Related Experiment Video
Updated: May 20, 2026

Nerve Excitability Assessment in Chemotherapy-induced Neurotoxicity
Published on: April 26, 2012
Cortical excitability decreases in Lennox-Gastaut syndrome
Radwa A B Badawy1, Richard A L Macdonell, Simon J Vogrin
1Department of Clinical Neurosciences, St Vincent's Hospital, Fitzroy, Victoria, Australia. badawyr@unimelb.edu.au
Purpose:
We used transcranial magnetic stimulation (TMS) to investigate cortical excitability changes in Lennox-Gastaut syndrome (LGS), anticipating we would find a marked increase in excitability compared to other patients with refractory epilepsies.
Methods:
Eighteen patients with LGS were studied. Motor threshold (MT), short intracortical inhibition (paired pulse TMS at 2 and 5 msec interstimulus intervals [ISIs]), intracortical facilitation (10 and 15 msec ISIs), and long intracortical inhibition (100-300 msec ISIs) were measured. Results were compared to those of 20 patients with chronic refractory idiopathic generalized epilepsy (IGE), 20 patients with chronic refractory focal epilepsy, and 20 healthy nonepilepsy controls.
Key Findings:
A significant decrease in cortical excitability was observed in LGS compared to the other two groups with refractory epilepsy as evidenced by increased MT and intracortical inhibition at both short (2, 5 msec ISIs), and long (100-300 msec ISIs) as well as decreased intracortical facilitation (10, 15 msec ISIs), (p < 0.01; effect sizes ranging from 0.3 to 1.8). Cortical excitability was also lower in LGS compared to nonepilepsy controls (increased MT and decreased intracortical facilitation; p < 0.05; effect sizes ranging from 0.5 to 0.9).
Significance:
Interictal cortical excitability is decreased in LGS; a feature that distinguishes it from other refractory epilepsy syndromes. This decrease may be an important mechanism for the neurobehavioral comorbidities associated with LGS.
More Related Videos
09:48Intracortical Inhibition Within the Primary Motor Cortex Can Be Modulated by Changing the Focus of Attention
Published on: September 11, 2017
09:51Recording Synaptic Plasticity in Acute Hippocampal Slices Maintained in a Small-volume Recycling-, Perfusion-, and Submersion-type Chamber System
Published on: January 1, 2018
Related Concept Videos
Antiepileptic Drugs: Glutamate Antagonists
Antiepileptic Drugs: GABAergic Pathway Potentiators
The key GABA pathway potentiators used in epilepsy management are as follows.
Benzodiazepines are a well-known class of drugs used for their...
Long-term Depression
Calcium Ion Concentration Mechanism
If over time, all...
Long-term Depression
Ligand-Gated Ion Channel Receptor: Gating Mechanism
Antiepileptic Drugs: Potassium Channel Activators
Ezogabine has gained approval as an adjunctive treatment...