Fast Five Quiz: Spinal Muscular Atrophy

Stephen L. Nelson, Jr, MD, PhD


January 14, 2021

In patients with SMA type 1, findings on sensory examination are normal. Deep tendon reflexes and sphincter abnormalities are absent, whereas muscle weakness is severe and progressive and hypotonia is evident.

No evidence of cerebral or central nervous system dysfunction is seen in patients with SMA.

SMA type 3 is characterized by slowly progressive proximal weakness. Going up and down stairs and other tasks associated with motor skills may become increasingly difficult. Bulbar dysfunction occurs late in the disease course, whereas it occurs early in SMA type 1.

Learn more about the presentation of SMA.


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