Thomas Agerbo Gaist

What is the title of your thesis?

Autoimmune Encephalitis: Epidemiology, Long-term Outcomes and Cost-of-illness.

At which department and/or research unit did you complete your PhD?

Neurological Research Unit, Department of Clinical Research, University of Southern Denmark. Department of Neurology, Odense University Hospital.

Who was your principal supervisor?

Professor Morten Blaabjerg, MD, PhD.

What question did you aim to answer with your thesis?

Autoimmune encephalitis is a rare disease in which the immune system attacks the brain, causing symptoms such as epileptic seizures, memory loss and psychosis. Treatment that suppresses the immune system is often effective, and autoimmune encephalitis is generally considered to have a good prognosis.

However, there is still much we do not know about how common the disease is and its long-term consequences. Using unique nationwide testing data, we aimed to determine the prevalence of the disease in Denmark and investigate its long-term consequences for patients and society.

What did you find?

We found that the disease is rare, but that it has become more common over time, probably because clinicians have become better at recognising it. On the surface, patients appeared to recover well, but a large proportion continued to experience problems with memory and fatigue several years after the illness had ended.

At the same time, significantly fewer returned to work, more were granted disability pension, and the disease was associated with substantial costs to society compared with people without the disease.

How did you do it?

We assembled a national cohort of patients by combining test results with medical record data.

We then invited adult patients to take part in a clinical study in which we carried out a detailed assessment of cognition, fatigue, anxiety/depression and quality of life.

Finally, we linked our patient cohort with data from the Danish national registers, allowing us to compare the patients with similar people from the general population over time.

How can your research be applied (in the clinic, society, etc.)?

We show that the previous assumption that patients do well in the long term is not necessarily true. Clinicians should be aware of cognitive problems, fatigue and the risk of reduced ability to work in this patient group after treatment has ended.