Blood oxygenation level–dependent (BOLD) activation associated with interictal epileptiform discharges in a patient with fixation-off sensitivity (FOS) was studied using a combined electroencephalography–functional magnetic resonance imaging (EEG–fMRI) technique. An automatic approach for combined EEG–fMRI analysis and a subject-specific hemodynamic response function was used to improve general linear model analysis of the fMRI data. The EEG showed the typical features of FOS, with continuous epileptiform discharges during elimination of central vision by eye opening and closing and fixation; modification of this pattern was clearly visible and recognizable. During all 3 recording sessions EEG–fMRI activations indicated a BOLD signal decrease related to epileptiform activity in the parietal areas. This study can further our understanding of this EEG phenomenon and can provide some insight into the reliability of the EEG–fMRI technique in localizing the irritative zone.
PanayiotopoulosCP. Fixation-off, scotosensitive, and other visual-related epilepsies. Adv Neurol. 1998;75:139-157.
2.
PanayiotopoulosCP. Benign Childhood Partial Seizures and Related Epileptic Syndromes. London, England: John Libbey; 1999.
3.
KrakowKBaxendaleSAMaguireEA. Fixation-off sensitivity as a model of continuous epileptiform discharges: electroencephalographic, neuropsychological and functional MRI findings. Epilepsy Res. 2000;42:1-6.
4.
KurthCBittermannHJWegererVBleichSSteinhoffBJ. Fixation-off sensitivity in an adult with symptomatic occipital epilepsy. Epilepsia. 2001;42:947-949.
5.
IannettiGDDi BonaventuraCPantanoP. fMRI/EEG in paroxismal activity elicide by elimination of central vision and fixation. Neurology. 2002;58:976-979.
6.
Di BonaventuraCVaudanoAECarnìM. Long-term reproducibility of MRI activation in epilepsy patients with fixation-off sensitivity. Epilepsia. 2005;46:1149-1151.
7.
AvesaniMFormaggioEStortiS. f-MRI in epilepsy with spike and wave activity evoked by eye closure: different BOLD activation in a patient with idiopathic partial epilepsy with occipital spikes and a control group. Neuroradiol J. 2008;21:159-165.
8.
StrigaroGPrandiPVarrasiCMonacoFCantelloR. Cortical excitability changes associated with fixation-off sensitivity: a case report. Epilepsia. 2011;52(8):e89-e92.
9.
BittarRGAndermannFOlivierA. Interictal spikes increase cerebral glucose metabolism and blood flow: a PET study. Epilepsia. 1999;40:170-178.
10.
KrakowKWoermannFGSymmsMR. EEG-triggered functional MRI of interictal epileptiform activity in patients with partial seizures. Brain. 1999;122(pt 9):1679-1688.
11.
Salek-HaddadiADiehlBHamandiK. Hemodynamic correlates of epileptiform discharges: an EEG-fMRI study of 63 patients with focal epilepsy. Brain Res. 2006;1088:148-166.
12.
GholipourTMoellerFPittauFDubeauFGotmanJ. Reproducibility of interictal EEG-fMRI results in patients with epilepsy. Epilepsia. 2011;53:433-442.
13.
PesaresiICosottiniMBelmonteG. Reproducibility of BOLD localization of interictal activity in patients with focal epilepsy: intrasession and intersession comparisons. MAGMA. 2011;24:285-296.
14.
StortiSFFormaggioEFranchiniE. A multimodal imaging approach to the evaluation of post-traumatic epilepsy. Magn Reson Mater Phys. 2012;25:345-360.
15.
DelormeAMakeigS. EEGLAB: an open source toolbox for analysis of single-trial EEG dynamics including independent component analysis. J Neurosci Methods. 2004;134:9-21.
16.
AllenPJJosephOTurnerR. A method for removing imaging artifact from continuous EEG recorded during functional MRI. Neuroimage. 2000;12:230-239.
17.
AllenPJPolizziGKrakowKFishDRLemieuxL. Identification of EEG events in the MR scanner: the problem of pulse artifact and a method for its subtraction. Neuroimage. 1998;8:229-239.
18.
FormaggioEStortiSFBertoldoAManganottiPFiaschiAToffoloGM. Integrating EEG and fMRI in epilepsy. Neuroimage. 2011;54:2719-2731.
19.
StortiSFFormaggioEBertoldoAManganottiPFiaschiAToffoloGM. Selection of optimal hemodynamic response function for fMRI analysis on acute stroke patients. In: DösselOSchlegelWC, eds. World Congress on Medical Physics and Biomedical Engineering, Munich, Germany, 2009. IFMBE Proceedings Vol. 25/1. Berlin, Germany: Springer; 2010:253-256.
20.
ManganottiPStortiSFFormaggioE. Effect of median-nerve electrical stimulation on BOLD activity in acute ischemic stroke patients. Clin Neurophysiol. 2012;123:142-153.
21.
HandwerkerDAOllingerJMD’EspositoM. Variation of BOLD hemodynamic responses across subjects and brain regions and their effects on statistical analyses. Neuroimage. 2004;21:1639-1651.
22.
StortiSFFormaggioEBertoldoAManganottiPFiaschiAToffoloGM. Modelling hemodynamic response function in epilepsy. Clin Neurophysiol. 2013; doi:pii:S1388-2457(13)00700-1.10.1016/j.clinph.2013.05.024.
23.
FristonKJHolmesAPWorsleyKJPolineJPFrithCDFrackowiakRSJ. Statistical parametric maps in functional imaging: a general linear approach. Hum Brain Mapp. 1995;2:189-210.
24.
ManganottiPFormaggioEGaspariniA. Continuous EEG-fMRI study in patients with partial epilepsy and focal interictal slow-wave discharges on EEG. Magn Reson Imaging. 2008;26:1089-1100.
25.
StortiSFFormaggioEBeltramelloAFiaschiAManganottiP. Wavelet analysis as a tool for investigating movement-related cortical oscillations in EEG-fMRI coregistration. Brain Topogr. 2010;23:46-57.
26.
HawcoCSBagshawAPLuYDubeauFGotmanJ. BOLD changes occur prior to epileptic spikes seen on scalp EEG. Neuroimage. 2007;35:1450-1458.
27.
KobayashiEHawcoCSGrovaCDubeauFGotmanJ. Widespread and intense BOLD changes during brief focal electrographic seizures. Neurology. 2006;66:1049-1055.
28.
DonaireAFalcónCCarrenoM. Sequential analysis of fMRI images: a new approach to study human epileptic networks. Epilepsia. 2009;50:2526-2537.
29.
BagshawAPAghakhaniYBénarCG. EEG-fMRI of focal epileptic spikes: analysis with multiple haemodynamic functions and comparison with gadolimium-enhanced MR angiograms. Hum Brain Mapp. 2004;22:179-192.
