Evidence map›Paper›PMID 40678914›Full record

ArticleMuscle & nerve2025

Clinical Utility of Far-Field Potentials in Amyotrophic Lateral Sclerosis.

Aicee Dawn Calma, Nathan Pavey, Claudia Santos Silva, Yukiko Tsuji, Mehdi A J Van den Bos, Michelle A Farrar, Parvathi Menon, Steve Vucic

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Muscle & nerve, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Article
  2. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors.

Aicee Dawn CalmaBrain and Nerve Research Centre, Concord Clinical School, University of Sydney, Concord Hospital, Sydney, New South Wales, Australia.
Nathan PaveyBrain and Nerve Research Centre, Concord Clinical School, University of Sydney, Concord Hospital, Sydney, New South Wales, Australia.
Claudia Santos SilvaBrain and Nerve Research Centre, Concord Clinical School, University of Sydney, Concord Hospital, Sydney, New South Wales, Australia.ORCID https://orcid.org/0000-0003-4495-6314
Yukiko TsujiBrain and Nerve Research Centre, Concord Clinical School, University of Sydney, Concord Hospital, Sydney, New South Wales, Australia.ORCID https://orcid.org/0000-0001-5805-0631
Mehdi A J Van den BosBrain and Nerve Research Centre, Concord Clinical School, University of Sydney, Concord Hospital, Sydney, New South Wales, Australia.
Michelle A FarrarDepartment of Neurology, Sydney Children's Hospital Network, Sydney, New South Wales, Australia.ORCID https://orcid.org/0000-0002-4472-0902
Parvathi MenonBrain and Nerve Research Centre, Concord Clinical School, University of Sydney, Concord Hospital, Sydney, New South Wales, Australia.ORCID https://orcid.org/0000-0001-6935-5852
Steve VucicBrain and Nerve Research Centre, Concord Clinical School, University of Sydney, Concord Hospital, Sydney, New South Wales, Australia.ORCID https://orcid.org/0000-0002-8323-873X

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

INTRODUCTION/

aimsFar field potentials (FFP) have been proposed as a reliable neurophysiological prognostic biomarker in amyotrophic lateral sclerosis (ALS). This study evaluates the diagnostic utility of ulnar nerve FFP in ALS.

methodsComprehensive peripheral neurophysiological assessments were conducted in 62 ALS and 43 ALS-mimicking disorder participants. The ulnar nerve was stimulated at the wrist, recording motor responses over the abductor digit minimi (ADM) muscle. Conventional compound muscle action potentials (CMAP), FFP, and near field potential amplitudes were recorded, alongside the split-hand index, neurophysiological index, motor unit number estimation (MScanFit-MUNE), and motor unit index (MUNIX). Diagnostic utility was evaluated using receiver operating characteristic (ROC) analysis.

resultsIn ALS, FFP amplitude was significantly lower (5.07 ± 0.36 mV) compared to ALS mimics (8.25 ± 0.40 mV, p < 0.001). FFP amplitude exhibited a moderate-to-strong correlation with neurophysiological biomarkers, including CMAP amplitude (ρ = 0.77, p < 0.001), split-hand index (ρ = 0.53, p < 0.001), neurophysiological index (ρ = 0.52, p < 0.001), MUNIX (ρ = 0.69, p < 0.001), and MScanFit-MUNE (ρ = 0.66, p < 0.001). Weak-to-moderate correlations were also observed with clinical measures of disease progression, including upper limb muscle strength, ALS functional rating score-revised (ALSFRS-R) and the rate of decline in the ALSFRS-R fine motor subscore. ROC analysis demonstrated that FFP amplitude reliably distinguished ALS from mimicking disorders (AUC = 0.80, 95% CI: 0.71-0.89), with consistent diagnostic accuracy across ALS phenotypes. DISCUSSION: The diagnostic capability of FFP amplitude was comparable to established neurophysiological biomarkers utilized in ALS. It is a promising prognostic and diagnostic biomarker for ALS. Its simplicity and reproducibility complement traditional neurophysiological measures, offering potential for clinical application in ALS diagnosis and monitoring.

Indexed as

Action PotentialsAmyotrophic Lateral SclerosisUlnar NerveAdultAgedElectromyographyFemaleHumansMaleMiddle AgedMuscle, SkeletalNeural ConductionROC Curveamyotrophic lateral sclerosisCMAPfar‐field potentialnear‐field potential

Identifiers

PMID40678914
PMCPMC12435138

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.