cerebellar ataxia

cerebellar ataxia

Etymology: L, cerebellum, small brain; Gk, ataxia, without order

a loss of muscle coordination caused by a lesion in the cerebellum.

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ataxia

failure of muscular coordination; irregularity of muscular action.

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cerebellar ataxia

ataxia characterized by defects in rate, range, force and direction of movement of limbs. There is a broad based stance, inability to maintain the head in the proper position so that it oscillates, there is hypermetria or hypometria, direction cannot be maintained and the animal falls easily, often in an exaggerated way.

congenital ataxia

cerebellar ataxia due to viral infection of the fetus, e.g. bovine virus diarrhea and feline panleukopenia, or to inheritance, e.g. in cattle. See also cerebellar atrophy.

copper-related ataxia

see copper nutritional deficiency.

enzootic ataxia

see enzootic ataxia.

equine sensory ataxia

see enzootic equine incoordination.

familial convulsions and ataxia of cattle

see familial convulsions and ataxia of cattle.

feline ataxia

see feline panleukopenia.

foal ataxia

see enzootic equine incoordination.

frontal ataxia

disturbance of equilibrium occurring in cases of tumor of the frontal lobe.

hereditary ataxia

see hereditary ataxia.

hound ataxia

a degenerative myelopathy of Foxhounds, Harrier hounds and Beagles. Affected dogs show increasing hindleg incoordination. A dietary cause is suspected.

locomotor ataxia

tabes dorsalis.

otarid ataxia

a syndrome in pinnipeds caused by nutritional deficiency of thiamin or enterotoxemia or hypoglycemia. Signs include heelwalking (elevation and curling of the rear toes) followed by running staggers, ataxia and violent falling.

progressive ataxia

an inherited disease of cattle in which hind limb ataxia commences at 6 months to 3 years of age and worsens over 1 to 2 more years to the point of recumbency. It is a myelin disorder with eosinophilic plaques in the cerebellar medula and peduncles. Called also progressive sensory ataxia of Charolais cattle.

sensorimotor ataxia

caused by moderate spinal cord lesions, manifested by weakness of movement, scuffing of toes, incomplete limb extension, knuckling, wobbly gait, easy falling, difficult rising.

sensory ataxia

ataxia due to loss of proprioception (joint position sense), resulting in poorly judged movements and becoming aggravated when the eyes are blindfolded.

spinal ataxia

see equine protozoal myeloencephalitis.

vestibular ataxia

a loss of balance with preservation of strength. If unilateral, the abnormality is asymmetrical; if bilateral, it is symmetrical.

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cerebellar

pertaining to the cerebellum.

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cerebellar abiotrophy

occurs in cattle, pigs and dogs. Affected young are normal at birth but at an early age ataxia and signs of cerebellar dysfunction appear, often progressing to complete immobilization. Cerebral function is usually normal. An inherited basis is suspected. In Kerry blue terriers, it is inherited as an autosomal recessive trait. Called also cerebellar neuronal abiotrophy.

cerebellar agenesis

absence of the cerebellum due to its non-appearance in the embryo.

cerebellar aplasia

see cerebellar atrophy (below).

cerebellar ataxia

the incoordination of gait characterized by exaggerated movements. There is no paresis. There is exaggerated strength and distance of movement—hypermetria. Caused usually by damage to the cerebellum or to the spinocerebellar tracts. May be congenital due to cerebellar atrophy or acquired due to inflammation or malacia of the cerebellum.

cerebellar atrophy

degeneration and loss of cells—Purkinje and granular cells of the cerebellum. Present at birth or soon after, is congenital in sheep, cattle, Arab horses, dogs and cats. Some of the diseases are inherited, some are known to be due to virus infection in utero, e.g. bovine virus diarrhea, feline panleukopenia. Some are in fact abiotrophies, premature aging of tissues. In the latter the animals are normal at birth but develop classical signs later. Segmental atrophy occurs in pigs but is asymptomatic.

cerebellar coning

see cerebellar lipping (below), brain herniation.

cerebellar cortex

the superficial gray matter of the cerebellum.

cerebellar dysfunction

see cerebellar ataxia (above).

cerebellar dysmelinogenesis

recorded in Chow Chow dogs; characterized by congenital head tremor.

feline cerebellar ataxia

see feline panleukopenia.

cerebellar hypomyelinogenesis

abnormally reduced myelination in the cerebellum; characterized clinically by severe neonatal tremor.

cerebellar hypoplasia

deficiency of cells of the cerebellum, the degree and distribution of which is variable. See cerebellar atrophy (above).

inherited cerebellar defects

includes cerebellar abiotrophy, atrophy, agenesis, hypoplasia, neuraxonal dystrophy.

cerebellar lipping

caused by diffuse cerebral edema. The vermis of the cerebellum protrudes through the foramen magnum and lies like a tongue over the medulla.

cerebellar neuronal abiotrophy

see cerebellar abiotrophy (above).

cerebellar neuraxonal dystrophy

reported in collie sheepdogs. The lesion is limited to axons and there are no lesions in the cerebellar folial neurons.

cerebellar syndrome

see cerebellar ataxia (above).

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cerebellar ataxia

Neurology A condition characterized by a usually abrupt onset of unsteady gait, nystagmus, and dysarthria, which in children may persist in the form of residual movement or behavioral disorders. See Ataxia.