Sferics and headache: a prospective study

Sferics are low frequency, low intensity electromagnetic pulses radiating f rom distant meteorological events and other yet unknown sources. It has bee n hypothesized that sferics are part of the purported sensitivity to weathe r changes reported by headache sufferers. We tested this proposal. Patients (migraine and/or tension headache) enrolled in a randomized clinical trial gave daily headache data (intensity, frequency, duration of headache) for at least 18 weeks. Concurrently, a sferics measurement station in the vicin ity of the patients recorded frequency and intensity of sferics. Usable hea dache data from 21 patients and the corresponding sferics series were subje cted to time series analysis applying ARIMA models and then cross-correlate d. We found significant and consistent cross-correlations of moderate size at lag 0 in one patient between ARIMA-filtered headache intensity and frequ ency (r=0.18) and amplitude of sferics (r=0.20). We conclude that in an uns elected sample of headache patients some may indeed be susceptible to the l ow intensity type of electromagnetic radiation exemplified by sferics pulse s. This phenomenon warrants further scrutiny.