Related Experiment Videos
Increased excitability of the human corticospinal system with hyperventilation
1Department of Neurology, University of California, Davis Medical Center, Sacramento 95817, USA.
Electroencephalography and Clinical Neurophysiology
|September 19, 1998
Summary
Hyperventilation enhances the excitability of the human corticospinal system, as shown by increased motor evoked potentials (MEPs) and F-wave responses. This finding may explain clinical effects observed in conditions like absence seizures.
Area of Science:
- Neuroscience
- Human Physiology
Background:
- Hyperventilation is known to induce generalized spike-wave discharges in absence seizures and affect visual function in multiple sclerosis.
- It increases excitability in peripheral axons and hippocampal neurons in animals, but direct evidence in the human central nervous system is lacking.
Purpose of the Study:
- To investigate the effects of hyperventilation on the human corticospinal system's excitability.
- To determine if hyperventilation influences neuronal excitability within the central nervous system in humans.
Main Methods:
- Studied the impact of hyperventilation on motor evoked potentials (MEPs) via transcranial magnetic stimulation.
- Assessed F-wave responses during hyperventilation in six human subjects.
Main Results:
- Hyperventilation, reducing end-tidal pCO2 to 15 mm Hg or less, enhanced MEP amplitude and shortened onset latency.
- F-wave amplitudes increased without changes in onset latency.
Conclusions:
- Hyperventilation demonstrably increases the excitability of the human corticospinal system.
- This heightened central nervous system excitability may underlie clinical observations, including the facilitation of spike-wave discharges.