Somatosensory Evoked Potential: General Considerations On High Amplitude Cortical Component
Keywords:
somatosensory evoked potential, cortical components, epilepsies, partial, epilepsy, temporal lobeAbstract
The cortical components of the somatosensory evoked potential present great interindividual variability in view of the physiological and pathological changes that occur during development and aging. Dawson in 1946 described the cortical component with elevated amplitude in patients with progressive myoclonic epilepsy. Other studies have shown that the association of the cortical component with high amplitude would be associated with the occurrence of cortical myoclonus, not being present in subcortical and segmental myoclonus. In SEP studies in benign partial epilepsies of childhood, it was observed that early cortical components present normal latencies and amplitudes, while those with medium and long latencies may present high amplitudes with normal morphology and latency. The origin of the cortical component with high amplitude is not clear. It has been proposed that the high amplitude reflects an increase in the excitability of cortical areas, especially areas of the primary sensory cortex, due to a primary cortical disorder of inhibitory interneurons, or due to a failure of the inhibitory influences of subcortical structures.
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