Neurologic, psychiatric, and sleep investigations after treatment of anti-leucine-rich glioma-inactivated protein 1 (LGI1) encephalitis in Spain: a prospective cohort study. 

March 12, 2024

A recently published study is providing a close look at anti-LGI1 encephalitis which, after anti-NMDA receptor encephalitis, is the second most common autoimmune encephalitis. Anti-LGI1 encephalitis most often affects middle aged patients who come to medical attention because of the quick onset (over a few weeks to a few months) of memory loss. Less commonly these patients are seen for new seizures or a fast decline in mental abilities that is different from the onset of dementia due to Alzheimer disease that occurs more slowly. In contrast to the majority of patients with anti-NMDA receptor encephalitis who fully or almost fully recover, around 70% of anti-LGI1 encephalitis patients have persistent disabilities. To improve this outcome the researchers of this study wanted to get a better picture of the persistent problems these patients had.  

To do this the investigators evaluated 24 patients, starting several months after they had been treated for anti-LGI1 encephalitis. Then over a 1 year period the patients had 3 evaluations that included detailed neurological, neuropsychological, and psychiatric examinations, overnight sleep studies in the hospital sleep lab, EEGs and brain MRI.  

At the first study visit, that was for most of the patients, a few months after completion of treatment for the encephalitis, only about 20% of the patients had more or less fully recovered. The remaining 80% of patients still had symptoms and deficits that affected their life. What was interesting was that some of these problems were only picked up by the testing as the patients themselves did not complain of these. For example, almost all the patients had abnormal sleep studies but they did not complain of sleep problems. While neuropsychological testing detected problems with thinking and problem solving the patients did not realize they had these issues. By the second and third visits all the patients had improved somewhat but the majority still had some problems that once again were only picked up by the testing.  

Do we have to be concerned about problems a patient does not complain about?  Sleep is a good example to answer this. Sleep is a complex activity and normal sleep is very important for our general good health and brain function. Persistent sleep problems can lead to disturbances in memory, thinking and reasoning. However, many people with a change in the complexity of their sleep do not realize they have a serious sleep problem that may be affecting their brain function.  The good news is that some sleep disturbances can be treated and this can lead to improvement. 

I found this study very exciting because it tells us that many patients with anti-LGI1 encephalitis who are not doing well close to two years from diagnosis and treatment might be helped by finding and treating these unnoticed problems. Maybe the sum of these unnoticed problems is the cause or at least part of why they are not better. This is not just speculation. In this study several of the patients who were found to have an unnoticed problem received therapy and they improved. 

Moving forward, physicians who follow these patients can anticipate and test for these problems and when found, provide treatment. It is also possible that unnoticed problems occur with other autoimmune encephalitis and would benefit from detailed re-examination even a few years after initial diagnosis and treatment? Further studies will help answer this question and should lead to improved outcomes for all these patients.  

Amaia Muñoz-Lopetegi, Mar Guasp, Laia Prades, Eugenia Martinez-Hernandez, Mireia Rosa-Justícia, Victor Patricio, Thaís Armangué, Lorena Rami González, Roger Borràs, Josefina Catro-Fornieles, Albert Compte, Carles Gaig, Joan Santamaria, Josep Dalmau. Lancet Neurology 2024;23:256-266.            

Some of you may remember Amaia Muñoz-Lopetegi as a 2021 AEA Community Seed Grant recipient. Thank you to the AEA community for making research like this possible. The AEA Community Seed Grant funds research that has direct implications for people with AE. Together we are doing good things!

Thank you Myrna Rosenfeld, MD, a member of the AEA Medical Advisory Board for providing the March 2024 AEA Research Review.