Differentiations in the Vestibular Caloric Test Results by means of Butterfly Patterns from 1970 till 2010
Abstract
Differentiations in the Vestibular Caloric Test Results by means of Butterfly Patterns from 1970 till 2010Bencsik
Bencsik Beata et all
Principally, the caloric test of Barany is the most systematic test only stimulating one inner ear receptor, i. e., the lateral vestibular semicircular canal.
Opposite to audiometry, you have no masking problems.
For evaluating objectively and quantitatively the nystagmus responses, Claussen introduced vector analysis of the culmination phase by integrating the Gaussian distribution and going to the very center of this integral. The nystagmus beat rates then are reflecting in a differentiation over 30 seconds, the representative central response. This has the great advantage that, amongst othersthe digital transfer of the beats to a simple signal detection can be easily evaluated.
However, also the slow phase and other parameters can be integrated, but this is not as effective and precises as the beat rate as such.
Principally, each of the four quadrants may express three states, i. e., normal, inhibited, desinhibited. So, mathematically, the butterfly system can encode 34 different patterns, i. e. 81 different butterfly types. It is a great advantage in classifying different disorders, which are related to typical trinary codifications. For instance, the peripheral vestibular inhibition usually goes with the right complete vestibular inhibition into 1100, or left complete inhibition into 0011, whereas the central nystagmus generator inhibiton of the mesencephalon goes with an inhibited right-beating nystagmus, i. e. into 1001, or the centrally inhibited left-beating nystagmus into 0110.
The nystagmus pattern found most frequently is the so-called major butterfly of the all-over central desinhibition, which can be encoded by 2222 or a monolateral brainstem desinhibition, which can be encoded by 0022 (then, the lesion is mostly on the right side) or 2200 (then the lesion mostly is on the left side of the brain stem).
For the questions to our neurootological databank, we regularly use the following system:
1.) Caloric tests
2.) Standardization of caloric tests
3.) Caloric butterfly or butterfly
4.) Databanks and normal ranges of caloric tests
