title: Cervical Spinal Cord Atrophy Profile in Adult SMN1-Linked SMA.
abstract: OBJECTIVE
  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.
  
  
  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.
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, INSERM, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France.
authors.forename: Mohamed-Mounir
authors.initials: MM
authors.lastname: El Mendili
authors.affiliation: APHP, Hôpital Pitié-Salpêtriere, Département des Maladies du Système Nerveux, Centre référent SLA, Paris, France.|APHP, Hôpital Pitié-Salpêtriere, Service d'Explorations Fonctionnelles, Paris, France.
authors.forename: Timothée
authors.initials: T
authors.lastname: Lenglet
authors.affiliation: APHP, Centre de Référence Maladies Neuromusculaires Paris-Est, Institut de Myologie, Paris, France.
authors.forename: Tanya
authors.initials: T
authors.lastname: Stojkovic
authors.affiliation: APHP, Centre de Référence Maladies Neuromusculaires Paris-Est, Institut de Myologie, Paris, France.
authors.forename: Anthony
authors.initials: A
authors.lastname: Behin
authors.affiliation: APHP, Centre de Référence Maladies Neuromusculaires Paris-Est, Institut de Myologie, Paris, France.
authors.forename: Raquel
authors.initials: R
authors.lastname: Guimarães-Costa
authors.affiliation: APHP, Hôpital Pitié-Salpêtriere, Département des Maladies du Système Nerveux, Centre référent SLA, Paris, France.
authors.forename: François
authors.initials: F
authors.lastname: Salachas
authors.affiliation: APHP, Hôpital Pitié-Salpêtriere, Département des Maladies du Système Nerveux, Centre référent SLA, Paris, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Meininger
authors.affiliation: APHP, Hôpital Pitié-Salpêtriere, Département des Maladies du Système Nerveux, Centre référent SLA, Paris, France.
authors.forename: Gaelle
authors.initials: G
authors.lastname: Bruneteau
authors.affiliation: APHP, Hôpital Pitié-Salpêtriere, Département des Maladies du Système Nerveux, Centre référent SLA, Paris, France.
authors.forename: Nadine
authors.initials: N
authors.lastname: Le Forestier
authors.affiliation: APHP, Centre de Référence Maladies Neuromusculaires Paris-Est, Institut de Myologie, Paris, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Laforêt
authors.affiliation: APHP, Hôpital Pitié-Salpêtriere, Service de Neuroradiologie, Paris, France.|Sorbonne Universités, UPMC Univ Paris 06, UMR-S975, Inserm U975, CNRS UMR7225, Centre de recherche de l'Institut du Cerveau et de la Moelle épinière-CRICM, Centre de Neuroimagerie de Recherche-CENIR, Paris, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Lehéricy
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, INSERM, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France.
authors.forename: Habib
authors.initials: H
authors.lastname: Benali
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, INSERM, Laboratoire d'Imagerie Biomédicale, F-75013, Paris, France.|APHP, Hôpital Pitié-Salpêtriere, Département des Maladies du Système Nerveux, Centre référent SLA, Paris, France.
authors.forename: Pierre-François
authors.initials: PF
authors.lastname: Pradat
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D066193:Cervical Cord / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D053580:Muscle Strength / Q000502:physiology; D009134:Muscular Atrophy, Spinal / Q000378:metabolism / Q000473:pathology*; D013116:Spinal Cord / Q000378:metabolism / Q000473:pathology*; D055533:Survival of Motor Neuron 1 Protein / Q000235:genetics* / Q000378:metabolism
chemical_list: D055533:Survival of Motor Neuron 1 Protein