Susana Pinto1, Pedro Alves1, Bernardo Pimentel1, Michael Swash2, Mamede de Carvalho3. 1. Institute of Physiology, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Portugal. 2. Institute of Physiology, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Portugal; Department of Neurology, Royal London Hospital, Queen Mary University of London, London, UK; Department of Neuroscience, Royal London Hospital, Queen Mary University of London, London, UK. 3. Institute of Physiology, Instituto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Portugal; Department of Neurosciences, Hospital de Santa Maria-CHLN, Lisbon, Portugal. Electronic address: mamedemg@mail.telepac.pt.
Abstract
OBJECTIVE: To evaluate the correlation between diaphragm thickness assessed by ultrasound (US) with respiratory function tests and the diaphragm motor responses, in patients with amyotrophic lateral sclerosis (ALS). METHODS: 42 consecutive ALS patients were studied (11 with bulbar-onset), excluding patients with marked orofacial paresis. Investigation included: revised ALS functional rating scale (ALSFRS-R), forced vital capacity (FVC), maximal voluntary ventilation (MVV), maximal inspiratory (MIP) and expiratory (MEP) pressures, nasal inspiratory pressure during sniff (SNIP); peak-to-peak amplitude of the diaphragmatic motor response to phrenic nerve stimulation (Diaphragm-CMAP), diaphragmatic thickness measured by ultrasound during maximal inspiration and during maximal expiration. Patients were analysed in bulbar or spinal subgroups. Correlations and multiple linear regression models were studied. RESULTS: The mean age at disease onset was 58.4 ± 11.1 years and with a mean disease duration of 17.8 ± 13.6 months. Ultrasound studies of diaphragm thickness in full inspiration correlated with diaphragm CMAP in the whole population and in spinal-onset patients; and were similar in the two groups. Multiple linear modelling showed that FVC, SNIP and MVV were dependent on the change of thickness (p=0.001, 0.001 and 0.020, respectively) and that MIP and MEP were related to diaphragm CMAP p=0.003 and p=0.025, respectively). CONCLUSION: Diaphragm thickness correlates with Diaphragm-CMAP, except in bulbar-onset patients. Respiratory tests are dependent on both diaphragm thickness and Diaphragm-CMAP. SIGNIFICANCE: US thickness of the diaphragm correlates with the number of functional motor units as assessed by the phrenic nerve motor amplitude.
OBJECTIVE: To evaluate the correlation between diaphragm thickness assessed by ultrasound (US) with respiratory function tests and the diaphragm motor responses, in patients with amyotrophic lateral sclerosis (ALS). METHODS: 42 consecutive ALSpatients were studied (11 with bulbar-onset), excluding patients with marked orofacial paresis. Investigation included: revised ALS functional rating scale (ALSFRS-R), forced vital capacity (FVC), maximal voluntary ventilation (MVV), maximal inspiratory (MIP) and expiratory (MEP) pressures, nasal inspiratory pressure during sniff (SNIP); peak-to-peak amplitude of the diaphragmatic motor response to phrenic nerve stimulation (Diaphragm-CMAP), diaphragmatic thickness measured by ultrasound during maximal inspiration and during maximal expiration. Patients were analysed in bulbar or spinal subgroups. Correlations and multiple linear regression models were studied. RESULTS: The mean age at disease onset was 58.4 ± 11.1 years and with a mean disease duration of 17.8 ± 13.6 months. Ultrasound studies of diaphragm thickness in full inspiration correlated with diaphragm CMAP in the whole population and in spinal-onset patients; and were similar in the two groups. Multiple linear modelling showed that FVC, SNIP and MVV were dependent on the change of thickness (p=0.001, 0.001 and 0.020, respectively) and that MIP and MEP were related to diaphragm CMAP p=0.003 and p=0.025, respectively). CONCLUSION: Diaphragm thickness correlates with Diaphragm-CMAP, except in bulbar-onset patients. Respiratory tests are dependent on both diaphragm thickness and Diaphragm-CMAP. SIGNIFICANCE: US thickness of the diaphragm correlates with the number of functional motor units as assessed by the phrenic nerve motor amplitude.
Authors: Laura López-Viñas; Juan Vega-Villar; Esmeralda Rocío-Martín; Patricia García-García; Elena De La Rosa Santiago; Jose María Galván-Román; Rybel Wix-Ramos Journal: Eur J Transl Myol Date: 2022-06-21
Authors: C E McIlduff; M G Martucci; C Shin; K Qi; A K Pacheck; H Gutierrez; M Mortreux; S B Rutkove Journal: Clin Neurophysiol Date: 2020-07-17 Impact factor: 3.708