Effects of Rehabilitative Intervention for Augmenting Cough Function in Patients with Multiple System Atrophy.

Objectives: One of the causes of death in patients with multiple system atrophy (MSA) is aspiration pneumonia caused by cough dysfunction. This study aimed to identify an effective approach to improve coughing and to explore the establishment of criteria for the use of gastrostomy based on cough and respiratory dysfunctions. Methods: Eighteen probable MSA patients participated in the study. They were categorized into air stacking and non-air stacking groups. First, we investigated how the inspiration volume changes by applying maximum insufflation capacity (MIC). Second, peak cough flow (PCF) was measured by different cough augmentation methods: 1) spontaneous coughing (SpC); 2) SpC with MIC (SpC + MIC); 3) SpC with manually assisted cough (MAC) (SpC + MAC); and 4) SpC with MIC and MAC (SpC + MIC + MAC). Among these four conditions, PCF values were compared to determine the most effective approach for cough augmentation. Receiver operating characteristic analysis was performed on percent forced vital capacity (%FVC) to determine an index for discriminating PCF below160 L/min, which indicates a high risk of suffocation, involving SpC and SpC + MIC. Results: Inspiration volume increased significantly with MIC in both groups (P < 0.05), and PCF increased significantly with MIC in the air stacking group (P < 0.01). PCF could not be maintained at 160 L/min when %FVC fell below 59%, even when MIC was applied. Conclusions: PCF increases with MIC in patients with MSA. It may be meaningful to consider the timing of gastrostomy introduction based on the severity of cough and respiratory dysfunction.