Page 860 - Problem-Based Feline Medicine

39. The cat with tremor or twitching

Rodney S Bagley

KEY SIGNS
● Head and/or body tremor.
● Twitching.

MECHANISM?
● Tremor is an involuntary, rhythmic, oscillatory movement of all or part of the body. It results
from the alternate or synchronous contraction of reciprocally innervated, antagonistic muscles.

WHERE?
● Disease of the nervous system (central and peripheral) and muscle may result in tremor, shak-
ing or twitching.
● Usually tremors with increased amplitudes and slower frequencies (coarse tremor) are associ-
ated with cerebellar disorders. Those tremors with decreased amplitudes and faster frequencies
(fine tremor) are associated with diffuse central nervous system disease or muscle weakness.
● Tremor can have differing amplitudes (the distance traveled during the movement) and fre-
quencies (how fast the tremor is).
WHAT?
● Disease of the nervous system that results in persistent, generalized (whole body) tremor is
usually diffuse (encephalitis).

QUICK REFERENCE SUMMARY
Diseases causing tremor or twitching
COARSE TREMOR AND TWITCHING (INTENTIONAL)
DEGENERATIVE

● Degenerative cerebellar diseases (p 857)
Using storage diseases as an example, these diseases tend to be breed-associated. Clinical signs usu-
ally begin in cats less than 1 year of age. Slowly progressive signs are typical and there is no hyper-
esthesia. When the disease involves the cerebellum, ataxia and hypermetria are most common.

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