Electrophysiological study of the snout reflex in normal subjects and in parkinsonian and pseudobulbar patients.

The snout reflex appeared to be electrophysiologically present in a great majority of normal subjects. Nevertheless, a facilitation of the R2 responses of the snout reflex was found in parkinsonian patients while in pseudobulbar patients an augmentation of the R1 took place. The snout reflex, therefore, seemed to behave in a similar way as the blink reflex. In order to explain the reported findings the authors took into account the different effects of the lesions of the lateral and ventral motor system upon the oligo- and multisynaptic reflexes.