Disorder - Myotonia

Organ Systems Involved
Musculoskeletal

Alternative disorders described within LIDA

Feline muscular dystrophy; Feline myopathy; Feline muscular dystrophy, Duchenne and Becker types; Myasthenia gravis

Alternative Names
Myotonic myopathy; Non-dystrophic myopathy; Myotonia congenital

Presenting Signs

Myotonia is a congenital condition that results in continued, active contraction of muscle after the voluntary effort or stimulation has stopped. The response of the muscles to activity is generally inappropriate or disproportionate to what is normally expected. For example, following a startle, they may twitch involuntarily and continue twitching for a few minutes.

Affected cats walk with a short, choppy or stiff gait that improves with exercise. They can also appear uncoordinated in movement. Alternatively, cats with myotonia can present with weakness or episodes of collapse. They are often reluctant to move, and when at rest, they have involuntary muscle movements or muscle spasms. The muscle spasms may occur in any muscle, including the eyelid and facial muscles. As a consequence of the inappropriate muscle activity, affected cats can have difficulty eating – usually because they have problems opening their mouth. Their voice may also become unusual. In addition the muscles of their forelimbs can be quite enlarged.

Cats at Risk

Juveniles

PubMed References
Myotonia

Contributor
Nicole Rous