title: Neurophysiological and BOLD signal uncoupling of giant somatosensory evoked potentials in progressive myoclonic epilepsy: a case-series study.
abstract: In progressive myoclonic epilepsy (PME), a rare epileptic syndrome caused by a variety of genetic disorders, the combination of peripheral stimulation and functional magnetic resonance imaging (fMRI) can shed light on the mechanisms underlying cortical dysfunction. The aim of the study is to investigate sensorimotor network modifications in PME by assessing the relationship between neurophysiological findings and blood oxygen level dependent (BOLD) activation. Somatosensory-evoked potential (SSEP) obtained briefly before fMRI and BOLD activation during median-nerve electrical stimulation were recorded in four subjects with typical PME phenotype and compared with normative data. Giant scalp SSEPs with enlarger N20-P25 complex compared to normal data (mean amplitude of 26.2 ± 8.2 μV after right stimulation and 27.9 ± 3.7 μV after left stimulation) were detected. Statistical group analysis showed a reduced BOLD activation in response to median nerve stimulation in PMEs compared to controls over the sensorimotor (SM) areas and an increased response over subcortical regions (p < 0.01, Z > 2.3, corrected). PMEs show dissociation between neurophysiological and BOLD findings of SSEPs (giant SSEP with reduced BOLD activation over SM). A direct pathway connecting a highly restricted area of the somatosensory cortex with the thalamus can be hypothesized to support the higher excitability of these areas.
authors.affiliation: Department of Computer Science, University of Verona, Verona, Italy.
authors.forename: Silvia F
authors.initials: SF
authors.lastname: Storti
authors.affiliation: Department of Neuroscience-DSN, University of Padova, Padova, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Del Felice
authors.affiliation: Neurophysiopathology and Epilepsy Centre, IRCCS Foundation Carlo Besta Neurological Institute, Milan, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Canafoglia
authors.affiliation: Foundation IRCCS San Camillo Hospital, Venice, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Formaggio
authors.affiliation: Franz Tappeiner Hospital, Department of Neurology, Merano, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Brigo
authors.affiliation: University Hospital Verona, Department of Neuroradiology, Verona, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Alessandrini
authors.affiliation: Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Italy.
authors.forename: Luigi G
authors.initials: LG
authors.lastname: Bongiovanni
authors.affiliation: Department of Computer Science, University of Verona, Verona, Italy.
authors.forename: Gloria
authors.initials: G
authors.lastname: Menegaz
authors.affiliation: Department of Medical, Surgical and Health Sciences, Clinical Neurology Unit, Cattinara University Hospital, Trieste, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Manganotti
mesh_terms: D000328:Adult; D001931:Brain Mapping; D004558:Electric Stimulation; D004569:Electroencephalography; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008475:Median Nerve / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology; D008875:Middle Aged; D020191:Myoclonic Epilepsies, Progressive / Q000097:blood / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D064926:Neurophysiological Monitoring; D010100:Oxygen / Q000097:blood; D011930:Reaction Time; D013003:Somatosensory Cortex / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*
chemical_list: D010100:Oxygen