The theoretical foundations of Ruttin’s symptom

In the chapter concerning the history of discoveries concerning the equilibrium system I mentioned that the symptoms of a sudden destruction of the labyrinth had already been thoroughly described by numerous researchers in the 19th century - Flourens 1825, Goltz 1870, Bechterew 1883, Ewald 1892. In 1911 Ruttin described the phenomenon of slow balancing nystagmus reactions in rotation tests together with the regression of the clinical features connected with the permanent destruction of the labyrinth. The compensation of the post-rotary reactions, in the entire and permanent destruction of the vestibule, was later called Ruttin’s symptom. The researcher observed the behavior of post-rotary nystagmus after a sudden destruction of one labyrinth. In the initial period the duration of post-rotary nystagmus towards the diseased side was shorter than towards the healthy side. In the next period of time he observed lengthening of the duration of nystagmus towards the diseased side and the reduction of the duration of nystagmus towards the healthy side. At a certain moment he observed compensation of time in post-rotary reactions to the right and left, although they were temporal values smaller than in healthy people. This state was named compensation by Ruttin. However, later studies showed that this phenomenon did not appear identically in all cases, and its mechanism was more complex than it had been supposed. Soon remarks concerning the definition of compensation began to appear. Mittermaier quoted according to (1) claimed that the term "compensation" was wrongly used here. This author maintained  that in these cases there is no compensation in the meaning of replacement but there is compensation of the tension between the damaged and the unimpaired side. A hundred years have passed since the description of this phenomenon but nobody has presented its theoretical foundations. In fact, the hallmarks of vestibular compensation are fully exhausted by vestibular habituation and this term should not be used any longer (see the chapter on vestibular compensation). Thanks to deciphering of the principles of operation of the vestibulocerebellar system I was able to describe the vestibular habituation process in detail earlier. The compensation of the nystagmus reaction in post-rotary reactions can be obtained in an appropriate time of the habituation process after suitable inhibition of the cerebellar hemisphere related to the unimpaired labyrinth. Depending on the size of the vestibular habituation we can record different responses in post-rotation  tests, including the lack of reaction towards the healthy labyrinth. Finding a longer nystagmus reaction towards the damaged labyrinth in a post-rotation  test is not paradoxical at all as it was presented by certain authors in repeated scientific article.

REFERENCES

1. Ukleja Z.: Compensation. In: Clinical Otoneurology edited by Zbigniew Bochenek. PZWL. 1977.