Open AccessCervical Spinal Cord Atrophy Profile in Adult SMN1-Linked SMA
Author(s) -
Mohamed-Mounir El Mendili,
Timothée Lenglet,
Tanya Stojkovic,
Anthony Béhin,
Raquel GuimarãesCosta,
François Salachas,
Vincent Meininger,
Gaëlle Bruneteau,
Nadine Le Forestier,
Pascal Laforêt,
Stéphane Lehericy,
Habib Benali,
PierreFrançois Pradat
Publication year - 2016
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0152439
Subject(s) - smn1 , sma* , spinal muscular atrophy , spinal cord , medicine , atrophy , weakness , motor neuron , anatomy , muscle atrophy , pathology , mathematics , disease , combinatorics , psychiatry
Purpose The mechanisms underlying the topography of motor deficits in spinal muscular atrophy (SMA) remain unknown. We investigated the profile of spinal cord atrophy (SCA) in SMN1-linked SMA, and its correlation with the topography of muscle weakness. Materials and Methods Eighteen SMN1-linked SMA patients type III/V and 18 age/gender-matched healthy volunteers were included. Patients were scored on manual muscle testing and functional scales. Spinal cord was imaged using 3T MRI system. Radial distance (RD) and cord cross-sectional area (CSA) measurements in SMA patients were compared to those in controls and correlated with strength and disability scores. Results CSA measurements revealed a significant cord atrophy gradient mainly located between C3 and C6 vertebral levels with a SCA rate ranging from 5.4% to 23% in SMA patients compared to controls. RD was significantly lower in SMA patients compared to controls in the anterior-posterior direction with a maximum along C4 and C5 vertebral levels ( p-values < 10 −5 ). There were no correlations between atrophy measurements, strength and disability scores. Conclusions Spinal cord atrophy in adult SMN1-linked SMA predominates in the segments innervating the proximal muscles. Additional factors such as neuromuscular junction or intrinsic skeletal muscle defects may play a role in more complex mechanisms underlying weakness in these patients.