24.01.19

A broad range of infections was associated with an increased risk of being diagnosed with epilepsy. This is reported in a new study based on almost two million children and young adults in Denmark.

It is well-known that infections in the brain and the nervous system are linked to an increased risk of epilepsy. New research has caused suspicion that other types of infection may be important to the risk of developing epilepsy.

In a large study, researchers at Aarhus University Hospital, Aarhus University and Psychiatric Center Copenhagen have investigated if there is an association between other types of infections and the risk of developing epilepsy. The results have just been published in Epilepsia, a leading international journal on research in epilepsy.

- The study showed that a broad range of infections was associated with an increased risk of epilepsy, indicating that infection processes and the immune defense system could be involved in the development of epilepsy, says consultant Jakob Christensen, who is part of the research team.

The 1,938,555 persons born in Denmark between 1982 and 2012 were part of the study, and researchers used registers to find out how many of these persons had been in contact with the hospital because of an infection and if they were later diagnosed with epilepsy. The persons in the study were followed until the end of 2012; this was equivalent to more than 28 million person-years.

A total of 25,825 persons in the study were diagnosed with epilepsy during the study period and of those 8,235 (32%) had previously had contacts with a hospital due to an infection. The study showed that those who had had contacts with a hospital due to an infection had a 78% increased risk of epilepsy compared to those who had not had a contact to a hospital due to an infection.

- The detailed national registries and the equal access to the healthcare system in Denmark have made it possible to follow a very large and representative group of children and young adults for many years. This has provided us with research results of a high quality, which have given rise to considerable international attention, says Jakob Christensen.

Infections in the brain and the central nervous system resulted in the largest increase in risk of epilepsy, but there was a higher prevalence of epilepsy regardless of the organ affected by infection and regardless of whether the infection was caused by bacteria or a virus.

The study also showed that that there was a time connection between the infection and the epilepsy diagnosis. Moreover, more hospital contacts caused by infection and thus the severity of the infections increased the risk for epilepsy.

Behind the research result:

Study type: Registry study based on Danish health registries

Collaborators: Researchers from Department of Neurology, Aarhus University Hospital, Psychiatric Center Copenhagen and the National Centre for Registry-based Research at Aarhus University

External financing: Central Denmark Region, the Lundbeck Foundation Initiative for Integrative

Psychiatric Research - iPSYCH, the Novo Nordisk Foundation, Lundbeckfonden og Epilepsiforeningen

Publication: Peer reviewed article in Epilepsia

Conflicts of interest: Jakob Christensen has received fees from UCB Nordic and Eisai AB as a scientific counsellor and has received fees from UCB Nordic and Eisai AB for presentations and has received financing of a journey by UCB Nordic. Jakob Christensen also takes part in other studies involving the companies: Pfizer, Novartis, Eisai AB, and Sage Therapeutics. Inc. The other authors report no conflicts of interest.

Read the scientific article:

Ahlers FS, Benros ME, Dreier JW, Christensen J. Infections and risk of epilepsy in children and young adults: A nationwide study. Epilepsia. 2018;00:1–9. https://doi.org/10.1111/epi.14626

Further information:

Jakob Christensen, PhD, DMSci, Clinical associate professor, consultant, Department of Neurology, Aarhus University Hospital and Department of Clinical Medicine, Aarhus University.

Tel.: +45 60 86 58 99

E-mail: jakob@clin.au.dk