The Complex Relationship Between Epilepsy and Headache and the Concept of Ictal Epileptic Headache

The possible link/comorbidity (causal or not causal) between epilepsy and headaches has been a topic of debate for over a hundred years, ever Since William Richard Gowers’s time. In recent decades, new data have emerged in favor of a non-random relationship between these two entities. They are both characterized by transient attacks of altered brain function with a clinical, pathophysiological, genetic and therapeutic overlap, and may thus mimic each other. Indeed, the clinical distinction between headache and epilepsy may make the differential diagnosis a highly challenging task. Both are common and often co-morbid, with headache attacks in epilepsy being temporally related to the occurrence of epileptic seizures as a pre-ictal, ictal, post-ictal or inter-ictal event. Yet, they are both paroxysmal and chronic neurological disorders that share many clinical and epidemiological aspects, and they may both present with visual, cognitive, sensitive-sensorial and motor signs/symptoms; these neurophysiologicl phenomena arise from the cerebral cortex and are modulated by sub-cortical connections. Even from an epidemiological point of view, data in the literature regarding the co-morbidity between headache and epilepsy appear to be quite distinct in children. What makes this scenario even more variegated and complex are new data suggesting that a headache may, in some cases, even be the only ictal manifestation of an epileptic seizure. The latter condition, the so-called “ictal epileptic headache”, is a new entity that has recently been cited in the new classification of headache disorders (ICHD-III), whose diagnostic criteria have very recently been defined and published. The data that have led, over the last decade, to the proposed “diagnostic criteria” for “ictal epileptic headache” are reported below. In this regard, it is crucial to stress that the authors who proposed the diagnostic criteria for ictal epileptic headache, have deliberately and consciously chosen “criteria” that underestimate the phenomenon so as to avoid spreading panic among both patients and physicians, who tend to be reluctant to accept this concept because of the stigma attached to the diagnosis of epilepsy. In the future, once this concept (i.e. “headache” as the sole ictal epileptic manifestation) has been more widely accepted, it will hopefully be possible to propose “different and less restrictive” criteria than those recently published.