hesitance in speech and in written word production, along with right central facial palsy. All patients showed the typical MRI changes associated with BCS, such as concentric rings or a whorled appearance on T2-weighted and contrast-enhanced T1-weighted images. They were treated with high dosage i.v. steroid with clinical improvement and followed-up for 3 years with different clinical course. Two patients fulfilled the revised McDonald criteria for MS and received preventive therapy, natalizumab and fingolimod, respectively, whereas the third patient is still stable without clinical and radiological evolution. All of them did not have new exacerbations or MRI lesions over 2-4 year follow-up. Our descriptions demonstrate the heterogeneity of clinical presentation of BCS. Moreover, these case reports suggest that BCS may neither be rapidly progressive nor fatal and may be considered part of the MS spectrum. In line with this hypothesis, current treatments for MS were effective in our patients.

Decreased circulating miRNA levels in patients with primary progressive multiple sclerosis.

Emerging evidence underlines the importance of micro(mi)RNAs in the pathogenesis of multiple sclerosis (MS). Free-circulating miRNAs were investigated in serum from MS patients compared to controls. Statistically significant decreased levels of miR-15b, miR-23a and miR-223 were observed in MS patients (p < 0.05). Results were validated and replicated in two further independent MS populations. A direct correlation between miRNA levels and the EDSS score was determined in PPMS (p < 0.007). The generalized trend toward miRNA down-regulation could result in over-expression of target genes involved in disease pathogenesis. Circulating miRNA profiling could thus represent a new avenue to identify easily detectable disease biomarkers.

Expression and Genetic Analysis of MicroRNAs Involved in Multiple Sclerosis.

Evidence underlines the importance of microRNAs (miRNAs) in the pathogenesis of multiple sclerosis (MS). Based on the fact that miRNAs are present in human biological fluids, we previously showed that miR-223, miR-23a and miR-15b levels were downregulated in the sera of MS patients versus controls. Here, the expression levels of these candidate miRNAs were determined in peripheral blood mononuclear cells (PBMCs) and the serum of MS patients, in addition to three genotyped single nucleotide polymorphisms (SNPs). Mapping in the genomic regions of miR-223, miR-23a and miR-15b genes, 399 cases and 420 controls were tested. Expression levels of miR-223 and miR-23a were altered in PBMCs from MS patients versus controls. Conversely, there were no differences in the expression levels of miR-15b. A significantly decreased genotypic frequency of miR-223 rs1044165 T/T genotype was observed in MS patients. Moreover, the allelic frequency of miR-23a rs3745453 C allele was significantly increased in patients versus controls. In contrast, there were no differences in the distribution of miR-15b SNP. In conclusion, our results suggest that miR-223 and miR-23a could play a role in the pathogenesis of MS. Moreover, miR-223 rs1044165 polymorphism likely acts as a protective factor, while miR-23a rs3745453 variant seems to act as a risk factor for MS.

Association between enlarged perivascular spaces and cerebrospinal fluid aquaporin-4 and tau levels: report from a memory clinic.

Background: Perivascular spaces (PVS) are fluid-filled compartments that dilate in response to many different conditions. A high burden of enlarged PVS (EPVS) in the centrum semiovale (CSO) has been linked to neurodegeneration. Moreover, an increase in cerebrospinal fluid (CSF) levels of aquaporin-4 (AQP4), a water channel expressed on PVS-bounding astrocytes, has been described in patients with neurodegenerative dementia. Our aim was to investigate the relationship between neurodegenerative diseases and two putative glymphatic system biomarkers: AQP4 and EPVS. Methods: We included 70 individuals, 54 patients with neurodegenerative diseases and 16 subjects with non-degenerative conditions. EPVS were visually quantified on MRI-scans applying Paradise's scale. All subjects underwent lumbar puncture for the measurement of AQP4 levels in the cerebrospinal fluid (CSF). CSF levels of amyloid-ß-1-42, phosphorylated and total tau (tTau) were also measured. Linear regression analyses were adjusted for age, sex, education and disease duration, after excluding outliers. Results: Cerebrospinal fluid (CSF)-AQP4 levels were independent predictors of total (ß = 0.28, standard error [SE] = 0.08, p = 0.001), basal ganglia (ß = 0.20, SE = 0.08, p = 0.009) and centrum semiovale EPVS (ß = 0.37, SE = 0.12, p = 0.003). tTau levels predicted CSO-EPVS (ß = 0.30, SE = 0.15, p = 0.046). Moreover, increased levels of AQP4 were strongly associated with higher levels of tTau in the CSF (ß = 0.35, SE = 0.13, p = 0.008). Conclusion: We provide evidence that CSO-EPVS and CSF-AQP4 might be clinically meaningful biomarkers of glymphatic dysfunction and associated neurodegeneration.

Banks of the Superior Temporal Sulcus in Alzheimer's Disease: A Pilot Quantitative Susceptibility Mapping Study.

BACKGROUND: Brain iron homeostasis is disrupted in neurodegeneration and areas of iron overload partially overlap with regions of amyloid and tau burden in Alzheimer's disease (AD). Previous studies demonstrated alterations in brain iron accumulation in AD using quantitative susceptibility mapping (QSM). OBJECTIVE: Here, we investigate brain alterations of QSM values in AD and non-AD patients as compared to healthy controls (HC) in the superior temporal sulcus and its banks (BANKSSTS), one of the top AD-affected regions. METHODS: Thirty-four patients who underwent brain MRI including a multi-echo gradient-echo sequence were subdivided into AD (n = 19) and non-AD (n = 15) groups according to their clinical profile, CSF (Aß42/40) and/or amyloid-PET status. Ten HC were also included. QSM values were extracted from left and right BANKSSTS and compared among groups. Correlation and binomial regression analyses between QSM values and CSF-AD biomarkers were conducted. RESULTS: QSM in left BANKSSTS was significantly different among groups (p = 0.003, H = 11.40), being higher in AD. QSM values in left BANKSSTS were correlated with Aß42 (rho -0.55, p = 0.005), Aß42/40 (rho -0.66, p < 0.001), pTau (rho 0.63, p < 0.001), tTau (rho 0.56, p = 0.005), tTau/Aß42 (rho 0.68, p < 0.001) and pTau/Aß42 (rho 0.71, p < 0.001). No correlations between QSM values and amyloid-PET SUVR in the left BANKSSTS were found. QSM values in left BANKSSTS showed good accuracy in discriminating AD (AUC = 0.80, CI95 % [0.66-0.93]). Higher QSM values were independent predictors of Aß42 (B = 0.63, p = 0.032), Aß42/40 (B = 0.81, p = 0.028), pTau (B = 0.96, p = 0.046), tTau (B = 0.55, p = 0.027), and tTau/Aß42 (B = 1.13, p = 0.042) positivity. CONCLUSION: Our preliminary data support the potential role of increased QSM values in the left BANKSSTS as an auxiliary imaging biomarker in AD diagnosis.