Afferent input to the medullary dorsal horn from the contralateral face inrat

Sensory deficits on the contralateral face in Wallenberg's lateral medullar y syndrome (WS) may be due to an involvement of the crossing contralateral trigeminothalamic tract. Alternatively, neurons within the medullary dorsal horn (MDH) get input from the contralateral face. MDH neurons supplying th e supraorbital nerve area in rat were recorded by electrophysiological tech niques. In this first study on contralateral projections, about 60% of the neurons received excitatory afferent input from the contralateral face as w ell as the ipsilateral supraorbital area. Thus, contralateral sensory defic its in WS may be due to an involvement of these neurons. (C) 1999 Elsevier Science B.V. All rights reserved.