title: Involvement of spinal sensory pathway in ALS and specificity of cord atrophy to lower motor neuron degeneration.
abstract: Our objective was to demonstrate that ALS patients have sensory pathway involvement and that local cord atrophy reflects segmental lower motor neuron involvement. Twenty-nine ALS patients with spinal onset and twenty-one healthy controls were recruited. Diffusion tensor imaging (DTI), magnetization transfer and atrophy index were measured in the spinal cord, complemented with transcranial magnetic stimulations. Metrics were quantified within the lateral corticospinal and the dorsal segments of the cervical cord. Significant differences were detected between patients and controls for DTI and magnetization transfer metrics in the lateral and dorsal segments of the spinal cord. Fractional anisotropy correlated with ALSFRS-R (p = 0.04) and motor threshold (p = 0.02). Stepwise linear regression detected local spinal cord atrophy associated with weakness in the corresponding muscle territory, i.e. C4 level for deltoid and C7 level for hand muscles. In conclusion, impairment of spinal sensory pathways was detected at an early stage of the disease. Our data also demonstrate an association between muscle deficits and local spinal cord atrophy, suggesting that atrophy is a sensitive biomarker for lower motor neurons degeneration.
authors.affiliation: UMR-678, INSERM-UPMC, Groupe Hospitalier Pitié-Salpêtrière, Paris, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Cohen-Adad
authors.forename: Mohamed-Mounir
authors.initials: MM
authors.lastname: El Mendili
authors.forename: Régine
authors.initials: R
authors.lastname: Morizot-Koutlidis
authors.forename: Stéphane
authors.initials: S
authors.lastname: Lehéricy
authors.forename: Vincent
authors.initials: V
authors.lastname: Meininger
authors.forename: Sophie
authors.initials: S
authors.lastname: Blancho
authors.forename: Serge
authors.initials: S
authors.lastname: Rossignol
authors.forename: Habib
authors.initials: H
authors.lastname: Benali
authors.forename: Pierre-François
authors.initials: PF
authors.lastname: Pradat
mesh_terms: D000344:Afferent Pathways / Q000473:pathology / Q000503:physiopathology; D000690:Amyotrophic Lateral Sclerosis / Q000473:pathology / Q000503:physiopathology*; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons; D009134:Muscular Atrophy, Spinal / Q000473:pathology / Q000503:physiopathology*; D011984:Sensory Receptor Cells; D013116:Spinal Cord / Q000473:pathology / Q000503:physiopathology*