TRANSCUTANEOUS ELECTRICAL-STIMULATION AND VIBRATION OF NECK MUSCLES IN NEGLECT

Four neglect patients without visual field defects, one with a lesion of the right basal gangolia and three with a right, predominantly pari etal lesion, were examined with a cancellation and a copying task befo re, during and after neck muscle vibration, during transcutaneous elec trical stimulation of neck muscles and during vibration of hand muscle s on the left side. In all patients, neck muscle vibration improved ta sk performance, while transcutaneous electrical stimulation and hand v ibration had little or no effect. The present results demonstrate that the effect of neck muscle vibration cannot be explained as arousal an d activation due to unspecific sensory stimulation on the contralesion al side of the body. They rather argue for the assumption that the com pensatory effect of neck muscle vibration on neglect is an effect indu ced by the predominant activation of afferent Ia nerve fibres and thei r specific contribution to the central representation of egocentric sp ace.