Skip to Content
Medical Term:

spinal muscular atrophy


a heterogeneous group of degenerative diseases of the anterior horn cells in the spinal cord and motor nuclei of the brainstem; all are characterized by weakness. Upper motor neurons remain normal. These diseases include Werdnig-Hoffmann disease, spinal muscular atrophy types I and II (SMA1, SMA2); and Kugelberg-Welander disease, spinal muscular atrophy type III (SMA3).

See Also: Fazio-Londe disease

© Copyright 2017 Wolters Kluwer. All Rights Reserved. Review Date: Sep 19, 2016.