A magnetoencephalography study associated benzodiazepine treatment with a steeper spectral slope, complicating the interpretation of that signal as a disease biomarker.
The researchers studied 95 people with multiple sclerosis and 44 healthy controls using resting-state magnetoencephalography. They measured the aperiodic spectral slope: how rapidly signal power declines as frequency increases. This is a proposed indirect marker of the balance between excitation and inhibition, not a direct measurement of neurotransmitter concentrations.
Participants with multiple sclerosis who received benzodiazepines had a significantly steeper slope than those who did not, with a reported p value of 0.01. The medication subgroup included 23 people, of whom 21 were women. Treatment was observed rather than randomly assigned.
Among participants with multiple sclerosis who were not taking benzodiazepines, the slope was steeper in those classified as cognitively impaired than in cognitively preserved participants or healthy controls. The investigators also found relationships with working-memory performance in selected prefrontal and parietal regions.
The same broad signal could therefore reflect more than one influence. A difference associated with medication exposure cannot automatically be attributed to multiple sclerosis itself. Conversely, a disease-associated difference does not establish that an unrecorded benzodiazepine was present. The study illustrates a confounding problem rather than validating a drug-identification test.
The investigators lacked benzodiazepine dose and treatment-duration information. The small, predominantly female medication subgroup limited comparisons across individual agents and exposure patterns. Clinical differences affecting prescribing may also contribute to the observed association.
The paper did not establish a blood-concentration relationship, a driving-impairment cutoff, or diagnostic sensitivity for benzodiazepine use. A brain-signal measurement should therefore be interpreted with the medication list, disease characteristics, cognitive assessment, and timing of exposure. Its potential value as a research biomarker does not make it a stand-alone explanation of an individual patient’s cognitive symptoms.
Original analysis of the supplied journal article, identified as PMC10619404.