The trial was an open-label randomized controlled trial comparing the effect of latent MTrPs injection therapy vs. budesonide-formoterol plus montelukast therapy in adult CVA patients. Signed informed consent was obtained from all participants. The trial took place at Qilu Hospital, Cheeloo College of Medicine of Shandong University, Jinan, China. This study was approved by the Human Research Ethics Committee of Qilu hospital (KYLL-202011-127) and registered in the Clinical Trial Registry Center (ChiCTR2100044079).
Before randomization, eligible patients entered a 2-week single-blind placebo run-in period. After the run-in period, a total of 110 patients were randomly assigned utilizing computer access to internet assignment in a 1:1.5 allocation ratio to undergo intervention or control group. Intervention group (n=44): latent MTrPs injection only once, sternocleidomastoid tender points, medial or lateral pterygoid muscle tender points, and so on. Control group (n=66): twice-daily budesonide-formoterol (160 ug budesonide and 4.5 ug of formoterol) plus montelukast 10mg for eight weeks. If patients have long-term poor asthma control during the trial, they will be allowed to use asthma rescue medication. Rescue medication was Salbutamol Sulphate Aerosol (GLAXO WELLCOME, S.A.: 100ug/treatment via a metered-dose inhaler, maximum usage 400 µg/d as needed).
Patients were recruited from the respiratory department of Qilu Hospital of Shandong University. After treatment, 36 weeks of follow up were carried out.
Patients 18 years of age or older who had received a clinical diagnosis of CVA (Global Initiative for Asthma [GINA] 2018 criteria(26, 27)) at least eight weeks. The other patient inclusion criteria are as follows: (1) <75 years old. (2) any sex or ethnicity. (3) All patients signed an informed consent. The exclusion criteria are as follows: (1) Cough is caused by other diseases. (2) Patients with a known hypersensitivity to lidocaine or vitamin B12. (3) Comorbidity includes chronic lung, cardiovascular, kidney, neurologic, or another systemic disease. (4) History of drug abuse (including oral corticosteroid) in the last three weeks. (5) Smoking within six months. (6) Pregnancy.
Latent MTrPs injection procedures
Drugs used for latent MTrPs injection containing vitamin B12 (JinYao Corp, Tianjin City, China; 1ml:1mg), 2% lidocaine injection (ZhaoHui Corp, Shanghai City, China; 5ml:200mg), and compound betamethasone injection (MSD Merck Sharp & Dohme AG, Switzerland; 1ml: 5 mg betamethasone bipropionate and 2 mg betamethasone bisodium phosphate) were diluted to 20ml with 0.9% saline for a single injection. The latent MTrPs injection was performed with needle 25 (0.5 * 36 mm) and a 20 ml syringe (We Go Corp, Weihai City, China).
The latent MTrPs main found in sternocleidomastoid, medial or lateral pterygoid muscles, splenius, and the greater or lesser occipital nerve by palpation. But it was difficult to palpate when some trigger points were hidden in muscles, and the finical therapeutic effects depend on the accuracy of palpated points(28). The sign of accurate latent MTrPs is confirmed by the ‘jump sign’ as shown by the patient, which may include withdrawal of the head, wrinkling of the face (or forehead), or a verbal response or muscle local twitch response (LTRs)(11, 12). Latent MTrPs palpation and injection procedure were performed as Travell and Simons’ “trigger point manual” recorded.
1. Medial or Lateral Pterygoid Muscles
Palpation was performed with progressive and sustained deep single-finger pressure on the skin’s surface to identify the latent MTrPs in medial or lateral pterygoid muscles. The patients were instructed to remain seated and keep his head and shoulder fixed to enable maximum relaxation of the researched muscles(29). Once trigger points were determined, the thumb of the therapist's one hand remained in a fixed position on the skin, disinfecting the surrounding skin, making the patients keep his/her mouth open (prevent needle blocking in the temporomandibular joint), the other hand take the syringe and insert it into muscles, adjusting the depth of the needle, when the patients felt referred pain, it is indicated that the needle was inserted into the latent MTrPs, then injecting 3-5ml liquid drugs. There are many small blood vessels adjacent to muscles; it is necessary to withdraw before injection to avoid intravascular injection. The other side was injected using the same technique.
2. Sternocleidomastoid Muscles
When palpating in sternocleidomastoid muscles, let the patient sit up with his/her head slightly inclined to one side, and the examiner pinched the muscle with his thumb and index finger to identify the latent MTrPs. The same technique injected the both side of sternocleidomastoid muscles.
3. Splenius Capitis Muscles
Let the patient seat with his/her arms crossed on the desk and his/her forehead fell on the forearm, identifying the trigger points by palpation. The injection technique is the same as the above, pressed the puncture points after injection to promote the better absorption of drugs. Palpation and injection procedures were performed by the same professor who had 20 years of experience.
Budesonide and formoterol Fumarate Powder for Inhalation (AstraZeneca AB: 160ug budesonide and 4.5ug of formoterol per inhaler, one inhaler every 12 hours, maximum usage four inhalers/d as needed) plus montelukast (Merck Sharp & Dohme Ltd: 10mg per night) for eight weeks.
The primary outcomes were changes in cough visual analog scale (VAS) scores from baseline to 1 week, 2 weeks, 4 weeks, 8 weeks, 12 weeks, 24weeks and 36 weeks after treatment; recurrence rate within 36 weeks. VAS is a validated summative cough variant asthma score ranging from 0 to 10 points, where VAS scores of 1-3, 4-6, and 7-10 points indicate mild, moderate, and severe asthma, respectively. The higher the score, the more serious the symptoms(30). VAS scores were divided into daytime cough scores and nighttime cough scores. Scores were assessed on a 6-point scale ranging from 0 to 5, with higher values indicating more severe cough symptoms. VAS changes less than 2 points compared with the baseline, which is regarded as recurrence.
The secondary outcomes mainly included changes in the ACQ-5 scores, ACT scores, AQLQ scores from baseline to 1 week, 2 weeks, 4 weeks, 8 weeks, 12 weeks, 24weeks and 36 weeks after treatment. The “Asthma Control Questionnaire” (ACQ) is a very common questionnaire for assessing asthma control. ACQ-5 includes five questions about the asthma symptoms of the previous week(31). Each scored ranged from 0 (no impairment) to 6 points (maximum impairment). The ACT also includes five questions about the asthma symptoms of the previous four weeks, each score ranging from 1 (max impairment) to 5 points (no impairment). The AQLQ contains twenty-seven questions about asthma symptoms and social and psychological problems during the previous 1 week. Each item is scored on a scale of 1 (severely impairment) to 7 points (no impairment). And the rate of rescue medication treatments administered within 36 weeks. Safety was evaluated according to the type and severity of adverse events (A.E.s). After latent MTrPs injection, there was a 30 minutes observation period. Patients were required to record any local or systemic effects during the follow-up period.
Used PASS Sample Size Software to estimate sample size. We calculated that 31 participants in the intervention group and 46 participants in the control group would provide the trial with at least 95 % power (2-sided α=0.05) to detect differences in the primary endpoint (VAS) between the two groups. We used the SPSS version 22.0 software and GraphPad Prism 8.3 for statistical analysis. Numerical results are presented as mean ± standard deviation. The Mann-Whitney U test was used to assess the difference between the two groups, and the paired Student’s t-test was used to assess the difference from baseline to 36 weeks within each group. For categorical endpoints, dates were compared using either the chi-square test or Fisher’s exact test. For continuous variables, the medians were compared with a Mann-Whitney U test. Difference in medians were calculated using the Hodges-Lehmann estimate. A P value less than 0.05 was considered to indicated statistical significance.