Related Experiment Video

Updated: Feb 13, 2026

Stimulating the Lip Motor Cortex with Transcranial Magnetic Stimulation
12:09

Stimulating the Lip Motor Cortex with Transcranial Magnetic Stimulation

Published on: June 14, 2014

19.8K

Motor evoked potentials by magnetic stimulation in acute ischaemic stroke : prognostic significance

K A Kumar1, Jmk Murthy1, Kumar K Ashok1

  • 1Department of Neurology, Nizam's Institute of Medical Sciences, Panjagutta, Hyderabad - 500482, India.

Neurology India
|March 16, 2018
PubMed

Insights

Transcranial magnetic stimulation (TMS) can predict outcomes in acute ischemic stroke patients. Early evaluation of motor evoked potentials (MEPs) using TMS helps determine recovery potential and guide treatment strategies.

Area of Science:

  • Neuroscience
  • Neurology
  • Clinical Electrophysiology

Background:

  • Ischemic stroke is a leading cause of long-term disability.
  • Early prediction of stroke outcomes is crucial for effective patient management.
  • Motor evoked potentials (MEPs) assess the integrity of the corticospinal tract.

Purpose of the Study:

  • To evaluate the utility of transcranial magnetic stimulation (TMS) in predicting motor recovery in acute ischemic stroke patients.
  • To correlate early MEP findings with long-term motor deficit and disability.

Main Methods:

  • 25 patients with ischemic stroke within 72 hours of onset underwent TMS to record motor evoked potentials (MEPs).
  • Motor power was assessed using the Medical Research Council (MRC) grading scale.
  • Disability was evaluated using the Rankin scale.

Main Results:

  • Patients were categorized into three groups based on MEPs: normal MEPs (Group I), prolonged central motor conduction time (CMCT) and/or abnormal MEP/CMAP ratios (Group II), and absent cortical MEPs (Group III).
  • Greater weakness and disability correlated with more abnormal or absent MEPs.
  • Patients with absent MEPs (Group III) showed no significant motor improvement at six months, while those with elicitable MEPs (Groups I & II) showed significant improvement.

Conclusions:

  • Early evaluation of motor evoked potentials (MEPs) using transcranial magnetic stimulation (TMS) is a valuable tool for predicting motor recovery in acute ischemic stroke.
  • Absent MEPs in the acute phase indicate a poor prognosis for motor recovery.
  • TMS-based MEP assessment can aid in stratifying patients and guiding therapeutic interventions for ischemic stroke.

More Related Videos

Extracting Visual Evoked Potentials from EEG Data Recorded During fMRI-guided Transcranial Magnetic Stimulation09:36

Extracting Visual Evoked Potentials from EEG Data Recorded During fMRI-guided Transcranial Magnetic Stimulation

Published on: May 12, 2014

14.3K
Author Spotlight: Increasing TMS Accessibility Through Braiding Techniques for Diverse Hair Types04:37

Author Spotlight: Increasing TMS Accessibility Through Braiding Techniques for Diverse Hair Types

Published on: August 9, 2024

1.4K

Related Concept Videos

Motor Unit Stimulation01:20

Motor Unit Stimulation

When the neuron of a motor unit fires an action potential, it triggers a series of events, leading to a twitch contraction in the muscle fibers. The process of excitation-contraction coupling is crucial in relaying the action potential to the muscle fibers.
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
3.9K
Magnetic Vector Potential01:15

Magnetic Vector Potential

In electrostatics, the electric field can be written as the negative gradient of the potential. In magnetostatics, the zero divergence of the magnetic field ensures that the magnetic field can be expressed as the curl of a vector potential. This potential is known as the magnetic vector potential.
Consider an ideal solenoid with n turns per unit length and radius R. If I is the current through the solenoid, the magnetic field inside the solenoid is expressed as the product of vacuum...
1.6K
Potential Due to a Magnetized Object01:24

Potential Due to a Magnetized Object

Magnetic dipoles in magnetic materials are aligned when placed under an external magnetic field. For paramagnets and ferromagnets, dipole alignment occurs in the direction of the magnetic field. However, the dipoles align opposite to the field in the case of diamagnets. This state of magnetic polarization due to the external field is called magnetization. Magnetization is defined as the dipole moment per unit volume. It plays a similar role to polarization in electrostatics.
The vector...
823
Action Potential: Phases of Stimulation01:28

Action Potential: Phases of Stimulation

The action potential is a complex electrical event that occurs in excitable cells, such as neurons and muscle cells. It consists of several distinct phases, each with specific characteristics.
Resting Phase:
In this phase, the cell's membrane is at its resting potential, typically around -70 millivolts (mV) for neurons. Inside the cell, there is a higher concentration of potassium ions (K+) and a lower concentration of sodium ions (Na+). Voltage-gated sodium channels are closed, and...
12.5K
Statistical Significance01:50

Statistical Significance

Once data is collected from both the experimental and the control groups, a statistical analysis is conducted to find out if there are meaningful differences between the two groups. A statistical analysis determines how likely any difference found is due to chance (and thus not meaningful). In psychology, group differences are considered meaningful, or significant, if the odds that these differences occurred by chance alone are 5 percent or less. Stated another way, if we repeated this...
22.2K
Significance of Center of Mass01:12

Significance of Center of Mass

The center of mass of an object is defined as the mass-weighted average position of all the particles that comprise the object. The significance of the center of mass of an object can be seen by looking at its dynamics. The time derivative of the center of mass gives its velocity, assuming that the object's mass remains constant over time. Furthermore, the total linear momentum of an object can be seen as the linear momentum of a single particle of the object's total mass moving with...
7.7K