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INVOLUNTARY MOVEMENTS

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Invol­untary­muscle­contractions

Shivering Tremor Tics Tetany Myoclonus Seizures(Con vulsions) Opisthotonos

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This is a continuous, repetitive twitching (uncontrolled motions)of skeletal muscles,

which is usually visible and palpable The muscle units involved may be small and cause only local skin movement

tremor is described as fasciculations The muscle units may be extensive movement much coarser and sufficient to

move the extremities, eyes or parts of the trunk This usually being indicative of cerebellar involvement

Tremor

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Diffuse diseases of the cerebrum, cerebellum, spinal cord Degenerative nervous system disease e.g. hypomyelinogenesis Toxic nervous system disease caused by a large number of poisons, Clostridium botulinum toxin in shaker foal syndrome; hyperkalemic periodic paralysis in the horse early stages of hypocalcemia in the cow (fasciculations of the eyelids and ears)

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Spasmodic twitching movements made at much longer intervals than in

tremor, the intervals being usually at least several seconds in duration Easily visible Caused by muscles that are ordinarily under voluntary control. May occur after traumatic injury to a spinal nerve

Tics­

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other name is backward tone a continuous spasm of the neck and limb muscles resulting in dorsal and

caudal extension of the head and neck with rigid extension of the limbs

Opisthotonos

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Tetanus is a continuous contraction of muscles without tremor Most com mon cause is Clostridium tetani intoxi cation The degree of muscular contraction can be exaggerated by stimu lation of the

affected animal and the limbs are rigid and cannot be passively flexed easily

Tetany

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Brief, intermittent tetanic contraction of the skeletal muscles that results in

the entire body being rigid for several seconds, followed by relaxa tion Inherited congenital myoclonus Horned and crossbred Hereford calves Entire body becomes rigid for 10-15 seconds

Myoclonus

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Violent muscular contractions affecting part or all of the body and occurring

for relatively short periods The convulsion may be clonic or tonic (clonic): the typical 'paddling' involuntary movement in which repeated muscle

spasms alternate with periods of relaxation (tonic): less common and are manifested by prolonged muscular spasm without

intervening periods of relaxation occur only rarely and chiefly in strychnine poisoning and in tetanus

Convulsions can originate from disturb ances anywhere in the prosencephalon, including cerebrum, thalamus or hypothalamus

Con vulsions are often subdivided into intracranial and extracranial

Convulsions­(­seizures,­fits,­ictus­)

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Intracranial convulsions Encephalomyelitis Meningitis Encephalomalacia Acute brain edema Brain ischemia, including increased intracranial pressure Local lesions caused by trauma ,abscess tumor, parasitic injury, Hemorrhage Inherited idiopathic epilepsy.

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Extracranial convulsions Brain hypoxia, as in acute circulatory or cardiac failure Toxic and metabolic diseases of the nervous system , including: Hepatic encephalopathy Hypoglycemia Hypomagnesaemia Congenital and inherited defects convulsions and ataxia in Angus cattle

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Involuntary , intermittent contractions of large muscle masses may result

in spas modic movements of individual limbs or parts of the body Stringhalt and Australian stringhalt of horses Inherited spastic paresis of cattle Inherited periodic spasticity of cattle Inherited congenital myotonia of cattle Inherited myotonia of goats

Involuntary­spastic­paresis