Tri-Band Rhythmicity on Quantitative EEG: A Clinically Applicable Marker for Sporadic Creutzfeldt-Jakob Disease

IntroductionSporadic Creutzfeldt-Jakob Disease (sCJD) is a rapidly progressive prion disease that can be challenging to distinguish from other dementias, especially in early stages or when classical EEG findings, such as periodic sharp wave complexes (PSWCs), are absent. This study aimed to assess the utility of quantitative EEG (QEEG) features-derived from Food and Drug Administration-approved software-in differentiating sCJD from non-sCJD dementias.MethodsEEG data from 78 participants were retrospectively analyzed: 19 sCJD patients, 49 non-sCJD dementia patients, and 10 healthy controls. sCJD cases were sourced from three centers, while matched non-sCJD cases and controls were selected from a single-center EEG database. Sixty seconds of artifact-free EEG during wakefulness or drowsiness were selected per participant. QEEG parameters-amplitude-integrated EEG (aEEG) and rhythmicity spectrogram (RS)-were extracted using Persyst^® software. Intergroup comparisons were conducted using the Kruskal-Wallis test with Holm-Sidák correction. Group-level rhythmicity patterns were also evaluated visually.ResultssCJD patients had significantly higher aEEG and RS values than non-sCJD patients across both hemispheres (aEEG: left <i>p</i> = .001, right <i>p</i> = .010; RS: left <i>p</i> = .001, right <i>p</i> = .003). A distinct "tri-band rhythmicity" pattern involving delta, theta, and low beta frequencies was uniquely observed in sCJD patients, including those without PSWCs on conventional EEG.ConclusionQEEG using clinically available software can reveal disease-specific electrophysiological features in sCJD. Tri-band rhythmicity may serve as a non-invasive adjunctive marker for early or atypical sCJD diagnosis, warranting further validation in prospective studies.