Purpose: Aim of the study was to analyzed the effect of afferent input on patterns of brain electrical activation in eour patients with progressive myoclonic epilepsy (PME) by measuring the somatosensory evoked potential (SSEP) amplitude at the scalp after median-nerve stimulation and examining the changes in the functional magnetic resonance imaging blood oxygen level-dependent (fMRI BOLD) signal. Method: To locate the right median nerve at the wrist, the stimulation intensity and electrode sites were altered until stimulation produced an observable thumb twitch. Current stimulation during fMRI recording was done in an alternating sequence of 26 seconds. Coregistration System (Micromed) was used. Result: High amplitude SSEPs diffused over the scalp with high amplitude N20 and P25 were oberved in all the patients, but it was associated with highly focal BOLD activation of the contralateral sensorimotor areas. By contrast, no diffuse activation of either the frontal or the posterior parietal cortical areas was observed, as seen with previously recorded data of SSEPs from a healthy control group. Conclusion: The highly focal BOLD activation in these patients suggests that cortex hyperexcitability might be limited to the sensorimotor cortex in PME. The combined EEG-fMRI findings highlight a dissociation between BOLD activation and neurophysiological findings.
|Titolo:||Highly focal BOLD activation on fMRI in patients with progressive myoclonic epilepsy and diffuse giant somatosensory evoked potentials.|
|Data di pubblicazione:||2012|
|Appare nelle tipologie:||04.02 Abstract in Atti di convegno|