Brain-derived tau secreted into CSF and blood consists of different N-terminal and mid-domain fragments, which may have a differential temporal course and thus, biomarker potential across the Alzheimer’s disease continuum or in other neurological diseases. While current clinically validated total tau assays target mid-domain epitopes, comparison of these assays with new biomarkers targeting N-terminal epitopes using the same analytical platform may be important to increase the understanding of tau pathophysiology.n = 342 total). The cohorts included participants across the Alzheimer’s disease continuum (n = 276), other dementias (n = 22), Creutzfeldt–Jakob disease (n = 24), acute neurological disorders (n = 18) and progressive supranuclear palsy (n = 22). Furthermore, we evaluated all three new total tau biomarkers in plasma (n = 44) and replicated promising findings with NTA total tau in another clinical cohort (n = 50).We developed three total tau immunoassays targeting specific N-terminal  or mid-region  epitopes, using single molecule array technology. After analytical validation, the diagnostic performance of these biomarkers was evaluated in CSF and compared with the Innotest total tau  in three clinical cohorts (P < 0.0001) and correlated with each other (sr = 0.53−0.95). NTA and NTB total tau, but not other total tau assays, distinguished amyloid-positive and amyloid-negative mild cognitive impairment with high accuracies  matching N-p-tau217 . All total tau assays were excellent in differentiating Alzheimer’s disease from other dementias . In Creutzfeldt–Jakob disease and acute neurological disorders, N-terminal total tau biomarkers had significantly higher fold changes versus controls in CSF (45–133-fold increase) than Innotest or MR total tau . In progressive supranuclear palsy, CSF concentrations of all total tau biomarkers were similar to those in controls. Plasma NTA total tau concentrations were increased in Alzheimer’s disease compared with controls in two independent cohorts (P = 0.0056 and 0.0033), while Quanterix total tau performed poorly (P = 0.55 and 0.44).In CSF, all total tau biomarkers were increased in Alzheimer’s disease compared with controls (Taken together, N-terminal-directed CSF total tau biomarkers increase ahead of standard total tau alternatives in the Alzheimer’s disease continuum, increase to higher degrees in Creutzfeldt–Jakob disease and acute neurological diseases and show better potential than Quanterix total tau as Alzheimer’s disease blood biomarkers. For progressive supranuclear palsy, other tau biomarkers should continue to be investigated. et al. develop new N-terminal-directed CSF total tau assays. They show that levels of these biomarkers both increase ahead of standard t-tau in patients on the Alzheimer’s disease continuum, and are higher in patients with CJD or acute neurological diseases compared to standard t-tau.Snellman and Lantero-Rodriguez  However, in addition to its various post-translational modifications,15 soluble tau is known to exist in proteolytic fragments of different lengths,16 and shorter N-terminal fragments lacking the mid-region cannot be detected by the classic t-tau assays. Previous work targeting different N-terminal epitopes of tau in CSF have shown that these fragments are increased in Alzheimer’s disease at the mild cognitive impairment (MCI) and dementia stages.17–19 In addition, p-tau assays targeting N-terminal fragments phosphorylated at threonine-181 (N-p-tau181) and threonine-217 (N-p-tau217) have shown earlier abnormal levels in CSF in comparison to mid-region p-tau181 across the Alzheimer’s disease continuum.21Immunoassays measuring t-tau in clinical routine, such as the fully automated Elecsys and Lumipulse methods, utilize antibodies targeting epitopes located in the mid-region of the protein.23 This knowledge has been applied to develop new p-tau immunoassays for use in blood, targeting different epitopes than the validated assays. In blood, N-p-tau181, N-p-tau217 and N-p-tau231 biomarkers  targeting N-terminal-to-mid-region epitopes is widely available. While CSF t-tau  was seen to be increased in Alzheimer’s disease at the MCI and dementia stages versus controls,18 and in individuals who later progressed to dementia.31 These findings, in agreement with p-tau data, suggest that truncation leading to shorter N-terminal fragments of tau is an early event in Alzheimer’s disease pathophysiology and that N-terminal tau forms might provide superior biomarker performance in plasma. However, it is unclear how different tau fragments compare as neurodegeneration markers in the Alzheimer’s disease continuum and other neurodegenerative disorders.Recently, tau was shown to consist of N-terminal and mid-region species in CSF and predominantly N-terminal forms in blood.omarkers  are incrThe aim of this study was to develop and validate novel t-tau immunoassays targeting N-terminal and mid-region epitopes using Simoa technology and subsequently investigate the levels of these new biomarkers versus clinically validated mid-region t-tau, p-tau and N-p-tau assays in CSF in clinical cohorts across the Alzheimer’s disease continuum, as well as across other neurological diseases including those known for high  and normal  t-tau levels. In addition, we performed an exploratory analysis in plasma, evaluating the biomarker potential of the different t-tau immunoassays versus the Quanterix t-tau in two independent cohorts.This was a cross-sectional, observational study conducted in collaboration with three centres .32 we developed two immunoassays targeting N-terminal-bearing tau fragments: (i) NTA t-tau, containing the N-terminal epitope mapped between amino acids (aa) 6–18 and 159–163; and (ii) NTB t-tau, containing epitopes at aa 6–18 and 194–198. In addition, we developed an assay targeting the mid-region aa 159–163 and 194–198 epitopes (MR t-tau) as a Simoa-based replica of the Innotest t-tau assay to enable direct comparison on the same analytical platform. For the NTA and MR t-tau immunoassays, mouse monoclonal antibody targeting aa 159–163  was used as a capture antibody. Mouse monoclonal antibodies targeting aa 6–18  and aa 194–198  were used as detectors, respectively. For the NTB t-tau assay, mouse monoclonal antibodies targeting aa 6–18  and aa 194–198  were used for capture and detection, respectively. Recombinant non-phosphorylated full-length Tau-441  was used as a calibrator in all the in-house t-tau assays. After optimizing the assay protocols, quantification limits, dilution linearity, precision, accuracy, and spike recovery were assessed for all three assays. More detailed description of the immunoassay development and validation processes are available in the Based on our recent success in developing N-terminal-directed N-p-tau181, N-p-tau217 and N-p-tau231 biomarkers,20 and were included to enable direct comparison between the classical mid-region (t-tau and p-tau181), N-t-tau and N-p-tau biomarkers. Plasma samples were analysed with commercial t-tau assays from Quanterix, i.e. the single-analyte Tau 2.0 kit (#101552) for the pilot cohort and the multiplexed Neurology 3-Plex kit (#101995), in-house N-p-tau181 and N-p-tau231 for the clinical cohort using previously published methods.26 Note that both of the Quanterix t-tau assays target identical epitopes.All biomarkers studied in this study are presented in n = 22) and biomarker-negative control patients (n = 22) clinically assessed in the Sahlgrenska University Hospital, Gothenburg, Sweden. Patients included in the Alzheimer’s disease group were assessed due to suspected Alzheimer’s disease, and no evidence of other neurological conditions was present. Patients in the neurological control group had consulted the clinic due to minor neurological or psychiatric symptoms, but those with a diagnosis of neurocognitive disorder were excluded, and Alzheimer’s disease core CSF biomarkers were within normal range. The groups were defined by their core Alzheimer’s disease CSF biomarker profiles .The pilot study included samples from CSF biomarker-positive Alzheimer’s disease patients  score = 21(16–25)], Aβ positive MCI , Aβ negative MCI , non-Alzheimer’s disease dementia  and Aβ− cognitively unimpaired neurological controls . The control group presented with subjective cognitive concerns or sensory disturbances but had a normal CSF Alzheimer’s disease biomarker profile. The non-Alzheimer’s disease dementia group included individuals with a diagnosis of alcohol-related dementia (n = 3), vascular dementia (n = 4), mixed vascular and non-Alzheimer’s disease cortical dementia (n = 7) and unspecified dementia (n = 8). A/T/N profiles were defined by core Alzheimer’s disease CSF biomarkers with local cut-offs .To study the profiles of different t-tau biomarkers in Alzheimer’s disease continuum, a clinic-based prospective memory centre cohort from the University Medical Centre, Ljubljana, Slovenia, was used. The cohort included individuals with biologically-defined Alzheimer’s disease, showing both biomarker positivity and clinical presentation  or progressive supranuclear palsy (n = 22) from the University Medical Centre, Ljubljana, Slovenia. Comparison between groups included the Alzheimer’s disease and neurological control groups described above.In addition to Alzheimer’s disease, we investigated individuals with a diagnosis of either CJD (n = 22) and biomarker negative control patients (n = 22) assessed in the Sahlgrenska University Hospital, Gothenburg, Sweden. Groups were defined as described above for the pilot CSF cohort.The plasma pilot cohort included samples from CSF biomarker-positive Alzheimer’s disease patients ], Aβ-positive MCI , Aβ-negative MCI , non-Alzheimer’s disease dementia  and neurological controls . The non-Alzheimer’s disease dementia group included individuals with a diagnosis of vascular  or frontotemporal dementia . A/T/N profiles were defined by core Alzheimer’s disease CSF biomarkers with local cut-offs .Pilot findings with plasma NTA t-tau were replicated using a clinic-based prospective memory centre cohort, the BioCogBank Paris Lariboisiére Cohort . CSF biomarker results, neuropsychological assessment, brain MRI and respective diagnostic criteria were used to establish reliable diagnosis of Alzheimer’s disease and other disorders. The cohort included patients with Alzheimer’s disease  to Alzheimer’s disease participants [21 (16–25)].In clinical CSF cohort 1 .In clinical cohort 2, the progressive supranuclear palsy and acute neurological disorders groups had normal levels of CSF AβP = 0.0015) and included more females  in the pilot cohort for NTB t-tau and Quanterix t-tau. There were no age or sex differences between the other groups. In the clinical plasma cohort, there were no age or sex differences between groups . The MMSE scores were significantly higher for the control (P = 0.0005) and Aβ-MCI groups (P = 0.024) compared with Alzheimer’s disease.The demographics for the plasma cohorts are presented in P ≤ 0.001; P = 0.22] and all t-tau assays discriminated Alzheimer’s disease from control patients , DeLongNTA-NTBP = 0.043] compared with NTB t-tau [AUC 78% (64–92%)]. All in-house CSF t-tau biomarkers were significantly correlated with each other  both in the whole cohort . For Innotest or MR t-tau, no significant differences between Aβ− MCI and Aβ+ MCI  or Aβ+ MCI and controls  were observed. On the contrary, both NTA and NTB t-tau showed significantly higher concentrations in Aβ+ MCI in comparison with the controls  and Aβ − MCI , and significantly better than MR t-tau  and exhibited similar performances to N-p-tau217  and N-p-tau181 . In addition, NTA and NTB t-tau assays performed significantly better than MR t-tau , Innotest t-tau  and Innotest p-tau181 [AUC 65% (52–78%); DeLongInno p-181-NTA,P = 0.016; DeLongInno p181-NTB, P = 0.024; MR-NTA,P = 0.013; DeLongMR-NTA, P = 0.012; P > 0.06 for all comparisons). Innotest t-tau and p-tau181 were used to stratify patients into diagnostic groups  and MR and Innotest t-tau . Each t-tau biomarker showed moderate negative correlation with CSF Aβ1-42 in the whole cohort , but no correlation was observed within any of the diagnostic groups , and MR t-tau and Innotest t-tau in mixed dementia  compared to unspecified dementia. All results are presented in We also performed an exploratory analysis within the non-Alzheimer’s disease dementia group. Even though our sample sizes were small, NTB t-tau was seen to be significantly lower in vascular dementia  but significantly better that both N-p-tau assays . Hepatic encephalopathy and limbic encephalitis were not included in this analysis (n = 1 for both). All results are presented in An exploratory analysis within the acute neurological disorders group showed no differences in tau concentrations between ischaemic stroke and status epilepticus, whereas all CSF t-tau biomarkers were significantly higher after ischaemic stroke compared to Alzheimer’s disease , and moderate to strong positive correlations with Innotest and MR t-tau .All CSF t-tau biomarkers were low in progressive supranuclear palsy, with concentrations being similar to the controls (P = 0.0056) and the clearest differentiation between the two groups, with an AUC of 75% (59–91%) (P = 0.043), whereas Quanterix Tau 2.0 and NTB t-tau showed similar concentrations in both groups  . More ovP = 0.0033) or patients with Aβ − MCI (P = 0.027), whereas no statistically significant differences were observed with the Quanterix t-tau , plasma N-p-tau181  and plasma N-p-tau231  in the whole cohort, whereas no correlation with Quanterix plasma t-tau was observed   .11 In brain, tau is mostly present as a full-length protein, whereas many different fragments of diverse lengths are known to exist in CSF, and these increase in concentration during the pathological process of Alzheimer’s disease.33–35 Studies using immunoprecipitation followed by mass spectrometry have shown that tau peptides C-terminal to position 254 are not detectable in CSF or blood, suggesting that tau content in these fluids consists of tau x-254 forms.26 However, extracting conclusions about the biomarker potential of different fragments is difficult, since no direct comparison between assays targeting mid-region and N-terminal phosphorylated and non-phosphorylated species has been performed on the same analytical platform or in the same large clinical cohorts. Since N-terminal tau forms are ubiquitous to CSF and blood, targeting this part of the tau molecule could generate biomarkers applicable to both fluid systems. We took advantage of our recent successful development of N-terminal-directed p-tau181, p-tau217 and p-tau231 biomarkers32 to design two novel ultrasensitive t-tau immunoassays (NTA and NTB t-tau) targeting N-terminal epitopes. To enable cross-biomarker comparisons using an identical analytical technology, we developed a third assay (MR t-tau) using the same antibodies used in the gold-standard Innotest t-tau. Thereafter, we performed diagnostic comparisons between the new versus classical t-tau biomarkers (with N-p-tau assays included for proof of concept) across the Alzheimer’s disease continuum and other neurological disorders using the same Simoa platform.Based on the current understanding about the complexity of tau protein, it has become obvious that it is a much more challenging biomarker to interpret than previously thought.35 we showed that all measured CSF mid-region and N-terminal t-tau fragments were increased in Alzheimer’s disease compared with controls and had high diagnostic accuracies for differentiating the two groups . However, in our study, only levels of N-terminal-bearing CSF tau biomarkers measured by NTA (HT7/Tau12) and NTB (1−100/BT2) t-tau increased significantly in early Aβ+ MCI when compared with controls. In addition, only NTA and NTB t-tau were able to distinguish between Aβ+ MCI and Aβ− MCI, showing equal performances as N-p-tau217 and N-p-tau181. On the contrary, all t-tau assays measured in CSF distinguished Alzheimer’s disease and other dementia cases with high accuracy (AUCs 90–100%). In this context, CSF MR t-tau performed significantly better than NTA or NTB (DeLong P ≤ 0.0012), but there were no significant differences between the CSF N-t-tau and N-p-tau assays (Delong P ≥ 0.06). Together, our findings agree with the previously presented hypothesis that during the Alzheimer’s disease pathophysiological process, tau fragments including the N-terminus are released early by neurons that are presumably affected by Aβ toxicity but still only at risk of developing tangle pathology.22 We also showed that this early increase can be detected with N-terminal directed assays targeting both phosphorylated and non-phosphorylated epitopes.Consistent with previous findings in CSF,37 However, in our study, mid-region-bearing fragments were still not significantly different in MCI (both Aβ− and Aβ+) than in controls. These seemingly contradictory findings could be explained by the fact that earlier Aβ+ MCI (A+/T−/N−) patients were included in our CSF study, and conversely, significant increases only in N-terminal-bearing tau biomarkers could be observed at this stage , meaning that the mid-region t-tau assays should also be able to capture the shorter N-terminal species bearing these epitopes. However, in our study, this was not the case. This apparent discrepancy might be explained by differences in the quantity of the different fragments. Using the same recombinant tau as the assay calibrator, we observed that the levels of CSF t-tau measured by NTA (0–85 pg/ml) and NTB (0–480 pg/ml) assays were pronouncedly lower than those measured by MR t-tau (0–2200 pg/ml) and Innotest t-tau (0–2600 pg/ml). Furthermore, tau truncation and excretion are regulated processes, and it has been hypothesized that, whereas full length tau is passively secreted from neurons, truncated forms are released through active secretion.In addition to exploring different stages within the Alzheimer’s continuum, it would be interesting to investigate differences in various CSF t-tau markers between different non-Alzheimer’s disease dementias. Here, we reported that all tau biomarkers were significantly higher in Alzheimer’s disease in comparison to other dementias and some differences were also observed within the non-Alzheimer’s disease dementia group; NTB t-tau was significantly lower in vascular dementia, and all mid-region fragments  in mixed dementia in comparison to unspecified dementia. However, due to our small sample size (3–8 per group) and heterogeneous nature of different dementias, we want to emphasize that these findings should be interpreted with caution and investigated in more detail on a larger non-Alzheimer’s disease dementia cohort in the future.3 Our results support the present understanding that tau deposition and metabolism in primary tauopathies differ from that in Alzheimer’s disease, and other forms of tau with better biomarker potential should still be explored to address these disorders.In addition to Alzheimer’s disease, CSF t-tau is known to be highly increased in CJD and acute neurological disorders due to the occurrence of rapid and aggressive neurodegeneration in these diseases. As expected, we also observed highly elevated concentrations of all investigated CSF t-tau biomarkers in both groups. Fold changes calculated against controls were higher for the N-t-tau biomarkers in comparison to MR t-tau, and measuring the N-terminal fragments improved the diagnostic accuracy between Alzheimer’s disease and CJD. However, the groups were well distinguished by all CSF t-tau biomarkers, thus this difference is likely not clinically relevant. In our study, we did not see differences between the CSF mid-region or N-terminal assays in their ability to differentiate non-Alzheimer’s disease dementia or progressive supranuclear palsy from controls. Previously, abnormally low levels of CSF t-tau were reported in progressive supranuclear palsy using in-house ELISAs targeting the same N-terminal epitopes as our in-house NTA and NTB t-tau assays for Simoa.29 This could be due to the interference caused by peripheral expression of tau and/or rapid metabolism and fragmentation of tau in plasma, resulting in fragments that might not be recognized by the commercial t-tau assays. Recently, plasma NT1, targeting shorter, N-terminal-bearing fragments of tau (BT2/Tau12), was able to differentiate Alzheimer’s disease from control subjects and predict future cognitive decline, suggesting that N-t-tau fragments could be more suitable blood biomarkers.39 In this study, we identified a novel plasma N-terminal biomarker (NTA) that also showed higher concentrations in Alzheimer’s disease compared with controls both in the pilot and clinical cohorts. Interestingly, plasma NTA concentrations in the clinical cohort also correlated strongly with CSF t-tau, as well as both plasma p-tau181 and p-tau231. These findings agree with previous studies suggesting that short, N-terminal-bearing fragments in plasma may present the same early response to Aβ seen in CSF and be less prone to degradation than the longer fragments.31Due to less invasive sampling and higher cost-effectiveness, blood biomarkers hold enormous potential for the screening and diagnosis of Alzheimer’s disease when compared to both CSF and imaging biomarkers. Plasma t-tau has also been shown to be increased in Alzheimer’s disease when compared to controls and Aβ+ MCI, however, high overlap between the diagnostic groups and lack of correlation with CSF t-tau has hindered its usability.18). Previously, Chen et al.18 also showed that NT1 performed better than another N-terminal biomarker NT2 (ADx202/Tau12) that requires a longer sequence (aa 6–224). When we compared our N-terminal assays with the commercial Quanterix t-tau , we saw poor performance of this biomarker in plasma in two different cohorts compared with both NTA and NTB t-tau. Even though the NTA and NTB t-tau still need to be further optimized and validated for blood, our findings (together with the earlier reports on NT1 and NT2) support the view that assays targeting minimal N-terminal sequences (including aa 6 targeted by the Tau12 and 1–100 antibodies) provide superior performance in detecting Alzheimer’s disease-relevant tau species in plasma when compared with assays targeting longer N-terminal or mid-region fragments.In contrast to CSF, where our NTA t-tau showed similar performance to NTB t-tau, the NTA t-tau assay (requiring a short minimum aa sequence of 6–159) performed better in plasma compared with NTB t-tau , and previously described in-house N-terminally targeted p-tau biomarkers (N-p-tau181 and N-p-tau217)In conclusion, we developed new t-tau immunoassays for the Simoa platform targeting both N-terminal and mid-region epitopes of tau and showed that different t-tau assays have different biomarker potential in the Alzheimer’s disease continuum both in CSF and plasma. NTA and NTB t-tau were able to discriminate MCI with and without underlying Aβ pathology, and therefore detecting early Alzheimer’s disease-related abnormalities in CSF, whereas all t-tau assays showed excellent performance in differentiating Alzheimer’s disease from other dementias. In addition, N-terminal-directed CSF t-tau biomarkers were seen to be increased to higher degrees in CJD and acute neurological disorders, both characterized by aggressive neurodegeneration. Most notably, plasma NTA t-tau was able to successfully differentiate Alzheimer’s disease from controls and correlated strongly with both plasma N-p-tau181 and N-p-tau231. Based on our findings, N-terminal-bearing forms of tau seem to be secreted into CSF in an early phase of the Alzheimer’s disease pathological process, and like N-p-tau, N-t-tau biomarkers could provide added value in the variety of tau assays available for further research.awab481_Supplementary_DataClick here for additional data file.


Dear Editor,Today, split cornea technique is an established procedure and is mostly used for two recipients by combining deep anterior lamellar keratoplasty (DALK) and Descemet membrane endothelial keratoplasty (DMEK) surgeries –7. Howevdecentral donor eye trephination also using a 17.5-mm trephine results in a corneoscleral donor transplant , most cornea banks perform a central scleral trephination using a trephine with 15.5 mm diameter Fig.  9]. For. For9]. ant Fig.  which caant Fig. . In our ant Fig.  and usedant Fig. . With thant Fig.  central ant Fig.  or for cThis is the most important advantage of this novel preparation technique. A single donor cornea might be used for up to three recipients, thus reducing the need for corneal tissue and—at least in the long run—limiting corneal donor tissue shortage . Our casFurthermore, these grafts have to be supplied by an external eye bank if the ophthalmology center is not having its own eye bank using this novel preparation technique.For the sake of completeness, this novel preparation technique is not necessary for all kinds of corneoscleral grafting. For very small corneoscleral defects, corneoscleral buttons arising after standard trephination for PK, DMEK, or DALK could be used instead of being discarded.However, in conclusion, this novel preparation technique of eccentric donor button preparation offers the opportunity to reduce the consumption of corneal donor tissue. Therefore, this modified trephination technique should be the standard approach in corneal donor transplant preparation if a block excision with tectonic corneoscleral graft is planned.


Acacetin  was coated to the bare skin of the rats' backs 1 h before UVA irradiation. HDF were treated different concentrations of Acacetin  and then irradiated with UVA (20 J/cm2). Acacetin was found to be effective in ameliorating UVA‐induced oxidative stress and cell death. Acacetin also prevented the UVA‐induced decrease of SIRT3, reduced the activation of mitogen‐activated protein kinases  and blocked the down‐regulated activation of oxidative stress in matrix metalloproteinases (MMPs). In addition, Acacetin increased the expressions of collagen‐promoting proteins (TGF‐β and Smad3). Finally, the SIRT3 inhibitor 3‐TYP blocked all protective effects of Acacetin, indicating that the protective effect of Acacetin against UVA photoaging is SIRT3‐dependent. Acacetin effectively mitigated photoaging by targeting the promotion of SIRT3, inhibiting the UVA‐induced increases in MMPs and pro‐inflammatory factors, and promoting TGF‐β and Smad3.Ultraviolet A (UVA) radiation is a major contributor to the pathogenesis of skin photoaging, and the aim of this study was to investigate the effect of Acacetin on skin photoaging in UVA‐irradiated mice and human dermal fibroblasts (HDF). Healthy dorsal depilated rats were irradiated with UVA 30 J/cm Acacetin prevents UVA‐induced photoaging by decreasing oxidative stress levels and increasing SIRT3 expression. Acacetin effectively alleviated the photoaging process by inhibiting UVA‐induced MMPs expressions and suppressing the increase of pro‐inflammatory factors, promoting TGF‐β and Smad3.  For UVA irradiation, straight tube reflective UVA lamps  were used. All rats received shaving of the back, and each group of rats was coated with the corresponding concentration of the solvent. A distance of 20 cm was kept between the back of rats and the lamp source in order to maintain the required radiation dose , UVA group (only UVA irradiation), 5‐Ac group (UVA irradiation plus 5 μg/mL Acacetin), 10‐Ac group (UVA irradiation plus 10 μg/mL Acacetin), 20‐Ac group (UVA irradiation plus 20 μg/mL Acacetin). After 24 h of cell plating, cells were co‐incubated with different concentrations of Acacetin  for 12 h, and then subjected to UVA irradiation (irradiation dose of 20 J/cm2).HDF cells were incubated in dulbecco's modified eagle medium containing 1% antibiotics and 10% foetal bovine serum at 37°C. An in vitro acute photoaging cell model was constructed using UVA irradiation of HDF at 20 J/cm33.1The bare skin of rats in the UVA group showed significant signs of erythema and wrinkles after UVA radiation compared with the control group, whereas the erythema and wrinkles were less pronounced in the groups coated with Acacetin than in the UVA group, and application of Acacetin reduced the increase in epidermis caused by UVA Figure  A. As shIn Figure 3.2As shown in Figure The protective effect of Acacetin on cell exposure to UVA irradiation was further investigated using 3‐TYP, an inhibitor of SIRT3. As shown in Figure 4UVA exposure eventually led to depletion of cellular antioxidant levels, reduced SOD activity and increased MDA and ROS levels in skin tissue of rat and HDF. However, application of Acacetin to the back of rats resulted in a decrease of oxidative stress levels. Similarly, in UVB‐induced photoaging in HDF and HaCaT cells, Acacetin regulates MMP‐1 by modulating the MAPK signalling pathway.Several natural substances have been reported to prevent UV‐induced aging through their antioxidant properties. The protective effect of topical application of orange peel cold‐pressed oil (a rich polymethoxyflavones source) against UV‐induced skin damage contributes to the maintenance of dermal structure and enhances superoxide dismutase, catalase and glutathione peroxidase in skin tissues; the protective effect of isoflavone extracts from soybean cake against UVB‐induced skin photoaging by inhibiting apoptosis and inflammatory responses. We sought to explore the molecular protective mechanism of Acacetin against UVA‐induced photoaging and results suggested that Acacetin treatment significantly could restore the level of SIRT3, reduce the accumulation of ROS, inhibit the expression of p38MAPK/AP‐1/MMPs and promote the TGF‐β/Smad3 pathway, thereby reducing collagen decay in a UVA irradiation model.It has been previously reported that UVA activates MAPK via ROS, triggering the activation of AP‐1 and c‐Fos and causing skin inflammation.The degradation of collagen is mainly regulated by MMPs, which play an important role in UVA‐induced photoaging.Decreased level of SIRT3 has been observed in tissue and cellular responses to UVA radiation. SIRT3 is known to play an important role in regulating mitochondrial functions, including energy metabolism and ROS homeostasis.This study showed that Acacetin prevents UVA‐induced photoaging by decreasing oxidative stress levels and increasing SIRT3 expression. In addition, Acacetin effectively alleviated the photoaging process by inhibiting UVA‐induced MMPs expressions and suppressing the increase of pro‐inflammatory factors, promoting TGF‐β and Smad3. Therefore, Acacetin can be used as a potential natural sunscreen ingredient.Jing Mu: Conceptualization (lead); funding acquisition (lead); writing – review and editing . Hong Chen: Data curation ; methodology ; writing – original draft ; writing – review and editing . Mengyi Ye: Methodology ; software ; writing – original draft ; writing – review and editing . Xiaoxia Zhang: Formal analysis ; methodology ; writing – original draft ; writing – review and editing . Huisheng Ma: Conceptualization (supporting); funding acquisition (supporting); writing – review and editing .The authors declare that they have no competing interests.Appendix S1Click here for additional data file.Figure S1–S3Click here for additional data file.Data S1Click here for additional data file.


Impaired cerebrospinal fluid (CSF) homeostasis is central to the pathogenesis of idiopathic intracranial hypertension (IIH), although the precise mechanisms involved are still not completely understood. The aim of the current study was to assess the CSF/serum ratio of neurofilament light chain levels (QNfL) as a potential indicator of functional CSF outflow obstruction in IIH patients.NfL levels were measured by single molecule array in CSF and serum samples of 87 IIH patients and in three control groups, consisting of 52 multiple sclerosis (MS) patients with an acute relapse, 21 patients with an axonal polyneuropathy (PNP), and 41 neurologically healthy controls (HC). QNfL was calculated as the ratio of CSF and serum NfL levels. Similarly, we also assessed the CSF/serum ratio of glial fibrillary acidic protein (QGFAP) levels to validate the QNfL data. Routine CSF parameters including the CSF/serum albumin ratio (QAlb) were determined in all groups. Lumbar puncture opening pressure of IIH patients was measured by manometry.CSF-NfL levels  and QNfL , but not serum NfL (S-NfL) levels, were associated with lumbar puncture opening pressure in IIH patients. CSF-NfL levels were increased in IIH patients, MS patients, and PNP patients, whereas sNfL levels were normal in IIH, but elevated in MS and PNP. Remarkably, QNfL (p < 0.0001) as well as QGFAP (p < 0.01) were only increased in IIH patients. QNfL was positively correlated with CSF-NfL levels  and negatively correlated with S-NfL levels  in HC, while it was only positively associated with CSF-NfL levels in IIH patients . An increase in blood-CSF barrier permeability assessed by QAlb did not lead to a decrease in QNfL in any cohort.The observed elevation of QNfL in IIH patients, which was associated with lumbar puncture opening pressure, indicates a reduced NfL transition from the CSF to serum compartment. This supports the hypothesis of a pressure-dependent CSF outflow obstruction to be critically involved in IIH pathogenesis.The online version contains supplementary material available at 10.1186/s12987-022-00403-2. Idiopathic intracranial hypertension (IIH) is characterized by signs and symptoms of a raised intracranial pressure, including headache and impaired optic nerve function due to pressure-induced papilledema. It is typically seen in obese women of childbearing age with an incidence of 12–20 per 100,000 in contrast to an incidence of only around 0.5–2 per 100,000 within the general population. The management of IIH typically involves weight loss recommendation and medical treatment with acetazolamide or topiramate [The pathogenic mechanisms that cause IIH have not yet been fully elucidated, but impaired CSF homeostasis seems to play a major role . Under pContinuous exchange between the CSF and the interstitial fluid of the brain is essential for central nervous system (CNS) homeostasis as it enables the distribution of required compounds across CNS regions and contributes to the clearance of waste products . One modSimilarly, the question of how and to what extent the CSF finally exits the brain and reaches the venous blood is also a subject of ongoing debate. CSF drainage occurs directly into the blood via arachnoid villi or granulations into the venous sinuses of the dura and into the lymphatic system via cranial and spinal nerves . An addiBased on these observations of physiological CSF circulation, Lenck et al. recently suggested a pathologic triad comprising the primary restriction of the venous CSF outflow pathway with secondary congestion of the glymphatic system and overflow of the lymphatic CSF outflow pathway to be responsible for the clinical manifestations of IIH .Neurofilament light chains (NfL) are structural scaffolding proteins expressed by neurons of the CNS and the peripheral nervous system (PNS), which can be detected at elevated levels in CSF and blood following neuronal injury. The precise mechanisms by which NfL traffics between parenchymal, CSF and blood compartments are currently unknown, although several hypotheses have recently been reviewed by Gafson et al. . FindingAs the extent of NfL level increase often correlates with the severity of clinical symptoms, NfL is currently evaluated as a diagnostic, prognostic and treatment response biomarker in many neurological diseases –20. A reThe strong correlation between NfL concentrations in CSF and serum in many neurological conditions –26 demon2O) [Between 2016 and 2022, 87 patients with a diagnosis of IIH (Table 2O) . The exc2O) .Table 1BAs control groups, we included 52 patients with relapsing-remitting multiple sclerosis (RRMS) or clinically isolated syndrome (CIS) according to the 2017 revised version of the McDonald diagnostic criteria , who undCSF analyses were performed in a standardized fashion as part of the routine diagnostic workup. CSF samples with artificial blood contamination (defined as erythrocyte count  > 100/µl) were excluded from the analyses. CSF concentrations of albumin were determined with immunonephelometry; quotients of albumin (QAlb) were defined as the ratio of CSF concentration to the corresponding serum concentration.d-galactopyranoside (RGP) was incubated at 33 °C for 60 min prior to running the assay. The coefficient of variation  of the two replicates was obtained by dividing the standard deviation of both replicates by the mean of both replicates multiplied by 100. CVs above 20% (or missing replicate result) were measured twice. Finally, the mean intra-assay CV of 7.8% was obtained by averaging all individual sample CVs . Two low and high controls, consisting of recombinant human antigen, were included in each sample run to monitor plate-to-plate variation, which was less than 10% overall for both assays . Measurements were performed in a blinded fashion without information about clinical data.NfL and GFAP levels were determined using the highly sensitive single molecule array (SiMoA) technology. Samples were measured in duplicates in several rounds by SiMoA HD-1  using the NF-Light Advantage and GFAP Discovery kits according to manufacturer’s instructions. Resorufin-β-To overcome the notion that S-NfL levels positively correlate with age and negatively correlate with body mass index (BMI), we calculated z-scores using a reference database of 10,133 blood samples from 5390 healthy individuals , correctAll statistical analyses were performed using GraphPad (version 9.3.1) or SPSS (version 28.0). Continuous variables were tested for normal distribution using the Shapiro-Wilk normality test. In case of normal distribution, continuous variables are depicted as mean ± standard deviation (SD), whereas non-normally distributed variables are referred to by their median and interquartile range (IQR). Categorical variables are described by numbers and percentages. Associations between two continuous variables were assessed using Spearman’s correlation analysis. Comparisons of the mean between two continuous variables were tested by Student’s t-test in case of normal distribution and by Mann-Whitney U test in non-normally distributed variables. In case of more than two continuous variables, comparisons of the mean were performed using Kruskal-Wallis test with post hoc pairwise comparisons using Wilcoxon rank sum exact test with Bonferroni correction. If not stated otherwise, we used Benjamini-Hochberg correction with a false discovery rate of 0.1 to account for multiple testing.2) and most of the patients presented with headache or visual impairment as first symptoms.Descriptive statistics of the IIH cohort are presented in Table CSF-NfL and S-NfL levels demonstrated a moderate positive correlation . Interestingly, only S-NfL levels were positively correlated with age at sampling , whereas CSF-NfL levels showed no association with age . Furthermore, S-NfL levels were unrelated to the lumbar puncture opening pressure at time point of sample collection . Furthermore, we looked at recently diagnosed and still treatment naïve MS patients with an acute relapse and patients with an axonal polyneuropathy (PNP) as two exemplary diseases with a central and peripheral source of NfL, respectively. Characteristics of the MS and PNP patients are depicted in Additional file 2(3) = 51.9, p < 0.0001, Fig. 2(3) = 41.8, p < 0.0001, Fig. S-NfL levels of IIH patients did not differ from those of HC, whereas the MS and PNP patients had increased S-NfL levels  in serum and CSF of IIH patients and neurologically healthy controls, and calculated the respective CSF-GFAP/S-GFAP ratio (QGFAP). The comparison of GFAP parameters between IIH patients and HCs showed similar trends as for NfL, although the differences were less pronounced. S-GFAP levels did not differ between IIH patients and HCs  vs. 53.7 (40.1–68.6), p = 0.72, Mann-Whitney test, Fig. 6.0–70.2 It is widely accepted that IIH is associated with a disturbance of CSF homeostasis, although the precise mechanisms involved are largely unknown. A pathologic cascade originating from an impairment of CSF outflow into the venous system has been suggested to play a crucial role in its pathogenesis . The herThe comparison of CSF-NfL, S-NfL, and QNfL levels in IIH patients with a number of control groups revealed several interesting findings Table .Table 3OFirst, we found that CSF-NfL levels of IIH patients were higher than in neurologically healthy controls and did not differ from MS patients with an acute relapse. A previous study on NfL in IIH described higher CSF-NfL levels in IIH patients with moderate to severe papilledema when compared to IIH patients with mild or no papilledema. Furthermore, the thickness of the retinal nerve fiber layer measured by optical coherence tomography was inversely correlated with CSF-NfL concentrations. Therefore, the authors suggested that the increased intracranial pressure resulted in axonal damage of the optic nerves reflected by a release of NfL to the CSF . HoweverSecond, S-NfL levels as well as z-scores of S-NfL  of our IThird, the CSF/serum ratio of NfL was markedly increased in IIH patients, whereas we observed no differences in QNfL values between the other groups. Remarkably, in MS patients with an acute relapse, QNfL values were normal. We considered two possible explanations for the observed differences in QNfL between MS and IIH patients: (1) increase in NfL transfer from CSF to serum in MS, or (2) decrease in NfL transfer from CSF to serum in IIH. Notably, the median CSF/serum ratio of albumin (QAlb), which is a marker of blood-CSF barrier integrity , was witIt should be noted that NfL is not only expressed by neurons of the CNS, but also by neurons of the PNS . TherefoThe findings of our current study support the assumption that QNfL can help to reveal the origin of NfL: in the non-neurological controls, QNfL was positively correlated with CSF-NfL levels and negatively correlated with S-NfL levels with similar correlation coefficients, which indicates that central and peripheral NfL release are balanced. In contrast, QNfL was only positively associated with CSF-NfL levels in MS patients, but unrelated to S-NfL levels, thus highlighting the evident central source of NfL release in these patients. In our cohort of IIH patients, QNfL also showed a positive correlation with CSF-NfL levels, but not with S-NfL levels, which underlines the imbalance between CSF and S-NfL levels with an excess of centrally localized NfL in this patient group. Viewed in isolation, this either could be due to an NfL release by neurons of the CNS or caused by an impaired transfer of NfL from CSF to serum. However, in consideration of all the current observations and recent publications discussed above, we think it is most likely attributable to a combination of both processes, i.e., a release of NfL to the CSF caused by damage of central neuronal structures and an impairment of CSF outflow into the venous blood, mirrored by the elevated QNfL in our IIH cohort.The eponymous characteristic of IIH is a rise in intracranial pressure (ICP), which, in clinical practice, is usually assessed by repeated measurements of the lumbar puncture opening pressure. Whether the observed elevated ICP is rather due to CSF hypersecretion or outflow obstruction is still under debate. Of note, tumors accounting for an elevated CSF production or conditions leading to a secondary outflow obstruction  have to be excluded before diagnosing IIH , 36. In QNfL might serve as a biomarker of disease severity in IIH, which is of special interest as the measurement of lumbar puncture opening pressure is time-consuming and interference-prone. However, although the positive correlation between QNfL and lumbar puncture opening pressure is significant, the strength of correlation is modest and there is a substantial scatter about the regression line. This suggests that additional, so far unknown, factors likely also influence the observed association. A prospective study including longitudinal measurements in a deeply characterized cohort that allows correction for potential confounding factors should be performed to improve the prognostic accuracy of QNfL. The next step would then be the evaluation of the suitability of QNfL to inform treatment decisions.In order to further evaluate our findings, we additionally assessed GFAP concentrations in IIH patients and the non-neurological controls. The measurement of GFAP was chosen since previous histopathological studies have reported the presence of patchy astrogliosis in IIH patients , and dueTaken together, our main findings comprise that lumbar puncture opening pressure of IIH patients shows the strongest association with the CSF/serum ratio of NfL and that this ratio is increased in IIH patients in comparison to our control groups. Moreover, the GFAP ratio was also elevated in IIH. These observations suggest an impaired clearance of brain tissue metabolites to the periphery in IIH patients, which is positively associated with lumbar puncture opening pressure elevation. This supports the recently evolving hypothesis concerning IIH pathogenesis comprising a pressure-dependent CSF outflow obstruction with secondary congestion of the glymphatic system , 12.Major strengths of our study are the inclusion of several control groups and the additional assessment of GFAP levels that allowed us to set the NfL measures into clinical context. However, our findings are limited by the comparatively small sample size and by the cross-sectional nature of our current data. Our observations are purely correlative and do not address the pathological mechanisms involved. Specifically, it is currently unknown how NfL is released into the CSF and blood. Recently, a study using a quantitative immunoprecipitation-mass spectrometry assay reported three major NfL fragments in CSF, whereas no full-length NfL was identified in CSF . Thus, oIn addition, our PNP cohort was significantly older than the other three groups, limiting the comparability in this study. We tried to overcome this problem by also calculating the z-scores for S-NfL. To evaluate the potential of QNfL as an additional or alternative disease severity biomarker in IIH, future studies are needed to evaluate the longitudinal alterations of NfL parameters and their development upon normalization of lumbar puncture opening pressure in sequential follow-up measurements of IIH patients.This study demonstrates that S-NfL is not a suitable biomarker to identify patients with IIH during the initial diagnostic work-up, but that CSF-NfL levels and especially the CSF/serum ratio of NfL correspond well with lumbar puncture opening pressure. Moreover, our findings indicate an impairment of NfL transfer from the CSF to serum compartment in IIH patients, which supports the hypothesis of a restricted CSF outflow with potential secondary congestion of the glymphatic system being critically involved in IIH pathogenesis.Additional file 1: Figure S1. Z-Scores for S-NfL, correcting for age and body mass index (BMI). Figure S2. Increased QNfL in IIH is associated with elevated CSF-NfL. Table S1. Spearman correlation of QNfL with S-NfL and CSF-NfL. Table S2. Characteristics of MS and PNP patients. Table S3. Spearman correlation of QAlb with S-NfL, CSF-NfL and QNfL. Table S4. QNfL derived from previously published CSF-NfL an P-NfL in patients with inflammatory polyneuropathies and controls (34).


The errors in part IV of the TT presented a correlation with a forward digit span too . With respect to MoCA domains, executive functioning, and orientation were related to the TT part V errors . The orientation also correlated with the TT part III . Conclusion: Our findings show that the TT performances in patients with right hemisphere stroke and without aphasia are related to impairments in auditory–verbal span/auditory working memory mostly for TT scores on subpart V as measured by the DST and to executive function and orientation, as measured by the MoCA subtests.Background: The Token Test (TT) is widely used to examine comprehension disorders in aphasic patients, but abilities other than language may affect a patient’s performance. This study aims to explore the correlation between the TT subtest performances and the performances in extra-linguistic cognitive areas in a cohort of patients from the Intensive Rehabilitation Post-Stroke (RIPS) study with a first, right hemisphere stroke and without aphasia, prospectively enrolled at admission to intensive inpatient post-acute rehabilitation. Methods: The patients were administered the TT (50-item version), the forward and backward digit span (DST), and the Montreal Cognitive Assessment (MoCA). Spearman’s partial correlations adjusted by age were used to evaluate the association between the number of errors in the TT and the other tests’ corrected scores. Results: Of the 37 patients enrolled in this study, 29.7% made 3–11 errors on the TT, 27.0% more than 11 errors, mostly in parts IV and V. The forward and backward digit span scores showed correlations with errors in part V of the TT (r = −0.408,  The Token Test (TT) ,2,3 is wOver the past years, several versions have been proposed, that differ in the number of items, type of stimuli, type of population, and scoring modalities; a digital version is also available  and, recAlthough the TT has been specifically developed to assess auditory language comprehension, its performance involves other cognitive processes, as it often happens with neuropsychological tests. Such processes include verbal short-term memory, working memory, and inhibitory control, that is the ability to ignore distracting and competing lexical information . This isTT is included in widespread batteries for Aphasia, such as the Aachener Aphasia Test, (AAT) , originaSeveral studies have attempted to assess which functions, other than language abilities, may influence TT performance ,23,24,25Other evidence, however, does not support this relationship. For example, in a study conducted on a large sample of veterans with acquired brain lesions, Koenigs et al.  observedCognitive control has also been linked to receptive language (10) (24). In these last papers the role of inhibitory control, tested by the Stroop test, was evaluated on auditory comprehension in patients with Wernicke’s aphasia. A significant negative correlation was observed; namely, the greater the Stroop interference effect, the lower the TT performance.Based on these premises, we aimed to investigate which other components besides language comprehension may affect TT performance. To pursue this goal, we studied TT performance in stroke patients with right hemisphere lesion (RHL). Although patients with RHL may experience communicative–linguistic difficulties  study , we veriClinicalTrials.gov (Registration number: NCT03968627) and approved by each center’s local ethics committees . The study was conducted following the principles of the Declaration of Helsinki.The data analyzed in this study come from a multicenter observational prospective study, investigating the predictors of functional outcomes at discharge from inpatient post-stroke rehabilitation, the RIPS study . This stThe National Institutes of Health Stroke Scale (NIHSS) [All the people admitted to either of the four rehabilitation units from December 2019 to December 2020 were systematically assessed for eligibility and recruited upon signing informed consent. The participants meeting the following inclusion criteria were included in this study: (1) adults (aged ≥ 18 years), (2) first-ever ischemic or hemorrhagic right stroke, diagnosed clinically and with brain imaging, (3) 30 days or less from the index event, (4) first-ever admission to the rehabilitation center for the considered condition, (5) Italian mother tongue, and (6) Scoring 0 at  (NIHSS)  aphasia For this analysis, we used data from right-handed patients, with a right hemisphere lesion, for whom the TT , togetheThe NIHSS  is a widExecutive Functioning: this part is composed of three tests: (a) an alternation task adapted from the trail-making B task, (b) phonemic fluency, and (c) verbal abstraction task;Attention: this part is composed of three tests: (a) serial backward subtraction, (b) letter detection by tapping, and (c) forward/backward digit span task;Language: this part is composed of two tests: (a) naming of three images of low-familiarity animals and (b) repetition of two syntactically complex sentences;Visuospatial: this part is composed of two tests: (a) three-dimension cube copy and (b) clock drawing task;Orientation: this part is composed of one task in which the patient is asked to answer specific questions over time and place;Memory: this part is composed of a single memory test composed of delayed recall of five nouns after approximately five minutes from a learning trial.The Montreal Cognitive Assessment (MoCA) test  is a cogAccording to Italian normative data, the score should be corrected for age and education. The scores included in this study were raw scores, adjusted according to the correction grids provided in the normative data .Token Test (TT) : The verThe forward and backward digit span (FDS) test : FDS maiThe NIHSS was assessed upon admission to the rehabilitation ward, the other neuropsychological tests were performed within a week of admission.The scores corrected for age, sex, and education were used for all the following analyses. Firstly, the Shapiro–Wilk test was performed for all continuous variables to determine whether the data were normally distributed. The variables were then summarized as mean and standard deviation (SD) or median and interquartile range (IQR), according to the test results. The categorical data were presented as frequencies with percentages. To investigate whether there was an association between the number of errors performed on the TT and neuropsychological tests adjusted partial correlations were conducted. To take into account the effect of age on TT performance, age was introduced in the analyses as a confounding factor. The absolute value of the correlation coefficient (r) represents a very strong correlation if above 0.80, a strong correlation if between 0.60 and 0.79, a moderate correlation if between 0.40 and 0.59, a weak correlation if between 0.20 and 0.39, and a very weak correlation if below 0.19 .p-value < 0.05 was considered statistically significant. The analyses were carried out using the SPSS 20.0 software package .The differences between different lesion locations  were assessed using the Kruskal–Wallis test. The post hoc Bonferroni correction for multiple comparisons was applied. In all the analyses, a n = 23, 62.2%). Twenty-two participants (59.5%) had an ischemic stroke, while 15 (40.5%) had a hemorrhagic stroke. Most of the participants (n = 16) had a lobar lesion (43.2%); 37.8% (n = 14), presented a lesion in subcortical structures. There were seven (18.9%) participants with any other lesion locations. The specifics on the lesion site for individual subjects are reported in the Out of the 278 stroke patients who were eligible for the RIPS study, 235 (85%) signed the informed consent and were enrolled. Of these, 37 met the inclusion criteria and were included in this analysis. The participants had a mean age of 73.5 years . Most of the participants were male , while the lower score was recorded in the memory area .The FDS corrected score obtained by participants ranged between 3.5 and 7.9 . The lower scores were obtained in the BDS test where values ranged from 1.8 to 7.1 . A performance lower than 5% of the normative sample was observed in 10.8% of the participants for FDS (score not exceeding 4.26) and 8.1% of the participants for BDS (score not exceeding 2.65). The MoCA mean corrected score obtained by participants was 19.5 (SD: 3.8); the higher score was recorded in the The neuropsychological test scores obtained by the participants are summarized in p = 0.0013). No significant correlation was found between FDS and subparts I–III . The corrected BDS scores correlated only with the TT subpart V, . Subparts I–IV showed no significant correlation with BDS  . A correlation was also found between orientation and TT subpart III  (The significant moderate negative correlations were found between the score obtained in the = 0.002) .The TT total error distributions according to the corrected score obtained in FDS and BDS tests are presented in p = 0.485) in the number of errors according to the lesion site. Similarly, no significant difference was found in FDS (p = 0.629) and BDS (p = 0.568) corrected scores between participants with subcortical, lobar, or other lesion locations.When the association between the number of TT total errors and the lesion location was investigated, no significant differences were observed  in a group of thirty-seven patients with right hemispheric stroke and without aphasia; these were prospectively recruited within a multicentric observational study. Although it is not possible to completely exclude an influence of the right hemispheric lesions on the verbal production necessary for the execution of the neuropsychological tests, by the choice of these inclusion/exclusion criteria, we aimed at excluding a significant linguistic component to the TT performance, while taking into consideration other non-verbal cognitive aspects that could be affected by a stroke.In order to exclude aphasic patients, we decided to select right-handed patients with unilateral right brain regions. To prevent the risk of including persons with inverted cortical representation, the aphasia NIHSS score was used to exclude patients with aphasia following right hemisphere stroke. This choice was aimed at focusing on potential pathological performances in the TT, most likely unrelated to verbal comprehension problems.Our sample included patients with stroke, which occurred within 30 days before the recruitment, of either ischemic or hemorrhagic etiology, by a proportion of either in line with the literature ,43. The In our analysis, we did not observe any difference between the forward and backward span, used as measures of short-term memory and working memory, respectively. This was rather unexpected, since working memory, namely the capacity to simultaneously process verbal information, should be theoretically more related to complex sentence decoding, than the simple maintenance of linguistic information over a short period  . HoweverAmong the cognitive models of verbal short-term memory, the phonological loop integrated into the working memory model proposed by Baddeley  is probaexecutive functions and orientation, while part III also correlated with orientation. The executive functions refer to complex higher-order functions and are considered to be linked to frontal cortical–subcortical circuits. They are involved in carrying out all the more complex tasks, including attentive supervision and self-monitoring. Instead, the significant relationship between the orientation area and the more complex TT subtest could be interpreted as an effect of more severe cognitive impairment: patients who fail in orientation MoCA subtests are those with a severe cognitive impairment and that for this reason are the ones who also fail in the TT complex subtests. On the other hand, it is important to remember that MoCA is a screening test, with very short tests for each cognitive function, and for this reason it does not provide a detailed neuropsychological investigation.Concerning the analysis conducted with MoCA groupings, again part V presents a correlation with Our results suggest that the existence of an association between auditory–verbal span/auditory working memory and TT performance in right-hemisphere stroke patients. Considering that both right and left hemisphere lesions can compromise short-term and working memory ,53,54, tHowever, further considerations are necessary. Not only the cognitive functions are mutually influenced, but also the neuropsychological tests aimed at assessing one specific function are in some measure influenced by other cognitive performances. For example, the digit span includes a linguistic component and attention underlies all other cognitive functions. Each conclusion must therefore be interpreted considering the numerous factors co-involved in the phenomenon observed. Furthermore, the TT Italian normative data do not need correction for age, while in other languages, such as German, a correction for demographic information is required. This could have influenced the cut-off, which is particularly high in the Italian population, in particular for the assessment of older persons.From a pragmatic, clinical practice perspective, our results point out other factors that may affect performance at the TT. Evaluating a non-aphasic right hemisphere patient with a TT may thus reveal or confirm impairments in the short term and working memory, while, when administering a TT to an aphasic patient, we must consider that the performance could also be affected by working memory components and attention. The clinical reasoning on the pattern of errors in a TT as well as in other neuropsychological tests, and the observation and interpretation of the patient’s behavior during the test administration, may guide the examiner in the analysis of the verbal comprehension disorder and help to adequately weigh the influence of linguistic and extra-linguistic factors, respectively.This study presents several limitations. First of all, the sample size is numerically restricted. This did not allow further analyses, such as the evaluation of a possible age effect by a further division into groups. Moreover, to assess the cognitive deficits related to the TT’s performance, we used screening tests, which are not as sensitive as a complete neuropsychological evaluation. Finally, a complete and exhaustive assessment of the language skills of patients was also not performed.On the other hand, the strengths of this study lie in its prospective nature, as well as in the homogeneity of this cohort, in reference to distance from the acute event.From the clinical perspective, our results emphasize the importance to investigate verbal short-term memory when assessing and treating verbal comprehension disorders, screening for possible deficits and eventually addressing them with appropriate cognitive rehabilitation treatment. Furthermore, our results also suggest that some caution should be adopted in interpreting TT results in aphasic patients. Indeed, TT errors may not highlight an exclusive problem in linguistic decoding, so the potential effect of other extra-linguistic factors must also be taken into account. This would imply that tests that are less dependent on these highlighted cognitive factors should possibly be used to assess verbal comprehension along with the TT.In fact, the “Aachener Aphasie Test” evaluation battery , which c


Cytomegalovirus (CMV) is an important opportunistic pathogen after transplantation. Some virological variation in transplant recipients is explained by donor and recipient CMV serostatus, but not all. Circadian variability of herpesviruses has been described, so we investigated the effect of time of day of transplantation on posttransplant CMV viremia.We performed a retrospective analysis of 1517 patients receiving liver or kidney allografts at a single center from 2002 to 2018. All patients were given preemptive therapy with CMV viremia monitoring after transplantation. Circulatory arrest and reperfusion time of donor organ were categorized into 4 periods. Patients were divided into serostatus groups based on previous CMV infection in donor and recipient. CMV viremia parameters were compared between time categories for each group. Factor analysis of mixed data was used to interrogate this complex data set.P < .001). After controlling for this, there was no evidence of time of day of transplantation affecting CMV parameters in any serostatus group, by logistic regression or factor analysis of mixed data.Live-donor transplant recipients were less likely to develop viremia than recipients of deceased-donor organs (48% vs 61%; We found no evidence for a circadian effect of transplantation on CMV viremia, but these novel results warrant confirmation by other centers. Using a large data set on preemptive cytomegalovirus therapy for solid-organ transplant recipients, we found no association between time of day of transplantation and cytomegalovirus viremia but found increased viremia in recipients of deceased-donor compared with live-donor transplants. Cytomegalovirus (CMV) is a member of the Herpesviridae family of double-stranded DNA viruses. It is an important opportunistic pathogen that affects a high proportion of patients after transplantation , 2. GiveVariation in posttransplant virological parameters illustrates that transplant recipients have markedly different phenotypes. Some of this variation is explained by previous CMV infection in either the donor or the recipient of the organ, as measured by the presence of CMV immunoglobulin G (IgG) antibodies in the donor or recipient before transplantation, producing 3 subgroups of transplant recipients: donor positive for CMV IgG and recipient negative (D+R−), donor negative and recipient positive (D−R+), and both donor and recipient positive (D+R+) [Subgrouping transplant recipients according to donor/recipient CMV serostatus does not completely explain posttransplant viral load variability. One factor that may affect CMV viremia is the timing of transplantation. Viruses are obligate intracellular pathogens that rely on host metabolism for their replication. There is extensive evidence from cell culture and animal models that virus replication and reactivation is modulated according to the time of day and that this effect can be blocked by deletion of genes that mediate cellular circadian rhythms (reviewed in ). This eWe carried out a retrospective case note analysis of transplant recipients who received liver or kidney allografts rom 2002 to 2018 at the Royal Free Hospital, London, United Kingdom. All patients were given preemptive therapy using whole-blood samples collected twice a week for the first 60 days after transplantation, then once a week until day 90. CMV load was monitored with quantitative polymerase chain reaction, using a method reported elsewhere , until SUntil 1 July 2012, preemptive therapy was started in all patients when the viral load was ≥3000 genomes per milliliter (≥2520 IU/mL). The protocol then changed for the D+R− subset, who were treated when their first polymerase chain reaction–positive result was obtained . Patientam), day (10 am to 4 pm), evening (4–10 pm), and night (10 pm to 4 am). Virological data were collected as in previous studies and included presence of viremia, duration of viremia, peak viral load, and treatment requirement. The study was approved by the South Central–Oxford B Research Ethics Committee.We analyzed demographic data . To capture potential circadian effects on the donor organ at time of removal or introduction into a new host, we recorded both the time of circulatory arrest of the donor  and the reperfusion time of the organ in the recipient. These parameters were collected from patient notes and the times of day were categorized into 4 classifications before analysis: morning . Statistical analysis of the baseline data and viremic parameters was carried out using Stata 15 software, with χP values . LogistiBecause the data set contained a mixture of qualitative and quantitative variables, we used factor analysis of mixed data (FAMD), an approach similar to principal component analysis that is suitable for data sets containing mixed variable types. FAMD was performed on data from patients, using R software (version 4.1.0), RStudio (version 1.4.1717), and R packages FactoMineR  and factA total of 1517 patients were included in the analysis: 243 in the D+R−, 543 in the D+R+, and 731 in the D+R+ subgroup.P = .56) or reperfusion time (P = .50). There was also no evidence for an association between donor sex and circulatory arrest time (P = .11), but there was a statistically significant difference in reperfusion time, with relatively fewer men with reperfusion times during the day .Demographic characteristics of transplant recipients, divided by the time of circulatory arrest in the donor and of reperfusion in the recipient, are shown in P < .001). We also found a difference in time of day for kidney versus liver transplantation, with relatively more kidney circulatory arrest times occurring during the day and reperfusion times at night or in the morning .As expected, there was evidence of a difference in time of day of transplantation between deceased-donor and live-donor transplants, with organs from live donors more frequently transplanted during in the day .Logistic regression analysis found no evidence of an association between viremia and either circulatory arrest time or reperfusion time in the D+R− subgroup see . The samLogistic regression analysis also found no evidence of an association between viremia and circulatory arrest or reperfusion times in the D−R+ subgroup see . The samAs in the other subgroups, logistic regression analysis found no evidence of an association between viremia and either circulatory arrest or reperfusion times in the D+R+ subgroup see . The samP = .02), however, no consistent pattern was seen in other virological parameters for this season/serotype group.Results for the effect of season on CMV viremia for each serogroup are shown in Given the large numbers of variables present within the data set, we perform a multivariate analysis to investigate whether any particular factors were associated with CMV viremia when considered as a whole. Furthermore, given that live transplants tended to be skewed toward a particular time of day, we limited the FAMD analysis to only deceased-donor transplants.When evaluating the impact of the qualitative variables , we agaiWhile the weightings of the other qualitative variables along the first dimension are relatively small compared with the variables discussed above, there are some interesting points to note. Namely, having a female donor is weighted approximately 0.25 in the positive direction, while having a male donor is weighted approximately 0.25 in the negative direction, suggesting that having a female donor leads to a greater risk of CMV viremia. This may be partially explained by a higher frequency of D+ organs coming from female compared with male donors . In terms of the impact of seasons, winter appears to be the least “risky” season for CMV viremia associated with transplantation, although the impact of seasonality is minor at most and may be reflect a wide range of factors. Finally, all variables associated with “time of day” have extremely small weightings along the first dimension, indicating that they have little impact on the risk of CMV viremia.We did not find any evidence of an association between time of day of solid organ transplantation and later viremia in any of the donor-recipient subgroups. There were also no seasonality differences in our data. These findings were confirmed with use of the FAMD, showing little effect of timing parameters.To the best of our knowledge, ours is the first study to address this question, so we suggest that colleagues in other transplant centers examine their data to facilitate a future meta-analysis. Our center uses preemptive therapy, and it would be interesting to see if those using prophylaxis have evidence of circadian effects linked to late-onset disease and the development of antiviral resistance , 19. FutOur study has several possible limitations. First, there are multiple possible confounders masking an association. For example, we do not know the occupation of donors or recipients and whether they were shift workers, and we do not have information about preceding hospital admission, as the hospital environment is known to disrupt circadian rhythms. Moreover many patients will be admitted to an intensive care unit after transplantation, with well-documented circadian disruption (reviewed in ). All ofThis study did confirm previous study findings. First, the serotype subgroups showed a risk pattern similar to that inn previous studies, with the D+R− subgroup the most likely to develop viremia, and the D−R+ subgroup the least likely . Second,As expected, we did find deceased-donor transplant recipients had longer median cold ischemia times (613 vs 158 minutes in live-donor transplant recipients), and we hypothesized that this could be the cause of increased CMV viremia in these patients; however, there was no evidence that a longer cold ischemia time was associated with viremia in either simple analysis or the FAMD. An alternative explanation for this finding could be that CMV replicates faster in a deceased-donor organ before reperfusion owing to decreased tissue perfusion, or that the immune response in the recipient of a deceased-donor organ favors CMV reactivation. High-dose corticosteroids are used as “conditioning” for deceased-donor organ recipients in some settings and could explain CMV reactivation in these organs; however this regimen is not routinely used in UK hospitals. We suggest that future randomized controlled trials of antiviral drugs or vaccines against CMV should consider stratifying by type of donor organ.In conclusion, the current study did not find any circadian or seasonal effect on the development of CMV viremia after transplantation. However, this is the first study of its kind, and we would therefore encourage a similar analysis at other transplant centers, particularly comparing centers using prophylactic CMV regimens. We did confirm the finding that deceased-donor transplant recipients are at higher risk of CMV viremia than live-donor recipients, extending this observation to patients receiving preemptive therapy, and we therefore suggest adjustment for or stratification of these patients in future studies.The Journal of Infectious Diseases online. Supplementary materials consist of data provided by the author that are published to benefit the reader. The posted materials are not copyedited. The contents of all supplementary data are the sole responsibility of the authors. Questions or messages regarding errors should be addressed to the author.Supplementary materials are available at jiac055_suppl_Supplementary_TablesClick here for additional data file.


Cerebrospinal fluid (CSF) analysis for detecting amyloid positivity may be as reliable as positron emission tomography (PET). We evaluated the performance of the amyloid beta (Aβ)42/40 ratio for predicting amyloid positivity by PET, compared with Aβ42 alone, and phosphorylated tau 181 (pTau181)/Aβ42 and total tau (tTau)/Aβ42 ratios, using fully automated CSF immunoassays  in a heterogeneous cohort of patients with a range of cognitive disorders reflecting the typical population of a memory clinic.n = 44) or mild-to-moderate dementia (n = 27) due to Alzheimer’s disease (AD), and 32 patients were undergoing treatment for non-AD-related cognitive disorders. Aβ42, pTau181, and tTau concentrations were measured in CSF samples using the respective Elecsys® CSF immunoassays modified for use on the cobas e 411 analyzer; Aβ40 concentrations were measured using a non-commercially available robust prototype assay. Sensitivities/specificities for amyloid positivity cut-offs (Youden-derived and pre-defined) were calculated, and receiver operating characteristic analyses determined area under the curve (AUC) versus amyloid PET status. Limitations include a small sample size, use of a pre-analytical protocol not in accordance with the Elecsys CSF immunoassay method sheets, and the lack of a pre-defined cut-off for Aβ42/40.CSF samples from 103 patients with known amyloid PET status  were retrospectively selected from one site in Germany; 71 patients were undergoing treatment for mild cognitive impairment  versus amyloid PET were 0.78 (0.68−0.88) for Aβ42, 0.88 (0.81−0.95) for pTau181/Aβ42, 0.87 (0.80−0.95) for tTau/Aβ42, and 0.90 (0.83−0.97) for Aβ42/40.CSF Aβ42/40 ratio can predict PET amyloid positivity with high accuracy in patients with a range of cognitive disorders when evaluating Aβ pathology independent of tau and neurodegeneration for research purposes. The performance of Aβ42/40 was comparable with pTau181/Aβ42 and tTau/Aβ42 used in clinical practice and better than Aβ42 alone. Both pTau181/Aβ42 and tTau/Aβ42 ratios outperformed Aβ42 alone -flutemetamol PET  [18F]-flutemetamol more accurately than Aβ42 alone; AUC values were 0.912−0.975 for Aβ42/40 and Aβ42/38 ratios, compared with 0.810−0.916 for Aβ42 alone -Pittsburgh Compound B, [18F]-florbetaben, and [18F]-florbetapir. Amyloid PET positivity was visually assessed following United States Food and Drug Administration-approved algorithms by two independent raters who were blinded to each other and to the clinical information. In the event of discordant readings (n = 2), a case discussion was initiated between the two raters, and consensus was achieved.PET scans were conducted at the Department of Nuclear Medicine, Technical University of Munich  on a Siemens Biograph mMR or Biograph mCT , using one of three different PET tracers: ; mean age [standard deviation], 66.37 [± 9.75] years): 44 (42.72%) patients were diagnosed with MCI due to AD; 27 (26.21%) patients with mild-to-moderate dementia due to AD; 17 (16.50%) patients with FTLD ; eight (7.77%) patients with MCI of unclear origin; five (4.85%) patients with depression; one (0.97%) patient with alcohol dependence; and one (0.97%) patient with SCD  are shown in Table Concordance of the individual CSF biomarkers and biomarker ratios with amyloid PET status  than Aβ42 alone (0.78 [95% CI: 0.68–0.88]), with Aβ42/40 ratio exhibiting the highest AUC point estimate  demonstrated robust differentiation between amyloid PET-positive and -negative patients  research framework as the focus of diagnostic techniques for AD shifts from confirming the presence of symptomatic AD to identifying patients at an earlier stage of the disease . PreviouIn this study, we evaluated the performance of fully automated, research-use CSF immunoassays to determine whether they perform as well as the Elecsys CSF assay versions approved for clinical use. All individual CSF biomarkers and biomarker ratios demonstrated good concordance with amyloid PET for the detection of amyloid positivity in a heterogeneous cohort of patients with a broad range of cognitive disorders, extending on previous evidence in more homogeneous cohorts. Our results showed that the CSF Aβ42/40 ratio had higher concordance with amyloid PET than Aβ42 alone and demonstrated comparable performance to the pTau181/Aβ42 and tTau/Aβ42 ratios. The Aβ42/40 ratio also demonstrated robust differentiation between amyloid PET-positive and PET-negative patients, which was comparable to that observed using pTau181/Aβ42 and tTau/Aβ42 ratios.Consistent with Janelidze et al., our findings suggest that the CSF Aβ42/40 ratio may better differentiate amyloid-positive from amyloid-negative individuals compared with Aβ42 alone . The higA possible reason for the CSF Aβ42/40 ratio outperforming Aβ42 in our study, which was attributable primarily to a higher specificity, is the normalization of interpatient variability in Aβ production, as the level of Aβ peptide production differs between individuals. As a result, it is possible to obtain false-positive results if only Aβ42 is assessed. The Aβ42/40 ratio may compensate for this by assessing two Aβ peptides, of which the latter, Aβ40, is less affected by AD –15, 21. By using ratios of one protein to any other brain-derived protein, physiological fluctuations might be compensated for . A/(N) rIn agreement with previous studies , 10, ourOne strength of our study is the heterogeneous patient population. Patients with a variety of diagnoses were enrolled, reflecting the situation encountered in the routine setting of a memory clinic. Limitations include the relatively small sample size and the use of samples from the study center biobank, which were acquired and handled in a standardized manner, but not in accordance with the pre-analytical protocol recommended in Elecsys CSF immunoassay method sheets. This posed the risk of affecting the pre-defined assay cut-off values, as well as assay performance; for example, we observed coefficients of variation that were higher than expected. Additionally, a pre-defined cut-off has not been established for the Aβ42/40 ratio; therefore, we used a Youden-derived cut-off that was specific to the cohort of patients enrolled. This posed the risk of introducing an element of bias to the clinical performance of the assays.We demonstrate that the CSF Aβ42/Aβ40 ratio measured using fully automated, research-use CSF immunoassays can predict amyloid positivity as determined by PET with high accuracy in patients with a broad range of cognitive disorders reflecting a typical heterogeneous population of a memory clinic. The performance of the Aβ42/40 ratio in detecting amyloid positivity by PET was higher than using Aβ42 alone and comparable with the performance of the pTau181/Aβ42 and tTau/Aβ42 ratios. Our results add to previously reported literature demonstrating the strong clinical performance of pTau181/Aβ42 and tTau/Aβ42 ratios in detecting amyloid positivity in homogenous cohorts. Taken together, these findings suggest CSF biomarker analysis could provide a cost-effective alternative to PET in the AD diagnostic pathway.


Upper limb impairment is common after stroke, and many will not regain full upper limb function. Different technologies based on surface electromyography (sEMG) have been used in stroke rehabilitation, but there is no collated evidence on the different sEMG-driven interventions and their effect on upper limb function in people with stroke.Synthesize existing evidence and perform a meta-analysis on the effect of different types of sEMG-driven interventions on upper limb function in people with stroke.PubMed, SCOPUS, and PEDro databases were systematically searched for eligible randomized clinical trials that utilize sEMG-driven interventions to improve upper limb function assessed by Fugl-Meyer Assessment (FMA-UE) in stroke. The PEDro scale was used to evaluate the methodological quality and the risk of bias of the included studies. In addition, a meta-analysis utilizing a random effect model was performed for studies comparing sEMG interventions to non-sEMG interventions and for studies comparing different sEMG interventions protocols.2 55%). Similarly, no difference in the overall effect was found for the meta-analysis comparing different types of sEMG interventions . Twenty out of the twenty-four studies, including participants with varying impairment levels at all stages of stroke recovery, reported statistically significant improvements in upper limb function at post-sEMG intervention compared to baseline.Twenty-four studies comprising 808 participants were included in this review. The methodological quality was good to fair. The meta-analysis showed no differences in the total effect, assessed by total FMA-UE score, comparing sEMG interventions to non-sEMG interventions (14 studies, 509 participants, SMD 0.14, P 0.37, 95% CI –0.18 to 0.46, IThis review and meta-analysis could not discern the effect of sEMG in comparison to a non-sEMG intervention or the most effective type of sEMG intervention for improving upper limb function in stroke populations. Current evidence suggests that sEMG is a promising tool to further improve functional recovery, but randomized clinical trials with larger sample sizes are needed to verify whether the effect on upper extremity function of a specific sEMG intervention is superior compared to other non-sEMG or other type of sEMG interventions. Stroke is one of the leading causes of disability in adults . ApproxiUpper limb rehabilitation is crucial to maximize outcomes and decrease disability . Along wSurface EMG (sEMG), in which electrodes placed over the skin record the electrical activity of a muscle or group of muscles, has been used for neurorehabilitation for more than five decades . sEMG caIn stroke, sEMG has been used for upper limb rehabilitation since the beginning of the 90s . The visTaking the large variety of clinical application areas of sEMG, more knowledge is needed to better understand the benefits, possibilities, and potential clinical effects of the different types of sEMG interventions on motor recovery after stroke . PreviouThe present systematic review and meta-analysis was registered in the PROSPERO database prior analysis (CRD42021243372), and the PRISMA 2020 statement was followed .One of the authors (MM-N) conducted an online search in PubMed, Scopus, and PEDro databases, including relevant articles in English published between January 2000 and May 2021. The search terms used are shown in Studies were eligible for inclusion if participants were older than 18 years and had an upper limb motor impairment due to stroke. Only randomized control trials (RCT) using sEMG interventions to improve upper limb function were included. The sEMG signal needed to be obtained from the upper limb, and the protocol was required to explicitly state the number of sessions, time, and frequency of treatment. Fugl-Meyer Assessment of Upper Extremity (FMA-UE)  needed tOne reviewer performed the screening for title and abstract for relevance (MM-N). Following, full texts of all potentially pertinent articles were reviewed by two authors . Then, the two reviewers’ opinions were compared, and any disagreement was resolved by a third reviewer (MAM).The data from the included studies were extracted by one reviewer (MM-N) and independently checked by a second reviewer (MBK). The extracted data included: study characteristics , participant characteristics , interventions , treatment protocol , setting , outcomes , main results and conclusions.Time since stroke was classified as acute (< 7 days), subacute (7 days to 6 months), and chronic (≥ 6 months) . The uppThe sEMG interventions used in different studies were categorized into subgroups according to their type of application: sEMG-triggered neuromuscular stimulation (sEMG-NMS), sEMG providing visual and/or auditory biofeedback (sEMG-BFB), sEMG-driven robotic device (sEMG-RT), or a combination of those. The control or comparison interventions that did not include sEMG were categorized as non-sEMG interventions .For studies comparing different sEMG interventions protocols with each other, the interventions were categorized as Intervention 1 when the sEMG interventions was utilized alone, and as Intervention 2 when the sEMG intervention was combined with another training modality .The methodological quality of the randomized controlled trials was assessed independently by two reviewers  using the Physiotherapy Evidence Database (PEDro) scale. This scale is used to evaluate the quality and potential risk of bias of randomized controlled trials . A thirdThe included studies comparing sEMG interventions with non-sEMG interventions and studies comparing sEMG interventions with another sEMG intervention protocol were summarized and analyzed separately. For studies comparing more than two intervention protocols, each comparison was included independently under the respective type of sEMG intervention.2 test , subacute (n = 8), mixed subacute/chronic (n = 2), or acute/subacute (n = 1) stage of stroke recovery (n = 14) were conducted in hospital settings, followed by research laboratory (n = 4), home (n = 4), and mixed home and hospital setting (n = 1). One study did not report their treatment location (n = 12) used sEMG to trigger neuromuscular stimulation, 6 used sEMG to drive robotic devices, 2 to provide visual and/or auditory biofeedback, and 6 studies combined different types of sEMG interventions  (n = 15), followed by both elbow and wrist (n = 5) (n = 2) (n = 2) (n = 12) (n = 20) reported statistically significant improvements in FMA-UE scores compared to the baseline scores   reportedn = 12)  reportedn = 12)  reported (n = 5) , elbow ( (n = 2) , 2020, a (n = 2) . Half of(n = 12)  incorpor(n = 12) , pushing(n = 12) , virtual(n = 12) , daily l(n = 12) , and oth(n = 12) . The maje scores , 4.2 55%, The meta-analysis revealed no differences for the total effect of sEMG interventions compared to non-sEMG interventions on the total FMA-UE score  to protocols combining sEMG interventions with another training modality (Intervention 2)  were included in the systematic review, and 20 studies were included in the meta-analyses. The results of the meta-analyses revealed no differences for the total effect of sEMG interventions compared to non-sEMG interventions nor for studies comparing sEMG interventions with another sEMG intervention protocol when assessed by FMA-UE total score. Moreover, it is worth to notice that sEMG is not an intervention used in solitary but a tool to complement and enhance treatment effects of different neuromuscular rehabilitation interventions.The present systematic review and meta-analysis synthesizes the effects of different surface electromyography-driven interventions on upper limb function in people with stroke. A total of 24 studies  of sEMG interventions compared to non-sEMG interventions, nor sEMG interventions compared to sEMG interventions combined with other therapies, were found in our meta-analyses. Although we included several types of sEMG-driven interventions, the results could not verify which single or combined sEMG-intervention was most beneficial for upper limb function. Notably, most of the included studies reported statistically significant improvements on upper limb function compared to baseline FMA-UE scores, and these effects were shown even on participants with severe stroke in the chronic stage of stroke recovery.Even though, surface EMG-driven interventions are promising for promoting upper limb function in people with stroke, more randomized controlled trials with larger sample sizes, unified methodology and outcome measures are required to establish the effectiveness of the different types of sEMG interventions in combination with other therapies. Considering the high-intensity training that sEMG interventions can offer, future studies should further explore its effectiveness in home settings, especially in chronic stroke cases.The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author/s.MAM, MM-N, MBK, and AN organized the database. MAM, MM-N, and MBK screened the included studies. MM-N performed the meta-analysis and wrote the first draft of the manuscript. All authors contributed to conception and design of the study, manuscript revision, read, and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.