Polygraphic Investigations and Back-Averaging Techniques in the Study of Epileptic Motor Phenomena

Abstract

The term polygraphy refers to the simultaneous recording of multiple physiologic measures. The main aim of polygraphic monitoring is to correlate behavioral manifestations with changes occurring in a set of physiologic parameters. In epileptology, polygraphic investigations complemented with simultaneous video recording and computerized back-averaging techniques can be extremely useful in the description and comprehension of epileptic motor phenomena. Indeed, polygraphic studies can be valuable: (a) to detect subtle and unnoticed clinical events; (b) to define the clinical features of different epileptic manifestations; (c) to describe the semiology of epileptic seizures, contributing to the syndromic diagnosis; and (d) to clarify the physiopathogenetic mechanisms underlying epileptic phenomena. This chapter illustrates the usefulness of polygraphic recording in the detection and characterization of epileptic motor phenomena and its contribution in defining epileptic seizures and epileptic syndromes. In addition we will introduce some concepts on computerized back-averaging of the polygraphic signal, and we will illustrate its usefulness to obtain valuable pathophysiological information in particular in the study of myoclonus.