Are Sarcopenia and Cognitive Dysfunction Comorbid after Stroke in the Context of Brain-Muscle Crosstalk?

The extract of chrysanthemum flos mitigates post-stroke sarcopenia by inhibiting PANoptosis and restoring muscle homeostasis

BACKGROUND

Sarcopenia and muscle weakness are prevalent complications of ischemic stroke (IS), with limited pharmacological options. This study identifies high-dose extracts of Chrysanthemum Flos (ECF) as a potential therapy for post-stroke muscle dysfunction by targeting PANoptosis-a pro-inflammatory programmed cell death pathway. Through its anti-inflammatory and antioxidant properties, ECF attenuates muscle atrophy and enhances functional recovery, offering novel insights into ISS treatment.

PURPOSE

To evaluate the therapeutic efficacy of high-dose ECF in ischemic stroke-induced sarcopenia (ISS) and elucidate its regulatory role in PANoptosis-mediated muscle degeneration and protein homeostasis.

METHODS

Preparation of a rat middle cerebral artery occlusion (MCAO) model using intravascular wire thrombus blockade. Cerebral injury was assessed using laser speckle contrast imaging, triphenyltetrazolium chloride (TTC) staining, and Zea-Longa neurological scoring. ECF's effects on muscle function were evaluated through gait analysis, muscle morphology (length and weight), grip strength, electromyography, and H&E staining. RNA sequencing was conducted to elucidate transcriptomic alterations and enriched pathways associated with ECF in ISS. PANoptosis-mediated myofiber and L6 cell damage was analyzed by flow cytometry (FC), immunofluorescence (IF), immunohistochemistry (IHC), and western blotting (WB). ECF composition and quality were validated using liquid chromatography-mass spectrometry (LC-MS).

RESULTS

ISS rats showed 83 % reductions in endurance, grip strength, and EMG signals compared to sham (p < 0.01), which improved to 70 % of normal after ECF treatment. ECF significantly increased muscle fiber area, alleviated mitochondrial damage, and improved sarcomere structure (p < 0.001). RNA-seq identified TNF signaling and PANoptosis (apoptosis, pyroptosis, necroptosis) as key drivers of ISS-induced muscle injury. The TNF-targeted inhibitor R7050 further confirmed TNF-α as a critical activator of Z-DNA binding protein 1 (ZBP1). ECF treatment significantly reduced tissue inflammation (p < 0.01) and inhibited ZBP1 expression (p < 0.01). Following ISS, key PANoptosis-related proteins, including ZBP1, Gasdermin D N-terminal fragment (GSDMD-N), Cleaved-Caspase3, Caspase6, Caspase8, phosphorylated mixed-lineage kinase domain-like (p-MLKL), Phosphorylated Receptor-Interacting Protein Kinase 1 (p-RIPK1), Phosphorylated Receptor-Interacting Protein Kinase 3 (p-RIPK3), and NOD-like receptor family pyrin domain containing 3 (NLRP3), were significantly upregulated (p < 0.05), while ECF-H treatment significantly suppressed their expression (p < 0.05, p < 0.01). Additionally, ECF significantly promoted the expression of muscle protein synthesis factors (myogenic differentiation 1 (MyoD1) and recombinant myosin heavy chain 1 (MYH), p < 0.01) and inhibited protein degradation factors (muscle RING-finger protein-1 (MuRF1) and muscle atrophy F-Box protein (MAFbx), p < 0.01), thus maintaining muscle protein homeostasis. The results from PCR, WB, IHC, IF, and FC experiments were consistent with RNA-seq findings.

CONCLUSIONS

ECF ameliorates ISS in MCAO rats by inhibiting muscle PANoptosis, which simultaneously reduces protein degradation and enhances protein synthesis.

Association of the sarcopenia index with cognitive impairment in a middle-aged to older patients with acute ischemic stroke or transient ischemic attack: A multicenter cohort study

OBJECTIVES

The sarcopenia (SI) index, defined as the serum creatinine to cystatin C ratio, is considered a predictor of poor muscle health and malnutrition, which is related to major adverse cardiovascular events. However, the effect of the SI index on cognitive function in stroke patients remains unknown. In this study, we aimed to examine the association between the SI and longitudinal cognitive impairment in patients with acute ischemic stroke or transient ischemic attack.

RESEARCH DESIGN AND METHODS

Participants who met the inclusion criteria in this national, multicenter, prospective cohort study were enrolled from the Impairment of Cognition and Sleep (ICONS) study of the China National Stroke Registry-3 (CNSR-3). They were categorized into four groups according to the quartile of the SI index. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA) scale. Multivariable-adjusted logistic regression models were performed to evaluate the association between the SI index and post-stroke cognitive impairment (PSCI) at the 3-month follow-up. Moreover, discrimination tests were used to evaluate the incremental predictive value of the SI index beyond the potential risk factors. Furthermore, we performed subgroup analyses to test interactions.

RESULTS

Among the enrolled participants, the lower the SI index was, the worse the cognitive performance. At the 3-month follow-up, participants in the lowest SI quartile group exhibited a 42% increase in the risk of cognitive impairment relative to the highest quartile group [OR 0.58 (95% CI 0.37-0.90)]. Moreover, after applying the discrimination test, adding the SI index into the potential risk factors resulted in a slight improvement in predicting the risk of cognitive impairment [NRI 14% (P = 0.01)].

CONCLUSION

This study demonstrated that a lower sarcopenia index was positively associated with a higher prevalence of PSCI. Monitoring the SI index in stroke patients and early identification and treatment of individuals with low SI level may be helpful to reduce the risk of cognitive impairment.

Sarcopenia, frailty prevalence, and related factors in patients with stroke: A cross-sectional analytical study from Turkey

BACKGROUND

Sarcopenia and frailty may develop at varying rates depending on the metabolic, structural, and functional changes in the muscle structure after stroke.

OBJECTIVE

To evaluate the prevalence of sarcopenia and frailty in patients with stroke and affecting clinical parameters.

METHODS

This was a cross-sectional and analytical study. Twenty-six (49.1%) women and 27 men (50.9%) with stroke with an average age of 60.2 ± 10.3 (median = 62) years were included in the study. To evaluate physical performance, balance, and mobility, we used the 4-meter walk test (4-MWT), timed up and go test, chair sit and stand test, and the Berg Balance Scale (BBS). Sarcopenia was diagnosed according to the Asian Working Group for Sarcopenia 2019 criteria. The SARC-F scale was used for sarcopenia.

RESULTS

The average stroke duration was 21.6 ± 18.2 months. Prefrailty was present in 14 (26.4%) patients, frailty was present in 34 (64.2%) patients, and two (3.8%) patients were normal. Sarcopenia was detected in 28 (52.8%) patients. According to handgrip strength, the prevalence of low muscle strength was 17% (n= 9). In the sarcopenic group, female sex (p= 0.005) was more frequent, 4-MWT was longer (p= 0.003), chair stand test results were lower (p< 0.001), the clinical frailty scale (CFS) was higher (p< 0.001), fall risk was higher compared with the BBS (p< 0.001), there was lower HG strength (p= 0.009), lower malnutrition scores (PNI, prognostic nutritional index, p< 0.001), and lower lymphocyte counts (p= 0.037). EAT-10 scores and dysphagia presence (p= 0.026), the presence of malnutrition (p< 0.021) and Nottingham Health Profile score (p< 0.001) were higher in the sarcopenic group.

CONCLUSION

Sarcopenia and frailty frequently develop in patients with chronic stroke, with low lymphocyte counts, physical performance, muscle strength, and mobility and balance scores, and it is associated with poor prognostic factors including high disease severity, dysphagia, malnutrition, risk of falling, and poor quality of life.

Assessing Stroke-Related Sarcopenia in Chronic Stroke: Identification of Clinical Assessment Tools-A Pilot Study

Stroke-related sarcopenia has recently been defined as the muscle atrophy consequent to stroke and assessing it following the guidelines with simple clinical tools is crucial in chronic stroke survivors. The aim of this study was to determine the characteristics of patient-friendly instruments sarcopenia in a chronic stroke sample (SG) compared to non-stroke counterparts (CG). Each participant underwent a single assessment which consisted of: SARC-F questionnaire, assessment of muscle strength (hand grip and five-times sit-to-stand test, 5STS), the calf circumference (CC) of both legs, the short physical performance battery (SPPB), and the 10 m walk test. A total of 68 participants were included (SG, n = 34 and CG, n = 34). All variables showed statistical differences (p < 0.05) between the SG and the CG, except handgrip although it showed lower values for SG. The values of the 5STS (16.26 s) and the SPPB (7 points) were below to the cutoff values for the SG. The five-times sit-to-stand test, SPPB, and gait speed can lead clinicians to detect stroke-related sarcopenia. Maximum handgrip shows a trend of low values for men and women in the SG, however, CC did not detect sarcopenia in our sample.

Association of Temporalis Muscle Mass with Early Cognitive Impairment in Older Patients with Acute Ischemic Stroke

The prognostic value of temporal muscle mass has been studied in various neurological disorders. Herein, we investigated the association between temporal muscle mass and early cognitive function in patients with acute ischemic stroke. This study included 126 patients with acute cerebral infarction aged ≥65 years. Temporal muscle thickness (TMT) was measured using T2-weighted brain magnetic resonance imaging at admission for acute stroke. Within 2 weeks of stroke onset, skeletal mass index (SMI) and cognitive function were assessed using bioelectrical impedance analysis and the Korean version of the Montreal Cognitive Assessment (MoCA), respectively. Pearson's correlation analyzed the correlation between TMT and SMI, and multiple linear regression analyzed independent predictors of early post-stroke cognitive function. TMT and SMI were significantly positively correlated (R = 0.36, p < 0.001). After adjusting for covariates, TMT was an independent predictor of early post-stroke cognitive function, stratified by the MoCA score (β = 1.040, p = 0.017), age (β = -0.27, p = 0.006), stroke severity (β = -0.298, p = 0.007), and education level (β = 0.38, p = 0.008). TMT may be used as a surrogate marker for evaluating skeletal muscle mass because it is significantly associated with post-stroke cognitive function during the acute phase of ischemic stroke; therefore, TMT may help detect older patients at a high risk of early post-stroke cognitive impairment.

Effects of Voluntary Wheel Running Exercise on Chemotherapy-Impaired Cognitive and Motor Performance in Mice

Chemotherapy-induced cognitive impairment (chemobrain) and muscle wasting (cachexia) are persisting side effects which adversely affect the quality of life of cancer survivors. We therefore investigated the efficacy of physical exercise as a non-pharmacological intervention to reverse the adverse effects of chemotherapy. We examined whether physical exercise in terms of voluntary wheel running could prevent chemotherapy-induced cognitive and motor impairments in mice treated with the multi-kinase inhibitor sorafenib. Adult male BALB/c mice were subdivided into runner and non-runner groups and orally administered with sorafenib (60 mg/kg) or vehicle continuously for four weeks. Mice could freely access the running wheel anytime during sorafenib or vehicle treatment. We found that sorafenib treatment reduced body weight gain (% of change, vehicle: 3.28 ± 3.29, sorafenib: -9.24 ± 1.52, p = 0.0004), impaired hippocampal-dependent spatial memory in the Y maze (exploration index, vehicle: 35.57 ± 11.38%, sorafenib: -29.62 ± 7.90%, p < 0.0001), increased anhedonia-like behaviour in the sucrose preference test (sucrose preference, vehicle: 66.57 ± 3.52%, sorafenib: 44.54 ± 4.25%, p = 0.0005) and impaired motor skill acquisition in rotarod test (latency to fall on day 1: 37.87 ± 8.05 and day 2: 37.22 ± 12.26 s, p > 0.05) but did not induce muscle wasting or reduce grip strength. Concomitant voluntary running reduced anhedonia-like behaviour (sucrose preference, sedentary: 44.54 ± 4.25%, runners: 59.33 ± 4.02%, p = 0.0357), restored impairment in motor skill acquisition (latency to fall on day 1: 50.85 ± 15.45 and day 2: 168.50 ± 37.08 s, p = 0.0004), but failed to rescue spatial memory deficit. Immunostaining results revealed that sorafenib treatment did not affect the number of proliferating cells and immature neurons in the hippocampal dentate gyrus (DG), whereas running significantly increased cell proliferation in both vehicle- (total Ki-67⁺ cells, sedentary: 16,687.34 ± 72.63, exercise: 3320.03 ± 182.57, p < 0.0001) and sorafenib-treated mice (Ki-67⁺ cells in the ventral DG, sedentary: 688.82.34 ± 38.16, exercise: 979.53 ± 73.88, p < 0.0400). Our results suggest that spatial memory impairment and anhedonia-like behaviour precede the presence of muscle wasting, and these behavioural deficits are independent of the changes in adult hippocampal neurogenesis. Running effectively prevents body weight loss, improves motor skill acquisition and reduces anhedonia-like behaviour associated with increased proliferating cells and immature neurons in DG. Taken together, they support physical exercise rehabilitation as an effective strategy to prevent chemotherapy side effects in terms of mood dysregulation and motor deficit.

A Review of the Measurement of the Neurology of Gait in Cognitive Dysfunction or Dementia, Focusing on the Application of fNIRS during Dual-Task Gait Assessment

Poor motor function or physical performance is a predictor of cognitive decline. Additionally, slow gait speed is associated with poor cognitive performance, with gait disturbances being a risk factor for dementia. Parallel declines in muscular and cognitive performance (resulting in cognitive frailty) might be driven primarily by muscle deterioration, but bidirectional pathways involving muscle–brain crosstalk through the central and peripheral nervous systems are likely to exist. Following screening, early-stage parallel declines may be manageable and modifiable through simple interventions. Gait–brain relationships in dementia and the underlying mechanisms are not fully understood; therefore, the current authors critically reviewed the literature on the gait–brain relationship and the underlying mechanisms and the feasibility/accuracy of assessment tools in order to identify research gaps. The authors suggest that dual-task gait is involved in concurrent cognitive and motor activities, reflecting how the brain allocates resources when gait is challenged by an additional task and that poor performance on dual-task gait is a predictor of dementia onset. Thus, tools or protocols that allow the identification of subtle disease- or disorder-related changes in gait are highly desirable to improve diagnosis. Functional near-infrared spectroscopy (fNIRS) is a non-invasive, cost-effective, safe, simple, portable, and non-motion-sensitive neuroimaging technique, widely used in studies of clinical populations such as people suffering from Alzheimer’s disease, depression, and other chronic neurological disorders. If fNIRS can help researchers to better understand gait disturbance, then fNIRS could form the basis of a cost-effective means of identifying people at risk of cognitive dysfunction and dementia. The major research gap identified in this review relates to the role of the central/peripheral nervous system when performing dual tasks.

Effect of Improvement in Sarcopenia on Functional and Discharge Outcomes in Stroke Rehabilitation Patients

This cross-sectional study investigated the proportion of patients’ recovery from sarcopenia status and the relationship between improvement in sarcopenia (IS) and function and discharge outcome in hospitalized patients with stroke. This study included patients with stroke, aged 65 years or more, with a diagnosis of sarcopenia, who were admitted to a convalescent rehabilitation ward. Sarcopenia was diagnosed according to the Asian Working Group for Sarcopenia 2019 criteria. Patients were divided according to the presence or absence of sarcopenia at discharge: IS group and non-improvement in sarcopenia (NIS) group. Among the 227 participants (mean age: 80.5 years; 125 females), 30% (69/227) of the patients were in the IS group, while 70% (158/227) were in the NIS group. The IS group showed a higher Functional Independence Measure (FIM) than the NIS group (median 112 vs. 101, p = 0.003). The results demonstrated that IS was independently associated with higher FIM (partial regression coefficient, 5.378; 95% confidence interval (CI), 0.709–10.047). The IS group had higher odds of home discharge than the NIS group (odds ratio, 2.560; 95% CI, 0.912–7.170). In conclusion, recovery from sarcopenia may be associated with better function in patients with stroke.