Reliability of phrenic nerve conduction study: In healthy controls and in patients with primary lateral sclerosis. Issue 5 (May 2020)

• Record Type: Journal Article
• Authors: Torrieri, Maria Claudia; Miranda, Bruno; Gromicho, Marta; Pinto, Susana; de Carvalho, Mamede
• Is Part Of: Clinical neurophysiology. Volume 131:Issue 5(2020:May)
• Page Start: 994
• Page End: 999
• Publication Date: 2020-05
• Subjects: Amyotrophic lateral sclerosis -- Phrenic nerve motor response -- Primary lateral sclerosis -- Reliability -- Respiratory function; Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2020.02.010
• Languages: English
• ISSNs: 1388-2457

Abstract

Highlights: Phrenic nerve conduction provides information on respiratory function in amyotrophic lateral sclerosis. Phrenic nerve latency, amplitude and area are reliable measurements. This test should be considered as a reliable measure of respiratory function. Abstract: Objective: Phrenic nerve conduction study is a marker of hypoventilation in amyotrophic lateral sclerosis. We aimed to evaluate its intra-rater reliability in healthy subjects and in a cohort of Primary Lateral Sclerosis (PLS) patients. Methods: Eighteen healthy subjects and 16 PLS patients were included. All subjects underwent three phrenic nerve conduction evaluations (time interval: 1 week for healthy controls; 1 year for PLS patients). We analyzed intra-rater reliability for five parameters of the diaphragmatic motor response: latency; negative-peak duration, area and amplitude; peak-to-peak amplitude. Results: Healthy subjects showed excellent inter-test reliability for most parameters (coefficients of variation <10%). In PLS patients coefficients of variation resulted <10% for latency and peak-to-peak amplitude, <20% for remaining parameters. Inter-test reliability was excellent for latency and peak-to-peak amplitude [intra-class correlation coefficient (ICC) > 0.9] and good for negative-peak amplitude and area (ICC 0.75 ≥ 0.9); duration was not reliable (ICC = 0.383). Negative peak and peak-to-peak amplitude had the least random error (respectively ±0.136 mV and ± 0.177 mV). All parameters showed homoscedasticity (R2 < 0.1). Conclusions: Intra-rater reliability is high for phrenic nerve study, especially for latency, peak-to-peak and negative-peak amplitude. Significance: Phrenic nerve conduction study is a reliable method to monitor respiratory function.