“MOONSTROKE”: Lunar patterns of stroke occurrence combined with circadian and seasonal rhythmicity—A hospital based study

Abstract

Both time of the day and season have been shown to have a significant effect on stroke incidence. In contrast, the role played by the moon has been little studied. We aimed to investigate the potential association of the lunar phase with the incidence of stroke subtypes [intracerebral hemorrhage (ICH), transient ischemic attack (TIA) and ischemic stroke (IS)], adjusted by circadian and seasonal variations. Consecutive stroke admissions to the Royal Melbourne Hospital (RMH) were analyzed from 2004-2011. Of 6252 patients, 4085 (65.3%) had confirmed dates and hour of the day. Of these, 632 (15.5%) had ICH, 658 (16.1%) presented with TIA and 2202 (53.9%) had IS. There were also 593 (14.5%) stroke mimics. We measured the association of stroke incidence with a particular lunar phase using an incidence rate ratio (IRR) with 95% confidence intervals (CI) using Poisson regression model (new moon set as reference). Compared with new moon phase, ICHs occurred significantly more during the first quarter (IRR, 1.55; 95%CI, 1.04 to 2.30; p = 0.03). More TIAs were observed during the first quarter and full moon than in new moon (IRR, 1.69; 95%CI, 1.16 to 2.46; p = 0.01; IRR, 1.52; 95%CI, 0.00 to 2.31; p = 0.05; respectively). Both ICH and TIA occurrence slightly decreased as lunar illumination increased (IRR, 0.99; 95%CI, 0.99 to 1.00; p = 0.01; IRR, 0.99; 95%CI, 0.99 to 1.00; p = 0.04; respectively). No association was found between lunar phase or illumination and IS. All stroke subtypes were less likely to happen between 12AM and 6AM than the remaining 18 h of the day. IS occurrence was significantly higher during the spring than summer (IRR, 1.14; 95%CI, 1.02 to 1.28; p = 0.03). For the patients older than 65 years, incidence of both ICH and IS was higher in spring than in summer (IRR, 1.33; 95%CI, 1.01 to 1.74; p = 0.04; IRR, 1.22; 95%CI, 1.06 to 1.39; p = 0.005; respectively). The lunar phase and illumination are associated with both ICH and TIA incidence. These findings should be tested on other stroke databases.

The association between lunar phase and intracranial aneurysm rupture: Myth or reality? Own data and systematic review

“…Furthermore, it is difficult to ignore a common belief among medical professionals that moon has an impact on human health [12]. Substantial evidence suggests that lunar phases can be associated with the incidence of acute neurological and vascular disorders, including hemorrhagic stroke [8], gastrointestinal bleeding, [22], seizures [23] and myocardial infarction [24]. However, others did not find an association of moon phases with the incidence of seizures [25] and ischemic stroke [8].…”

“…Substantial evidence suggests that lunar phases can be associated with the incidence of acute neurological and vascular disorders, including hemorrhagic stroke [8], gastrointestinal bleeding, [22], seizures [23] and myocardial infarction [24]. However, others did not find an association of moon phases with the incidence of seizures [25] and ischemic stroke [8]. Moon may also impact other bodily functions, such as blood pressure and sleep [26] that can subsequently predispose to intracranial aneurysm rupture.…”

“…Clinical risk factors of intracranial aneurysm rupture include increasing age, arterial hypertension, atherosclerosis, greater aneurysm size, smoking and heavy alcohol consumption [3–5]. Circadian and seasonal rhythmic variations are associated with vascular functioning [6] and were implicated in the risk to develop acute cerebrovascular events [7, 8]. For example, cold weather, epidemic influenza [9] and spring season [10] were linked to greater risk of intracranial aneurysm rupture.…”

“…An increasing body of evidence suggests that lunar phases can be associated with the incidence of acute cerebrovascular events. It was shown that full moon is associated with greater incidence of hemorrhagic stroke, transient ischemic attack [8] and unexplained stroke symptoms [13] but not with ischemic stroke. There is a common belief, which is based mostly on anecdotal experiences, that the waxing phase of the moon can be associated with greater surgical complication risk [14] and that the incidence of intracranial aneurysm rupture increases during the new moon phase [15].…”

Influence of Weekday of Surgery on Operative Complications. An Analysis of 25.000 Surgical Procedures

“…Hardly any study could provide serious evidence for a lunar effect on illness. An exemption being a recent study on 6.250 consecutive stroke admissions in Canada though showed a higher incidence of intracerebral hemorrhage and transient ischemic attack during the first quarter of the lunar phase and full moon, whereas ischemic stroke was not influenced, which is difficult to explain biologically [23].…”