Effectiveness of the physiotherapy interventions on complex regional pain syndrome in patients with stroke: A systematic review and meta-analysis

Harnessing theta waves: tACS as a breakthrough in alleviating post-stroke chronic pain

Neural oscillations play a critical role in the regulation of brain functions, with theta waves (4-8 Hz) in the sensorimotor cortex significantly influencing pain perception and modulation. These oscillations can modulate pain signal transmission, emotional cognition, and neuroplasticity. Post-stroke chronic pain is a common and complex symptom that imposes significant physiological and psychological burdens on patients. Transcranial alternating current stimulation (tACS), a non-invasive brain stimulation technique, can synchronize specific frequency neural activities, reorganize brain networks, and modulate neuroplasticity by adjusting specific frequency neural oscillations. In recent years, tACS has been widely applied in the research and treatment of various neurological and psychiatric disorders. This study aims to systematically summarize the current research progress on the regulation of θ oscillations in sensorimotor cortex by tACS. By reviewing relevant experimental and clinical studies, we explore the specific mechanisms of θ oscillations in pain perception and modulation and analyze the mechanisms and effects of tACS modulation of θ oscillations. Additionally, we examine the central and peripheral neural mechanisms of post-stroke chronic pain, emphasizing the critical role of the sensorimotor cortex in pain processing. In conclusion, tACS shows potential for modulating sensorimotor cortex θ oscillations and alleviating post-stroke chronic pain. This research provides new insights into the neural modulation mechanisms related to pain and offers potential new directions for developing novel therapies. Future clinical studies and technological optimizations are necessary to ensure the effectiveness and feasibility of tACS in clinical practice.

Effect of high-intensity laser therapy and mirror therapy on complex regional pain syndrome type I in the hand area: A randomized controlled trial

BACKGROUND

Complex regional pain syndrome type I (CRPS-I) is a painful condition with peripheral and central nervous system dysfunction, disproportionate inflammation, and the resultant muscle atrophy and restriction of motion. The use of high-intensity laser therapy (HILT) is being considered to reduce inflammation and neural and musculoskeletal pain. As maladaptive neuroplasticity occurs, peripheral treatment may not be enough and a combination of peripheral and centrally-focused interventions may be required.

PURPOSE

To explore the impact of HILT combined with mirror therapy (MT) on pain intensity, swelling, functional ability, range of motion (ROM), and electromyography (EMG) activity in CRPS-I.

STUDY DESIGN

Randomized, sham-controlled, single-blind clinical trial.

METHODS

Twenty-four CRPS-I patients were randomly assigned to two groups of HILT at 5 watts with an energy density of 20 J/cm², combined with MT and sham HILT and MT for six sessions. Pain was assessed by the Visual Analog Scale (VAS) before, the third session, and after the treatment. Hand swelling, function, and ROM were measured by a motion analysis system, and EMG of the hand muscles was also evaluated.

RESULTS

Pain significantly decreased in the HILT group. Compared to before treatment, the VAS mean difference in the third session was -2 ± 0.8 in the HILT group versus -0.4 ± 0.5 in the sham group (p < 0.001, ηp2 = 0.57). The VAS mean difference for before-after treatment was -4.2 ± 1.2 in the HILT group versus -1.4 ± 0.6 in the sham group (p < 0.001, ηp2 = 0.69). The other outcomes, like function, effusion, ROM, and EMG activity, were also in favor of the HILT group (p < 0.05).

CONCLUSIONS

Our study results offer conclusive evidence of pain reduction, a highly debilitating symptom in CRPS-I, even after the third HILT treatment session. Additionally, HILT effectively reduced swelling, improved performance, and enhanced muscle activity in CRPS-I.

Chronic post-ischemic pain (CPIP) a model of complex regional pain syndrome (CRPS-I): Role of oxidative stress and inflammation

Complex regional pain syndrome (CRPS) presents as a persistent and distressing pain condition often stemming from limb trauma or ischemia, manifesting as either CRPS-I (without initial nerve injury) or CRPS-II (accompanied by nerve injury). Despite its prevalence and significant impact on functionality and emotional well-being, standard treatments for CRPS remain elusive. The multifaceted nature of CRPS complicates the identification of its underlying mechanisms. In efforts to elucidate these mechanisms, researchers have turned to animal models such as chronic post-ischemic pain (CPIP), which mirrors the symptoms of CRPS-I. Various mechanisms have been proposed to underlie the acute and chronic pain experienced in CRPS-I, including oxidative stress and inflammation. Traditional treatment approaches often involve antidepressants, non-steroidal anti-inflammatory drugs (NSAIDs), and opioids. However, these methods frequently fall short of providing adequate relief. Accordingly, there is a growing interest in exploring alternative treatments, such as antioxidant supplementation, anti-inflammatory agents, and non-pharmacological interventions. Future research directions should focus on optimizing treatment strategies and addressing remaining gaps in knowledge to improve patient outcomes. This review aims to delve into the pathophysiological mechanisms implicated in the CPIP model, specifically focusing on oxidative stress and inflammation, with the ultimate goal of proposing innovative therapeutic strategies for alleviating the symptoms of CRPS-I.

Prognosis of Pain After Stroke During Rehabilitation Depends on the Pain Quality

OBJECTIVE

Pain after a stroke interferes with daily life and the rehabilitation process. This study aimed to clarify the prognosis of pain in subgroups of patients with pain after a stroke using pain quality data.

METHODS

The study included 85 patients with pain after stroke undergoing exercise-based rehabilitation. Items of the Neuropathic Pain Symptom Inventory (NPSI) were used, and patients with pain after stroke were clustered according to their scores of NPSI. Other clinical assessments, such as physical and psychological conditions, were assessed by interviews and questionnaires, and then these were compared among subgroups in a cross-sectional analysis. Longitudinal pain intensity in each subgroup was recorded during 12 weeks after the stroke and the patients' pain prognoses were compared between subgroups.

RESULTS

Four distinct subgroups were clustered: cluster 1 (cold-evoked pain and tingling), cluster 2 (tingling only), cluster 3 (pressure-evoked pain), and cluster 4 (deep muscle pain with a squeezing and pressure sensation). The cross-sectional analysis showed varying clinical symptoms among the subgroups, with differences in the prevalence of joint pain, limited range of motion, somatosensory dysfunction, and allodynia. There were no significant differences in pain intensity at baseline among the subgroups. A longitudinal analysis showed divergent prognoses of pain intensity among the subgroups. The pain intensity in cluster 4 was significantly alleviated, which suggested that musculoskeletal pain could be reduced with conventional exercise-based rehabilitation. However, the pain intensity of patients in clusters 1 and 2 remained over 12 weeks.

CONCLUSION

The study classified patients into clinically meaningful subgroups using pain quality data and provided insight into their prognosis of pain. The findings could be useful for guiding personalized rehabilitation strategies for pain management.

IMPACT

Assessment of pain quality in patients with pain after stroke leads to personalized rehabilitation for pain management.

Efficacy of Rehabilitative Intervention on Pain and Function in Patients With Upper Limb Complex Regional Pain Syndrome

Aim:

Investigate the efficacy of physical therapy in the management of complex regional pain syndrome (CRPS)

Methods:

We conducted a systematic review on 3 databases: MEDLINE, EMBASE, and CENTRAL. The applied methods are stated in the protocol and registered in OSF: 10.17605/OSF.IO/SF49B.

Results:

At the end of the screening process, 12 RCTs were included. Included studies presented heterogeneous and multicomponent interventions. Physical therapy interventions resulted valuable in the management of CRPS. Motor imagery and some physical agents therapies are effective in reducing pain and for functional improvements.

Conclusion:

Physiotherapy is a central treatment for patients with CRPS.

An machine learning model to predict quality of life subtypes of disabled stroke survivors

OBJECTIVE

Stroke causes serious physical disability with impaired quality of life (QoL) and heavy burden on health. The goal of this study is to explore the impaired QoL typologies and their predicting factors in physically disabled stroke survivors with machine learning approach.

METHODS

Non-negative matrix factorization (NMF) was applied to clustering 308 physically disabled stroke survivors in rural China based on their responses on the short form 36 (SF-36) assessment of quality of life. Principal component analysis (PCA) was conducted to differentiate the subtypes, and the Boruta algorithm was used to identify the variables relevant to the categorization of two subtypes. A gradient boosting machine(GBM) and local interpretable model-agnostic explanation (LIME) algorithms were used to apply to interpret the variables that drove subtype predictions.

RESULTS

Two distinct subtypes emerged, characterized by short form 36 (SF-36) domains. The feature difference between worsen QoL subtype and better QoL subtype was as follows: role-emotion (RE), body pain (BP) and general health (GH), but not physical function (PF); the most relevant predictors of worsen QoL subtypes were help from others, followed by opportunities for community activity and rehabilitation needs, rather than disability severity or duration since stroke.

INTERPRETATION

The results suggest that the rehabilitation programs should be tailored toward their QoL clustering feature; body pain and emotional-behavioral problems are more crucial than motor deficit; stroke survivors with worsen QoL subtype are most in need of social support, return to community, and rehabilitation.