A link between lunar phase and medically unexplained stroke symptoms: An unearthly influence?

Objective effects on human behaviour and health have been postulated for centuries; associations between phase of the moon and both vascular and psychiatric disease have been reported. We hypothesised that admission with medically unexplained stroke symptoms would be influenced by lunar cycle. s missions to the Western Infirmary Acute Stroke Unit are recorded in a comprehensive database. We analysed admissions between January 1, 1993, and September 30, 2006 (inclusive). Association between admission rate, phase of the moon, and a series of other culturally significant dates was calculated using chi-square testing. s were 7219 admissions during the study period, comprising 167 complete lunar cycles. Stroke admissions were evenly spread throughout lunar phases (P=.72). Admission with medically unexplained stroke symptoms was significantly increased during full moon phases (P=.023). There was no variation in admission rates during other significant dates. sion was a statistically significant association between admission to the acute stroke unit with a diagnosis of medically unexplained stroke symptoms and lunar phase. The reasons for this observed variation remain elusive; our data do not support a convincing biological or psychosocial aetiology.