Treatment Of Swallowing Disorder Caused By Stroke

Dysphagia is common in stroke patients and is an independent predictor of outcome,which can lead to dehydration,malnutrition or increased risk of aspiration pneumonia.This may increase mortality and length of hospital stay.Its damage not only has physical effects but also emotional and social effects.and it may even lead to depression and reduced quality of life.It is not surprising that swallowing disorder is associated with high costs and requires urgent effective treatment.Recently,neuromuscular electrical stimulation(NMES)and transcranial direct current stimulation(tDCS)have been studied for swallowing disorder.It has been assumed that the electrical stimulation assists swallowing either by eliciting muscle contractions or by increasing the sensory input to the central nervous system.Transcuataneous electrical nerve stimulation(TENS)technology is a kind of NMES,which is a non-invasive technique that can be used for the treatment of swallowing dysfunction,the technology uses surface electrodes input specific low-frequency current to human body.Unlike NMES.tDCS has a direct effect on the central nervous system,it is a non-invasive technique that provides a steady flow of weak polarizing currents via an electrode placed over the swallowing sensorimotor cortex.At the cellular level,tDCS influences neuron excitability by hyperpolarized(cathodal)or depolarized(anodal)resting membrane potential and appears to have little or no effect on the resting state.Anodal tDCS increases the excitability of cortical circuits,whereas cathodal tDCS reduces their excitability.PART ONEObjective:To evaluate and compare the effects of transcuataneous electrical nerve stimulation(TENS)acting on the sensory input or on motor muscle in treating dysphagic patients with medullary infarction.Design:Prospective randomized controlled study.Participants:Dysphagic patients with medullary infarction(N=82).Interventions:Participants were randomized over 3 intervention groups:traditional swallowing therapy,sensory approach combined with traditional swallowing therapy,and motor approach combined with traditional swallowing therapy.Electrical stimulation sessions were for 20 minutes,twice a day,for 5d/wk,over a 4-week period.Main Outcome Measures:Swallowing function was evaluated by the water swallowing test,Standardized Swallowing Assessment.and Dysphagia Outcome and Severity Scale,quality of life was evaluated by the Swallowing-Related Quality of Life(SWAL-QOL)scale,and cognition by the Mini-Mental State Examination(MMSE).Results:There were no statistically significant differences between the groups in age.gender,duration,MMSE score,or severity of the swallowing disorder(p>0.05).All groups showed improved swallowing function(p 0.01).the sensory approach combined with traditional swallowing therapy group showed significantly greater improvement than other two groups,and the motor approach combined with traditional swallowing therapy group showed greater improvement than the traditional swallowing therapy group(p<0.05).SWAL-QOL scores improved in all groups.SWAL-QOL scores increased more significantly in the sensory approach combined with traditional swallowing therapy and the motor approach combined with traditional swallowing therapy groups than in the traditional swallowing therapy group,and the sensory approach combined with traditional swallowing therapy and the motor approach combined with traditional swallowing therapy groups showed statistically significant differences(p = 0.04).Conclusions:TENS that targets either sensory input or motor muscle coupled with traditional therapy is conducive to recovery from dysphagia and improves quality of life for dysphagic patients with medullary infarction.Sensory approach appears to be better than motor approach.TENS is a relatively safe form of treatment for swallowing rehabilitation.PART TWOObjective:To observe the effects and safety of transcuataneous electrical nerve stimulation(TENS)in treating dysphagic patients with non-acute stroke.Participants:Dysphagic patients with non-acute stroke(N=60).Interventions:Participants were randomized over 2 intervention groups:30 patients in the control group and the treatment group,respectively.The control group was treated with manual swallowing function training,while the treatment group was given TENS treatment combined with manual swallowing function training.Treatment sessions were for 30 minutes.twice a day,for 5d/wk,over a 4-week period.Main Outcome Measures:Swallowing function was evaluated by the water swallowing test,Standardized Swallowing Assessment,and Dysphagia Outcome and Severity Scale,and cognition by the Mini-Mental State Examination(MMSE).Results:There were no statistically significant differences between the groups in age,gender,duration,lesion region.MMSE score,or severity of the swallowing disorder(p>0.05).Both groups showed improved swallowing function(p ≤0.01),the treatment group showed significantly greater improvement than the control group(p<0.05).There were no obvious adverse reactions occurred in the experiment,only 5 cases(16.7%)had local skin redness or mild allergy under the electrodes;12 cases(40%)patients had a slight metallic taste while TENS was given,which can be alleviated shortly after electrical stimulation.There were no patients remove from study due to the above skin reactions and oral odor.Conclusions:The therapeutic effect of TENS combined with manual swallowing function training group appears to be better than that of manual swallowing training group for dysphagic patients with non-acute stroke.TENS is a relatively safe form of treatment for swallowing rehabilitation.PART THREEObjective:The aim of this systematic review was to assess the effectiveness and safety of transcranial direct current stimulation in people with swallowing disorder.Methods:PubMed,EMBASE,Cochrane Library,Web of Science.ScienceDirect,and EBSCO were searched for studies that described the treatment effects of tDCS on the swallow function with no restrictions regarding language or year of publication.All texts identified by the search strategy were deduplicated and evaluated by inclusion and exclusion criteria,data from included studies were discussed and extracted into a table.Two reviewers assessed methodological quality of each included study independently.Reviewer Manager 5.0 was used to analyze all the extracted data.A meta-analysis on the effects sizes of the reviewed was performed.Results:Eight randomized studies were identified.Of the three studies involving participants with swallowing disorder as a result of stroke,the swallowing function in the anodal tDCS group improved significantly greater than those in the sham tDCS group(p = 0.02),with no significant heterogeneity(P = 0.8.I2 = 42%).Two studies applied anodal tDCS(20 min 1mA)over the ipsilesional hemisphere.the overall effect was not significant(p =0.41)just after the treatment,and moderate heterogeneity was observed(P = 0.09.I2 = 65%).however.we found anodal was more efficient than sham tDCS(p = 0.01)at long-term f-ollow-up.with no significant heterogeneity(P = 0.11,I2 = 61%).The overall rates of effectiveness are over 80%.Of the 8 studies,no significant adverse effects,such as headaches,visual disturbances,seizures,or significant skin irritation,were reported,except a little discomfort,such as a mild tingling sensation under the electrodes,and no one dropped out from the tDCS group.The primary limitation of this review relates to the small sample size of included studies.Conclusions:This review indicated that tDCS applied over the swallowing motor cortex may have potential therapeutic benefits for swallowing disorder owing to its effect on cortical excitability,tDCS seems to be a relatively safe form of treatment for swallowing rehabilitation.