Stiff person spectrum disorder

What is Stiff person spectrum disorder?

A rare neurological disorder comprising fluctuating trunk and limb stiffness, painful muscle spasms, task-specific phobia, an exaggerated startle response, and ankylosing deformities such as fixed lumbar hyperlordosis.

Other condition names

  • Moersch-Woltman syndrome
  • SMS
  • SPS
  • Stiff man syndrome

Inheritance type

Not applicable


  • Europe: 1-9 in 1,000 000

Age of Onset

  • Adult
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