Aperiodic Offset and Alpha Power Rise in Parkinson's Resting EEG

Parkinson's disease shows a measurable resting-state scalp EEG signature: an increased aperiodic offset and heightened alpha power, according to a preprint posted on medRxiv.

The study examined resting-state EEG activity in Parkinson's disease patients and reports two converging findings. First, the aperiodic component of the power spectrum — the 1/f-like background activity that reflects broadband cortical excitation–inhibition balance — shows an elevated offset in PD patients relative to controls. Second, alpha-band power is increased in the patient group.

Because the work appears as a preprint and has not yet undergone peer review, the findings should be treated as preliminary. The posting does not detail the full cohort size, montage specification, or medication status of participants, so readers should await the peer-reviewed version for those parameters.

For clinical neurophysiology readers, the report speaks to a growing effort to extract disease-specific biomarkers from routine scalp EEG. The aperiodic offset, separable from periodic oscillatory activity using spectral parameterization approaches, has attracted interest as a marker of cortical E/I balance in neurodegenerative disease. If confirmed in larger, well-characterized cohorts — with dopaminergic medication state, disease duration, and cognitive status controlled — an elevated offset plus increased alpha power could support EEG-based phenotyping of PD in the reading room or as an outcome measure in trials.

The immediate clinical implication remains limited. No diagnostic device or algorithm described in the preprint carries FDA clearance, and the findings do not establish EEG as a diagnostic test for Parkinson's disease. What the study demonstrates is a group-level spectral difference in resting-state scalp recordings between PD patients and controls.

Confirmation in independent cohorts, ideally with longitudinal recording and correlation against motor and cognitive measures, will determine whether these spectral features track disease progression or treatment response. Until then, the results add Parkinson's disease to the list of conditions where the aperiodic and periodic structure of the resting EEG carries clinically relevant information.