[Does weather modify headaches? An empirical evaluation of bio-weather categorization]. / Hat das Wetter Einfluss auf Kopfschmerzen? Eine Evaluation der Biowetterklassen.

BACKGROUND: Headache patients frequently refer to the weather as a triggering factor for their headaches. Apart from a literature review, we tested empirically the generally used classification of weather epochs into a so called bio-weather categorization. METHOD: Headache diary data (frequency, duration, intensity) of 98 patients in a headache trial were correlated with the concurrent bio-weather classification. RESULTS: Correlations were small and significant only for the summer-half of the year (contingency coefficients between 0.04 and 0.06). The classification of certain types of weather as headache prone as used in the current bio-weather classification could only partly be verified. CONCLUSION: There is a clear but small correlation between headache and weather. More, and more fine-grained, studies are warranted, especially for identifying those patients at risk for weather prone headaches. Clinically more important is the weather as a source of causal attributions.

Sferics and headache: a prospective study.

Sferics are low frequency, low intensity electromagnetic pulses radiating from distant meteorological events and other yet unknown sources. It has been hypothesized that sferics are part of the purported sensitivity to weather 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 vicinity of the patients recorded frequency and intensity of sferics. Usable headache data from 21 patients and the corresponding sferics series were subjected to time series analysis applying ARIMA models and then cross-correlated. We found significant and consistent cross-correlations of moderate size at lag 0 in one patient between ARIMA-filtered headache intensity and frequency (r = 0.18) and amplitude of sferics (r = 0.20). We conclude that in an unselected sample of headache patients some may indeed be susceptible to the low intensity type of electromagnetic radiation exemplified by sferics pulses. This phenomenon warrants further scrutiny.

The gap effect in pro-saccades and anti-saccades in psychometric schizotypes.

Schizophrenic patients and their first-degree relatives exhibit deficits in the anti-saccade task. In the present study, anti-saccade task performance was examined in subjects with 'high' and 'low' expressions of the schizotypal personality trait. For that purpose, the SPQ-G, the German adaptation of the Schizotypal Personality Questionnaire (SPQ; Raine, 1991), was filled in by 489 university students. Twenty and 21 participants with 'high' and 'low' SPQ-G scores, respectively, were compared with respect to saccadic eye movements elicited under the overlap and 200 ms gap conditions of the pro- and anti-saccade tasks. Each task block comprised 150 trials, 75 to either side in random order. The order of presentation of the task blocks was counterbalanced across the participants of each group. Saccadic reaction times were slower during the anti- as compared to the pro-saccade task and under the overlap as compared to the gap condition. Direction errors occurred almost exclusively during the anti-saccade task, express saccades mainly under the pro-saccadic gap condition. High-schizotypal participants did not differ significantly from low-schizotypal participants in any of these measures. While these results might suggest normal anti-saccade task performance in schizotypal personality as defined by the SPQ-G, the sampling strategy adopted in the present study is the more plausible explanation for the lack of group differences.