Effect of weather on temporal pain patterns in patients with temporomandibular disorders and migraine

Patients with masticatory muscle pain and migraine typically report that the intensity of pain fluctuates over time and is affected by weather changes. Weather variables, such as ambient temperature and humidity, may vary significantly depending on whether the individual is outdoor or indoor. It is, therefore, important to assess these variables at the individual level using portable monitors, during everyday life. This study aimed to determine and compare the temporal patterns of pain in individuals affected with facial and head pain and to investigate its relation with weather changes. Eleven patients (27·3 ± 7·4 years) with chronic masticatory muscle pain (MP) and twenty (33·1 ± 8·7 years) with migraine headache (MH) were asked to report their current pain level on a visual analogue scale (VAS) every hour over fourteen consecutive days. The VAS scores were collected using portable data-loggers, which were also used to record temperature, atmospheric pressure and relative humidity. VAS scores varied markedly over time in both groups. Pain VAS scores fluctuate less in the MP group than in the MH group, but their mean, minimum and maximum values were higher than those of migraine patients (all P < 0·05). Pain scores <2 cm were more common in the MH than in the MP group (P < 0·001). Perceived intensity of pain was negatively associated with atmospheric pressure in the MP group and positively associated with temperature and atmospheric in the MH group. Our results reveal that patients with masticatory muscle pain and patients with migraine present typical temporal pain patterns that are influenced in a different way by weather changes

О собственном времени очага сильного землетрясения

The physics of earthquakes was contriubuted to by the concept of proper time of the source of a strong earthquake, which is different from universal (calendar) time. The earlier idea of proper time was implicit and has been considered only in relation to the physics of aftershocks. The present paper extends the applicability of the concept of proper time, proposes a possible way of its measuring, and provides an example to illustrate the procedure for sequential ordering of earthquakes by proper time. The object of this study is a global activity of strong (M≥7) earthquakes. We consider the sequence of earthquakes as a Poisson-type random process. Comparatively weak earthquakes are used as the "underground clock", the tick of which marks the proper time. The Poisson distribution is compared with the distributions for two sequences of strong earthquakes. One of the sequences is ordered by universal time, and another - by proper time. The studies indicate the distribution of events ordered by proper time is closer to the Poisson distribution than that of events ordered by universal time. We attribute this to the non-stationarity of the geological medium, which is an immanent property of the Earth's lithosphere.В физику землетрясений введено понятие о собственном времени очага сильного землетрясения, отличном от универсального (календарного) времени. Ранее использовалась идея о собственном времени, но неявно и только лишь в узкой области, относящейся к физике афтершоков. В данной работе расширена область применимости представления о собственном времени, указан возможный способ его измерения и приведен пример, иллюстрирующий процедуру упорядочивания последовательности землетрясений в собственном времени. В качестве объекта исследования выбрана глобальная активность сильных землетрясений (М≥7). Последовательность землетрясений мы рассматриваем как случайный процесс пуассоновского типа. В качестве «подземных часов», тиканье которых отмечает ход собственного времени, использованы сравнительно слабые землетрясения. Распределение Пуассона сопоставлено с распределениями для двух последовательностей сильных землетрясений, одна из которых упорядочена по универсальному времени, а другая - по собственному. Результат испытания показал, что распределение событий, упорядоченных по собственному времени, ближе к распределению Пуассона, чем распределение событий, упорядоченных по универсальному времени. Авторы объясняют это нестационарностью геологической среды, которая является имманентным свойством литосферы Земли