19 - Epileptic stereotypies in children

Summary

Introduction

Abnormal, seemingly purposeless, repetitive motor behaviours are typical manifestations of seizures of temporal or frontal origin and are referred to as automatisms. In adults, these ‘epileptic automatisms’ or ‘epileptic stereotypies’ (Penfield & Jasper, 1954), are usually recognized as clearly different fromthe normal patient's behaviour and also because there are usually other simultaneous manifestations of temporal or frontal seizures. However, in very young children and especially when stereotypies are the only epileptic symptoms, the situation is more complicated, because stereotypies can be seen in a variety of circumstances and have very different causes.

Before further discussion of ‘epileptic stereotypies’, the use of the term ‘stereotypy’ needs first to be clarified (Ridley, 1994; Mason, 1991). Stereotypies are defined as repetitive, similar, non-goal-directed (purposeless) movements. This definition is wide and can apply to many types of abnormal movements, for example tremors and tics. It leaves many open questions: repetitive implies a certain frequency and regularity of successive occurrence, but this can be quite variable. Similar means that the movement is always the same, but variations in intensity, rapidity and complexity are frequently observed from one episode of stereotypy to the next. The movement itself can be simple and without apparent significance, or complex and in this case appears as an organized deliberate gesture which is part of the person's repertoire. Finally, non-goal directed implies that it is involuntary and automatic and beyond the person's control. However, stereotypies can appear goal directed even if they are not made with a deliberate intention (for instance, chasing an insect on one's face). The dichotomy automatic/voluntary is not so straightforward as one might think (Jeannerod, 1983). These difficulties should be acknowledged when using the term clinically.