Evoked potentials and headache

: The multiform clinical varieties of idiopathic headache still represent an unclearly defined nosological entity; what is more, there is still no definitive etiopathogenetic and clinical classification which is unanimously supported by specialists in this sector. Moreover, given that the physiopathological mechanism which triggers off the various forms of headache is still not completely clear, yet it is obvious that research is focused on the identification of a test which is valid in terms of clinical diagnosis but at the same time can contribute towards neurophysiological examination. In order for a test to be of practical use also in terms of neurophysiological research, as well as being diagnostic, it should be able to examine the patient's neurosensory function, offering advantages in clinical terms, and contribute to clarifying the role of neurotransmitters in pain genesis. The test must also be non-invasive, offer comparable results, be repeatable after short intervals and be well tolerated by children. These represent the fundamental characteristics of a test which is applicable to the heterogeneous population of headache sufferers. In this context evoked potentials (EPs), using various forms of sensorial stimulus, appear to represent the ideal test; by exploring the well known and anatomically well defined neuronal systems at various levels of the CNS, they also help to explore the neurotransmitter function of the former, providing further information regarding the genesis of the crisis. A review of the literature examined in the present study showed the validity of the tests both in discriminating the various clinical forms of headache and supplying important information regarding the neurotransmitter-related genesis of the chain of nervous and vascular alterations leading to cephalic pain.