INTRACEREBRAL RECORDING OF POTENTIALS ACCOMPANYING SIMPLE LIMB MOVEMENTS - A SEEG STUDY IN EPILEPTIC PATIENTS

Objectives: Slow potentials appearing during simple repetitive acral l imb movement were investigated. Twenty-six patients suffering from dru g resistant partial epilepsies and explored with implanted intracerebr al electrodes were examined using two protocols. Methods: In 18 patien ts, readiness potential (RP), in 13 patients contingent negative varia tion (CNV), and in 7 patients both protocols, were tested. The recordi ngs from leads with evident pathological EEG activity were excluded fr om evaluation. The results concerning the slow potentials preceding th e movements in RP and CNV protocols have already been published. Resul ts: The movement-accompanying slow potentials (MASP) were polyphasic o r monophasic, started before or during the movement. In the primary mo tor cortex they followed the pre-movement potentials depending on the protocol: in the RP paradigm they were present only contralateral to t he movement, but were bilateral in the CNV protocol. In other areas th ey either followed the potentials preceding the movement, in some case s with opposite polarity, or they occurred alone. MASP was recorded in motor and supplementary motor, premotor and prefrontal, midtemporal, somatosensory, superior parietal and cingular cortices. The cingular c ortex was heavily involved in the self-paced movements but rarely in t he cued movements. Conclusion: The major involvement of the cingular g yrus contrasted with the absence of slow potentials in temporal limbic structures. MASP is evidently a heterogenic phenomenon. Its genesis c ould be involved in a spread of information through the relevant struc tures. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.