Subclinical spinal muscular atrophy in a 60-year-old man.

Spinal muscular atrophy is an autosomal recessive genetic disease that can manifest with different phenotypes, classified as types 1 to 4, being type 4 the mildest form. We report a case of a 60-year-old man presenting with sudden onset of numbness in the right upper limb and with a family history of a 48-year-old brother with progressive weakness. At the first visit, his exam was unremarkable, except for a mild paresis of the right elbow extension and reduced right bicipital and tricipital reflexes. Electromyography revealed chronic motor neuronopathy and the genetic study confirmed a diagnosis of spinal muscular atrophy. At the follow-up visit his complains improved and his neurologic exam returned to normal. To our knowledge, this patient is the oldest asymptomatic SMA individual ever reported. This case highlights the need to exclude late onset spinal muscular atrophy in patients with indolent motor neuronopathy.