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Biomedical subjects

R Salvesen

Publications and source records attributed to R Salvesen.

60 records · Page 4Linked to original sources
PubMedDate not supplied

Migraine, as compared to other headaches, is worse during midnight-sun summer than during polar night. A questionnaire study in an Arctic population.

OBJECTIVE: To investigate potential seasonal variation of migraine and other headaches in an Arctic population where light conditions are extreme during both winter and summer. BACKGROUND: Due to the immense seasonal variation in sunlight, focus on seasonal migraine variation in a population living in an Arctic area is interesting even from a theoretical point of view. METHODS: Northern Norway comprises the three Norwegian counties north of the Arctic Circle. There are three neurology centers in this region, which provide service for approximately half a million people. During a 2-year period, 1403 patients (0.3% of the population) were referred to these centers for a specialist assessment of their headache. A questionnaire was mailed to all these patients; the questionnaire included questions on headache characteristics to make it possible to identify migraine according to the International Headache Society criteria. Questions on seasonal variation of headache were also included. RESULTS: One thousand fifty-two patients (75%) returned the questionnaire. Nineteen percent reported that their headaches clearly did vary with season; 11% experienced more headache during polar night, while 7% had more symptoms during midnight sun season. When the migraine and nonmigraine groups were compared, significant differences were demonstrated. Patients with nonmigrainous headache were more likely to have increased headaches during the dark winter season, while patients with migraine experienced more headache during the summer (P =.002). CONCLUSIONS: Patients with migraine were more likely to have headache during the bright Arctic summer season, and this distinguishes migraine from other headaches in this study. This observation may pertain to the increased light sensitivity and recently demonstrated cortical hyperexcitability in patients with migraine, and may perhaps suggest a role of the hypothalamus and/or melatonin secretion in migraine pathophysiology.

Adolescent↗
PubMedDate not supplied

Cluster headache: a comparison of the proportions of abnormal recordings for several derived variables in tyramine pupillometry.

Tyramine pupillometry was performed in 27 cluster headache patients and in 45 healthy controls. Asymmetry variables, i.e. symptomatic(S)-nonsymptomatic(NS) side diameter difference and the ratios (S/NS, log NS/S or S/S+NS) displayed higher sensitivities than variables which express the function of the symptomatic and the nonsymptomatic side pupil separately. Thirty percent of patients had abnormal S-NS values at maximal pupillary dilatation. The statistical properties of different ratio variables are discussed and it is concluded that the transformed ratio (log(NS/S], anisocoria (S-NS) and the anisocoria index (S/S+NS) may be superior to the conventional S/NS ratio.

Arousal↗
PubMedDate not supplied

Electronic pupillometry in healthy controls. Response to sympathicomimetics.

The ocular sympathetic function was examined in 79 healthy volunteers (37 males and 42 females) by electronic pupillography. Pupillary diameters were first estimated under standard light conditions prior to drug application, these diameters being termed "basal values". Then, the pupils were stimulated pharmacologically by instillation of various sympathicomimetic drugs: tyramine tests were carried out in 42 individuals (24 females; 18 males), hydroxyamphetamine tests in 38 (22 females and 16 males), and phenylephrine tests in 43 individuals (23 females and 20 males). Generally, only a minor variation in the frequency of asymmetries was observed between sexes as well as between the various age groups, both when calculating the increase in pupillary diameter in millimeters, in per cent, and as the anisocoria index. In agreement with previous investigations, pupil size was found to diminish with age. The use of an age-matched control material is mandatory when comparing pupillographic recordings in patients in various categories, in the ordinary condition, as well as after topical drug administration.

Adolescent↗