A New Method for Measuring Bell-Shaped Chest Induced by Impaired Ribcage Muscles in Spinal Muscular Atrophy Children

Antonella LoMauro, Paolo Banfi, Chiara Mastella, Katia Alberti, Giovanni Baranello, Andrea Aliverti

Research output: Contribution to journalArticle

Abstract

The involvement of the respiratory muscular pump makes SMA children prone to frequent hospitalization and morbidity, particularly in type 1. Progressive weakness affects ribcage muscles resulting in bell-shaped chest that was never quantified. The aims of the present work were: (1) to quantify the presence of bell-shaped chest in SMA infants and children and to correlate it with the action of ribcage muscles, assessed by the contribution of pulmonary ribcage to tidal volume (ΔVRC, p); (2) to verify if and how the structure of the ribcage and ΔVRC, p change after 1-year in SMA type 2. 91 SMA children were studied in supine position during awake spontaneous breathing: 32 with type 1 (SMA1, median age: 0.8 years), 51 with type 2 (SMA2, 3.7 years), 8 with type 3 (SMA3, 5.4 years) and 20 healthy children (HC, 5.2 years). 14 SMA2 showed negative ΔVRC, p (SMA2px), index of paradoxical inspiratory inward motion. The bell-shaped chest index was defined as the ratio between the distance of the two anterior axillary lines at sternal angle and the distance between the right and left 10th costal cartilage. If this index was < < 1, it indicated bell shape, if ~1 it indicated rectangular shape, while if > 1 an inverted triangle shape was identified. While the bell-shaped index was similar between HC (0.92) and SMA3 (0.91), it was significantly (p < 0.05) reduced in SMA2 (0.81), SMA2px (0.74) and SMA1 (0.73), being similar between the last two. There was a good correlation (Spearman's rank correlation coefficient, ρ = 0.635, p < 0.001) between ribcage geometry and ΔVRC, p. After 1 year, ΔVRC, p reduced while bell-shaped chest index did not change being significantly lower than HC. The shape of the ribcage was quantified and correlated with the action of ribcage muscles in SMA children. The impaired ribcage muscles function alters the ribcage structure. HC and SMA3 show an almost rectangular ribcage shape, whereas SMA2, SMA2px and SMA1 are characterized by bell-shaped chest. In SMA, therefore, a vicious cycle starts since infancy: the disease progressively affects ribcage muscles resulting in reduced expansion of lung and ribcage that ultimately alters ribcage shape. This puts the respiratory muscles at mechanical disadvantage.

Original languageEnglish
Pages (from-to)703
JournalFrontiers in Neurology
Volume9
DOIs
Publication statusPublished - 2018

Fingerprint

Spinal Muscular Atrophy
Thorax
Muscles
Rib Cage
Lung
Respiratory Muscles
Supine Position
Tidal Volume
Nonparametric Statistics

Cite this

A New Method for Measuring Bell-Shaped Chest Induced by Impaired Ribcage Muscles in Spinal Muscular Atrophy Children. / LoMauro, Antonella; Banfi, Paolo; Mastella, Chiara; Alberti, Katia; Baranello, Giovanni; Aliverti, Andrea.

In: Frontiers in Neurology, Vol. 9, 2018, p. 703.

Research output: Contribution to journalArticle

@article{2d66ecb806f34b569e428ab9fb8f4d32,
title = "A New Method for Measuring Bell-Shaped Chest Induced by Impaired Ribcage Muscles in Spinal Muscular Atrophy Children",
abstract = "The involvement of the respiratory muscular pump makes SMA children prone to frequent hospitalization and morbidity, particularly in type 1. Progressive weakness affects ribcage muscles resulting in bell-shaped chest that was never quantified. The aims of the present work were: (1) to quantify the presence of bell-shaped chest in SMA infants and children and to correlate it with the action of ribcage muscles, assessed by the contribution of pulmonary ribcage to tidal volume (ΔVRC, p); (2) to verify if and how the structure of the ribcage and ΔVRC, p change after 1-year in SMA type 2. 91 SMA children were studied in supine position during awake spontaneous breathing: 32 with type 1 (SMA1, median age: 0.8 years), 51 with type 2 (SMA2, 3.7 years), 8 with type 3 (SMA3, 5.4 years) and 20 healthy children (HC, 5.2 years). 14 SMA2 showed negative ΔVRC, p (SMA2px), index of paradoxical inspiratory inward motion. The bell-shaped chest index was defined as the ratio between the distance of the two anterior axillary lines at sternal angle and the distance between the right and left 10th costal cartilage. If this index was < < 1, it indicated bell shape, if ~1 it indicated rectangular shape, while if > 1 an inverted triangle shape was identified. While the bell-shaped index was similar between HC (0.92) and SMA3 (0.91), it was significantly (p < 0.05) reduced in SMA2 (0.81), SMA2px (0.74) and SMA1 (0.73), being similar between the last two. There was a good correlation (Spearman's rank correlation coefficient, ρ = 0.635, p < 0.001) between ribcage geometry and ΔVRC, p. After 1 year, ΔVRC, p reduced while bell-shaped chest index did not change being significantly lower than HC. The shape of the ribcage was quantified and correlated with the action of ribcage muscles in SMA children. The impaired ribcage muscles function alters the ribcage structure. HC and SMA3 show an almost rectangular ribcage shape, whereas SMA2, SMA2px and SMA1 are characterized by bell-shaped chest. In SMA, therefore, a vicious cycle starts since infancy: the disease progressively affects ribcage muscles resulting in reduced expansion of lung and ribcage that ultimately alters ribcage shape. This puts the respiratory muscles at mechanical disadvantage.",
author = "Antonella LoMauro and Paolo Banfi and Chiara Mastella and Katia Alberti and Giovanni Baranello and Andrea Aliverti",
year = "2018",
doi = "10.3389/fneur.2018.00703",
language = "English",
volume = "9",
pages = "703",
journal = "Frontiers in Neurology",
issn = "1664-2295",
publisher = "Frontiers Research Foundation",

}

TY - JOUR

T1 - A New Method for Measuring Bell-Shaped Chest Induced by Impaired Ribcage Muscles in Spinal Muscular Atrophy Children

AU - LoMauro, Antonella

AU - Banfi, Paolo

AU - Mastella, Chiara

AU - Alberti, Katia

AU - Baranello, Giovanni

AU - Aliverti, Andrea

PY - 2018

Y1 - 2018

N2 - The involvement of the respiratory muscular pump makes SMA children prone to frequent hospitalization and morbidity, particularly in type 1. Progressive weakness affects ribcage muscles resulting in bell-shaped chest that was never quantified. The aims of the present work were: (1) to quantify the presence of bell-shaped chest in SMA infants and children and to correlate it with the action of ribcage muscles, assessed by the contribution of pulmonary ribcage to tidal volume (ΔVRC, p); (2) to verify if and how the structure of the ribcage and ΔVRC, p change after 1-year in SMA type 2. 91 SMA children were studied in supine position during awake spontaneous breathing: 32 with type 1 (SMA1, median age: 0.8 years), 51 with type 2 (SMA2, 3.7 years), 8 with type 3 (SMA3, 5.4 years) and 20 healthy children (HC, 5.2 years). 14 SMA2 showed negative ΔVRC, p (SMA2px), index of paradoxical inspiratory inward motion. The bell-shaped chest index was defined as the ratio between the distance of the two anterior axillary lines at sternal angle and the distance between the right and left 10th costal cartilage. If this index was < < 1, it indicated bell shape, if ~1 it indicated rectangular shape, while if > 1 an inverted triangle shape was identified. While the bell-shaped index was similar between HC (0.92) and SMA3 (0.91), it was significantly (p < 0.05) reduced in SMA2 (0.81), SMA2px (0.74) and SMA1 (0.73), being similar between the last two. There was a good correlation (Spearman's rank correlation coefficient, ρ = 0.635, p < 0.001) between ribcage geometry and ΔVRC, p. After 1 year, ΔVRC, p reduced while bell-shaped chest index did not change being significantly lower than HC. The shape of the ribcage was quantified and correlated with the action of ribcage muscles in SMA children. The impaired ribcage muscles function alters the ribcage structure. HC and SMA3 show an almost rectangular ribcage shape, whereas SMA2, SMA2px and SMA1 are characterized by bell-shaped chest. In SMA, therefore, a vicious cycle starts since infancy: the disease progressively affects ribcage muscles resulting in reduced expansion of lung and ribcage that ultimately alters ribcage shape. This puts the respiratory muscles at mechanical disadvantage.

AB - The involvement of the respiratory muscular pump makes SMA children prone to frequent hospitalization and morbidity, particularly in type 1. Progressive weakness affects ribcage muscles resulting in bell-shaped chest that was never quantified. The aims of the present work were: (1) to quantify the presence of bell-shaped chest in SMA infants and children and to correlate it with the action of ribcage muscles, assessed by the contribution of pulmonary ribcage to tidal volume (ΔVRC, p); (2) to verify if and how the structure of the ribcage and ΔVRC, p change after 1-year in SMA type 2. 91 SMA children were studied in supine position during awake spontaneous breathing: 32 with type 1 (SMA1, median age: 0.8 years), 51 with type 2 (SMA2, 3.7 years), 8 with type 3 (SMA3, 5.4 years) and 20 healthy children (HC, 5.2 years). 14 SMA2 showed negative ΔVRC, p (SMA2px), index of paradoxical inspiratory inward motion. The bell-shaped chest index was defined as the ratio between the distance of the two anterior axillary lines at sternal angle and the distance between the right and left 10th costal cartilage. If this index was < < 1, it indicated bell shape, if ~1 it indicated rectangular shape, while if > 1 an inverted triangle shape was identified. While the bell-shaped index was similar between HC (0.92) and SMA3 (0.91), it was significantly (p < 0.05) reduced in SMA2 (0.81), SMA2px (0.74) and SMA1 (0.73), being similar between the last two. There was a good correlation (Spearman's rank correlation coefficient, ρ = 0.635, p < 0.001) between ribcage geometry and ΔVRC, p. After 1 year, ΔVRC, p reduced while bell-shaped chest index did not change being significantly lower than HC. The shape of the ribcage was quantified and correlated with the action of ribcage muscles in SMA children. The impaired ribcage muscles function alters the ribcage structure. HC and SMA3 show an almost rectangular ribcage shape, whereas SMA2, SMA2px and SMA1 are characterized by bell-shaped chest. In SMA, therefore, a vicious cycle starts since infancy: the disease progressively affects ribcage muscles resulting in reduced expansion of lung and ribcage that ultimately alters ribcage shape. This puts the respiratory muscles at mechanical disadvantage.

U2 - 10.3389/fneur.2018.00703

DO - 10.3389/fneur.2018.00703

M3 - Article

VL - 9

SP - 703

JO - Frontiers in Neurology

JF - Frontiers in Neurology

SN - 1664-2295

ER -