Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Corticomotor threshold to magnetic stimulation: normal values and repeatability

K R Mills1, K A Nithi

  • 1University Department of Clinical Neurology, Radcliffe Infirmary, Oxford, United Kingdom.

Muscle & Nerve
|May 1, 1997
PubMed
Summary
This summary is machine-generated.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Anti-MuSK antibodies in a case of ocular myasthenia gravis.

Journal of neurology, neurosurgery, and psychiatry·2006
Same author

Lorazepam-induced effects on silent period and corticomotor excitability.

Experimental brain research·2006
Same author

Predicting response to treatment in chronic inflammatory demyelinating polyradiculoneuropathy.

Journal of neurology, neurosurgery, and psychiatry·2005
Same author

The use of transcranial magnetic stimulation in the clinical evaluation of suspected myelopathy.

Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia·2005
Same author

Abnormal cortical excitability in sporadic but not homozygous D90A SOD1 ALS.

Journal of neurology, neurosurgery, and psychiatry·2005
Same author

The basics of electromyography.

Journal of neurology, neurosurgery, and psychiatry·2005

This study introduces a new method for determining the lower threshold (LT) and upper threshold (UT) of corticomotor excitation using magnetic stimuli. These thresholds are crucial for assessing central motor conduction and are reliably determined with this novel technique.

Area of Science:

  • Neuroscience
  • Clinical Neurophysiology

Background:

  • Assessing central motor conduction relies on corticomotor excitation thresholds.
  • Current methods for defining these thresholds are often arbitrary, with limited data using figure-of-eight coils.

Purpose of the Study:

  • To introduce and validate a new method for determining the lower threshold (LT) and upper threshold (UT) of magnetic stimuli-evoked corticomotor excitation.
  • To establish reliable and repeatable threshold measurements for clinical assessment.

Main Methods:

  • A novel method was developed to determine LT (highest intensity with zero response probability) and UT (lowest intensity with one response probability).
  • This technique utilizes a figure-of-eight coil optimally positioned over the hand motor cortex, minimizing stimulus requirements.
  • Measurements were performed on the relaxed first dorsal interosseous muscle.

Related Experiment Videos

Main Results:

  • Both LT and UT were found to be normally distributed and independent of age, gender, and hemisphere.
  • In 55 control subjects (102 hands), mean +/- SD UT was 46.6 +/- 9.4% and LT was 38.0 +/- 8.6% of maximum stimulator output.
  • Repeatability analysis showed significant changes over 1-3 months were >13% for UT and >11% for LT at the 5% level.

Conclusions:

  • The described method provides a reliable and repeatable approach to quantifying corticomotor excitation thresholds (LT and UT).
  • These findings establish normative data and repeatability estimates for LT and UT, crucial for accurate central motor conduction assessment.