Central responses evoked by tactile stimulation: Technical note

The electrical stimulation of peripheral nerves is one of the commonest ways to study the sensory pathways from the peripheral nerve to the cortex. Such stimulation, however, involves all types of nerve fibres regardless of their specific function. In the past, we devised a technical procedure to record peripheral responses by selectively activating fibres innervating cutaneous mechanoreceptors. In the present paper, we illustrate the method that we developed to record cortical responses evoked by mechanical stimulation. The analysis of the tactile evoked potentials needs an adequate procedure to acquire and to elaborate the signals. Difficulties in setting these parameters make mechanical SEPs not routinely performed. This study is a first step in the development of a reliable system to record mechanical SEPs for clinical purposes.