Effects of high frequency electromagnetic field (EMF) emitted by mobile phones on the human motor cortex.

Bioelectromagnetics · 2007 · No effect · Low evidence

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No effectLow evidencePaper 5063

In 10 normal volunteers, neither MEPs elicited by single-pulse TMS nor SICI were affected after 30 minutes of mobile phone EMF exposure compared with sham. In two multiple sclerosis patients, mobile phone exposure had no effect on MEP parameters even though c…

Study snapshot

PublicationBioelectromagnetics · 2007

Study typerandomized_trial

Reported directionNo effect

Evidence ratingLow

Abstract

We investigated whether the pulsed high frequency electromagnetic field (EMF) emitted by a mobile phone has short term effects on the human motor cortex. We measured motor evoked potentials (MEPs) elicited by single pulse transcranial magnetic stimulation (TMS), before and after mobile phone exposure (active and sham) in 10 normal volunteers. Three sites were stimulated (motor cortex (CTX), brainstem (BST) and spinal nerve (Sp)). The short interval intracortical inhibition (SICI) of the motor cortex reflecting GABAergic interneuronal function was also studied by paired pulse TMS method. MEPs to single pulse TMS were also recorded in two patients with multiple sclerosis showing temperature dependent neurological symptoms (hot bath effect). Neither MEPs to single pulse TMS nor the SICI was affected by 30 min of EMF exposure from mobile phones or sham exposure. In two MS patients, mobile phone exposure had no effect on any parameters of MEPs even though conduction block occurred at the corticospinal tracts after taking a bath. As far as available methods are concerned, we did not detect any short-term effects of 30 min mobile phone exposure on the human motor cortical output neurons or interneurons even though we can not exclude the possibility that we failed to detect some mild effects due to a small sample size in the present study. This is the first study of MEPs after electromagnetic exposure from a mobile phone in neurological patients.

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AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typerandomized_trial

Effect directionno_effect

Population10 normal volunteers; 2 patients with multiple sclerosis

Sample size12

ExposureRF · 30 min

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

Outcomes measured

Motor evoked potentials (MEPs) elicited by single-pulse TMS (motor cortex, brainstem, spinal nerve stimulation sites)
Short interval intracortical inhibition (SICI) assessed by paired-pulse TMS

Limitations

Small sample size (10 volunteers; 2 MS patients)
Authors note mild effects could have been missed due to limited power
Short-term exposure only (30 minutes)

View raw extracted JSON

{
  "study_type": "randomized_trial",
  "exposure": {
    "band": "RF",
    "source": "mobile phone",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "30 min"
  },
  "population": "10 normal volunteers; 2 patients with multiple sclerosis",
  "sample_size": 12,
  "outcomes": [
    "Motor evoked potentials (MEPs) elicited by single-pulse TMS (motor cortex, brainstem, spinal nerve stimulation sites)",
    "Short interval intracortical inhibition (SICI) assessed by paired-pulse TMS"
  ],
  "main_findings": "In 10 normal volunteers, neither MEPs elicited by single-pulse TMS nor SICI were affected after 30 minutes of mobile phone EMF exposure compared with sham. In two multiple sclerosis patients, mobile phone exposure had no effect on MEP parameters even though conduction block occurred after taking a bath.",
  "effect_direction": "no_effect",
  "limitations": [
    "Small sample size (10 volunteers; 2 MS patients)",
    "Authors note mild effects could have been missed due to limited power",
    "Short-term exposure only (30 minutes)"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "mobile phone",
    "radiofrequency",
    "pulsed high frequency electromagnetic field",
    "motor cortex",
    "transcranial magnetic stimulation",
    "motor evoked potentials",
    "short interval intracortical inhibition",
    "multiple sclerosis",
    "sham exposure"
  ],
  "suggested_hubs": []
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1002/bem.20318
PubMed: 17516508

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