[Neurophysiological and functional assessment of patients with difficult-to-control asthma]

Due to the inadequate response to inhaled corticoids, patients with difficult-to-control asthma (DCA) are submitted to oral corticoids or use of Omalizumab. Although it is necessary to treat these patients, a significant relationship between steroid usage and both peripheral and respiratory weakness muscle, results in implications such as loss of quality of life and compromised lung function. Nonetheless, it is not known whether these patients suffer neurophysiological changes due to drug effect.

To investigate the neurophysiological and functional characteristics of patients with DCA in order to gain a better understanding of the condition.

A cross-sectional study was carried out involving three groups of patients: DCA-C (use of oral corticosteroids), DCA-O (use of omalizumab) and CG (healthy controls matched for age). The assessment involved the six-minute walk test, sit-to-stand test, static balance on a pressure platform, patellar and Achilles reflexes and quadriceps strength in the dominant leg.

The results revealed no statistically significant differences between the control group and DCA groups in relation to neurophysiological aspects. However, the DCA groups exhibited a significant reduction in functional capacity [decreased muscle strength (p < 0.05), shorter distance covered on walk test (p < 0.05) and lesser number of repetitions on sit-to-stand test (p < 0.05)] in comparison to the control group.

Individuals with DCA exhibited a reduction in functional capacity. The DCA-C group also demonstrated a reduction in muscle strength when compared with control group, likely caused by the continual use of corticoids. However, no neurophysiological alterations were found in the studied population.