Exploration of reliable assessment of respiratory function in amyotrophic lateral sclerosis.

OBJECTIVE: To identify potentially useful objective indicators for early assessment of respiratory dysfunction in amyotrophic lateral sclerosis (ALS). METHODS: Forty ALS patients were enrolled and followed every 3 months for one year. Baseline assessments included dyspnea complaints, ALSFRS-R, the ALS Respiratory Symptom Score (ARES), physical examination (including lower lung mobility), phrenic nerve conduction studies, diaphragm ultrasound, and multi-region ultrasound fasciculation detection. Forced vital capacity (FVC%) was also measured. Logistic regression (binary outcomes) and linear regression (continuous outcomes) were used to identify predictors of respiratory decline at 6 and 12 months. RESULTS: At 6 months, decreased right lower lung mobility (β = 1.771, 95%CI:1.047-2.495, p = 0.038), bulbar fasciculations (OR = 2.198, 95%CI:1.527-2.868, p = 0.001), and lumbosacral fasciculations (OR = 2.117, 95%CI:1.516-2.839, p = 0.001) independently predicted a higher post-progression rate. At 12 months, cervical fasciculations predicted a higher post-progression rate (OR = 1.644, 95%CI:1.130-2.157, p = 0.017). Traditional measures (FVC%, diaphragm ultrasound, phrenic CMAP) showed limited short-term predictive value. CONCLUSION: Lower lung mobility on physical examination and ultrasound-detected fasciculations in bulbar, cervical, and lumbosacral regions are potentially valuable objective markers for predicting disease progression in ALS. These exploratory findings suggest they may complement conventional pulmonary function tests, but require validation in larger independent cohorts.