Table edge test
The table edge test ( Placing Reaction ) is a neurological test in veterinary medicine that is used on smaller animals, especially dogs and cats . It belongs to the so-called posture and position reactions .
execution
To do this, the vet grips the animal around the chest with one arm, while the free hand covers the animal's eyes (a blindfold can also be used for heavier animals). Now the animal is slowly led against an obstacle (mostly the edge of a table) with its front paws. When the back of the forefoot is touched, the animal immediately places the paws on the tabletop in the normal state. The test is then checked without holding your eyes; the paws are usually put on before touching the edge of the table.
Neural structures involved
This test examines a rather complex chain of reflexes . It begins with the mechanoreceptors of the skin ( tactile perception , so-called epicritical sensitivity ). Their impulses are conducted via the dorsal cord of the spinal cord ( Fasciculus cuneatus (BURDACH), part of the lemniscale system ) via the brain stem to the sensory cerebral cortex ( cortex ) in the parietal lobe .
The response reaction is triggered via an interconnection to the motor cortex in the frontal lobe . From there it runs via the motor pathways of the upper motor neuron (more precisely via the pyramidal system ) to the motor root cells in the spinal cord ( lower motor neuron ), which then activate the corresponding muscles. In the test with open eyes, the visual pathway and the connections between the visual and motor cortex are also tested.
evaluation
If the test is positive with closed eyes and negative with open eyes, the damage is certainly not in the efferent (executive) thigh, but in the visual system .
In the opposite case, the sensitive afference , i.e. the nerve pathways to the brain, or the parietal lobe itself are obviously affected.
If the reaction is disturbed with both open and closed eyes, the damage is very likely to be in the motor system, since simultaneous damage to the sensory and visual cortex is very rare. If the forebrain is damaged (motor cortex), the reaction on the opposite (contralateral) side of the body is disturbed because the pyramidal tract crosses at the extended medulla . Unilateral damage to the spinal cord tract, i.e. behind the pyramid junction, leads to a failure on the same side (ipsilateral).
See also
literature
- André Jaggy: Atlas and textbook of small animal neurology . Schlütersche, Hannover 2005, ISBN 3-87706-739-5 .
- Marc Vandevelde among others: Veterinary neurology. A guide for study and practice. 2nd revised and expanded edition. Paul Parey Verlag, Berlin 2001, ISBN 3-8263-3224-5 .
