Randomized Controlled Trial On Latent Myofascial Trigger Points Injection For Adult Cough Variant Asthma

BackgroundCough variant asthma(CVA)is a chronic inflammatory airway disease characterized by airway hyper-responsiveness(AHR),of which cough is the only symptom.Cough is the contraction of the vocal cords,diaphragm,sternocleidomastoid muscle and other respiratory-related muscle groups caused by the AHR.Chronic cough can lead to repeated contractions and chronic strain in the head and neck relevant muscles,ultimately contributing to the formation of latent MTrPs in the head and neck.In contrast,latent MTrPs can also irritate or compress the surrounding nerves,leading to cough.It has been shown that latent MTrPs can induce autonomic dysfunction such as dizziness,tinnitus,insomnia,abnormal mucus secretion and AHR.We therefore hypothesize that pathophysiological abnormalities of latent MTrPs may disrupt the balance of sympathetic and parasympathetic nerves in the autonomic network of the head and neck,leading to abnormal constriction of airway smooth muscle and AHR,which may play an essential role in the etiology of CVA.ObjectiveThis article was to explore the efficacy and safety of latent MTrPs injection therapy on CVA patients.MethodsA total of 110 patients were included in this study and randomly assigned to either the intervention group or the control group in a 1:1.5 ratio.Group I(n=44):single injection therapy with latent MTrPs,sternocleidomastoid,medial or lateral pterygoid muscles,splenius capitis muscles,and sternoclavicular joint trigger points.Group C(n=66):budesonide-formoterol plus montelukast for 8 weeks.Patients were subsequently followed up at 1w,2w,4w,8w,12w,24w and 36w after treatment.Primary endpoints were cough VAS score at 36w and recurrence rate at week 36.Secondary endpoints included ACT(Asthma Control Test)scores,ACQ5(Asthma Control Questionnaire)scores and AQLQ scores(Asthma Patient Quality of Life Questionnaire)during follow-up;proportion of using rescue medication at week 36;and the occurrence of adverse reactions during follow up.Results1.The effect of latent MTrPs injection therapy on cough VAS score and recurrence rate at 36w in CVAThere were significant differences between groups in change from week 1 to 36 weeks in cough VAS,cough VAS scores were significantly lower in group I than in group C(36w,1.70±1.49 and 3.18±2.04;P=0.001).The recurrence rate at 36w was significantly lower in group I than in group C(36w,5.00%vs.34.55%,P=0.001).It can be inferred from the above results that latent MTrPs injection therapy can improve cough symptoms and reduce the recurrence rate of CVA.2.Effects of latent MTrPs injection therapy on the degree of asthma control and quality of life in CVA patientsThe degree of asthma control was significantly better in Group I than in Group C throughout the follow-up period:ACT scores(36w,21.38±2.65 and 18.53±3.00;P<0.001);ACQ5 scores(36w,0.85±0.55 and 1.52±0.62;P<0.001);AQLQ scores(36w,174.40±18.22 and 151.69±24.04;P<0.001).To sum up,latent MTrPs injection therapy can not only enhance the asthma control level of CVA patients,but also improve the quality of life of patients.3.Latent MTrPs injection therapy on asthma rescue medication and safety assessment in CVA patientsProportions of using asthma rescue medication was lower in Group I compared to Group C(36w,5.00%vs.29.10%,P=0.003).The frequency of adverse events was lower and there was no statistical difference between the two groups(7.50%vs.14.55%,P=0.462).The above results suggest that latent MTrPs injection therapy may reduce the use of rescue medication in CVA patients,and also has good safety.ConclusionsLatent MTrPs injection therapy can significantly improve the cough symptoms of CVA,reduce the use of rescue medication,improve the quality of life,and have good tolerance and high safety.