Using EEG and MEG to characterize extreme delta brush in a patient with anti-NMDA receptor encephalitis

Abstract

Background Extreme delta brush (EDB) is considered a potential marker for anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis. The brain regions involved in EDB are unclear. Case presentation A 16-year-old woman with anti-NMDAR encephalitis who was experiencing psychosis was admitted. Electroencephalography (EEG) and magnetoencephalography (MEG) were used to analyze EDB in the patient. EDB on EEG could be disturbed by opening and closing the eyes, by occipital alpha rhythms and by sleep-wake cycles. The MEG results showed beta activity originating from bilateral superior parietal lobes. However, the delta wave originated from bilateral superior temporal gyri, the right middle temporal gyrus, the right inferior frontal gyrus, and the left inferior parietal lobe. Conclusions Delta wave and beta activity might originate from different brain regions. Beta activity might be transmitted forward to the frontotemporal lobe and superimposed with delta activity to form EDB on EEG.

Introducing a New Mobile Electroencephalography System and Evaluating Its Quality in Comparison to Clinical Electroencephalography

“…This indicates the presence of heightened Delta activity during eyes-open conditions compared to eyes-closed conditions. This pattern is also apparent in the time domain, consistent with previous studies [30].…”

Linking brain networks to cognition with magnetoencephalography in paediatric autoimmune encephalitis

“…The delta band specificity may be linked to the abnormalities that are commonly reported in AE patient EEG. For example, extreme delta brush (delta activity with superimposed bursts of beta frequency), which can also be observed with MEG 27, 3 and generalised rhythmic delta activity are common observations in NMDARE 39 . Slowing of brain activity (in the delta frequency range) is frequently noted in ADEM 87, 88 and NMDARE 89 patient EEG.…”

“…Resting-state network connectivity and topology were assessed within delta and theta frequency bands because of their relevance for cognition 41, 42 and their previously observed alterations in adult AE studies (with the exception of Miao et al reporting a MEG study on a 16 year old patient) 27, 37, 57, 86 .…”

“…Magnetoencephalography (MEG) is an alternative non-invasive method used for measuring functional brain dynamics 26 , but studies in AE are limited to case reports. 27, 28 MEG provides a direct measure of neuronal activity, unlike fMRI which relies on a surrogate signal based on blood oxygenation levels. MEG can reveal widespread changes in functional connectivity with higher temporal resolution than fMRI, which is especially relevant to examining synchrony of neural oscillations across brain regions 29 .…”