Phrenic nerve conduction studies as a biomarker of respiratory insufficiency in amyotrophic lateral sclerosis.

Our objective was to examine the value of phrenic nerve conduction studies (PNCS) in quantifying diaphragm dysfunction in ALS, as no ideal test of respiratory insufficiency exists in ALS. We prospectively recorded bilateral PNCS, forced vital capacity (FVC), maximum inspiratory pressure (MIP), sniff nasal inspiratory pressure (SNIP), respiratory rate, ALSFRS-R, and respiratory symptoms in 100 ALS patients attending our clinic over a nine-month period. Survival data were collected for two years.

Effects of noninvasive ventilation on sleep outcomes in amyotrophic lateral sclerosis.

Study Objectives: The objective was to study the effects on noninvasive ventilation on sleep outcomes in patient with ALS, specifically oxygenation and overall sleep quality.

Methods: Patients with ALS who met criteria for initiation of NIV were studied with a series of 2 home PSG studies, one without NIV and a follow-up study while using NIV. Primary outcome was a change in the maximum overnight oxygen saturation; secondary outcomes included change in mean overnight oxygen saturation, apnea and hypopnea indexes, sleep latency, sleep efficiency, sleep arousals, and sleep architecture.