ABSTRACT
Seizure activity has long been associated with alterations in consciousness. Philosophical
and neurologic debates concerning the definition of consciousness have led to confusion
regarding an adequate third person assessment of a subjective experience. In order
to avoid these controversies, neurologic evaluation of consciousness has focused on
operational definitions that permit an objective assessment of behavioral responses
that are constituent functions of consciousness. Clinical experience has demonstrated
that ictal and post-ictal alterations in consciousness may be associated with loss
of selected behavioral responses depending upon the focus and spread of seizure activity.
Ictal electrophysiologic studies and brain stimulation has assisted in determining
the anatomic structures involved in specific behavioral alterations.
Consciousness-dependent mental activity can be modeled as a series of interactive
parallel information channels that can be selectively disrupted at any stage of processing
giving rise to ictal behavioral patterns. While such modeling fails to grasp the subjective
nature of consciousness, it offers the clinical community an objective measure of
those responses believed to be dependent on consciousness.
Keywords
consciousness - seizure - perception - brain stimulation - memory
