S62 



HANDBOOK OF PHYSIOLOGY 



NEUROPHYSIOLOGY 



from operative interference with the different parts 

 of the labyrinth has been an important source of 

 knowledge concerning the function of the two sets of 

 end organs. It was Ewald who first drew attention to 

 a tonic action of the labyrinth. The operation of 

 double labyrinthectomy produces slackness of muscles 

 in various parts of the body. This has been \erified 

 by McNally & Tait (70) who were aijle to show that 

 denervation of the canals __did not interfere with 

 muscular tone, whereas denervation of the uj ri£le. 

 did. The general effects of extirpation of the semicircu- 

 lar canals, so far as disturbances of equilibrium and 

 occurrence of forced movements are concerned, 

 resemble those resulting from operations upon the 

 cerebellum. 



If the organ on one side is destroyed , an aljnormal 

 asymmetrical posture of the head an d trunk results 

 ifrom the tjnequa l influence of the laljvrinths on the 

 tnnf nf the ner k muscles of the two sides. The result 

 is a continuously acting righting reflex which causes 

 the trunk to be curved and makes the animal tend to 

 roll over and over. Cold blooded vertebrates are much 

 disturbed by unilateral ablation of the labyrinths. 

 Extirpation of the labyrinth in monkeys is followed by 

 nystagmus with the quick component towards the 

 normal side and rotation of head and neck to the 

 same side. Rabbits, cats and dogs are rather less 

 disturbed. 



In man the effects are less enduring than in the 

 monkey. A sudden ablation or a rapid destruction of 

 one labvrinth causes a vertigo. \'estibular symptoms, 



such as nystagmus, past pointing, tendency to fall and 

 vertigo, are frequently accompanied by symptoms 

 pointing to an involvement of the autonomic system. 

 Nausea and vomiting, lowering of _art eria! pressure , 

 t achycardia and recess ive perspiration may occur in 

 the beginning. The intensity of the vertigo renders 

 the sufferer unable to m aintain erec t posture. \Vhen 

 examined in bed, the patient is poised in the least 

 uncomfortable position and resists any head move- 

 ment for fear that any alteration will increase the 

 vertigo and bring on a spell of severe nausea and vom- 

 iting. The face is pallid and the skin is clammy. 

 Diar rhea mav alternate with the vomiting. The 

 direction of the horizon tal or rotatory nystagim is 

 present is always to the healthy side. The vertigo 

 likewise is to the healthy side. The distressing vestib- 

 ular symptoms subside gradually and a compl ete 

 reco\ey y from the vestibular disability usually occurs 

 at the end of one or two month s. 



A complete bilateral loss of vestibular function 

 does not produce the vestibular syndrome that is 

 found following an acute destruction of one labyrinth. 

 There is no nystagmus and novcrtigo. A disturbance 

 of equilibrium is always present and the patient, when 

 depr ived of the visual sense, is unabl e to _mainia in 

 n ormal postur e and locom otjon. When submerged in 

 water, he is disoriented and is as likely to swim down- 

 ward as upward in attempting to reach the surface. 

 These symptoms are perman ent, although partial 

 compensation takes place. 



REFERENCES 



I. .\dri.^n, E. D. J. Physiol. lOi : 389, 1943. 

 Q. Andersson, S. .^nd B. E. Gernandt. Acta oin-laryng. 

 Suppl. 116: 10, 1954- 



3. Andersson, S. and B. E. Gernandt. J. ,\europhysiol. 



19: 5'^4. 1956- 



4. Aronson, L. J. Nerv. Ment. Dts. 78; 250, 1933. 



5. Arslan, K. Rev. taiyiig. 55: 79, 1934. 



6. Ashcroft, D. W. and C. S. Hallpike. J. Laryngol. £? 

 Otol. 49: 450, 1934. 



7. Barany, R. Physiologie und Pathologie drs Bogengangappa- 

 rales beim Menschen. Vienna: Deuticke, 1907. 



8. Bartels, M. von Graefes Arch. Ophth. 76: i, 1910. 



9. Bender, M. B. and E. A. Weinstein. A. M. A. Arch. 

 Neurol & Psychiat. 52: 106, 1944. 



10. Bohm, E. and B. E. Gernandt. Acta physiol. scandinav. 23: 



320, 195'- 



11. Breuer, J. Arch. ges. Phyiiol. 44; 135, 1889. 



12. Breuer, J. Arch. ges. Physiol. 48: 195, 1891. 



13. Camis, M. The Physiology oj the Vestibular Apparatus. Ox- 

 ford; Clarendon Press, 1930. 



14. Cawthorne, F. E., G. Fitzgerald and C. S. Hallpike. 

 Brain 65: 138, 1942. 



15. Cohen, M. J. J. Physiol. 130: 9, 1955. 



16. Crum Brown, A. J. Anal. Physiol. 8: 327, 1875. 



17. DE Burlet, H. M. and C. Versteegh. Acta uto-rhiiio- 

 laryng. belg. Suppl. 13: i, 1930. 



18. DE Kleyn, a. .\nd V. Schenk. Acta oto-rhmo-laryng. belg. 



•5:439. •93I- 



19. DE ViTO, R. v., .a. Brusa and ."K. .Arduini. J. Neuro- 



physiol. 19: 241, 1956. 



20. DE Vries, H. Progress in Biophysics and Biophysical Chemistry. 

 London: Pergamon Press, 1956, vol. 6. 



21. Dodge, R. J. Exper. Psychol. 4: 247, 1921. 



22. Dodge, R. J. Exper. Psychol. 6: 107, 1923. 



23. Dohlman, G. Ada oto-laryng. Suppl. 5, 1925. 



24. Dohlman, G. Proc. Roy. Soc. Med. 28; 1371, 1935. 



25. Dow, R. S. J. Neurophysiol. 2: 543, 1939. 



26. Dusser de Barenne, J. G. Handbook oJ General Expert- 

 mental Psychology. Worcester Clark Univ. Press, 1934. 



27. Eckel, VV. Arch. Ohren- Nasen- u. Kehlkopjh. 164: 487, 



1954- 



28. Engstrom, H. and B. Rexed. ^Ischr. mikroskup.-anal 



Forsch. 47 : 448, 1 940. 



