Circadian and circaseptan rhythms in human epilepsy: a retrospective cohort study
Abstract
BACKGROUND
Epilepsy has long been suspected to be governed by cyclic rhythms, with seizure rates rising and falling periodically over weeks, months, or even years. The very long scales of seizure patterns seem to defy natural explanation and have sometimes been attributed to hormonal cycles or environmental factors. This study aimed to quantify the strength and prevalence of seizure cycles at multiple temporal scales across a large cohort of people with epilepsy.
METHODS
This retrospective cohort study used the two most comprehensive databases of human seizures (SeizureTracker [USA] and NeuroVista [Melbourne, VIC, Australia]) and analytic techniques from circular statistics to analyse patients with epilepsy for the presence and frequency of multitemporal cycles of seizure activity. NeuroVista patients were selected on the basis of having intractable focal epilepsy; data from patients with at least 30 clinical seizures were used. SeizureTracker participants are self selected and data do not adhere to any specific criteria; we used patients with a minimum of 100 seizures. The presence of seizure cycles over multiple time scales was measured using the mean resultant length (R value). The Rayleigh test and Hodges-Ajne test were used to test for circular uniformity. Monte-Carlo simulations were used to confirm the results of the Rayleigh test for seizure phase.
FINDINGS
We used data from 12 people from the NeuroVista study (data recorded from June 10, 2010, to Aug 22, 2012) and…
How strong is the evidence?
Evidence Hub reads this as a cohort study, done in people. Its evidence level is 3 of 5 (Moderate · trial / cohort / secondary analysis). Trials without a large randomized design, cohorts and secondary analyses give moderate evidence. Reported size: 1,118 participants or records.
Read the paper
Related studies
- Contribution of social science to large scale biodiversity conservation: A review of research about the Natura 2000 network
- The alignment of agricultural and nature conservation policies in the European Union
- Determination of ecological significance based on geostatistical assessment: a case study from the Slovak Natura 2000 protected area
- Routledge Handbook of the Study of the Commons
- Farmers' acceptance of results-based agri-environmental schemes: A German perspective
- Approaches to Identify the Value of Seminatural Habitats for Conservation Biological Control
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.