2 Werdnig – Hoffmann disease

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Location of neurons affected by spinal muscular atrophy in the spinal cord

Werdnig – Hoffmann disease = SMA type I (Infantile)

• Autosomal Recessive.

• Usual age of onset : 0-6months

• Marked hypotonia, Sluggish movement and fasciculation of tongue (Floppy Neonate).

• Atrophy of spinal anterior horn cells.

• Sparing : Extraoccular muscles and sphincters.

• Death by 2-4yr age

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Dubowitz disease = SMA type II (Intermediate)

Kugelberg – Welander disease = SMA type III (juvenile)

Adult onset - Type IV

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Img source: http://en.wikipedia.org/wiki/File:Polio_spinal_diagram.PNG