Chronic Pain Syndromes After Ischemic Stroke

Deep brain stimulation and motor cortex stimulation for central post-stroke pain: a systematic review and meta-analysis

INTRODUCTION

Deep brain stimulation (DBS) and motor cortex stimulation (MCS) are invasive interventions in order to treat various neuropathic pain syndromes such as central post-stroke pain (CPSP). While each treatment has varying degree of success, comparative analysis has not yet been performed, and the success rates of these techniques using validated, objective pain scores have not been synthesized.

METHODS

A systematic review and meta-analysis was conducted in accordance with PRISMA guidelines. Three databases were searched, and articles published from January 2000 to October 2024 were included (last search date October 25, 2024). Meta-Analysis was performed using random effects models. We evaluated the performance of DBS or MCS by assessing studies that reported pain relief using visual analogue scale (VAS) or numerical rating scale (NRS) scores.

RESULTS

Of the 478 articles identified, 32 were included in the analysis (330 patients-139 DBS and 191 MCS). The improvement in mean VAS score for patients that underwent DBS post-surgery was 48.6% compared to a score of 53.1% for patients that had MCS. The pooled number of patients who improved after DBS was 0.62 (95% CI, 0.51-0.71, I2 = 16%). The pooled number of patients who improved after MCS was 0.64 (95% CI, 0.53-0.74, I2 = 40%).

CONCLUSION

The use of neurosurgical interventions such as DBS and MCS are last-resort treatments for CPSP, with limited studies exploring and comparing these two techniques. While our study shows that MCS might be a slightly better treatment option, further research would need to be done to determine the appropriate surgical intervention in the treatment of CPSP.

Multi-regional sequential pain syndrome

Objective

To report a novel clinical entity, "Multi-regional Sequential Pain Syndrome" (MRSPS), and evaluate the relationship between hypoperfusion, cryptogenic vertebral artery dissection (CVAD), and MRSPS.

Methods

A 59-year-old female patient, with a chronic MRSPS condition spanning 10-30 years, underwent a comprehensive diagnostic evaluation including cranial CTA, MRI, DSA, and CT perfusion, culminating in the identification of CVAD via dynamic contrast-enhanced computed tomography (DCE-CT). The treatment strategy integrated repairing CVADs with stent implantation to address the hypoperfusion and MRSPS.

Results

Following intervention, hypoperfusion achieved complete improvement, and the patient achieved the complete resolution of pain and vertigo, with the modified Rankin Scale (mRS) score of 0 at the 1-year follow-up, signifying full neurological recovery.

Conclusion

CVADs, a key cause of brain tissue hypoperfusion in MRSPS, can be effectively treated by repair to alleviate the syndrome.

EZH2-mediated suppression of TIMP1 in spinal GABAergic interneurons drives microglial activation via MMP-9-TLR2/4-NLRP3 signaling in neuropathic pain

Effective management of neuropathic pain remains a significant challenge due to the limited understanding of its underlying mechanisms. We found that the FDA-approved enhancer of zeste homolog 2 (EZH2) inhibitor, EPZ6438, can prevent the development of neuropathic pain caused by chronic constriction injury (CCI). Therefore, we utilized EPZ6438 as a probe to investigate the molecular events involved in the early stage of neuropathic pain. RNA-seq analysis reveals that EPZ6438 significantly upregulates Timp1 transcription in the spinal cord of mice. As a specific endogenous inhibitor of MMP-9, tissue inhibitor of metalloproteinase 1 (TIMP1) levels significantly decrease in the cerebrospinal fluid of both neuropathic pain patients and the CCI rat models. Importantly, intrathecal administration of mouse recombinant TIMP1 protein (rmTIMP1) reverses CCI-induced mechanical and thermal hyperalgesia. Mechanistically, substance P released from primary sensory neurons suppresses TIMP1 in spinal GABAergic interneurons by elevating EZH2 expression, which enhances H3K27me3 enrichment at the Timp1 promoter. Blocking spinal NK1R effectively prevents the downregulation of TIMP1 and alleviates CCI-induced hyperalgesia. The imbalance between TIMP1 and MMP-9 leads to NLRP3 activation in spinal microglia and increases IL-1β maturation via TLR2/4 pathway. TIMP1 injection eliminates MMP-9-induced NLRP3 activation and blocks hyperalgesia, suggesting that TIMP1 is a critical gatekeeper in preventing neuroinflammation during neuropathic pain development.

Pain Reduction with Repeated Injections of Botulinum Toxin A in Upper Limb Spasticity: A Longitudinal Analysis from the ULIS-III Study

Pain reduction is a common goal of the treatment of upper limb spasticity with botulinum toxin (BoNT-A). ULIS-III was a large international, observational, longitudinal study (N = 953) conducted in real-life clinical practice over two years. In this secondary post hoc analysis, we examine whether goals for pain reduction were met over repeated injection cycles. We report serial changes in pain severity and explore predictors of pain reduction and injection frequency. Patients were selected if pain reduction was a primary/secondary goal for at least one cycle (n = 438/953). They were assessed at the start and end of each cycle using the goal attainment T-score alongside a self-report of pain severity (range 0-10). Across all cycles, pain-related goals were set for 1189/1838 injections (64.7%) and were achieved in 839 (70.6%). Patients continued to show a significant reduction in pain (p < 0.001) for each injection up to seven cycles, with some cumulative benefit (p < 0.001). Those requiring more frequent injections tended to have higher starting pain scores and a smaller reduction in pain score, but these differences were not significant when other covariates (age, previous injection history, time since onset, severity and distribution of spasticity) were taken into account (p > 0.713). Conclusion: Repeated BoNT-A administration continued to result in a significant reduction in upper limb spasticity-related pain, regardless of patient-related factors.

Neuropathic Symptoms and Frequency of Chronic Pain in an International Online Sample of Individuals with Sub-Acute and Chronic Stroke

Background/Objectives: Chronic pain is common following a stroke and is associated with increased disability. Yet, little is known about the chronic pain experience in the stroke population. This study aimed to identify and explore the features and neuropathic symptoms of chronic pain in individuals with longstanding stroke. Methods: This observational study utilized an online survey that was developed for individuals who have had a stroke (>3 months). Data sought included participant demographics, medical history, and details of the stroke(s). Participants who reported experiencing chronic pain completed the Numerical Rating Scale for Pain, the Neuropathic Pain Symptom Inventory, and body maps to indicate region(s) of pain. Results: A total of 533 individuals with longstanding stroke participated. Chronic pain was reported as being experienced by 60% of participants and was more frequently experienced by individuals who reported being female (p = 0.002). Moderate or severe pain intensity was commonly reported (mean = 5.98, SD = 1.89). Individuals with chronic pain post-stroke reported a range of neuropathic symptoms rather than a common pain experience, with combinations of spontaneous, paroxysmal, and evoked pains in addition to pain associated with paraesthesia/dysaesthesia. Pain involving the upper limb was the most common region (shoulder 39%, hand and forearm 38%), followed by the lower limb (foot 30%, leg 29%). Having multiple strokes was associated with a higher frequency of chronic pain (p = 0.01), as was peripheral vascular disease (p < 0.001) and lipid disorders (p = 0.001). Conclusions: These findings highlight the varied nature of chronic pain experienced by individuals following a stroke, while also detailing stroke and medical history associated with chronic pain. It builds on existing knowledge of chronic pain post-stroke and provides new insight into the neuropathic symptoms experienced. This knowledge has the potential to assist in the development of tailored interventions based on addressing pain symptomatology and health literacy.

Prevalence, Trajectory, and Factors Associated With Patient-Reported Nonmotor Outcomes After Stroke: A Systematic Review and Meta-Analysis

Importance

The evidence on nonmotor outcomes after acute ischemic stroke and intracerebral hemorrhage (ICH) is limited and domain-specific. The prevalence, natural history, and factors associated with nonmotor outcomes across multiple domains are unclear.

Objective

To synthesize the published data and to identify the prevalence, natural history, and factors associated with multidomain nonmotor outcome burden in patients with stroke.

Data Sources

A search of PubMed, MEDLINE, EMBASE, and PsycINFO databases between January 1999 to June 2023 was supplemented by search of bibliographies of the key articles.

Study Selection

The analysis included prospective cohort studies that reported nonmotor outcomes across 10 domains: anxiety, depression, fatigue, sleep disturbance, social participation, pain, bladder dysfunction, bowel dysfunction (constipation and fecal incontinence), and sexual dysfunction assessed by patient-reported scales.

Data Extraction and Synthesis

Two reviewers independently assessed studies, extracting baseline data, nonmotor prevalence, and follow-up information. Pooled prevalence of nonmotor outcomes was estimated using random-effects models. Meta-regression models were used to analyze natural history and factors associated with nonmotor outcomes. Subgroup analysis was used to assess prevalence by symptom description within each nonmotor domain. Publication bias and study quality were assessed using funnel plots and the Newcastle-Ottawa scale.

Results

A total of 279 prospective cohort studies met the inclusion criteria (117 440 participants with stroke; median [IQR] age, 65 [59-70] years; 209 of 279 studies with more male than female participants) with a nonmotor outcome follow-up period ranging from 30 days to 10 years after stroke. The most prevalent adverse nonmotor outcomes by pooled prevalence were sleep disturbance (59.9%; 95% CI, 53.9%-63.9%), sexual dysfunction (59.8%; 95% CI, 50.0%-69.5%), constipation (58.2%; 95% CI, 53.9%-62.6%), reduced social participation (56.5%; 95% CI, 52.1%-60.8%), bladder dysfunction (45.9%; 95% CI, 38.0%-53.8%), and fatigue (45.2%; 95% CI, 40.7%-49.5%). Meta-regression analysis showed no significant improvement over time for most nonmotor outcomes, except pain (coefficient = -11.0%; P = .05) and sexual dysfunction (coefficient = -24.1%; P < .001). The heterogeneity ranged between 52% and 98% across all studies. The common factors associated with adverse nonmotor outcomes were female sex, studies with mixed stroke cohort (ischemic stroke or ICH), and older age.

Conclusions and Relevance

Patient-reported nonmotor outcomes were common after stroke. Sexual dysfunction, sleep disturbance, constipation, reduced social participation, bladder dysfunction, and fatigue were most prevalent. These adverse outcomes often persisted over time, especially in women, older adults, and those in studies with mixed stroke cohorts.

Predicting pain and its association with mortality in patients with stroke

BACKGROUND AND OBJECTIVES

Poststroke pain (PSP) is a prevalent and severe consequence of stroke, encompassing central, neuropathic, and nonneuropathic pain. In this study, we aimed to investigate clinical factors associated with PSP three months after stroke and concurrently explore the association between PSP and one-year mortality.

METHODS

This registry-based study comprised data from stroke patients admitted to three hospitals in Sweden between November 2014 and June 2019. The outcome was PSP three months after stroke. Twelve (out of 28) predictor variables were selected by three machine learning methods, and a multivariable binary logistic regression model was fitted for predicting PSP. The association between PSP and one-year poststroke mortality was examined using Cox proportional hazards models.

RESULTS

Among 4,160 stroke patients participating in the three-month follow-up, 54.7% reported PSP. Antiplatelet use, diabetes, hemiparesis, sensory deficits, and need for assistance before stroke were significant predictors of PSP. Male sex, being born in Sweden, higher income, and regular prestroke physical activity predicted the absence of PSP. After adjustment for age, sex, region of birth, and stroke severity, patients experiencing PSP had a significantly higher one-year mortality rate than those without pain, and the most severe level of pain (constant pain) was associated with the highest cumulative mortality.

CONCLUSION

The study findings indicate treatable factors associated with PSP, which highlight areas of improvement in management strategies. Clinicians should recognize that PSP is associated with increased one-year mortality, emphasizing the importance of pain prevention and treatment for enhanced poststroke outcomes.

Acupuncture and its role in the treatment of ischemic stroke: A review

Acupuncture is a traditional Chinese medicine therapy that is treatment by placing a needle or pressure in a specific position on the patient's skin. Although used in the treatment of various diseases, acupuncture is effective in the treatment of ischemic stroke (IS), and has made some progress in the mechanism of action of the treatment of this disease. IS is difficult to treat, and there is a high rate of disability. Drug therapy is usually the first line of treatment, but adjuvant therapy has outstanding efficacy in promoting the rehabilitation of the disease and preventing sequelae. Among them, acupuncture is getting more and more attention as a more popular treatment method. Therefore, this study excavates the high-quality randomized controlled trials and meta-analysis of acupuncture for IS in recent years to further summarize the efficacy of acupuncture for IS. In this review, we provide an overview of the current understanding of acupuncture and IS, and the current studies investigating the effectiveness of acupuncture in the treatment of IS.

Usefulness of Mirogabalin in Central Neuropathic Pain After Stroke: Post Hoc Analysis of a Phase 3 Study by Stroke Type and Location

INTRODUCTION

Central post-stroke pain (CPSP) is a common type of central neuropathic pain (CNeP) that can occur following the onset of stroke. The oral gabapentinoid mirogabalin besylate (mirogabalin) is a selective α2δ ligand that is effective for the treatment of CNeP, including CPSP. However, it is unknown whether the analgesic effect of mirogabalin on CPSP varies in patients with different background factors.

METHODS

This was a post hoc subgroup analysis of a multinational, open-label, long-term phase 3 study of mirogabalin for the treatment of CNeP conducted between March 2019 and December 2020. Data from patients with CPSP were stratified by type of stroke (ischemic or hemorrhagic), stroke location (thalamus, putamen, brainstem, or other), presence/absence of motor weakness, median time since stroke (≥ 59 or < 59 months), and median duration of CPSP (≥ 55.5 or < 55.5 months). Efficacy was assessed with the short-form McGill Pain Questionnaire (SF-MPQ), and treatment-emergent adverse events (TEAEs) and adverse drug reactions (ADRs) were recorded.

RESULTS

This subanalysis included all 94 patients with CPSP from the phase 3 study; all were Japanese, and the mean age was 65.3 years. The least squares mean change [95% confidence interval] in SF-MPQ visual analog scale (VAS) score from baseline at week 52 (last observation carried forward) was - 17.0 [- 22.1, - 11.9] mm. Among the subgroups, least squares mean changes in SF-MPQ VAS scores were not different. Most TEAEs were mild or moderate; severe TEAEs occurred in six patients (6.4%). Somnolence (25.5%), peripheral edema (13.8%), dizziness (11.7%), and weight gain (6.4%) were the most common ADRs, and the types and frequencies of ADRs were similar among subgroups.

CONCLUSION

Mirogabalin was generally effective and well tolerated in patients with CPSP, regardless of background factors such as stroke type or location, presence/absence of motor weakness, time since stroke, and duration of CPSP.

TRIAL REGISTRATION

Trial registration number NCT03901352.

Advancements in Modern Treatment Approaches for Central Post-Stroke Pain: A Narrative Review

PURPOSE OF REVIEW

Central post-stroke pain (CPSP) poses a multifaceted challenge in medical practice, necessitating a thorough and multidisciplinary approach for its diagnosis and treatment. This review examines current methods for addressing CPSP, highlighting both pharmacological and non-pharmacological therapies. It covers the mechanisms and clinical effectiveness of these treatments in managing CPSP and emphasizes the importance of personalized treatment plans, given the varied causes of CPSP.

RECENT FINDINGS

Recent advancements have illuminated diverse treatment modalities for CPSP. Pharmacotherapy spans from conventional analgesics to anticonvulsants and antidepressants, tailored to mitigate the neuropathic characteristics of CPSP. Non-pharmacological interventions, including physical therapy and psychological strategies, are pivotal in managing CPSP's chronic nature. For cases resistant to standard treatments, advanced interventions such as nerve blocks and surgical procedures like deep brain stimulation (DBS) or motor cortex stimulation (MCS) are considered. Additionally, innovative technologies such as neuromodulation techniques and personalized medicine are emerging as promising avenues to enhance therapeutic outcomes and improve quality of life for individuals grappling with CPSP.

SUMMARY

Modern approaches in managing CPSP require an interdisciplinary and patient-centric approach. Customizing treatment plans to address the specific etiology and symptoms of CPSP is crucial. Pharmacotherapy remains fundamental, encompassing medications such as anticonvulsants and antidepressants tailored to manage neuropathic pain. Integrating non-pharmacological interventions is crucial for providing comprehensive care. Additionally, investigating innovative technologies and personalized medicine presents promising opportunities to enhance treatment results and elevate the quality of life for those suffering from CPSP. Ultimately, an integrated approach that acknowledges the multifaceted nature of CPSP is essential for effective management and patient well-being.

Contributions of neuroimaging in central poststroke pain: a review

BACKGROUND

 Central neuropathic poststroke pain (CNPSP) affects up to 12% of patients with stroke in general and up to 18% of patients with sensory deficits. This pain syndrome is often incapacitating and refractory to treatment. Brain computed tomography and magnetic resonance imaging (MRI) are widely used methods in the evaluation of CNPSP.

OBJECTIVE

 The present study aims to review the role of neuroimaging methods in CNPSP.

METHODS

 We performed a literature review of the main clinical aspects of CNPSP and the contribution of neuroimaging methods to study its pathophysiology, commonly damaged brain sites, and possible differential diagnoses. Lastly, we briefly mention how neuroimaging can contribute to the non-pharmacological CNPSP treatment. Additionally, we used a series of MRI from our institution to illustrate this review.

RESULTS

 Imaging has been used to explain CNPSP pathogenesis based on spinothalamic pathway damage and connectome dysfunction. Imaging locations associated with CNPSP include the brainstem (mainly the dorsolateral medulla), thalamus (especially the ventral posterolateral/ventral posteromedial nuclei), cortical areas such as the posterior insula and the parietal operculum, and, more recently, the thalamocortical white matter in the posterior limb of the internal capsule. Imaging also brings the prospect of helping search for new targets for non-pharmacological treatments for CNPSP. Other neuropathic pain causes identified by imaging include syringomyelia, multiple sclerosis, and herniated intervertebral disc.

CONCLUSION

 Imaging is a valuable tool in the complimentary evaluation of CNPSP patients in clinical and research scenarios.

Role of Brain Derived Neurotrophic Factor and Related Therapeutic Strategies in Central Post-Stroke Pain

Brain-derived neurotrophic factor (BDNF) is vital for synaptic plasticity, cell persistence, and neuronal development in peripheral and central nervous systems (CNS). Numerous intracellular signalling pathways involving BDNF are well recognized to affect neurogenesis, synaptic function, cell viability, and cognitive function, which in turn affects pathological and physiological aspects of neurons. Stroke has a significant psycho-socioeconomic impact globally. Central post-stroke pain (CPSP), also known as a type of chronic neuropathic pain, is caused by injury to the CNS following a stroke, specifically damage to the somatosensory system. BDNF regulates a broad range of functions directly or via its biologically active isoforms, regulating multiple signalling pathways through interactions with different types of receptors. BDNF has been shown to play a major role in facilitating neuroplasticity during post-stroke recovery and a pro-nociceptive role in pain development in the nervous system. BDNF-tyrosine kinase receptors B (TrkB) pathway promotes neurite outgrowth, neurogenesis, and the prevention of apoptosis, which helps in stroke recovery. Meanwhile, BDNF overexpression plays a role in CPSP via the activation of purinergic receptors P2X4R and P2X7R. The neuronal hyperexcitability that causes CPSP is linked with BDNF-TrkB interactions, changes in ion channels and inflammatory reactions. This review provides an overview of BDNF synthesis, interactions with certain receptors, and potential functions in regulating signalling pathways associated with stroke and CPSP. The pathophysiological mechanisms underlying CPSP, the role of BDNF in CPSP, and the challenges and current treatment strategies targeting BDNF are also discussed.

Is there a relationship between somatosensory impairment and the perception of pain in stroke survivors? An exploratory study

Pain and somatosensory impairments are commonly reported following stroke. This study investigated the relationship between somatosensory impairments (touch detection, touch discrimination and proprioceptive discrimination) and the reported presence and perception of any bodily pain in stroke survivors. Stroke survivors with somatosensory impairment ( N  = 45) completed the Weinstein Enhanced Sensory Test (WEST), Tactile Discrimination Test, and Wrist Position Sense Test for quantification of somatosensation in both hands and the McGill Pain Questionnaire, visual analog scale and the Neuropathic Pain Symptom Inventory (NPSI) for reporting presence and perception of pain. No relationship was observed between somatosensory impairment (affected contralesional hand) of touch detection, discriminative touch or proprioceptive discrimination with the presence or perception of pain. However, a weak to moderate negative relationship between touch detection in the affected hand (WEST) and perception of pain intensity (NPSI) was found, suggesting that stroke survivors with milder somatosensory impairment of touch detection, rather than severe loss, are likely to experience higher pain intensity [rho = -0.35; 95% confidence interval (CI), -0.60 to -0.03; P  = 0.03]. Further, a moderate, negative relationship was found specifically with evoked pain (NPSI) and touch detection in the affected hand (rho = -0.43; 95% CI, -0.72 to -0.02; P  = 0.03). In summary, our findings indicate a weak to moderate, albeit still uncertain, association, which prevents making a definitive conclusion. Nevertheless, our findings contribute to our understanding of the complexities surrounding the experience of pain in survivors of stroke and provide direction for future studies.

Time From Hospital Arrival Until Endovascular Thrombectomy and Patient-Reported Outcomes in Acute Ischemic Stroke

Importance

The time-benefit association of endovascular thrombectomy (EVT) in ischemic stroke with patient-reported outcomes is unknown.

Objective

To assess the time-dependent association of EVT with self-reported quality of life in patients with acute ischemic stroke.

Design, Setting, and Participants

Data were used from the Safety and Efficacy of Nerinetide in Subjects Undergoing Endovascular Thrombectomy for Stroke (ESCAPE-NA1) trial, which tested the effect of nerinetide on functional outcomes in patients with large vessel occlusion undergoing EVT and enrolled patients from March 1, 2017, to August 12, 2019. The ESCAPE-NA1 trial was an international randomized clinical trial that recruited patients from 7 countries. Patients with EuroQol 5-dimension 5-level (EQ-5D-5L) index values at 90 days and survivors with complete domain scores were included in the current study. Data were analyzed from July to September 2023.

Exposure

Hospital arrival to arterial puncture time and other time metrics.

Main Outcomes and Measures

EQ-5D-5L index scores were calculated at 90 days using country-specific value sets. The association between time from hospital arrival to EVT arterial-access (door-to-puncture) and EQ-5D-5L index score, quality-adjusted life years, and visual analog scale (EQ-VAS) were evaluated using quantile regression, adjusting for age, sex, stroke severity, stroke imaging, wake-up stroke, alteplase, and nerinetide treatment and accounting for clustering by site. Using logistic regression, the association between door-to-puncture time and reporting no or slight symptoms (compared with moderate, severe, or extreme problems) was determined in each domain (mobility, self-care, usual activities, pain or discomfort, and anxiety or depression) or across all domains. Time from stroke onset was also evaluated, and missing data were imputed in sensitivity analyses.

Results

Among 1105 patients in the ESCAPE-NA1 trial, there were 1043 patients with EQ-5D-5L index values at 90 days, among whom 147 had died and were given a score of 0, and 1039 patients (mean [SD] age, 69.0 [13.7] years; 527 male [50.7%]) in the final analysis as 4 did not receive EVT. There were 896 survivors with complete domain scores at 90 days. There was a strong association between door-to-puncture time and EQ-5D-5L index score (increase of 0.03; 95% CI, 0.02-0.04 per 15 minutes of earlier treatment), quality-adjusted life years (increase of 0.29; 95% CI, 0.08-0.49 per 15 minutes of earlier treatment), and EQ-VAS (increase of 1.65; 95% CI, 0.56-2.72 per 15 minutes of earlier treatment). Each 15 minutes of faster door-to-puncture time was associated with higher probability of no or slight problems in each of 5 domains and all domains concurrently (range from 1.86%; 95% CI, 1.14-2.58 for pain or discomfort to 3.55%; 95% CI, 2.06-5.04 for all domains concurrently). Door-to-puncture time less than 60 minutes was associated higher odds of no or slight problems in each domain, ranging from odds ratios of 1.49 (95% CI, 1.13-1.95) for pain or discomfort to 2.59 (95% CI, 1.83-3.68) for mobility, with numbers needed to treat ranging from 7 to 17. Results were similar after multiple imputation of missing data and attenuated when evaluating time from stroke onset.

Conclusions and Relevance

Results suggest that faster door-to-puncture EVT time was strongly associated with better health-related quality of life across all domains. These results support the beneficial impact of door-to-treatment speed on patient-reported outcomes and should encourage efforts to improve patient-centered care in acute stroke by optimizing in-hospital processes and workflows.

Effect of ultrasound-guided injection of botulinum toxin type A into shoulder joint cavity on shoulder pain in poststroke patients: study protocol for a randomized controlled trial

BACKGROUND

Hemiplegic shoulder pain (HSP) is a common complication after stroke. It severely affects the recovery of upper limb motor function. Early shoulder pain in hemiplegic patients is mainly neuropathic caused by central nerve injury or neuroplasticity. Commonly used corticosteroid injections in the shoulder joint can reduce shoulder pain; however, the side effects also include soft tissue degeneration or increased tendon fragility, and the long-term effects remain controversial. Botulinum toxin injections are relatively new and are thought to block the transmission of pain receptors in the shoulder joint cavity and inhibit the production of neuropathogenic substances to reduce neurogenic inflammation. Some studies suggest that the shoulder pain of hemiplegia after stroke is caused by changes in the central system related to shoulder joint pain, and persistent pain may induce the reorganization of the cortical sensory center or motor center. However, there is no conclusive evidence as to whether or not the amelioration of pain by botulinum toxin affects brain function. In previous studies of botulinum toxin versus glucocorticoids (triamcinolone acetonide injection) in the treatment of shoulder pain, there is a lack of observation of differences in changes in brain function. As the content of previous assessments of pain improvement was predominantly subjective, objective quantitative assessment indicators were lacking. Functional near-infrared imaging (fNIRS) can remedy this problem.

METHODS

This study protocol is designed for a double-blind, randomized controlled clinical trial of patients with post-stroke HSP without biceps longus tenosynovitis or acromion bursitis. Seventy-eight patients will be randomly assigned to either the botulinum toxin type A or glucocorticoid group. At baseline, patients in each group will receive shoulder cavity injections of either botulinum toxin or glucocorticoids and will be followed for 1 and 4 weeks. The primary outcome is change in shoulder pain on the visual analog scale (VAS). The secondary outcome is the assessment of changes in oxyhemoglobin levels in the corresponding brain regions by fNIRS imaging, shoulder flexion, external rotation range of motion, upper extremity Fugl-Meyer, and modified Ashworth score.

DISCUSSION

Ultrasound-guided botulinum toxin type A shoulder joint cavity injections may provide evidence of pain improvement in patients with HSP. The results of this trial are also help to analyze the correlation between changes in shoulder pain and changes in cerebral hemodynamics and shoulder joint motor function.

TRIAL REGISTRATION

Chinese clinical Trial Registry, ChiCTR2300070132. Registered 03 April 2023, https://www.chictr.org.cn/showproj.html?proj=193722 .

Innovations in Stroke Recovery and Rehabilitation: Poststroke Pain

Pain can be a significant barrier to a stroke survivors' functional recovery and can also lead to a decreased quality of life. Common pain conditions after stroke include headache, musculoskeletal pain, spasticity-related pain, complex regional pain syndrome, and central poststroke pain. This review investigates the evidence of diagnostic and management guidelines for various pain syndromes after stroke and identifies opportunities for future research to advance the field of poststroke pain.

Post stroke pain: Is there under-diagnosis in Black versus White patients?

Stroke incidence is higher and stroke outcomes are poorer in Black patients compared to White patients. Poststroke pain, however, is not a well understood stroke outcome. Using the National Institutes of Health All of Us Research Program database, we hypothesized that the dataset would demonstrate proportionately higher relative risk of poststroke pain in the Black poststroke patient population compared to the White poststroke patient population. However, our analysis showed that Black stroke patients were diagnosed with poststroke pain at a similar rate as White stroke patients. As our results are not consistent with other poststroke outcomes in the literature, this study identifies a potentially underdiagnosed patient population, highlighting the need for further research.

Prevalence, patterns, and predictors of patient-reported non-motor outcomes at 30 days after acute stroke: Prospective observational hospital cohort study

BACKGROUND

Adverse non-motor outcomes are common after acute stroke and likely to substantially affect quality of life, yet few studies have comprehensively assessed their prevalence, patterns, and predictors across multiple health domains.

AIMS

We aimed to identify the prevalence, patterns, and the factors associated with non-motor outcomes 30 days after stroke.

METHODS

This prospective observational hospital cohort study-Stroke Investigation in North and Central London (SIGNAL)-identified patients with acute ischemic stroke or intracerebral hemorrhage (ICH) admitted to the Hyperacute Stroke Unit (HASU) at University College Hospital (UCH), London, between August 1, 2018 and August 31, 2019. We assessed non-motor outcomes (anxiety, depression, fatigue, sleep, participation in social roles and activities, pain, bowel function, and bladder function) at 30-day follow-up using the Patient-Reported Outcome Measurement Information System-Version 29 (PROMIS-29) scale and Barthel Index scale.

RESULTS

We obtained follow-up data for 605/719 (84.1%) eligible patients (mean age 72.0 years; 48.3% female; 521 with ischemic stroke, 84 with ICH). Anxiety (57.0%), fatigue (52.7%), bladder dysfunction (50.2%), reduced social participation (49.2%), and pain (47.9%) were the commonest adverse non-motor outcomes. The rates of adverse non-motor outcomes in ⩾ 1, ⩾ 2 and ⩾ 3 domains were 89%, 66.3%, and 45.8%, respectively; in adjusted analyses, stroke due to ICH (compared to ischemic stroke) and admission stroke severity were the strongest and most consistent predictors. There were significant correlations between bowel dysfunction and bladder dysfunction (κ = 0.908); reduced social participation and bladder dysfunction (κ = 0.844); and anxiety and fatigue (κ = 0.613). We did not identify correlations for other pairs of non-motor domains.

CONCLUSION

Adverse non-motor outcomes were very common at 30 days after stroke, affecting nearly 90% of evaluated patients in at least one health domain, about two-thirds in two or more domains, and almost 50% in three or more domains. Stroke due to ICH and admission stroke severity were the strongest and most consistent predictors. Adverse outcomes occurred in pairs of domains, such as with anxiety and fatigue. Our findings emphasize the importance of a multi-domain approach to effectively identify adverse non-motor outcomes after stroke to inform the development of more holistic patient care pathways after stroke.

Hemiplegic shoulder pain affects ipsilesional aiming movements after stroke: a cross-sectional study

BACKGROUND

Hemiplegic shoulder pain (HSP) is common after stroke. The pain perception may exacerbate changes in the motor behavior of the ipsi-lesional upper limb, contributing to the functional decline of an individual's motor performance.

OBJECTIVE

This study evaluates the influence of pain perception on the aiming movements performed with the ipsilesional upper limb in individuals with unilateral chronic stroke.

METHODS

A cross-sectional study was conducted with 41 participants divided into three groups: 1) stroke with contralesional shoulder pain ≥ 3 by the Visual Numerical Pain Scale (SPSG; n = 13); 2) stroke no shoulder pain (nSPSG; n = 14); and 3) healthy control (CTG; n = 14) matched by sex and age. Individuals with stroke were matched for the severity of sensorimotor impairment by the Fugl-Meyer upper limb subscale and the injured hemisphere side. Stroke groups performed aiming movements with the ipsilesional upper limb and the CTG with the corresponding limb using a pen tip on the sensitive surface of a digitizing tablet. Performance across groups was compared by one-way analysis of variance, considering the time since injury as a covariate. The planning and execution variables of the movement trajectory were analyzed, and the significance was set at 5%.

RESULTS

Trajectories of the SPSG were slower (p = .010; η2 = 0.22), were less smooth (p = .002; η2 = 0.30), had more directional error (p = .002; η2 = 0.28), and were less accurate (p = .034; η2 = 0.17) than the CTG. The nSPSG and CTG showed similar performance.

CONCLUSIONS

The perception of pain impairs aiming movements performed with the ipsilesional upper limb in individuals with unilateral chronic stroke.

The trajectory of pain and pain intensity in the upper extremity after stroke over time: a prospective study in a rehabilitation population

PURPOSE

To assess the presence of upper extremity pain after stroke over time and the course of its intensity in patients with persistent pain.

MATERIALS AND METHODS

Patients with stroke completed a question on the presence of upper extremity pain (yes/no) and rated its intensity with a visual analogue scale (0-10) at 3, 18, and 30 months after starting multidisciplinary rehabilitation. The presence of upper extremity pain and its intensity over time were analysed with Generalized Estimating Equations models and Linear Mixed Models, respectively.

RESULTS

678 patients were included. The proportions of patients reporting upper extremity pain were 41.8, 36.0, and 32.7% at 3, 18, and 30 months, respectively, with the decline in proportions reaching statistical significance (odds ratio 0.82, 95% confidence interval 0.74-0.92, p < 0.001). At all time points, in those reporting pain the median intensity was 5.0 (interquartile ranges (IQR) 4.0-7.0 at 3 and 3.0-6.0 at 18 and 30 months). In the 73 patients with persistent pain, there was no significant change in intensity over time.

CONCLUSIONS

The proportion of patients reporting upper extremity pain after stroke was considerable, despite a significant decrease in 2.5 years. In patients reporting persistent pain, the intensity did not change over time.IMPLICATIONS FOR REHABILITATIONAbout one-third of patients with stroke reported upper extremity pain at 30 months after starting rehabilitation.In patients with stroke who reported persistent upper extremity pain, there was no significant change in pain intensity over time.There is room for improvement of diagnosis and treatment of upper extremity pain in patients with stroke.

Central neuropathic pain

Central neuropathic pain arises from a lesion or disease of the central somatosensory nervous system such as brain injury, spinal cord injury, stroke, multiple sclerosis or related neuroinflammatory conditions. The incidence of central neuropathic pain differs based on its underlying cause. Individuals with spinal cord injury are at the highest risk; however, central post-stroke pain is the most prevalent form of central neuropathic pain worldwide. The mechanisms that underlie central neuropathic pain are not fully understood, but the pathophysiology likely involves intricate interactions and maladaptive plasticity within spinal circuits and brain circuits associated with nociception and antinociception coupled with neuronal hyperexcitability. Modulation of neuronal activity, neuron-glia and neuro-immune interactions and targeting pain-related alterations in brain connectivity, represent potential therapeutic approaches. Current evidence-based pharmacological treatments include antidepressants and gabapentinoids as first-line options. Non-pharmacological pain management options include self-management strategies, exercise and neuromodulation. A comprehensive pain history and clinical examination form the foundation of central neuropathic pain classification, identification of potential risk factors and stratification of patients for clinical trials. Advanced neurophysiological and neuroimaging techniques hold promise to improve the understanding of mechanisms that underlie central neuropathic pain and as predictive biomarkers of treatment outcome.

Prevalence, Trajectory, and Predictors of Poststroke Pain: Retrospective Analysis of Pooled Clinical Trial Data Set

BACKGROUND

Poststroke pain remains underdiagnosed and inadequately managed. To inform the optimum time to initiate interventions, we examined prevalence, trajectory, and participant factors associated with poststroke pain.

METHODS

Eligible studies from the VISTA (Virtual International Stroke Trials Archives) included an assessment of pain. Analyses of individual participant data examined demography, pain, mobility, independence, language, anxiety/depression, and vitality. Pain assessments were standardized to the European Quality of Life Scale (European Quality of Life 5 Dimensions 3 Level) pain domain, describing no, moderate, or extreme pain. We described pain prevalence, associations between participant characteristics, and pain using multivariable models.

RESULTS

From 94 studies (n>48 000 individual participant data) in VISTA, 10 (n=10 002 individual participant data) included a pain assessment. Median age was 70.0 years (interquartile range [59.0-77.1]), 5560 (55.6%) were male, baseline stroke severity was National Institutes of Health Stroke Scale score 10 (interquartile range [7-15]). Reports of extreme pain ranged between 3% and 9.5% and were highest beyond 2 years poststroke (31/328 [9.5%]); pain trajectory varied by study. Poorer independence was significantly associated with presence of moderate or extreme pain (5 weeks-3 months odds ratio [OR], 1.5 [95% CI, 1.4-1.6]; 4-6 months OR, 1.7 [95% CI, 1.3-2.1]; >6 months OR, 1.5 [95% CI, 1.2-2.0]), and increased severity of pain (5 weeks-3 months: OR, 1.2 [95% CI, 1.1-1.2]; 4-6 months OR, 1.1 [95% CI, 1.1-1.2]; >6 months, OR, 1.2 [95% CI, 1.1-1.2]), after adjusting for covariates. Anxiety/depression and lower vitality were each associated with pain severity.

CONCLUSIONS

Between 3% and 9.5% of participants reported extreme poststroke pain; the presence and severity of pain were independently associated with dependence at each time point. Future studies could determine whether and when interventions may reduce the prevalence and severity of poststroke pain.

Sex differences in pain expressed by patients across diverse disease states: individual patient data meta-analysis of 33,957 participants in 10 randomized controlled trials

ABSTRACT

The experience of pain is determined by many factors and has a significant impact on quality of life. This study aimed to determine sex differences in pain prevalence and intensity reported by participants with diverse disease states in several large international clinical trials. Individual participant data meta-analysis was conducted using EuroQol-5 Dimension (EQ-5D) questionnaire pain data from randomised controlled trials published between January 2000 and January 2020 and undertaken by investigators at the George Institute for Global Health. Proportional odds logistic regression models, comparing pain scores between females and males and fitted with adjustments for age and randomized treatment, were pooled in a random-effects meta-analysis. In 10 trials involving 33,957 participants (38% females) with EQ-5D pain score data, the mean age ranged between 50 and 74. Pain was reported more frequently by females than males (47% vs 37%; P < 0.001). Females also reported greater levels of pain than males (adjusted odds ratio 1.41, 95% CI 1.24-1.61; P < 0.001). In stratified analyses, there were differences in pain by disease group ( P for heterogeneity <0.001), but not by age group or region of recruitment. Females were more likely to report pain, and at a higher level, compared with males across diverse diseases, all ages, and geographical regions. This study reinforces the importance of reporting sex-disaggregated analysis to identify similarities and differences between females and males that reflect variable biology and may affect disease profiles and have implications for management.

Neurotechnology for Pain

Neurotechnologies for treating pain rely on electrical stimulation of the central or peripheral nervous system to disrupt or block pain signaling and have been commercialized to treat a variety of pain conditions. While their adoption is accelerating, neurotechnologies are still frequently viewed as a last resort, after many other treatment options have been explored. We review the pain conditions commonly treated with electrical stimulation, as well as the specific neurotechnologies used for treating those conditions. We identify barriers to adoption, including a limited understanding of mechanisms of action, inconsistent efficacy across patients, and challenges related to selectivity of stimulation and off-target side effects. We describe design improvements that have recently been implemented, as well as some cutting-edge technologies that may address the limitations of existing neurotechnologies. Addressing these challenges will accelerate adoption and change neurotechnologies from last-line to first-line treatments for people living with chronic pain.

The Feasibility and Benefits of a Virtual Yoga Practice for Stroke Survivors With Aphasia

PURPOSE

The purpose of this study was to (a) examine the feasibility of a virtual, adapted, aphasia-friendly yoga program for people with aphasia; (b) evaluate evidence of improvement in patient-reported outcomes and word retrieval; (c) explore the immediate impact of a yoga session on participant subjective emotional state; and (d) assess participant motivation and perceived benefits of participating in a yoga program.

METHOD

This feasibility study employed a mixed-method design to document the feasibility of a virtual, 8-week adapted yoga program. A pre-/posttreatment design was used to assess patient-reported outcome measures for resilience, stress, sleep, and pain, as well as word-finding abilities. Semistructured interviews with participants were thematically analyzed to provide insight into participants' motivation and perceptions regarding their experience.

RESULTS

Comparisons of pre- and postprogram group means suggest that participation in an 8-week adapted yoga program may positively impact perceptions of resilience (large effect), stress (medium effect), sleep disturbance (medium effect), and pain (small effect) for people with aphasia. Findings from within-session reports and brief, semistructured interviews with participants indicated positive outcomes and subjective experiences and suggest that people with aphasia are motivated to participate in yoga for a variety of reasons.

CONCLUSIONS

This study is an important first step in confirming the feasibility of an adapted, aphasia-friendly yoga program offered via a remote platform for people with aphasia. The findings support recent work suggesting that yoga may be a potent adjunct to traditional rehabilitation efforts to improve resilience and psychosocial aspects in persons with aphasia.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.22688125.

Acupuncture for thalamic pain after stroke: A systematic review and meta-analysis

OBJECTIVE

To evaluate the efficacy and safety of acupuncture on thalamic pain after stroke.

METHODS

The self-established database was searched from 8 Chinese and English databases to June 2022, and the randomized controlled trials articles on the comparative treatment of thalamic pain after stroke with acupuncture were included. That visual analog scale, present pain intensity score, pain rating index, the total efficiency, and adverse reactions were mainly used to evaluate the outcomes.

RESULTS

A total of 11 papers were included. Meta-analysis showed that acupuncture appeared to be more effective than drugs for treatment of thalamic pain, as assessed by the visual analog scale [mean difference (MD) = -1.06, 95% confidence interval (CI) (-1.20, -0.91), P < .00001], the present pain intensity score [MD = -0.27, 95% CI (-0.43, -0.11), P = .001], the pain rating index [MD = -1.02, 95% CI (-1.41, -0.63), P < .00001], and the total efficiency [risk ratio = 1.31, 95% CI (1.22,1.41), P < .00001]. Meta-analysis results show that there is no significant difference in safety between acupuncture and drug therapy [risk ratio = 0.50, 95% CI (0.30,0.84), P = .009].

CONCLUSION

Studies have shown that acupuncture in the treatment of thalamic pain is effective, and it does not prove to have a higher safety than drug treatment, therefore a large-scale multicenter randomized controlled trials study is needed to further prove.

Heart Disease and Stroke Statistics-2023 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2023 Statistical Update is the product of a full year's worth of effort in 2022 by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. The American Heart Association strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional COVID-19 (coronavirus disease 2019) publications, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Bibliometric Analysis of Post-Stroke Pain Research Published from 2012 to 2021

Background and Purpose

Pain is one of the most common symptoms in patients after stroke. It is a distressing experience that affects patients' quality of life, and it is highly prevalent in clinical practice. The pathogenesis mechanisms of PSP are not so clear, and there is currently a lack of effective medical treatments, hence it is necessary to establish a sufficient understanding of this disease. Limited number of studies have applied bibliometric methods to systematically analyze studies on post-stroke pain. This study aimed to systematically analyze scientific studies conducted worldwide on post-stroke pain from 2012 to 2021 to evaluate global trends in this field using a bibliometric analysis.

Methods

Publications related to post-stroke pain from 2012 to 2021 were obtained from the Web of Science Core Collection database. Bibliometrics Biblioshiny R-package software was used to analyze the relationship of publication year with country, institution, journals, authors, and keywords and to generate variant visual maps to show annual publications, most relevant countries, authors, sources, keywords, and top-cited articles.

Results

In this study, 5484 papers met the inclusion criteria. The annual growth rate of publications was 5.13%. The USA had the highest number of publications (1381, 25.2%) and citations (36,395), and the University of Toronto had the highest number of papers (156, 2.8%). "Stroke", "management", "pain", "risk", "prevalence", "ischemic stroke", "risk factors", "disease", "diagnosis" and "therapy" are the top 10 keywords.

Conclusion

The global research interest regarding PSP has maintained growing over the past ten years. Both central post stroke pain and hemiplegic shoulder pain are the hottest research subjects. Further investigations are needed in order to reveal the mystery of the pathophysiologic mechanisms of CPSP, and high-quality well-designed trials of potential treatments of CPSP and HSP are also needed.

Efficacy and safety of different antidepressants and anticonvulsants in central poststroke pain: A network meta-analysis and systematic review

OBJECTIVE

To evaluate the efficacy and safety of different antidepressants and anticonvulsants in the treatment of central poststroke pain (CPSP) by network meta-analysis and provide an evidence-based foundation for clinical practice.

METHODS

PubMed, Cochrane Library, EMBASE, CNKI, APA PsycINFO, Wanfang, VIP and other databases were searched by computer to find clinical randomized controlled studies (RCTs) on drug treatment of CPSP. The retrieval time limit was from the establishment of each database to July 2022. The quality of the included RCTs was evaluated using the bias risk assessment tool recommended by Cochrane. Stata 14.0 was used for network meta-analysis.

RESULTS

A total of 13 RCTs, 1040 patients and 9 drugs were finally included. The results of the network meta-analysis showed that the effectiveness ranking as rated by the visual analog scale (VAS) was gabapentin > pregabalin > fluoxetine > lamotrigine > duloxetine > serqulin > amitriptyline > carbamazepine > vitamin B. Ranking according to the numerical rating scale (NRS) was pregabalin > gabapentin > carbamazepine. Ranking derived from the Hamilton depression scale (HAMD) was pregabalin > duloxetine > gabapentin > amitriptyline.

CONCLUSION

All nine drugs can relieve the pain of CPSP patients to different degrees; among them pregabalin and gabapentin have the most significant effect, and gabapentin and pregabalin also have the most adverse reactions. In the future, more multicenter, large sample, double-blind clinical randomized controlled trials need to be carried out to supplement and demonstrate the results of this study.

Pharmacotherapies for Central Post-Stroke Pain: A Systematic Review and Network Meta-Analysis

Background

Central post-stroke pain (CPSP) is a common condition. Several pharmacotherapies have been applied in practice. However, the comparative effectiveness among these pharmacotherapies is unknown.

Aim

The aim of this study is to study the comparative effectiveness among differential pharmacotherapies for CPSP through a network meta-analysis.

Methods

We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science from inception to 30 March 2022, without any language restriction. Two reviewers independently screened the retrieved articles, extracted data, and evaluated the risk of bias (RoB). The outcome of interest of the study was the change in the scores of pain intensity scales. We estimated standard mean differences (SMDs) between treatments and calculated corresponding 95% CIs.

Results

Thirteen randomized controlled trials (529 participants) were included after a screen of 1774 articles. Compared with placebo, pamidronate (SMD -2.43, 95% CI -3.54 to -1.31; P − score = 0.93), prednisone (SMD -2.38, 95% CI -3.09 to -1.67; P − score = 0.92), levetiracetam (SMD -2.11, 95% CI -2.97 to -1.26; P − score = 0.87), lamotrigine (SMD -1.39, 95% CI -2.21 to -0.58; P − score = 0.73), etanercept (SMD -0.92, 95% CI -1.8 to -0.03; P − score = 0.59), and pregabalin (SMD -0.46, 95% CI -0.71 to -0.22; P − score = 0.41) had significantly better treatment effect. Pamidronate, prednisone, and levetiracetam ranked as the first three most effective treatments. In subgroup analyses, prednisone, levetiracetam, lamotrigine, and pregabalin were more effective than placebo as oral pharmacotherapies, while etanercept was more effective than placebo as injectable pharmacotherapy.

Conclusions

Our study confirmed that pamidronate, prednisone, and guideline-recommended anticonvulsants were effective for reducing pain intensity for CPSP. Pamidronate and prednisone showed better effect than other pharmacotherapies, which warrants further investigation.

Central Neuropathic Pain Syndromes: Current and Emerging Pharmacological Strategies

Central neuropathic pain is caused by a disease or lesion of the brain or spinal cord. It is difficult to predict which patients will develop central pain syndromes after a central nervous system injury, but depending on the etiology, lifetime prevalence may be greater than 50%. The resulting pain is often highly distressing and difficult to treat, with no specific treatment guidelines currently available. This narrative review discusses mechanisms contributing to central neuropathic pain, and focuses on pharmacological approaches for managing common central neuropathic pain conditions such as central post-stroke pain, spinal cord injury-related pain, and multiple sclerosis-related neuropathic pain. Tricyclic antidepressants, serotonin-norepinephrine reuptake inhibitors, and gabapentinoids have some evidence for efficacy in central neuropathic pain. Medications from other pharmacologic classes may also provide pain relief, but current evidence is limited. Certain non-pharmacologic approaches, neuromodulation in particular, may be helpful in refractory cases. Emerging data suggest that modulating the primary afferent input may open new horizons for the treatment of central neuropathic pain. For most patients, effective treatment will likely require a multimodal therapy approach.

Dissecting neuropathic from poststroke pain: the white matter within

ABSTRACT

Poststroke pain (PSP) is a heterogeneous term encompassing both central neuropathic (ie, central poststroke pain [CPSP]) and nonneuropathic poststroke pain (CNNP) syndromes. Central poststroke pain is classically related to damage in the lateral brainstem, posterior thalamus, and parietoinsular areas, whereas the role of white matter connecting these structures is frequently ignored. In addition, the relationship between stroke topography and CNNP is not completely understood. In this study, we address these issues comparing stroke location in a CPSP group of 35 patients with 2 control groups: 27 patients with CNNP and 27 patients with stroke without pain. Brain MRI images were analyzed by 2 complementary approaches: an exploratory analysis using voxel-wise lesion symptom mapping, to detect significant voxels damaged in CPSP across the whole brain, and a hypothesis-driven, region of interest-based analysis, to replicate previously reported sites involved in CPSP. Odds ratio maps were also calculated to demonstrate the risk for CPSP in each damaged voxel. Our exploratory analysis showed that, besides known thalamic and parietoinsular areas, significant voxels carrying a high risk for CPSP were located in the white matter encompassing thalamoinsular connections (one-tailed threshold Z > 3.96, corrected P value <0.05, odds ratio = 39.7). These results show that the interruption of thalamocortical white matter connections is an important component of CPSP, which is in contrast with findings from nonneuropathic PSP and from strokes without pain. These data can aid in the selection of patients at risk to develop CPSP who could be candidates to pre-emptive or therapeutic interventions.

Sex Differences in the Long-Term Consequences of Stroke

Stroke is the fifth leading cause of death and as healthcare intervention improves, the number of stroke survivors has also increased. Furthermore, there exists a subgroup of younger adults, who suffer stroke and survive. Given the overall improved survival rate, bettering our understanding of long-term stroke outcomes is critical. In this review we will explore the causes and challenges of known long-term consequences of stroke and if present, their corresponding sex differences in both old and young survivors. We have separated these long-term post-stroke consequences into three categories: mobility and muscle weakness, memory and cognitive deficits, and mental health and mood. Lastly, we discuss the potential of common preclinical stroke models to contribute to our understanding of long-term outcomes following stroke.

Heart Disease and Stroke Statistics-2022 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2022 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population and an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, and the global burden of cardiovascular disease and healthy life expectancy.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

ROBOCOP (ROBOtic Care of Poststroke Pain): Study Protocol for a Randomized Trial to Assess Robot-Assisted Functional and Motor Recovery and Impact on Poststroke Pain Development

Background

Stroke is one of the most frequent causes of death and disability worldwide. It is accompanied by the impaired motor function of the upper extremities in over 69% of patients up to hemiplegia in the following 5 years in 56% of cases. This condition often is characterized by chronic poststroke pain, difficult to manage, further worsening quality of life. Poststroke pain occurs within 3–6 months. Robot-assisted neurorehabilitation using the Automatic Recovery Arm Motility Integrated System (ARAMIS) has proven efficacy in motor function recovery exploiting the movements and the strength of the unaffected arm. The rationale of the ROBOCOP (ROBOtic Care of Poststroke pain) randomized trial is the assessment of the impact of robot-assisted functional and motor recovery on the prevention of poststroke pain.

Methods

A total of 118 patients with hemiplegic arms due to stroke will be enrolled and randomly allocated with a 1:1 ratio to ARAMIS or conventional neurorehabilitation group. After a baseline screening at hospital discharge, ARAMIS or conventional rehabilitation will be performed for 8 weeks. The primary endpoint is the prevention of the development of poststroke pain and the secondary endpoints are prevention of spasticity and efficacy in clinical motor rehabilitation. The primary outcome measures consist in the visual analog scale and the doleur neuropatique 4 and the secondary outcome measures include: the Modified Ashworth Scale, the Resistance to Passive movement Scale; the Upper Extremity Subscale of the Fugl–Meyer Motor Assessment; the Action Research Arm Test; the Barthel Index for activities of daily living; and the magnetic resonance imaging (MRI) recovery-related parameters. After baseline, both primary and secondary outcome measures will be performed in the following time points: 1 month after stroke (t₁, half of the rehabilitation); 2 months after stroke (t₂, after rehabilitation); and 3 months (t₃) and 6 months (t₄) after stroke, critical for poststroke pain development.

Discussion

This is the first clinical trial investigating the efficacy of robot-assisted neurorehabilitation using ARAMIS on poststroke pain prevention. This study could remarkably improve the quality of life of stroke survivors.

Upper extremity motor abilities and cognitive capability mediate the causal dependency between somatosensory capability and daily function in stroke individuals

Stroke individuals’ daily function has been demonstrated to be influenced by their somatosensory capability, cognitive capability, and upper extremity (UE) motor abilities. However, the structural relationships among these abilities on stroke individuals’ independence in daily function remain unclear. We analyzed the pretest measures of 153 stroke individuals in outpatient rehabilitation settings by structural equation modeling to determine the structural relationship among somatosensory capability, UE muscle strength, UE motor function, and cognitive capability that influences independence in daily function. The standardized results indicated somatosensory capability negatively influenced UE muscle strength, but positively influenced UE muscle strength mediated by UE motor function. UE muscle strength, then, positively influenced individuals’ independence in daily function. On the other hand, somatosensory capability positively influenced cognitive capability, which marginally and positively affected the performance of independence in daily function. To the best of our knowledge, this is the first study to demonstrate the influence of somatosensory capability on the daily function is mediated mainly by motor functions and marginally by cognitive capability. This structural model may allow future clinical therapists to design more effective task-related training protocols to promote the independence in daily function for stroke individuals.

Association of chronic pain with comorbidities and health care utilization: a retrospective cohort study using health administrative data

ABSTRACT

Health administrative data provide a potentially robust information source regarding the substantial burden chronic pain exerts on individuals and the health care system. This study aimed to use health administrative data to estimate comorbidity prevalence and annual health care utilization associated with chronic pain in Newfoundland and Labrador, Canada. Applying the validated Chronic Pain Algorithm to provincial Fee-for-Service Physician Claims File data (1999-2009) established the Chronic Pain (n = 184,580) and No Chronic Pain (n = 320,113) comparator groups. Applying the Canadian Chronic Disease Surveillance System coding algorithms to Claims File and Provincial Discharge Abstract Data (1999-2009) determined the prevalence of 16 comorbidities. The 2009/2010 risk and person-year rate of physician and diagnostic imaging visits and hospital admissions were calculated and adjusted using the robust Poisson model with log link function (risks) and negative binomial model (rates). Results indicated a significantly higher prevalence of all comorbidities and up to 4 times the odds of multimorbidity in the Chronic Pain Group (P-value < 0.001). Chronic Pain Group members accounted for 58.8% of all physician visits, 57.6% of all diagnostic imaging visits, and 54.2% of all hospital admissions in 2009/2010, but only 12% to 16% of these were for pain-related conditions as per recorded diagnostic codes. The Chronic Pain Group had significantly higher rates of physician visits and high-cost hospital admission/diagnostic imaging visits (P-value < 0.001) when adjusted for demographics and comorbidities. Observations made using this methodology supported that people identified as having chronic pain have higher prevalence of comorbidities and use significantly more publicly funded health services.

Dorsal root ganglion stimulation for treatment of central poststroke pain in the lower extremity after medullary infarction

ABSTRACT

We report a case of relief in central poststroke pain of the lower extremity by stimulation of the dorsal root ganglion (DRG). Central poststroke pain is a poorly understood and even more poorly managed condition that can greatly impact the quality of life. To the best of our knowledge, this investigation is the first to describe the successful treatment of previously intractable chronic pain caused by stroke using DRG stimulation. Noting the anatomical structures and the physiological function, the efficacy of DRG stimulation in central poststroke pain could be explained in a neurophysiological manner. This clinical observation successfully builds on the existing understanding around the pathophysiology of central pain and offers the possibility of nondrug therapy for the treatment of this often refractory chronic pain syndrome.

Impairment in Health-Related Quality of Life among Community-Dwelling Stroke Survivors

INTRODUCTION

Health utility instruments are increasingly being used to measure impairment in health-related quality of life (HRQoL) after stroke. Population-based studies of HRQoL after stroke and assessment of differences by age and functional domain are needed.

METHODS

We used the Canadian Community Health Survey linked with administrative databases to determine HRQoL using the Health Utilities Index Mark 3 (HUI3) among those with prior hospitalization or emergency department visit for stroke and compared to controls without stroke. We used multivariable linear regression to determine the difference in HUI3 between those with stroke and controls for the global index and individual attributes, with assessment for modification by age (<60, 60-74, and 75+ years) and sex, and we combined estimates across survey years using random effects meta-analysis.

RESULTS

Our cohort contained 1240 stroke survivors and 123,765 controls and was weighted to be representative of the Canadian household population. Mean health utility was 0.63 (95% confidence interval [CI] 0.58, 0.68) for those with stroke and 0.83 (95% CI 0.82, 0.84) for controls. There was significant modification by age, but not sex, with the greatest adjusted reduction in HUI3 among stroke respondents aged 60-74 years. Individual HUI3 attributes with the largest reductions in utility among stroke survivors compared to controls were mobility, cognition, emotion, and pain.

CONCLUSIONS

In this population-based study, the reduction in HUI3 among stroke survivors compared to controls was greatest among respondents aged 60-74, and in attributes of mobility, cognition, emotion, and pain. These results highlight the persistent impairment of HRQoL in the chronic phase of stroke and potential targets for community support.

Influence of mobility restrictions on post-stroke pain

OBJECTIVES

The objective of this study was to investigate the role of mobility limitations and vitality, as well as additional factors such as comorbidities, to predict post-stroke pain.

MATERIALS & METHODS

This study included cross-sectional data from 214 participants living in varied settings in different parts of Sweden. Participants were asked to complete the Stroke Impact Scale, Medical Outcomes Study Short Form 36, and Self-administered Comorbidity Questionnaire to evaluate mobility, vitality, comorbidities, and pain. Descriptive statistics were used for demographic and clinical characteristics. Binary logistic regression analysis was performed to predict the pain domain score on Medical Outcomes Study Short Form 36.

RESULTS

The mean age of all participants in the sample was 66 years (SD 14); 43.4% of the study population were women. After analyses, "standing without losing balance and vitality'' were found to be significant predictors in the model which explained the pain score on Medical Outcomes Study Short Form 36.

CONCLUSIONS

In conclusion, the results suggest that restrictions in mobility and low vitality have an important role on the occurrence of post-stroke pain. Having post-stroke pain could be due to not able to stand without losing balance and low vitality. Thus, rehabilitation professionals may consider the importance of these factors, especially mobility restrictions, in preventing post-stroke pain.

Age-Related Disparities in the Quality of Stroke Care and Outcomes in Rehabilitation Hospitals: The Australian National Audit

INTRODUCTION

Stroke affects all ages. Despite increased incidence in those <65 years, little is known about age-based differences in inpatient rehabilitation management and outcomes.

OBJECTIVES

To investigate management and outcomes, comparing younger (<65 years) and older (≥65 years) patients with stroke, who received inpatient rehabilitation.

METHODS

Multicentre, cross-sectional study using data from Australian hospitals who participated in the Stroke Foundation national stroke rehabilitation audit (2016-2018). Chi-square tests compared characteristics and care by age. Multivariable regression models were used to compare outcomes by age (e.g. length of stay). Models were adjusted for sex, stroke type and severity factors.

RESULTS

7,165 audited cases from 127 hospitals; 23% <65 years (66% male; 72% ischaemic stroke). When compared to older patients, younger patients were more likely male (66% vs 52%); identify as Aboriginal or Torres Strait Islander (6% vs 1%); be less disabled on admission; receive psychology (46% vs 34%) input, and community reintegration support, including return to work (OR 1.47, 95% CI 1.03, 2.11), sexuality (OR 1.60, 95% CI 1.39, 1.84) and self-management (OR 1.39, 95% CI 1.23, 1.57) advice. Following adjustment, younger patients had longer lengths of stay (coeff 3.54, 95% CI 2.27, 4.81); were more likely to be independent on discharge (aOR 1.96, 95% CI 1.68, 2.28); be discharged to previous residences (aOR 1.64, 95% CI 1.41, 1.91) and receive community rehabilitation (aOR: 2.27, 95% CI 1.91, 2.70).

CONCLUSIONS

Age-related differences exist in characteristics, management and outcomes for inpatients with stroke accessing rehabilitation in Australia.

Health-Related Quality of Life and Psychological Features in Post-Stroke Patients with Chronic Pain: A Cross-Sectional Study in the Neuro-Rehabilitation Context of Care

This study aims at exploring disability, health-related quality of life (HrQoL), psychological distress, and psychological features in post-stroke patients with chronic pain. An observational cross-sectional study involving 50 post-stroke patients (25 with chronic pain and 25 without pain) was conducted. The primary outcome was the self-reported level of disability and HrQoL which were both assessed through the Stroke Impact Scale 3.0. Both psychological distress and specific psychological features (i.e., self-efficacy, coping strategies, psychological flexibility, perceived social support) were examined. Post-stroke patients with chronic pain reported statistically significant higher levels of disability and worse HrQoL, higher psychological distress and inflexibility, as well as a lower level of self-efficacy and problem-oriented coping strategies than patients without pain (p < 0.001). Finally, correlation analysis in the group of stroke survivors with pain showed that higher levels of disability were significantly related to higher psychological distress. This study confirms the negative influence of chronic pain on disability and HrQoL in post-stroke patients and presents preliminary insights on the association between chronic pain, disability, HrQoL, psychosocial distress, and the patient’s approach in dealing with personal difficulties and emotions. These findings carry further implications for multidisciplinary management of post-stroke patients with chronic pain.

Health-Related Quality of Life Among Patients With Acute Ischemic Stroke and Large Vessel Occlusion in the ESCAPE Trial

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Heart Disease and Stroke Statistics-2021 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2021 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors related to cardiovascular disease.

RESULTS

Each of the 27 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Functional pain disorders - more than nociplastic pain

BACKGROUND

Nociplastic pain has been recently introduced as a third mechanistic descriptor of pain arising primarily from alterations of neural processing, in contrast to pain due to tissue damage leading to nociceptor activation (nociceptive) or due to lesion or disease of the somatosensory nervous system (neuropathic). It is characterized by hyperalgesia and allodynia, inconsistency and reversibility, as well as dynamic cross-system interactions with biological and psychobehavioral factors. Along with this renewed understanding, functional pain disorders, also classified as chronic primary pain, are being reframed as biopsychosocial conditions that benefit from multimodal treatment.

OBJECTIVE

To summarize the current understanding of nociplastic pain and functional pain disorders, with a focus on conditions that are common in neurology practice.

METHODS

This was a narrative literature review.

RESULTS

Chronic back pain, fibromyalgia syndrome and complex regional pain syndrome are best understood within a biopsychosocial framework of pain perception that considers structural factors (predispositions and sequelae) and psychobehavioral mechanisms. Although pain is often the primary complaint, it should not be the only focus of treatment, as accompanying symptoms such as sleep or mood problems can significantly impact quality of life and offer useful leverage points for multimodal treatment. Analgesic pharmacotherapy is rarely helpful on its own, and should always be imbedded in a multidisciplinary setting.

Poststroke Pain

Pain is common but often underrecognized after stroke. Poststroke pain (PSP) hinders recovery, impairs quality of life, and is associated with the psychological state of patients with stroke. The most common subtypes of PSP include central PSP, complex regional pain syndrome, shoulder pain, spasticity-related pain, and headache. The pathophysiologies of these PSP subtypes are not yet clearly understood, and PSP is refractory to conventional treatment in many patients. However, recent studies have proposed potential pathophysiologies of PSP subtypes, which may help prioritize therapies that target specific mechanisms.

Pharmacotherapy to Manage Central Post-Stroke Pain

Central post-stroke pain is a chronic neuropathic pain syndrome following a cerebrovascular accident. The development of central post-stroke pain is estimated to occur in 8 to 55% of stroke patients and is described as constant or intermittent neuropathic pain accompanied by dysesthesia of temperature and/or pressure sensations. These pain and sensory deficits are within the area of the body corresponding to the stroke lesion. The onset of pain is usually gradual, though it can develop either immediately after stroke or years after. Given the diversity in its clinical presentation, central post-stroke pain is a challenging diagnosis of exclusion. Furthermore, central post-stroke pain is often resistant to pharmacological treatment options and a clear therapeutic algorithm has not been established. Based on current evidence, amitriptyline, lamotrigine, and gabapentinoids should be used as first-line pharmacotherapy options when central post-stroke pain is suspected. Other drugs, such as fluvoxamine, steroids, and Intravenous infusions of lidocaine, ketamine, or even propofol, can be considered in intractable cases. In addition, interventional therapies such as motor cortex stimulation or transcranial magnetic stimulation have been shown to provide relief in difficult-to-treat patients.

The prevalence and management of central post-stroke pain at a hospital in Zimbabwe

Background

Central post-stroke pain (CPSP) is a poorly diagnosed chronic pain. It is under-treated and usually mismanaged.

Objective

To establish the prevalence of CPSP and its management in stroke clinics at a tertiary hospital.

Methods

This was a cross-sectional design with stroke patients and health professionals from the stroke clinic at the tertiary hospital in Zimbabwe.

Results

Out of 166 stroke survivors, 8% had CPSP. Younger age (<60 years) was significantly associated with CPSP (P<0.003). Pain characteristics of CPSP were hyperaesthesia (10, 71%), electric shocks (9, 64%), temperature allodynia (9, 64%) and allodynia (12, 86%). Ten health professionals participated in the study: one (10%) reported using Douleur Neuropathique 4 (to diagnose neuropathic pain) and two (20%) reported using sensory tests. Four patients (44%) were on paracetamol (acetaminophen) and on weak opiates such as codeine. None of the patients were on anticonvulsants or antidepressants. Two medical doctors (50%) used weak opiates as second-line management. Five patients (36%) reported receiving a combination of massage, stretching, general exercise and moist heat or cryotherapy.

Conclusion

The prevalence of CPSP in the study group is within international range. There is a need for appropriate management and use of tests and outcome measures for diagnosis of CPSP.

Opioids in Post-stroke Pain: A Systematic Review and Meta-Analysis

Background: Post-stroke pain is one of the most common sequelae of stroke, which stands among the leading causes of death and adult-acquired disability worldwide. The role and clinical efficacy of opioids in post-stroke pain syndromes is still debated.

Objectives: Due to the important gap in knowledge on the management of post-stroke pain, this systematic review aimed at assessing the efficacy of opioids in post-stroke pain syndromes.

Methods: A literature search was conducted on databases relevant for medical scientific literature, i.e. PubMed/MEDLINE, Scopus, Web of Science and Cochrane Library databases from databases inception until August 31^st, 2020 for clinical trials assessing the effects of opioids and opioid antagonists on pain reduction and pain related symptoms in patients with post-stroke pain syndromes. Studies assessing the effects of other medications (e.g., tricyclic antidepressant, pregabalin) or non - pharmacological management strategies (e.g., neurostimulation techniques) were excluded. The selected studies have been subjected to examination of the risk of bias.

Results: The literature search retrieved 83,435 results. After duplicates removal, 34,285 articles were title and abstract screened. 25 full texts were assessed and 8 articles were identified to be eligible for inclusion in the qualitative summary and narrative analysis, of which three were placebo-controlled and two were dose-response. Among placebo-controlled studies, two evaluated the analgesic effect of morphine and one assessed the effects of the opioid antagonist naloxone on patients with central post-stroke pain. With regard to dose-response studies, both were on patients with central post-stroke pain, one assessing the efficacy of levorphanol, and the other on naloxone. Seven out of eight included studies showed an overall slight analgesic effect of opioids, with less consistent effects on other pain-related symptoms (e.g., mood, quality of life). The randomized controlled trials were subjected to meta-analysis and rating of the quality of evidence for the two outcomes considered according to GRADE (Grading of Recommendations, Assessment, Development and Evaluations) system. The overall results are inconclusive because of the small number of studies and of patients.

Conclusions: The limited number of the included studies and their heterogeneity in terms of study design do not support the efficacy of opioids in post-stroke pain and in pain-related outcomes. Large double-blind randomized clinical trials with objective assessment of pain and related symptoms are needed to further investigate this topic.

Functional Connectivity Analysis on Resting-State Electroencephalography Signals Following Chiropractic Spinal Manipulation in Stroke Patients

Stroke impairments often present as cognitive and motor deficits, leading to a decline in quality of life. Recovery strategy and mechanisms, such as neuroplasticity, are important factors, as these can help improve the effectiveness of rehabilitation. The present study investigated chiropractic spinal manipulation (SM) and its effects on resting-state functional connectivity in 24 subacute to chronic stroke patients monitored by electroencephalography (EEG). Functional connectivity of both linear and non-linear coupling was estimated by coherence and phase lag index (PLI), respectively. Non-parametric cluster-based permutation tests were used to assess the statistical significance of the changes in functional connectivity following SM. Results showed a significant increase in functional connectivity from the PLI metric in the alpha band within the default mode network (DMN). The functional connectivity between the posterior cingulate cortex and parahippocampal regions increased following SM, t (23) = 10.45, p = 0.005. No significant changes occurred following the sham control procedure. These findings suggest that SM may alter functional connectivity in the brain of stroke patients and highlights the potential of EEG for monitoring neuroplastic changes following SM. Furthermore, the altered connectivity was observed between areas which may be affected by factors such as decreased pain perception, episodic memory, navigation, and space representation in the brain. However, these factors were not directly monitored in this study. Therefore, further research is needed to elucidate the underlying mechanisms and clinical significance of the observed changes.