The Importance of the EEG: 3 new studies on the predictive value of the EEG

Posted on September 23, 2018

There has been a recent surge in studies reporting findings from electroencephalographic data in patients with anti-NMDA receptor encephalitis (ANMDARE). Most studies to-date have described the overall disease characteristics of ANMDARE, including EEG data, but these recent studies have undertaken to analyze these data in greater detail.

We recently reported on the findings of Dr. C. Steriade and her colleagues, reported in their paper titled, “Electroclinical Features of Seizures in Autoimmune Encephalitis”.  https://www.antinmdafoundation.org/electroclinical-features-of-seizures-associated-with-autoimmune-encephalitis/

This article sheds light on epilepsy patients who require screening for autoantibodies and the commensurate treatments and aims to identify autoimmune encephalitis patients who are at risk of developing post-encephalitis epilepsy.

A further study by Dr. Steriade and her colleagues, titled, “ Extreme delta – With or without brushes: A potential surrogate marker of disease activity in anti-NMDA-receptor encephalitis” – https://www.clinph-journal.com/article/S1388-2457(18)30239-6/fulltext, proposes that EEG data may serve as a biomarker for disease progression. Not all ANMDARE patients respond to first-line immunotherapy. Biomarkers are needed to track disease progression. Persistent delta rhythm on EEG may help to identify patients who may benefit from second-line immunotherapies.

A third study by Dr. M. Titulaer and his colleagues at the Erasmus Medical Centre in Rotterdam, Netherlands, titled, “Predictive Value of Electroencephalography in Anti-NMDA receptor encephalitis” https://jnnp.bmj.com/content/early/2018/08/22/jnnp-2018-318376 contributes several relevant findings:

  1. EEG recordings may predict clinical outcomes (replicating the findings of Dr. Steriade);
  2. Diffuse and focal slowing are the most common EEG findings;
  3. A normal EEG reading does not exclude anti-NMDA receptor encephalitis;
  4.  Extreme Delta Brushes (EDBs) are only present in severally affected patients but who may not necessarily be admitted to ICU;
  5.  Long-term severe electrographic abnormalities can be followed by good clinical outcome.

We hope that our Partner Physicians, patients, caregivers and advocates will find this new information useful