Cross-Species Convergence of Functional Connectivity Changes in Thalamic Pain Across Human Patients and Model Macaques

Thalamic pain can be understood as a network reorganization disorder. This study aimed to investigate functional connectivity (FC) in human patients and a macaque model of thalamic pain. In humans, resting-state FC was compared between patients with thalamic pain and healthy individuals. Furthermore, resting-state FC was compared in macaques, before and after the induction of thalamic pain in the same individuals. FC between the amygdala of the unaffected hemisphere and the brainstem was significantly higher in patients with thalamic pain. More specifically, a significantly higher FC was observed between the basolateral amygdala and the ventral tegmental area, which also significantly predicted the value of a visual analog scale of pain intensity in individual patients. The macaque model of thalamic pain also exhibited a significantly higher FC between the amygdala of the unaffected hemisphere and the brainstem, particularly between the basolateral amygdala and the midbrain. Furthermore, the previously reported significantly higher FC between the amygdala and the mediodorsal nucleus of the thalamus in macaques with thalamic pain was also reproduced in the human patients. Therefore, the present results suggest that the FC changes in the regions associated with emotion, memory, motivation, and reward are part of the underlying mechanisms of thalamic pain onset present in both human patients and model macaques. This cross-species convergence provides new insights into the neurological mechanisms underlying thalamic pain, paving the way for further studies and the development of therapeutic strategies. PERSPECTIVE: This article presents that the FC changes in the regions associated with emotion, motivation, and reward are part of the underlying mechanisms of thalamic pain in humans and macaques.

Efficacy and safety of pregabalin vs carbamazepine in patients with central post-stroke pain

OBJECTIVE

To compare the efficacy and safety of pregabalin and carbamazepine in patients with central post-stroke pain (CPSP).

METHODS

Patients included in the study were randomly assigned to either flexible-dose pregabalin treatment group or carbamazepine treatment group. The primary efficacy variable was face visual analog scale (F-VAS), the second efficacy assessment was used to assess the effect of treatment on mental health by Hamilton anxiety scale (HAMA) and Hamilton depression scale (HAMD).

RESULTS

The mean baseline pain score F-VAS was 6.47 in the pregabalin group and 6.58 in carbamazepine treatment group. F-VAS was significantly lower in the pregabalin group (1.64) than (3.94) carbamazepine treatment group after treatment. Pregabalin was significantly superior to carbamazepine in endpoint assessments on the HAMA and HAMD after treatment. F-VAS and HAMD were showed efficacy as early as week 2 and maintained for whole duration of the study. The average pregabalin dose in the 12-week study was 214.6 (150-375) mg/day. The mean dose (range) of carbamazepine received by the patients was 275.0 (200-400) mg/day. Mild or moderate, typically transient, somnolence and dizziness were the most common adverse events (AES). The differences of the side effects between the two groups were not significant.

CONCLUSIONS

Pregabalin, but not carbamazepine, may be effective in improving F-VAS, HAMA and HAMD in patients with CPSP.

Changes in the Brain Metabolism Associated with Central Post-Stroke Pain in Hemorrhagic Pontine Stroke: An 18F-FDG-PET Study of the Brain

Central post-stroke pain (CPSP) is an intractable neuropathic pain that can occur following central nervous system injuries. Spino-thalamo-cortical pathway damage contributes to CPSP development. However, brain regions involved in CPSP are unknown and previous studies were limited to supratentorial strokes with cortical lesion involvement. We analyzed the brain metabolism changes associated with CPSP following pontine hemorrhage. Thirty-two patients with isolated pontine hemorrhage were examined; 14 had CPSP, while 18 did not. Brain glucose metabolism was evaluated using 18F-fluorodeoxyglucose-positron emission tomography images. Additionally, regions revealing metabolic correlation with CPSP severity were analyzed. Patients with CPSP showed changes in the brain metabolism in the cerebral cortices and cerebellum. Compared with the control group, the CPSP group showed significant hypometabolism in the contralesional rostral anterior cingulum and ipsilesional primary motor cortex (Puncorrected < 0.001). However, increased brain metabolism was observed in the ipsilesional cerebellum (VI) and contralesional cerebellum (lobule VIIB) (Puncorrected < 0.001). Moreover, increased pain intensity correlated with decreased metabolism in the ipsilesional supplementary motor area and contralesional angular gyrus. This study emphasizes the role of the many different areas of the cortex that are involved in affective and cognitive processing in the development of CPSP.

Central Post-Stroke Pain: An Integrative Review of Somatotopic Damage, Clinical Symptoms, and Neurophysiological Measures

Introduction: The physiopathology of central post-stroke pain (CPSP) is poorly understood, which may contribute to the limitations of diagnostic and therapeutic advancements. Thus, the current systematic review was conducted to examine, from an integrated perspective, the cortical neurophysiological changes observed via transcranial magnetic stimulation (TMS), focusing on the structural damage, and clinical symptoms in patients with CPSP. Methods: The literature review included the databases EMBASE, PubMed, and ScienceDirect using the following search terms by MeSH or Entree descriptors: [("Cerebral Stroke") AND ("Pain" OR "Transcranial Magnetic Stimulation") AND ("Transcranial Magnetic Stimulation")] (through September 29, 2020). A total of 297 articles related to CPSP were identified. Of these, only four quantitatively recorded cortical measurements. Results: We found four studies with different methodologies and results of the TMS measures. According to the National Institutes of Health (NIH) guidelines, two studies had low methodological quality and the other two studies had satisfactory methodological quality. The four studies compared the motor threshold (MT) of the stroke-affected hemisphere with the unaffected hemisphere or with healthy controls. Two studies assessed other cortical excitability measures, such as cortical silent period (CSP), short-interval intracortical inhibition (SICI), and intracortical facilitation (ICF). The main limitations in the interpretation of the results were the heterogeneity in parameter measurements, unknown cortical excitability measures as potential prognostic markers, the lack of a control group without pain, and the absence of consistent and validated diagnosis criteria. Conclusion: Despite the limited number of studies that prevented us from conducting a meta-analysis, the dataset of this systematic review provides evidence to improve the understanding of CPSP physiopathology. Additionally, these studies support the construction of a framework for diagnosis and will help improve the methodological quality of future research in somatosensory sequelae following stroke. Furthermore, they offer a way to integrate dysfunctional neuroplasticity markers that are indirectly assessed by neurophysiological measures with their correlated clinical symptoms.

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.

Optimization of Early Mobilization Program for Patients With Acute Ischemic Stroke: An Orthogonal Design

Background and purpose: Early mobilization is considered to have favorable outcomes for stroke patients, but there is currently a lack of specific data to guide this early mobilization, including the initiation time, intensity, frequency, and duration of each activity. Therefore, the optimal strategy for early mobilization is unclear. In this study, we investigated the best combination of different factors to achieve early mobilization, to develop the optimal program.

Methods: We conducted an L₉ (3³) orthogonal experiment with a blinded follow-up assessment. Patients with ischemic stroke, admitted to a stroke unit within 24–72 h of its onset, were recruited. Eligible subjects were randomly assigned to one of nine different programs of early mobilization. The outcomes were assessed at baseline, discharge, and 1 and 3 months after discharge to observe the changes in various efficacy indicators and determine the main factors affecting outcome.

Results: We analyzed 57 of 63 patients, after six were excluded for poor compliance, failure to cooperate with the study, or worsening of the disease. The initiation time, intensity, and frequency of mobilization were the main factors affecting outcome (all P < 0.05), and the duration of each activity was a secondary factor (P > 0.05). A comprehensive analysis of the various parameters showed that the optimal level of the early mobilization program was an initiation time: 24–48 h after stroke; intensity: bed and chair transfer, sitting out of bed, standing and walking or climbing stairs when mobility permitted; frequency: 2–3 times/day; duration of each mobilization: determined according to the actual situation of the patient.

Conclusions: Early rehabilitation with high-intensity physical exercise at 24–48 h after the onset of stroke, 2–3 times/day, may benefit stroke patients. Applying the optimized program of early mobilization to stroke patients effectively alleviated their symptoms of neurological deficit, improved their capacity for self-care, restored their self-efficacy, improved their quality of life and social participation, and reduced post-stroke fatigue at 3 months.

Living the Full Catastrophe: A Mindfulness-Based Program to Support Recovery from Stroke

Decades of research suggest that Mindfulness-Based Stress Reduction (MBSR) training supports a greater capacity to live with chronic medical conditions and contributes to lowering stress levels. This paper introduces a model for a Mindfulness-Based Recovery from Stroke (MBRfS) for promoting stroke recovery, informed by the lived experience of the author (a stroke survivor and certified MBSR instructor), the research literature regarding MBSR training, and the specific challenges of stroke recovery. Four themes emerged from the autoethnographic analysis that informed the proposed model: Readiness to accept the stroke event and the acquired brain injury, navigating uncertainties of stroke recovery with awareness and self-responsibility for outcomes, trusting the inherent wisdom of the body as a stroke recovery "teacher", and increased capacity to integrate complex emotions with self-compassion, and a sense of wholeness. A four-component MBRfS model is offered, which consists of an integration amongst a modified MBSR framework, emergent attitudinal themes, and insights from the autoethnographic vignettes. The MBRfS model offers a path for providing participants with a supportive experience within stroke recovery. Recommendations and suggestions for future studies are offered to support the development of MBRfS for stroke survivors and their caregivers, as well as contributing to healthcare providers.

Dry needling for the management of spasticity, pain, and range of movement in adults after stroke: A systematic review

OBJECTIVE

To summarise the available evidence about the effectiveness of deep dry needling (DN) on spasticity, pain-related outcomes, and range-of-movement (ROM) in adults after stroke.

DESIGN

A computer search of Web of Science, Scopus, Medline, Cochrane Library, Cinahl, and Physiotherapy Evidence Database (PEDro) was conducted. A hand search of the reference lists of the selected studies and other relevant publications was also undertaken. Studies were assessed by two independent reviewers and included if they complied with the following criteria: (1) participants were adults after a stroke, (2) use of DN alone or within a multimodal approach, compared to no intervention or other treatments; (3) assessment of spasticity, pain, or joint ROM as a primary or secondary outcome. We included randomised controlled trials (RCTs), case series, and case reports. Data were extracted using a standardised protocol. The methodological quality of the studies was assessed with the Checklist for Measuring quality.

RESULTS

A total of sixteen studies, 7 of which were RCTs, were selected. All studies generally reported an improvement of spasticity level, pain intensity, and ROM after the use of DN, alone or combined with other interventions, in stroke survivors.

CONCLUSION

The management of adults after stroke with DN may impact positively on spasticity, pain, and ROM. However, there was significant heterogeneity across trials in terms of sample size, control groups, treated muscles, and outcome measures, and a meta-analysis was not feasible. Further research should include proper blinding, sham placebo DN as control intervention, and investigate long-term effects.

Involvement of descending pain control system regulated by orexin receptor signaling in the induction of central post-stroke pain in mice

Central post-stroke pain (CPSP) is a type of neuropathic pain for which the mechanism and relevant drug pathways remain unknown. Recently, it was reported that intracerebroventricular (ICV) administration of orexin-A suppresses pain and ischemia. In this study, we tested the role of orexin-A in CPSP induction in mice. Male ddY mice were subjected to 30 min of bilateral carotid artery occlusion (BCAO). CPSP was assessed by von Frey test. Colocalization of orexin 1 receptor (OX1R) with various neuron markers were determined by double-immunofluorescence. The hindpaw withdrawal responses to mechanical stimuli were significantly increased 3 days post-BCAO compared with those of sham groups. ICV injection of orexin-A dose-dependently suppressed BCAO-induced mechanical allodynia. These effects were inhibited by pre-treatment with SB334867 (an OX1R antagonist; ICV injection), yohimbine (a noradrenaline α₂ receptor antagonist; intrathecal (IT) injection), and WAY100635 (a serotonin 5-HT_1A receptor antagonist; IT injection), but not TCS OX2 29 (an OX2R antagonist; ICV injection). OX1R colocalized with TH (a noradrenergic neuron marker) and TPH (a serotonergic neuron marker) in the locus ceruleus (LC) and the rostral ventromedial medulla (RVM), respectively. The number of c-Fos positive cells in the LC and the RVM of BCAO mice was increased at 90 min after ICV injection of orexin-A compared to saline group. These results indicate that orexin-A/OX1R signaling plays an important role through activation of the descending pain control system in the induction of CPSP in mice.

Predictive Factors Associated with Pain Relief of Spinal Cord Stimulation for Central Post-stroke Pain

The efficacy and predictive factors associated with successful spinal cord stimulation (SCS) for central post-stroke pain (CPSP) have yet to be definitively established. Thus, this study evaluated the rates of pain relief found after more than 12 months and the predictive factors associated with the success of SCS for CPSP. The degree of pain after SCS in 18 patients with CPSP was assessed using the Visual Analog Scale preoperatively, at 1, 6 and 12 months after surgery, and at the time of the last follow-up. After calculating the percentage of pain relief (PPR), patients were separated into two groups. The first group exhibited continuing PPR ≥30% at more than 12 months (effect group) while the second group exhibited successful/unsuccessful trials followed by decreasing PPR <30% within 12 months (no effect group). Pain relief for more than 12 months was achieved in eight out of 18 (44.4%) patients during the 67.3 ± 35.5 month follow-up period. Statistically significant differences were found for both the age and stroke location during comparisons of the preoperative characteristics between the two groups. There was a significantly younger mean age for the effect versus the no effect group. Patients with stoke in non-thalamus were significantly enriched in effect group compared with those with stoke in thalamus. Multivariable analysis using these two factors found no statistical differences, suggesting that these two factors might possibly exhibit the same behaviors for the SCS effect. These results suggest that SCS may be able to provide pain relief in young, non-thalamus stroke patients with CPSP.

The role of NLRP3 inflammasome in stroke and central poststroke pain

BACKGROUND

NLRP3 inflammasome plays a prominent role in the pathogenesis and progression of many diseases, such as type 2 diabetes mellitus, obesity, atherosclerosis, and Alzheimer's disease. However, little knowledge is known about the role of NLRP3 inflammasome in central post-stroke pain (CPSP).

METHODS

We selected relevant studies by searching PubMed, Embase, and Medline from inception through February, 2018. We systematically reviewed available publications according to the terms "NLRP3 inflammasome" and "stroke" or "central post-stroke pain" in the title/abstract field.

RESULTS

We reviewed the articles and put forward two possible ways for NLRP3 inflammasome in CPSP. One way is that NLRP3 activation causes cerebral cortex injure, decreasing descending projection fiber to thalamus. Such condition may let GABAergic releases reduce, making the ventral basal (VB) neurons excitability increased. Finally, CPSP occur. Another way is that NLRP3 inflammasome leads to thalamic lesion and strengthens inflammatory response of microglia at the same time. Persistent inflammation causes GABAergic alteration in thalamus reticular neurons (TRN) to restrain VB interneurons functions, contributing to CPSP.

CONCLUSIONS

These possible mechanisms will help become knowledgeable about the occurrence CPSP and provide potential therapy for CPSP.

Musculoskeletal and central pain at 1 year post-stroke: associated factors and impact on quality of life

BACKGROUND AND PURPOSE

Pain is common in post-stroke patients and has been shown to be associated with depression, fatigue, and decreased quality of life (QOL). However, studies examining different types of post-stroke pain are scarce. We investigated differences in the related factors and their QOL impacts between musculoskeletal pain (MSP) and central post-stroke pain (CPSP).

METHODS

We assessed 364 consecutive stroke patients who were admitted to Asan Medical Center and contacted 12 months after stroke onset. We categorized pain and paresthesia as MSP, CPSP, combined pain, or other pain. Post-stroke depression (Beck Depression Inventory), fatigue (Fatigue Severity Scale), sleep disturbance (Verran Snyder-Halpern scale), social support (ENRICHED Social Support Instrument), and QOL (Medical Outcome Study 36-Item Short Form) were assessed.

RESULTS

Of the 364 patients analyzed, 135 (37.1%) had pain, 78 (21.4%) had MSP, 22 (6.0%) had CPSP, 16 (4.4%) had combined pain, and 19 (5.2%) had other pain. In multivariate analyses, CPSP was related to modified Rankin scale (P=.004), sensory dysfunction (P<.001), thalamus lesion (P=.001), medulla lesion (P=.007), and fatigue (P=.026). MSP was related to motor dysfunction (P<.001) and fatigue (P=.003). QOL varied among groups with different types of pain (P<.001) and was the poorest in patients with combined pain.

CONCLUSIONS

Pain is common 12 months post-stroke. The factors associated with CPSP and MSP differ, but are both closely associated with fatigue rather than depression. QOL is the poorest in patients with combined pain. Management of pain and fatigue may be important for improving the QOL in stroke patients.

Functional brain imaging: what has it brought to our understanding of neuropathic pain? A special focus on allodynic pain mechanisms

Brain responses to nociception are well identified. The same is not true for allodynic pain, a strong painful sensation in response to touch or innocuous cold stimuli that may be experienced by patients with neuropathic pain. Brain (or spinal cord) reorganization that may explain this paradoxical perception still remains largely unknown. Allodynic pain is associated with abnormally increased activity in SII and in the anterior insular cortex, contralateral and/or ipsilateral to allodynia. Because a bilateral increase in activity has been repeatedly reported in these areas in nociceptive conditions, the observed activation during allodynia can explain that a physiologically nonpainful stimulus could be perceived by the damaged nervous system as a painful one. Both secondary somatosensory and insular cortices receive input from the thalamus, which is a major relay of sensory and spinothalamic pathways, the involvement of which is known to be crucial for the development of neuropathic pain. Both thalamic function and structure have been reported to be abnormal or impaired in neuropathic pain conditions including in the basal state, possibly explaining the spontaneous component of neuropathic pain. A further indication as to how the brain can create neuropathic pain response in SII and insular cortices stems from examples of diseases, including single-case reports in whom a focal brain lesion leads to central pain disappearance. Additional studies are required to certify the contribution of these areas to the disease processes, to disentangle abnormalities respectively related to pain and to deafferentation, and, in the future, to guide targeting of stimulation studies.

Challenges in Recruitment for the Study of Noninvasive Brain Stimulation in Stroke: Lessons from Deep Brain Stimulation

OBJECTIVE

Noninvasive brain stimulation (NIBS) can augment functional recovery following stroke; however, the technique lacks regulatory approval. Low enrollment in NIBS clinical trials is a key roadblock. Here, we pursued evidence to support the prevailing opinion that enrollment in trials of NIBS is even lower than enrollment in trials of invasive, deep brain stimulation (DBS).

METHODS

We compared 2 clinical trials in stroke conducted within a single urban hospital system, one employing NIBS and the other using DBS, (1) to identify specific criteria that generate low enrollment rates for NIBS and (2) to devise strategies to increase recruitment with guidance from DBS.

RESULTS

Notably, we found that enrollment in the NIBS case study was 5 times lower (2.8%) than the DBS trial (14.5%) (χ(2) = 20.815, P < .0001). Although the number of candidates who met the inclusion criteria was not different (χ(2) = .04, P < .841), exclusion rates differed significantly between the 2 studies (χ(2) = 21.354, P < .0001). Beyond lack of interest, higher exclusion rates in the NIBS study were largely due to exclusion criteria that were not present in the DBS study, including restrictions for recurrent strokes, seizures, and medications.

CONCLUSIONS

Based on our findings, we conclude and suggest that by (1) establishing criteria specific to each NIBS modality, (2) adjusting exclusion criteria based on guidance from DBS, and (3) including patients with common contraindications based on a probability of risk, we may increase enrollment and hence significantly impact the feasibility and generalizability of NIBS paradigms, particularly in stroke.

Gabapentinoid Insensitivity after Repeated Administration is Associated with Down-Regulation of the α(2)δ-1 Subunit in Rats with Central Post-Stroke Pain Hypersensitivity

The α2δ-1 subunit of the voltage-gated Ca(2+) channel (VGCC) is a molecular target of gabapentin (GBP), which has been used as a first-line drug for the relief of neuropathic pain. GBP exerts its anti-nociceptive effects by disrupting trafficking of the α2δ-1 subunit to the presynaptic membrane, resulting in decreased neurotransmitter release. We previously showed that GBP has an anti-allodynic effect in the first two weeks; but this is followed by insensitivity in the later stage after repeated administration in a rat model of central post-stroke pain (CPSP) hypersensitivity induced by intra-thalamic hemorrhage. To explore the mechanisms underlying GBP insensitivity, the cellular localization and time-course of expression of the α2δ-1 subunit in both the thalamus and spinal dorsal horn were studied in the same model. We found that the α2δ-1 subunit was mostly localized in neurons, but not astrocytes and microglia. The level of α2δ-1 protein increased in the first two weeks after injury but then decreased in the third week, when GBP insensitivity occurred. Furthermore, the α2δ-1 down-regulation was likely caused by later neuronal loss in the injured thalamus through a mechanism other than apoptosis. In summary, the present results suggest that the GBP receptor α2δ-1 is mainly expressed in thalamic neurons in which it is up-regulated in the early stage of CPSP but this is followed by dramatic down-regulation, which is likely associated with GBP insensitivity after long-term use.

A Comprehensive Review of Central Post-Stroke Pain

Although central post-stroke pain is widely recognized as a severe chronic neuropathic pain condition, its consolidated definition, clinical characteristics, and diagnostic criteria have not been defined due to its clinically diverse features. The present study was undertaken to comprehensively review current literature and provide a more complete picture of central post-stroke pain with respect to its definition, prevalence, pathophysiology, clinical characteristics, and diagnostic problems, and to describe the range of therapies currently available. In particular, nursing care perspectives are addressed. It is hoped that this review will help nurses become knowledgeable about central post-stroke pain and provide valuable information for the drafting of effective nursing care plans that improve outcomes and quality of life for patients with central post-stroke pain.

Post-stroke pain hypersensitivity induced by experimental thalamic hemorrhage in rats is region-specific and demonstrates limited efficacy of gabapentin

Intractable central post-stroke pain (CPSP) is one of the most common sequelae of stroke, but has been inadequately studied to date. In this study, we first determined the relationship between the lesion site and changes in mechanical or thermal pain sensitivity in a rat CPSP model with experimental thalamic hemorrhage produced by unilateral intra-thalamic collagenase IV (ITC) injection. Then, we evaluated the efficacy of gabapentin (GBP), an anticonvulsant that binds the voltage-gated Ca(2+) channel α2δ and a commonly used anti-neuropathic pain medication. Histological case-by-case analysis showed that only lesions confined to the medial lemniscus and the ventroposterior lateral/medial nuclei of the thalamus and/or the posterior thalamic nucleus resulted in bilateral mechanical pain hypersensitivity. All of the animals displaying CPSP also had impaired motor coordination, while control rats with intra-thalamic saline developed no central pain or motor deficits. GBP had a dose-related anti-allodynic effect after a single administration (1, 10, or 100 mg/kg) on day 7 post-ITC, with significant effects lasting at least 5 h for the higher doses. However, repeated treatment, once a day for two weeks, resulted in complete loss of effectiveness (drug tolerance) at 10 mg/kg, while effectiveness remained at 100 mg/kg, although the time period of efficacious analgesia was reduced. In addition, GBP did not change the basal pain sensitivity and the motor impairment caused by the ITC lesion, suggesting selective action of GBP on the somatosensory system.

Evaluation of the Post Stroke Checklist: A Pilot Study in the United Kingdom and Singapore

Background

There is currently no standardized process for long-term follow-up care. As a result, management of post-stroke care varies greatly, and the needs of stroke survivors are not fully addressed. The Post Stroke Checklist was developed by the Global Stroke Community Advisory Panel as a means of standardizing long-term stroke care. Since its development, the Post Stroke Checklist has gained international recognition from various stroke networks and is endorsed by the World Stroke Organization to support improved stroke survivor follow-up and care.

Aims

The aim of this study was to evaluate the feasibility and usefulness of the Post Stroke Checklist in clinical practice and assess its relevance to stroke survivors in pilot studies in the United Kingdom and Singapore.

Methods

The Post Stroke Checklist was administered to stroke survivors in the United Kingdom ( n = 42) and Singapore ( n = 100) by clinicians. To assess the feasibility of the Post Stroke Checklist in clinical practice, an independent researcher observed the assessment and made notes relating to the patient–clinician interaction and their interpretations of the Post Stroke Checklist items. Patient and clinician satisfaction with the Post Stroke Checklist was assessed by three questions, responded to on a 0–10 numerical rating scale. Clinicians also completed a Pragmatic Face and Content Validity test to evaluate their overall impressions of the Post Stroke Checklist. In the United Kingdom, a subset of patients ( n = 14) took part in a concept elicitation interview prior to being administered the Post Stroke Checklist, followed by a cognitive debriefing interview to assess relevance and comprehension of the Post Stroke Checklist.

Results

The Post Stroke Checklist identified frequently reported problems for stroke survivors including cognition (reported by 47·2% of patients), mood (43·7%), and life after stroke (38%). An average of 3·2 problems per patient was identified across both countries (range 0–10). An average of 5 and 2·6 problems per patient were identified in the United Kingdom and Singapore, respectively. The average time taken to administer the Post Stroke Checklist was 17 mins (standard deviation 7·5) in Singapore and 13 mins (standard deviation 7·6) in the United Kingdom. Satisfaction ratings were high for patients (8·6/10) and clinicians (7·7/10), and clinician feedback via the Pragmatic Face and Content Validity test indicated that the Post Stroke Checklist is ‘useful’, ‘informative’, and ‘exhaustive’. All concepts measured by the Post Stroke Checklist were spontaneously discussed by patients during the concept elicitation interviews, suggesting that the Post Stroke Checklist is relevant to stroke survivors. Cognitive debriefing data indicated that the items were generally well understood and relevant to stroke. Minor revisions were made to the Post Stroke Checklist based on patient feedback.

Conclusions

The findings suggest that the Post Stroke Checklist is a feasible and useful measure for identifying long term stroke care needs in a clinical practice setting. Pilot testing indicated that the Post Stroke Checklist is able to identify a wide range of unmet needs, and patient and clinician feedback indicated a high level of satisfaction with the Post Stroke Checklist assessment. The items were generally well understood and considered relevant to stroke survivors, indicating the Post Stroke Checklist is a feasible, useful, and relevant measure of poststroke care.

Stroke service: how can we improve and measure outcomes? Consensus summary from a global stroke forum

The success of acute stroke treatment is first and foremost time-dependent, and the need for improvement in acute stroke management is demonstrated by the fact that only a minority of patients gain access to treatment - in particular, intravenous recombinant tissue plasminogen activator (IV tPA) - within the necessary time window. Standards of acute stroke care vary widely both regionally and nationally; consequently, various healthcare organizations have undertaken initiatives to measure and improve quality of care. To date, most quality measures have been process-based, focusing primarily on metrics of patient care in the acute hospital-based setting (e.g., time to recombinant tPA administration). Therefore, there remains a need for metrics designed to assess how improvements in process translate into patient outcomes. A global forum was convened to share best practice and provide consensus recommendations on core metrics for measuring improvements in access to care and patient outcomes. Recommendations for core metrics of patient outcomes include hospital-based outcomes (e.g., neurological status at 24 h, ambulatory status at discharge) and post-discharge outcomes (e.g., modified Rankin Scale score at 30 and/or 90 days). Recommendations for best practice relating to aspects of people, process, and technology involved in the stroke treatment pathway that may help provide improvements in these core outcome measures are also outlined.

Losses and gains: chronic pain and altered brain morphology

As in many fields of neuroscience, alterations in brain morphology, and specifically gray matter volume and cortical thickness, have been repeatedly linked to chronic pain disorders. Numerous studies have shown changes in cortical and subcortical brain regions suggesting a dynamic process that may be a result of chronic pain or contributing to a more generalized phenomenon in chronic pain including comorbid anxiety and depression. In this review, we provide a perspective of pain as an innate state of pain based on alterations in structure and by inference, brain function. A better neurobiological understanding of gray matter changes will contribute to our understanding of how structural changes contribute to chronic pain (disease driver) and how these changes may be reversed (disease modification or treatment).

Population-based study of central post-stroke pain in Rimini district, Italy

Central post-stroke pain (CPSP) is still an underestimated complication of stroke, resulting in impaired quality of life and, in addition to the functional and cognitive consequences of stroke, the presence of CPSP may be associated with mood disorders, such as depression, anxiety, and sleep disturbances. This type of pain may also impair activities of daily living and further worsen quality of life, negatively influencing the rehabilitation process. The prevalence of CSPS in the literature is highly variable (1%-12%) according to different studies, and this variability could be influenced by selection criteria and the different ethnic populations being investigated. With this scenario in mind, we performed a population-based study to assess the prevalence of CPSP and its main features in a homogeneous health district (Rimini, Italy), including five hospitals for a total population of 329,970 inhabitants. From 2008 to 2010, we selected 1,494 post-stroke patients and were able to interview 660 patients, 66 (11%) of whom reported pain with related tactile and thermal hyperesthesia, accompanied by needle puncture, tingling, swelling, and pressure sensations. Patients reported motor impairment and disability, which influenced their working ability, rehabilitation, and social life. Despite this severe pain state, there was a high percentage of patients who did not receive adequate treatment for pain.

Daily repetitive transcranial magnetic stimulation of primary motor cortex for neuropathic pain: a randomized, multicenter, double-blind, crossover, sham-controlled trial

There is little evidence for multisession repetitive transcranial magnetic stimulation (rTMS) on pain relief in patients with neuropathic pain (NP), although single-session rTMS was suggested to provide transient pain relief in NP patients. We aimed to assess the efficacy and safety of 10 daily rTMS in NP patients. We conducted a randomized, double-blind, sham-controlled, crossover study at 7 centers. Seventy NP patients were randomly assigned to 2 groups. A series of 10 daily 5-Hz rTMS (500 pulses/session) of primary motor cortex (M1) or sham stimulation was applied to each patient with a follow-up of 17days. The primary outcome was short-term pain relief assessed using a visual analogue scale (VAS). The secondary outcomes were short-term change in the short form of the McGill pain questionnaire (SF-MPQ), cumulative changes in the following scores (VAS, SF-MPQ, the Patient Global Impression of Change scale [PGIC], and the Beck Depression Inventory [BDI]), and the incidence of adverse events. Analysis was by intention to treat. This trial is registered with the University hospital Medical Information Network Clinical Trials Registry. Sixty-four NP patients were included in the intention-to-treat analysis. The real rTMS, compared with the sham, showed significant short-term improvements in VAS and SF-MPQ scores without a carry-over effect. PGIC scores were significantly better in real rTMS compared with sham during the period with daily rTMS. There were no significant cumulative improvements in VAS, SF-MPQ, and BDI. No serious adverse events were observed. Our findings demonstrate that daily high-frequency rTMS of M1 is tolerable and transiently provides modest pain relief in NP patients.

Development of a poststroke checklist to standardize follow-up care for stroke survivors

BACKGROUND

Long-term care for stroke survivors is fragmented and lacks an evidence-based, easy-to-use tool to identify persistent long-term problems among stroke survivors and streamline referral for treatment. We sought to develop a poststroke checklist (PSC) to help health care professionals identify poststroke problems amenable to treatment and subsequent referral.

METHODS

An instrument development team, supported by measurement experts, international stroke experts, and poststroke care stakeholders, was created to develop a long-term PSC. A list of long-term poststroke problem areas was generated by an international, multidisciplinary group of stroke experts, the Global Stroke Community Advisory Panel. Using Delphi methods, a consensus was reached on which problem areas on the list were most important and relevant to include in a PSC. The instrument development team concurrently created the actual checklist, which provided example language about how to ask about poststroke problem areas and linked patient responses to a specific referral process.

RESULTS

Eleven long-term poststroke problem areas were rated highly and consistently among stroke experts participating in the Delphi process (n = 12): secondary prevention, activities of daily living, mobility, spasticity, pain, incontinence, communication, mood, cognition, life after stroke, and relationship with caregiver. These problem areas were included in the long-term PSC.

CONCLUSIONS

The PSC was developed to be a brief and easy-to-use tool, intended to facilitate a standardized approach for health care providers to identify long-term problems in stroke survivors and to facilitate appropriate referrals for treatment.

Pain following stroke, initially and at 3 and 18 months after stroke, and its association with other disabilities

BACKGROUND AND PURPOSE

A general hypothesis is that pain following stroke (PFS) causes disabilities. However, the clinical implication of PFS on other disabilities after stroke and vice versa has not been fully investigated. The aims of this observational study were to analyze the correlation between PFS and other disabilities at different time points after stroke, whether PFS can be a predictor of coming disabilities and whether other disabilities can be predictors of coming PFS.

METHODS

Patients with a first-ever stroke were assessed initially (n = 109), and at 3 (n = 95) and 18 months (n = 66) after stroke for PFS, mobility, self-care as well as touch, proprioceptive, muscle tone, and movement functions.

RESULTS

PFS was correlated to impaired upper extremity movement function on all occasions, while the correlations between PFS and other disabilities varied across the three occasions. Initial PFS and PFS at 3 months did not independently predict coming disabilities. Initial mobility limitation independently predicted PFS at 3 months and impaired touch function, initially and at 3 months, independently predicted PFS at 18 months. No other disabilities independently predicted coming PFS.

CONCLUSIONS

The present results do not support the hypothesis that PFS causes other disabilities. Our results indicate that PFS is correlated to other disabilities; however, no ultimate conclusions can be drawn on causality. PFS was not a predictor of coming disabilities, while some disabilities were predictors of coming PFS.

The prevalence of central poststroke pain according to the integrity of the spino-thalamo-cortical pathway

OBJECTIVES

Little is known about the prevalence of central poststroke pain (CPSP) according to the integrity of the spino-thalamo-cortical pathway (STP). Using diffusion tensor tractography, we investigated the prevalence of CPSP according to the integrity of the STP in patients with intracerebral hemorrhage.

METHODS

We recruited 52 consecutive chronic patients and 10 normal control subjects. Patients were classified into two groups according to preservation of the integrity of the STP. Each group was divided into two subgroups according to the presence of CPSP.

RESULTS

The preserved group included 34 patients [CPSP subgroup, 16 (47%) patients; non-CPSP subgroup, 18 (53%) patients], and 18 patients were enrolled into the disrupted group [CPSP subgroup, 3 (17%) patients; non-CPSP subgroup, 15 (83%) patients]. The fractional anisotropy and mean diffusivity values of the CPSP and non-CPSP subgroups of the preserved group were decreased and increased when compared with those of the control group, respectively (p < 0.05).

CONCLUSIONS

We found that the prevalence of CPSP in patients with partial injury of the STP was higher than that of patients with complete injury of the STP. Partial injury of the STP appears to be more vulnerable to development of CPSP than complete injury of the STP in patients with intracerebral hemorrhage.

Pain following stroke: a population-based follow-up study

BACKGROUND AND PURPOSE

Chronic pain is increasingly recognized as a consequence of stroke. This study aimed to describe the prevalence and pain types of new onset chronic pain ("novel pain") in patients with stroke compared with a randomly selected reference group from the general population and to identify factors associated with pain development in stroke patients.

METHODS

In a population-based follow-up design, development of chronic pain after stroke was assessed by a questionnaire sent to consecutive stroke patients, registered in a Danish national stroke database, two years after their stroke. A randomly selected sex- and age-matched reference group from the same catchment area received a similar questionnaire about development of new types of chronic pain in the same time period. A total of 608 stroke patients and 519 reference subjects were included in the study.

RESULTS

Development of novel pain was reported by 39.0% of stroke patients and 28.9% of reference subjects (OR 1.57, CI 1.21-2.04), and was associated with low age and depression in a multivariate model. Daily intake of pain medication for novel pain was reported by 15.3% and 9.4% of the stroke and reference population, respectively. Novel headache, shoulder pain, pain from increased muscle stiffness, and other types of novel pain were more common in stroke patients, whereas joint pain was equally common in the two groups.

CONCLUSIONS

Development of chronic pain is more common in stroke patients compared with sex- and age-matched reference subjects. Evaluation of post-stroke pain should be part of stroke follow-up.

Poststroke fatigue: an emerging, critical issue in stroke medicine

Poststroke fatigue is a common and disabling condition. However, few studies on or therapeutic trials addressing poststroke fatigue have appeared in the literature. We aimed to review the prevalence, natural course, potential predisposing factors (physiological, psychocognitive, and organic), and pharmacological and nonpharmacological treatments of poststroke fatigue. Using PubMed CINAHL and PsycINFO, we reviewed all the available literature on poststroke fatigue and related issues. The prevalence of poststroke fatigue ranges from 23% to 75%, depending on the definition of fatigue and the characteristics of the patients included. Poststroke fatigue seems to be of complex etiology. Predisposing factors were physiological ones including functional disability, prestroke fatigue, medical comorbidities, medication, sleep disturbances, and nutritional problems; psychocognitive ones including depression and cognitive dysfunction; and organic ones including damage to particular brain areas with consequent neurochemical alterations, perfusion deficit, and neuroinflammation. Poststroke fatigue is a persistent and debilitating symptom in some patients, and can have adverse affects on patient's neurological recovery, quality of life, and mortality. Few therapeutic trials have been reported, and the therapy was rarely successful, possibly because of the complex nature of poststroke fatigue. Poststroke fatigue is a common and frequently disabling problem of complex etiology. Further studies are urgently needed to improve our understanding of the pathophysiology of poststroke fatigue and to develop better treatments for this condition.

Safety and efficacy of pregabalin in patients with central post-stroke pain

Pregabalin has demonstrated efficacy in several forms of neuropathic pain, but its long-term efficacy in central post-stroke pain (CPSP) is unproven. We evaluated the efficacy and safety of pregabalin versus placebo in patients with CPSP. A 13-week, randomized, double-blind, multicenter, placebo-controlled, parallel group study of 150 to 600 mg/day pregabalin was conducted in patients aged ≥18 years with CPSP. The primary efficacy endpoint was the mean pain score on the Daily Pain Rating Scale over the last 7 days on study drug up to week 12 or early termination visit. Secondary endpoints included other pain parameters and patient-reported sleep and health-related quality-of-life measures. A total of 219 patients were treated (pregabalin n=110; placebo n=109). A mean pain score at baseline of 6.5 in the pregabalin group and 6.3 in the placebo group reduced at endpoint to 4.9 in the pregabalin group and 5.0 in the placebo group (LS mean difference=-0.2; 95% CI=-0.7, 0.4; P=0.578). Treatment with pregabalin resulted in significant improvements, compared with placebo, on secondary endpoints including MOS-sleep, HADS-A anxiety, and clinician global impression of change (CGIC) P<0.05. Adverse events were more frequent with pregabalin than with placebo and caused discontinuation in 9 (8.2%) of pregabalin patients versus 4 (3.7%) of placebo patients. Although pain reductions at endpoint did not differ significantly between pregabalin and placebo, improvements in sleep, anxiety, and CGIC suggest some utility of pregabalin in the management of CPSP.

Aβ and Aδ but not C-fibres are involved in stroke related pain and allodynia: an experimental study in mice

Objectives

Cerebral ischaemia is a leading cause of death and disability, including severe complications such as memory disturbance, palsy, and spasticity. Central post-stroke pain (CPSP) is a complication of cerebral ischaemia, and is characterized clinically by spontaneous pain and attacks of allodynia and dysaesthesia. However, the detailed mechanisms of CPSP are not well established. Herein, we have examined alterations of the current stimulus threshold of primary afferent neurons or the nociceptive threshold against mechanical stimuli in mice receiving left middle cerebral artery occlusion (MCAO).

Methods

Alterations of current stimulus threshold and the development of mechanical allodynia in hind paws were measured after MCAO using a Neurometer and the von Frey filament test, respectively.

Key findings

Development of cerebral infarction was clearly observed on day 1 and day 3 after MCAO. For the estimation of current stimulus threshold measured by the Neurometer, the sensitivity of Aδ and Aβ fibres (at 2000 and 250 Hz stimulation, respectively) was significantly increased on day 3 after MCAO, while that of C fibres (at 5 Hz stimulation) was unaltered. In addition, the paw withdrawal threshold of the left hind paw as measured by the von Frey filament test was significantly decreased on day 1 and day 3 after MCAO when compared with day 0, while that in the right hind paw was not different.

Conclusions

The data suggested the development of bilateral hyperaesthesia in this model. Further, mechanical allodynia developed in the ipsilateral side to the MCAO. Potentially, myelinated A fibre-specific hypersensitization after stroke may have contributed to these symptoms.

Spinal cord stimulation for central poststroke pain

BACKGROUND

Although spinal cord stimulation (SCS) has been shown to be effective for treating neuropathic pain of peripheral origin, its effectiveness for central poststroke pain (CPSP) is not well established.

OBJECTIVE

We report our experience with SCS in 30 consecutive patients with intractable CPSP.

METHODS

All patients underwent a percutaneous SCS trial. When patients decided to proceed, they received a permanent SCS system. Pain intensity was evaluated by a visual analogue scale (VAS). The Patient Global Impression of Change (PGIC) scale was also assessed at the latest follow-up visit as an indicator of overall improvement.

RESULTS

During trial stimulation, pain relief was good (> or =50% VAS score reduction) in 9 patients (30%), fair (30%-49% reduction) in 6 patients (20%), and poor (<30% reduction) in 15 patients (50%). Ten patients elected to receive a permanent SCS system. Nine of these 10 patients were followed long-term (mean, 28 months; range, 6-62 months). Seven patients reported significant pain relief on the VAS (5 = good and 2 = fair). On the PGIC scale, 6 of these 7 patients reported a rating of 2 (much improved) and 1 reported a rating of 3 (minimally improved). Of the remaining 2 patients, 1 reported a rating of 4 (no change) and 1 reported a rating of 5 (minimally worse). The median VAS score in the 9 patients decreased significantly from 8.6 (range, 6.0-10.0) to 4.5 (range, 3.0-8.0; P = .008). There were no significant reported complications.

CONCLUSION

SCS may provide improved pain control in a group of patients with intractable CPSP and may have therapeutic potential for intractable CPSP.