Inspiratory Muscle Training in Adults With Cerebral Palsy: Long Term Effects: A Double-Blind Randomized, Controlled Trial.

Respiratory disease is one of the main causes of morbidity and mortality in adults with cerebral palsy (CP). The main objective of the study was to investigate the maintenance over time of improvements in respiratory parameters achieved with inspiratory muscle training (IMT). This was a randomized, controlled, double-blind trial and with allocation concealment performed on 27 institutionalized CP patients randomly distributed in two groups: "high intensity training group" (HIT) trained with a load of 40% of the maximum inspiratory pressure (MIP) and "low intensity training group" (LIT) with 20%. Respiratory strength and pulmonary function were evaluated throughout the study. Four weeks after IMT most improvements persisted. Twelve weeks after IMT, only HIT maintained significant improvements (p = 0.001) in MIP; 24 weeks after IMT, in the HIT group, MIP was 10% higher than the initial results and pulmonary function parameters were 1% lower. In the LIT group, respiratory strength and pulmonary function were lower than at baseline. Improvements achieved with IMT are reduced over time once the treatment ends. During the first 4 weeks posttreatment, the benefits persist but from the 12th week there was a progressive loss of the improvement reaching a total loss at 24 weeks. To be most effective, a higher MIP load is suggested for respiratory treatment, which must be maintained over time and interruptions should not be longer than 4 weeks. Clinical trial registration. The study was registered in the clinical trials database of the United States National Library of Medicine (www.clinicaltrials.gov) with the number of registration NCT04915170.