Evidence map›Paper›PMID 40622689›Full record

Trial reportEpilepsia2025

Distinct impacts of sodium channel blockers on the strength-duration properties of human motor cortex neurons.

Lorenzo Rocchi, Kate Brown, Alessandro Di Santo, Hannah Smith, Angel V Peterchev, John C Rothwell, Ricci Hannah

Abstract readRandomized Controlled Trial
In one paragraph

Trial report in Epilepsia, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

0numbers the graph read from it
0cells of the map it votes in
4citing 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

4 citing papers in PubMed.

  1. Trial
  2. Review
  3. Article
  4. 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

7 authors.

Lorenzo RocchiUniversity College London, London, UK.
Kate BrownUniversity College London, London, UK.
Alessandro Di SantoUniversity College London, London, UK.
Hannah SmithUniversity College London, London, UK.
Angel V PeterchevDuke University, Durham, North Carolina, USA.
John C RothwellUniversity College London, London, UK.
Ricci HannahUniversity College London, London, UK.ORCID https://orcid.org/0000-0001-5379-3292

Funding

Biology and Biophysics of the Cortical Response to Transcranial Magnetic StimulationR01NS117405 · NINDS · DUKE UNIVERSITY · PI PETERCHEV, ANGEL V, SOMMER, MARC A · 2020 to 2024
$3.3M
NeuroSimNIBS: Integrated electric field and neuronal response modeling for transcranial electric and magnetic stimulationR01MH128422 · NIMH · DUKE UNIVERSITY · PI Warren M. Grill, Angel V Peterchev · 2022 to 2026
$2.7M
MPS-TMS: Modular Pulse Synthesizer for Transcranial Magnetic Stimulation with Fully Adjustable Pulse Shape and SequenceTBDRF1MH124943 · NIMH · DUKE UNIVERSITY · PI PETERCHEV, ANGEL V · 2020 to 2020
$1.6M
Academy of Medical Sciences SBF009\1073NIMH NIH HHS R01 MH128422NIMH NIH HHS R01MH128422NIMH NIH HHS RF1 MH124943NIMH NIH HHS RF1MH124943NINDS NIH HHS R01 NS117405NINDS NIH HHS R01NS117405
6 · The paper itself

Abstract

objectiveThis study was undertaken to determine how voltage-gated sodium channel (VGSC) blockers modulate cortical excitability in vivo. VGSCs are critical for regulating axonal excitability, yet the effects of sodium channel-blocking medications on human cortical neurons remain poorly characterized. We aimed to address this gap using transcranial magnetic stimulation (TMS)-derived strength-duration measures as a noninvasive index of VGSC function.

methodsThirteen healthy adults received single doses of either carbamazepine, lacosamide, or placebo in a crossover design. TMS was used to assess changes in resting motor threshold and strength-duration properties, including rheobase and the strength-duration time constant, as indices of VGSC function.

resultsBoth medications elevated resting motor thresholds compared to placebo, indicating reduced excitability; however, their impacts varied according to TMS pulse width. Carbamazepine raised thresholds proportionally across all pulse widths, whereas lacosamide disproportionately influenced thresholds. Crucially, lacosamide reduced the strength-duration time constant and increased rheobase, whereas carbamazepine had minimal effects on both measures. SIGNIFICANCE: These results reveal subtle and unexpected differences in cortical neuron behavior following VGSC-blocking medication administration. Lacosamide's response aligns with the proposed mechanism of sodium conductance blockade, whereas carbamazepine's effects suggest distinct VGSC interactions or potential off-target effects. Our findings advance the understanding of VGSC-blocking medication interactions in the human cortex and underscore the importance of employing specific TMS measures to gain deeper insights into medication mechanisms of action in vivo. Such measures could serve as valuable adjuncts in medication development and patient monitoring.

Indexed as

CarbamazepineEvoked Potentials, MotorMotor CortexNeuronsSodium Channel BlockersVoltage-Gated Sodium Channel BlockersAdultCross-Over StudiesDouble-Blind MethodFemaleHumansLacosamideMaleTranscranial Magnetic StimulationYoung AdultCarbamazepineLacosamideSodium Channel BlockersVoltage-Gated Sodium Channel Blockersantiseizure medicationaxonal membranecortexion channeltranscranial magnetic stimulation

Identifiers

PMID40622689
PMCPMC12284445

What OpenQuestion holds

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Registered trials

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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.