Clinical neurophysiology in childhood headache

Several neurophysiological techniques are available for examining children with headache. The choice among them is made according to clinical features. Electroencephalography (EEG) is commonly performed in headache; abnormalities observed are heterogeneous, and specific patterns have been described in different forms of complicated migraine. Quantitative EEG, brain mapping and spectral analysis are at present useful mainly for research purposes and in migraine diagnosis. Polysomnography studies are just at the beginning but they have been providing interesting findings. Visual evoked potentials (VEPs) have demonstrated conflicting results: increased amplitudes observed in migraine children need to be replicated and methodological flaws need to be corrected. Event-related potentials (ERPs) have been used to shed light on cognitive processes related to migraine during development of the nervous system. Electromyography studies have documented increased spontaneous muscle activity in tension-type headache, but further studies are awaited. Overall, clinical neurophysiology is of primary interest in studying functional mechanisms of headache and migraine symptoms. In clinical practice, these procedures are not essential for diagnosis but are relevant for clarifying specific problems.