GENERALIZABILITY OF SENSORY GATING DURING PASSIVE MOVEMENT OF THE LEGS

Movement-related gating of somatosensory evoked potentials in the uppe r limb is restricted mainly to nerve stimulation supplying the moved l imb segment, In the lower limb, this principle may not be followed. Ti bial nerve (stimulation at the knee) somatosensory evoked potentials ( SEPs) and soleus ii reflexes exhibit quite similar patterns of modulat ion during movement. We hypothesised that movement-related gating of i nitial SEPs in the leg would be generalised from ipsilateral to contra lateral leg movement and that such sensory gating would not be general ised to modalities with no functional relevance to the movement. Somat osensory, visual, and auditory evoked potentials (SEPs, VEPs, and AEPs ) were recorded from scalp electrodes during unilateral passive moveme nt. Short-latency tibial nerve SEPs, representing the first cortical c omponents, and soleus ii reflexes in both the moved leg and the statio nary leg were attenuated compared to non-movement controls (p < 0.05). Neither VEPs nor middle latency AEPs were modulated (p > 0.05). We co nclude that sensory gating occurs during contralateral movement. This gating is absent in other sensory modalities with no apparent function al relationship to the imposed movement. (C) 1998 Elsevier Science B.V . All rights reserved.