RESUMO
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.
RESUMO
Purpose: In the thermal grill illusion, participants experience a feeling similar to burning pain. The illusion is induced by simultaneously touching warm and cool stimuli in alternating positions. In post-stroke pain, central sensitization is caused by a variety of factors, including damage to the spinothalamic tract and shoulder pain. Because the thermal grill illusion depends on central mechanisms, it has recently been suggested that it may be a useful indicator of central sensitization. Therefore, we hypothesized that post-stroke patients who are more likely to experience central sensitization may also be more likely to experience a thermal grill sensation of pain and discomfort than the likelihood among those who are less likely to experience central sensitization. However, the effects of the thermal grill illusion in post-stroke patients have not yet been reported. In this pilot study, we conducted the thermal grill illusion procedure in post-stroke patients and analyzed the relationship between clinical somatosensory functions and thermal grill sensations. We also conducted brain imaging analysis to identify brain lesion areas that were associated with thermal grill sensations. Patients and Methods: Twenty patients (65.7 ± 11.9 years old) with post-stroke patients participated in this study. The thermal grill illusion procedure was performed as follows: patients simultaneously touched eight water-filled copper bars, with the water temperature adjusted to provide alternate warm (40°C) and cold (20°C) stimuli. Results: Thermal grill sensation of pain and discomfort tended to be associated with the wind-up phenomenon in bedside quantitative sensory testing and thermal grill sensation of discomfort was also related to damage to the thalamic lateral nucleus. Conclusion: These findings suggest that the thermal grill illusion might measure central sensitization, and that secondary brain hyperactivity might lead to increased thermal grill sensations.
RESUMO
Background: Current therapeutic interventions for dysesthesias caused by spinal cord dysfunctions are ineffective. We propose a novel intervention using transcutaneous electrical nerve stimulation (TENS) for dysesthesias, and we present an in-depth case series. Patients and methods: Conventional high-frequency TENS and the novel dysesthesia-matched TENS (DM-TENS) were applied to 16 hands of nine patients with spinal cord dysfunction. The dysesthesia-matched TENS' stimulus intensity and frequency matched the intensity and somatosensory profile of the patients' dysesthesias. The Short-Form McGill Pain Questionnaire version-2 (SF-MPQ2) and quantitative sensory testing (QST) were applied during electrical stimulation/no stimulation. We determined intraclass correlation coefficients (ICCs) to evaluate the reliability of the setting and the effects on the dysesthesias and the change in subjective dysesthesia between each patient's baseline without TENS and DM-TENS. Results: We were able to apply electrical stimulation matching the patients' subjective dysesthesia for 14 hands (eight patients). TENS could not be applied for the remaining patient due to severe sensory deficits. Compared to the patients' baseline and high-frequency TENS, the DM-TENS provided significant decreases in tingling/pins-and-needles and numbness on the SF-MPQ2, and it significantly improved the dynamic and static mechanical detection on QST. Regarding the reliability of the dysesthesia-matched TENS settings, the ICCs (1,5) were intensity, 0.95; frequency, 1.00; and effect on dysesthesia, 0.98. Conclusion: DM-TENS improved the dysesthesias and mechanical hypoesthesia caused by spinal cord dysfunction. The effectiveness of DM-TENS particularly for tingling and numbness was clearly higher and was reliable within the patients. These results may suggest an effective treatment of dysesthesias in patients with spinal cord dysfunction. Clinical trial registration: [https://rctportal.niph.go.jp/s/detail/um?trial_id=UMIN000045332], identifier [UMIN000045332].
