Francesca Pittau

Patterns of altered functional connectivity in mesial temporal lobe epilepsy

Purpose:  In mesial temporal lobe epilepsy (MTLE) the epileptogenic area is confined to the mesial temporal lobe, but other cortical and subcortical areas are also affected and cognitive and psychiatric impairments are usually documented. Functional connectivity methods are based on the correlation of the blood oxygen level dependent (BOLD) signal between brain regions, which exhibit consistent and reproducible functional networks from resting state data. The aim of this study is to compare functional connectivity of patients with MTLE during the interictal period with healthy subjects. We hypothesize that patients show reduced functional connectivity compared to controls, the interest being to determine which regions show this reduction.

Widespread epileptic networks in focal epilepsies: EEG‐fMRI study

Purpose:  To assess the extent of brain involvement during focal epileptic activity, we studied patterns of cortical and subcortical metabolic changes coinciding with interictal epileptic discharges (IEDs) using group analysis of simultaneous electroencephalography and functional magnetic resonance imaging (EEG‐fMRI) scans in patients with focal epilepsy.

Contribution of EEG/fMRI to the definition of the epileptic focus

Objectives: To evaluate the clinical relevance of EEG/fMRI in patients with focal epilepsy, by assessing the information it adds to the scalp EEG in the definition of the epileptic focus. Methods: Forty-three patients with focal epilepsy were studied with EEG/fMRI using a 3-T scanner. Blood oxygen level−dependent (BOLD) signal changes related to interictal epileptic discharges (IEDs) were classified as concordant or not concordant with the scalp EEG spike field and as contributory if the BOLD signal provided additional information to the scalp EEG about the epileptic focus or not contributory if it did not. We considered patients having intracerebral EEG or a focal lesion on MRI as having independent validation. Results: Thirty-three patients had at least 3 IEDs during the EEG/fMRI acquisition (active EEG), and all had a BOLD response. In 29 of 33 (88%) patients, the BOLD response was concordant, and in 21 of 33 (64%) patients, the BOLD response was contributory. Fourteen patients had an independent validation: in 12 of these 14, the BOLD responses were validated and in 2 they were invalidated. Conclusions: A BOLD response was present in all patients with active EEG, and more specific localization of the epileptic focus was gained from EEG/fMRI in half of the patients who were scanned, when compared with scalp EEG alone. This study demonstrates that EEG/fMRI, in the context of a clinical practice, may contribute to the localization of the interictal epileptic generator in patients with focal epilepsy.

Functional connectivity in patients with idiopathic generalized epilepsy

Purpose:  Idiopathic generalized epilepsy (IGE) is characterized by electroencephalography (EEG) recordings with generalized spike wave discharges (GSWDs) arising from normal background activity. Although GSWDs are the result of highly synchronized activity in the thalamocortical network, EEG without GSWDs is believed to represent normal brain activity. The aim of this study was to investigate whether thalamocortical interactions are altered even during GSWD‐free EEG periods in patients with IGE.

Combining EEG and fMRI in the study of epileptic discharges

The combining of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) is a unique noninvasive method for investigating the brain regions involved at the time of epileptic discharges. The neuronal discharges taking place during an interictal spike or spike‐wave burst result in an increase in metabolism and blood flow, which is reflected in the blood oxygen–level dependent (BOLD) signal measured by fMRI. This increase is most intense in the region generating the discharge but is also present in regions affected by the discharge. On occasion, epileptic discharges result in decreased metabolism, the origin of which is only partially understood. EEG‐fMRI applied to focal epilepsy results in maxima of the BOLD signal most often concordant with other methods of localization and has been shown to help in localizing epileptic foci in nonlesional frontal lobe epilepsy. It has also demonstrated the involvement of the thalamus in generalized epileptic discharges. In patients with new‐onset epilepsy it could be used to evaluate the source and extent of the brain structures involved during discharges and their evolution as the disease progresses.

Prognostic factors in patients with mesial temporal lobe epilepsy

Purpose:  To disclose clinical, electrophysiologic, and neuroradiologic factors correlated to prognosis in patients with mesial temporal lobe epilepsy (MTLE).

Interobserver Reliability of Video Recording in the Diagnosis of Nocturnal Frontal Lobe Seizures

Summary:  Background: Nocturnal frontal lobe seizures (NFLS) show one or all of the following semeiological patterns: (1) paroxysmal arousals (PA: brief and sudden recurrent motor paroxysmal behavior); (2) hyperkinetic seizures (HS: motor attacks with complex dyskinetic features); (3) asymmetric bilateral tonic seizures (ATS: motor attacks with dystonic features); (4) epileptic nocturnal wanderings (ENW: stereotyped, prolonged ambulatory behavior).

Excessive Daytime Sleepiness and Subjective Sleep Quality in Patients with Nocturnal Frontal Lobe Epilepsy: A Case-Control Study

Summary:  Purpose: Nocturnal frontal lobe epilepsy (NFLE) may be associated with sleep fragmentation and reduced sleep efficiency. Daytime sleepiness and disturbed sleep quality have been reported in some patients. We investigated the occurrence of daytime sleepiness‐related symptoms and subjective sleep quality in patients with NFLE in comparison with matched controls.

Lateralizing Value of the Auditory Aura in Partial Seizures

Summary:  Purpose: To describe the semiological features of auditory aura and to assess their possible lateralizing value in partial epilepsy.

Reproducibility of interictal EEG-fMRI results in patients with epilepsy

Purpose:  Combined electroencephalography (EEG) and functional MRI (EEG‐fMRI) can be useful in the evaluation of epilepsy patients. The reproducibility of EEG‐fMRI findings needs to be established to consider it as a clinically valuable method. We addressed the intrasubject reproducibility of EEG‐fMRI and the possible superiority of higher magnetic field strength in patients who were scanned twice.