PHYSIOLOGICAL DEFICITS OCCURRING WITH LESIONS OF LABYRINTH AND FASTIGIAL NUCLEI

Abstract

Attempts were made to determine the effects of bilateral fastigial lesions in bilateral labyrinthectomized cats and bilateral labyrinthectomy in animals with prior lesions of the fastigial nuclei. Lesions of the above types were produced in 13 cats. The following principal conclusions were drawn: Bilateral lesions of either the fastigial nuclei or labyrinth produce similar, but not identical, disturbances which undergo significant attenuation with time; bilateral fastigial lesions in previously labyrinthectomized cats result in a summation of fastigial and labyrinthine deficits which do not undergo attenuation with time. The same summation of deficits occurs when lesions in these same sites are inflicted in reverse sequence. The hypothesis is presented that the physiological effects of isolated fastigial lesions and labyrinthectomy in the cat are similar, but independent phenomena, except in regard to mechanisms of accomodation.