Hemodynamic signal changes during volitional swallowing in dysphagia patients with different unilateral hemispheric stroke and brainstem stroke: A near-infrared spectroscopy study.

BACKGROUND AND OBJECTIVES: Strokes will result in decreased in cortical excitability and changed in the balance between the affected and unaffected hemispheres. Previous studies have focused on cortical changes in healthy subjects during swallowing, while they remain unknown in patients with stroke at different locations. Thus, the purpose of this study was to research cortical activation patterns of swallowing in patients with dysphagia and healthy subjects by the functional near-infrared spectroscopy (fNIRS). We also focus on the comparability of brain activation areas associated with swallowing between patients with different stroke locations and healthy subjects. METHODS: total of 104 participants were invited to our study, involving 86 patients with dysphagic unilateral hemispheric stroke and 18 age and sex matched healthy controls. The stroke patients were categorized into patients with left unilateral stroke lesions (n = 30), patients with right unilateral stroke lesions (n = 32) and patients with brainstem injury (n = 24) according to different stroke sites. All patients underwent a series of clinical swallowing function assessments, such as the Fiberoptic endoscopic dysphagia severity scale (FEDSS), penetration-aspiration scale (PAS) of Rosenbek, the gugging swallowing screen (GUSS) and the functional oral Intake scale (FOIS) after informed consent has been signed. All participants received the fNIRS system assessment. RESULTS: The results showed that extensive areas of the cerebral cortex activated during the swallowing tasks in healthy participants (P < FDR 0.05). For patients with left unilateral stroke lesions, the HbO concentration were strongest over the right hemisphere (P < FDR 0.05). In addition, a less severe activation was also observed in the left hemisphere. Comparable to patients with left unilateral stroke lesions, the strongest activation during swallowing task were found in the left hemisphere in patients with right unilateral stroke lesions (P < FDR 0.05). Similarly, the right hemisphere also has activated less. In contrast, patients with brain stem injury showed more bilaterally activation patterns. CONCLUSION: Our finding states that cortical activation areas differ between patients with different stroke locations and healthy subjects during swallowing. There was a more bilateral activation in healthy participants and patients with lesions in the brainstem while more cortical activation in unaffected hemisphere in patients with unilateral hemispheric stroke. It also provides a basis for the future treatment of dysphagia after stroke.

Effects of bilateral cerebellar repetitive transcranial magnetic stimulation in poststroke dysphagia: A randomized sham-controlled trial.

BACKGROUND: Although increasing evidence indicates that cerebellar repetitive transcranial magnetic stimulation (rTMS) may be beneficial in the treatment of dysphagia, its clinical efficacy is still uncertain. OBJECTIVE: To evaluate the effect of high-frequency cerebellar rTMS on poststroke dysphagia. METHODS: This was a randomized, sham-controlled, double-blind trial. A total of eighty-four study participants were randomly assigned into the cerebellum and control groups. The cerebellum group received bilateral 10 Hz rTMS treatment of the pharyngeal motor area of the cerebellum. The control group was administered with sham rTMS of the pharyngeal motor area of the cerebellum. All patients underwent the same conventional swallowing rehabilitation training after the intervention 5 days a week for a total of 10 days. Assessment of swallowing function was done before treatment (baseline), after treatment (2 weeks), and during follow-up (2 weeks after treatment) using the Fiberoptic Endoscopic Dysphagia Severity Scale (FEDSS) and the Penetration-Aspiration Scale (PAS). RESULTS: The interaction between time and intervention had a significant effect on PAS (P < 0.001) and FEDSS (P < 0.001). Compared to the control group, the cerebellum group exhibited significantly improved clinical swallowing function scores (PAS: P = 0.007, FEDSS: P = 0.002). CONCLUSION: Bilateral cerebellar rTMS is a potential new neurorehabilitation technique for post-stroke dysphagia. Studies should aim at investigating the therapeutic mechanism of cerebellar rTMS and improve this technique.

Hemodynamic signal changes and swallowing improvement of repetitive transcranial magnetic stimulation on stroke patients with dysphagia: A randomized controlled study.

Objective: Our study aims to measure the cortical correlates of swallowing execution in patients with dysphagia after repetitive transcranial magnetic stimulation (rTMS) therapy using functional near-infrared spectroscopy (fNIRS), and observe the change of pattern of brain activation in stroke patients with dysphagia after rTMS intervention. In addition, we tried to analyze the effect of rTMS on brain activation in dysphagia patients with different lesion sides. This study also concentrated on the effect of stimulating the affected mylohyoid cortical region by 5 Hz rTMS, providing clinical evidence for rTMS therapy of dysphagia in stroke patients. Methods: This study was a sham-controlled, single-blind, randomized controlled study with a blinded observer. A total of 49 patients completed the study, which was randomized to the rTMS group (n = 23) and sham rTMS group (n = 26) by the random number table method. The rTMS group received 5 Hz rTMS stimulation to the affected mylohyoid cortical region of the brain and the sham rTMS group underwent rTMS using the same parameters as the rTMS group, except for the position of the coil. Each patient received 2 weeks of stimulation followed by conventional swallowing therapy. Standardized Swallowing Assessment (SSA), Fiberoptic Endoscopic Dysphagia Severity Scale (FEDSS), Penetration-Aspiration Scale (PAS), and functional oral intake status were assessed at two times: baseline (before treatment) and 2 weeks (after intervention). Meanwhile, we use the fNIRS system to measure the cerebral hemodynamic changes during the experimental procedure. Results: The rTMS group exhibited significant improvement in the SSA scale, FEDSS scale, and PAS scale after rTMS therapy (all P < 0.001). The sham rTMS group had the same analysis on the same scales (all P < 0.001). There was no significant difference observed in clinical assessments at 2 weeks after baseline between the rTMS group and sham rTMS group (all P > 0.05). However, there were statistically significant differences between the two groups in the rate of change in the FEDSS score (P = 0.018) and PAS score (P = 0.004), except for the SSA score (P = 0.067). As for the removal rate of the feeding tube, there was no significant difference between the rTMS group and sham rTMS group (P = 0.355), but there was a significant difference compared with the baseline characteristics in both groups (P rTMS < 0.001, P shamrTMS = 0.002). In fNIRS analysis, the block average result showed differences in brain areas RPFC (right prefrontal cortex) and RMC (right motor cortex) significantly between the rTMS group and sham rTMS group after intervention (P channel30 = 0.046, P channel16 = 0.006). In the subgroup analysis, rTMS group was divided into left-rTMS group and right-rTMS group and sham rTMS group was divided into sham left-rTMS group and sham right-rTMS group. The fNIRS results showed no significance in block average and block differential after intervention between the left-rTMS group and sham left-rTMS group, but differences were statistically significant between the right-rTMS group and sham right-rTMS group in block average: channel 30 (T = -2.34, P = 0.028) in LPFC (left prefrontal cortex) and 16 (T = 2.54, P = 0.018) in RMC. After intervention, there was no significance in left-rTMS group compared with baseline, but in right-rTMS group, channel 27 (T = 2.18, P = 0.039) in LPFC and 47 (T = 2.17, P = 0.039) in RPFC had significance in block differential. In the sham rTMS group, neither sham left-rTMS group and sham right-rTMS group had significant differences in block average and block differential in each brain area after intervention (P > 0.05). Conclusions: The present study confirmed that a 5-Hz rTMS is feasible at the affected mylohyoid cortical region in post-stroke patients with dysphagia and rTMS therapy can alter cortical excitability. Based on previous studies, there is a dominant hemisphere in swallowing and the results of our fNIRS analysis seemed to show a better increase in cortical activation on the right side than on the left after rTMS of the affected mylohyoid cortical region. However, there was no difference between the left and right hemispheres in the subgroup analysis. Nevertheless, the present study provides a novel and feasible method of applying fNIRS to assessment in stroke patients with dysphagia.

Bilateral Cerebellar Intermittent Theta Burst Stimulation Combined With Swallowing Speech Therapy for Dysphagia After Stroke: A Randomized, Double-Blind, Sham-Controlled, Clinical Trial.

BACKGROUND: Previous studies have found that high-frequency repetitive transcranial magnetic stimulation (rTMS) of the cerebellar hemisphere could improve swallowing function, but whether intermittent theta burst stimulation (iTBS), which has similar excitatory effect and higher efficiency, can also improve swallowing function for dysphagia after stroke remains unclear. OBJECTIVE: This trial aimed to explore the efficacy and safety of bilateral cerebellar transcranial magnetic stimulation with iTBS for dysphagia after stroke. METHODS: Seventy patients with dysphagia after stroke were divided into 2 treatment groups: true bilateral cerebellar iTBS and sham bilateral cerebellar iTBS. The true iTBS group underwent ten 100% resting motor threshold (RMT) iTBS sessions for 2 weeks. In the sham iTBS group, the parameters were the same except that the figure-eight coil was perpendicular to the skull. Both groups received traditional swallowing rehabilitation treatment 5 times a week for 2 weeks. Swallowing function was assessed with the Fiberoptic Endoscopic Dysphagia Severity Scale (FEDSS), Penetration/Aspiration Scale (PAS), Standardized Swallowing Assessment (SSA), and Functional Oral Intake Scale (FOIS) at baseline, 2 weeks after the intervention, and at 4 weeks of follow-up. RESULTS: There were significant time and group interaction effects in both multi-factorial adjusted and unadjusted FEDSS, PAS, SSA, and FOIS score (P < .001). In the pairwise comparison of the swallowing parameters among the 2 groups, the FEDSS, PAS, SSA, and FOIS scores at 2 weeks and 4 weeks showed a significantly higher improvement in the iTBS simulation group than sham group (P < .05). In both the true iTBS and sham iTBS stimulation groups, all FEDSS, PAS, SSA, and FOIS scores were significantly improved over time (P < .001). CONCLUSIONS: The present study suggested that as a more efficient TMS stimulation mode, iTBS could efficiently improve swallowing function by stimulating the bilateral cerebellar hemisphere. In addition, 100% resting motor threshold bilateral cerebellar iTBS is a relatively safe treatment. CLINICAL TRIAL REGISTRATION: Effect analysis of repeated transcranial magnetic stimulation of cerebellar on dysphagia after stroke. www.chictr.org.cn. Identifier: ChiCTR2100042092.

The Effectiveness of Repetitive Transcranial Magnetic Stimulation for Post-stroke Dysphagia: A Systematic Review and Meta-Analysis.

Background: Repetitive transcranial magnetic stimulation (rTMS) applied to the mylohyoid cortical region has positive clinical effects on post-stroke. Therefore, we conducted a meta-analysis to investigate the efficacy of rTMS for patients with post-stroke dysphagia. Methods: According to PRISMA guidelines, we searched the databases of MEDLINE (PubMed), Cochrane Library, Embase, Web of Science, CNKI, Wangfang. We searched for studies of randomized controlled trials (RCTs) of rTMS to treat dysphagia after stroke and screened by inclusion and exclusion criteria. Features of RCTs were extracted. The heterogeneity of the trials was measured by I 2 statistic. Results: In total, 11 RCTs with 463 dysphagia patients fulfilled our inclusion criteria. In our analysis, rTMS demonstrated a great beneficial effect for post-stroke dysphagia when combined with traditional swallowing exercises. Moreover, a greatly significant difference (P = 0.008) was noted based on stimulation frequency (high frequency vs. low frequency). Additionally, no significant difference (P = 0.53) was observed based on stimulation site (affected vs. unaffected hemisphere). Conclusions: Overall, rTMS can effectively accelerate the improvement of swallowing function in patients with post-stroke swallowing disorders.

The Application of Brain-Computer Interface in Upper Limb Dysfunction After Stroke: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Objective: This study aimed to examine the effectiveness and safety of the Brain-computer interface (BCI) in treatment of upper limb dysfunction after stroke. Methods: English and Chinese electronic databases were searched up to July 2021. Randomized controlled trials (RCTs) were eligible. The methodological quality was assessed using Cochrane's risk-of-bias tool. Meta-analysis was performed using RevMan 5.4. Results: A total of 488 patients from 16 RCTs were included. The results showed that (1) the meta-analysis of BCI-combined treatment on the improvement of the upper limb function showed statistical significance [standardized mean difference (SMD): 0.53, 95% CI: 0.26-0.80, P < 0.05]; (2) BCI treatment can improve the abilities of daily living of patients after stroke, and the analysis results are statistically significant (SMD: 1.67, 95% CI: 0.61-2.74, P < 0.05); and (3) the BCI-combined therapy was not statistically significant for the analysis of the Modified Ashworth Scale (MAS) (SMD: -0.10, 95% CI: -0.50 to 0.30, P = 0.61). Conclusion: The meta-analysis indicates that the BCI therapy or BCI combined with other therapies such as conventional rehabilitation training and motor imagery training can improve upper limb dysfunction after stroke and enhance the quality of daily life.

Repetitive Transcranial Magnetic Stimulation at Different Sites for Dysphagia After Stroke: A Randomized, Observer-Blind Clinical Trial.

Background: The clinical efficacy of repetitive transcranial magnetic stimulation (rTMS) protocols on patients with poststroke dysphagia is still unclear. Objective: This trial aimed to explore and analyze the effectiveness of 5 Hz rTMS on the unaffected hemisphere, affected hemisphere, and cerebellum in stroke patients with dysphagia. Methods: This observer-blind and randomized controlled trial included a total of 147 patients with stroke. Patients were divided into four treatment groups: the unaffected hemispheric group, the affected hemispheric group, the cerebellum group and the control group. Each group received traditional dysphagia treatment 5 days a week for 2 weeks. All recruited patients except for those in the control group underwent 10 consecutive rTMS sessions for 2 weeks. For the affected hemispheric group and unaffected hemispheric group, 5 Hz rTMS was applied to the affected mylohyoid cortical region or to the unaffected mylohyoid cortical region. For the cerebellum group, 5 Hz rTMS was applied to the mylohyoid cortical representation of the cerebellum (4.3 cm lateral and 2.4 cm below the inion). The Fiberoptic Endoscopic Dysphagia Severity Scale (FEDSS), Penetration/Aspiration Scale (PAS), Gugging Swallowing Screen (GUSS), and Standardized Swallowing Assessment (SSA) were used to evaluate clinical swallowing function before the intervention (baseline), immediately after the intervention and 2 weeks after the intervention. Results: There were significant time and intervention interaction effects on the FEDSS, PAS, SSA, and GUSS scores (p < 0.05). In a direct comparison of the swallowing parameters of the four groups, the changes in FEDSS, PAS, SSA, and GUSS scores showed a significantly greater improvement in the unaffected hemispheric group, the affected hemispheric group and cerebellum group than in the control group (p < 0.05). Conclusions: Whether stimulating the unaffected hemisphere or the affected hemisphere, 5 Hz high-frequency rTMS on mylohyoid cortical tissue might have a positive effect on poststroke patients with dysphagia. In addition, cerebellar rTMS is a safe method that represents a potential treatment for poststroke dysphagia, and more clinical trials are needed to develop this technique further. Clinical Trial Registration: chictr.org.cn, identifier: ChiCTR2000032255.

The Effectiveness of Acupuncture for Dysphagia after Stroke: A Systematic Review and Meta-Analysis.

OBJECTIVES: This study reviewed and evaluated existing evidence of the efficacy of acupuncture as a clinical treatment for dysphagia after stroke. METHODS: Five English and four Chinese databases were searched from inception to March 2020. All randomized controlled trials (RCTs) incorporating acupuncture or acupuncture combined with other interventions for the treatment of dysphagia after stroke were enrolled. All data were independently assessed and extracted by two authors. The bias risk assessment recommended by the Cochrane Collaboration's tool was used to assess the quality of the selected studies. This meta-analysis was conducted by using RevMan 5.3. Pooled analyses were calculated by the mean difference (MD) and 95% confidence interval (CI). Heterogeneity was assessed by the I 2 test. RESULTS: Thirty-five studies involving 3024 patients were analyzed. The meta-analysis showed that the therapeutic efficacy of acupuncture combined with other interventions was better than that of the control group for the standardized swallowing assessment (SSA) score (MD = -3.78, 95% CI: -4.64 to -2.91, P < 0.00001), Ichiro Fujishima rating scale (IFRS) score (MD = 1.68, 95% CI: 1.16 to 2.20, P < 0.00001), videofluoroscopic swallowing study (VFSS) score (MD = 2.26, 95% CI: 1.77 to 2.74, P < 0.00001), and water swallowing test (WST) score (MD = -1.21, 95% CI: -1.85 to -0.57, P= 0.0002). In studies reporting adverse effects, no serious outcome from an adverse event was confirmed. CONCLUSION: This systematic review indicated that acupuncture could be an effective therapy for treating dysphagia after stroke although stricter evaluation standards and rigorously designed RCTs are needed.