In all patients, multifocal myoclonic jerks and seizures were a key feature, but myoclonic seizures were an early and prominent sign in the teenage/adult form only. Conversely, the childhood-onset form was characterized by initial and severe cognitive impairment coupled with electroretinogram and EEG attenuation. Cortical hyperexcitability, shown by the PPR and enlarged somatosensory evoked potentials, was a universal feature.

SUMMARYPurpose: To classify the grade of antiepileptic drug (AED) resistance in a cohort of patients with focal epilepsies, to recognize the risk factors for AED resistance, and to estimate the helpfulness of ''new-generation'' AEDs. Methods: We included 1,155 adults with focal epilepsies who were observed consecutively after 1990 and followed regularly at two epilepsy centers. We systematically collected the clinical, diagnostic, and therapeutic data using a custom-written database. We classified the patients as seizure-free or AED resistant according to the International League Against Epilepsy (ILAE) criteria, and we evaluated the risk factors associated with AED resistance using logistic regression analysis. We further grouped AED-resistant patients in different grades (I, II, and III) according to the number of AEDs already tried as proposed by Perucca.

Multimodal human brain mapping has been proposed as an integrated approach capable of improving the recognition of the cortical correlates of specific neurological functions. We used simultaneous EEG-fMRI (functional magnetic resonance imaging) and EEG-TDfNIRS (time domain functional near-infrared spectroscopy) recordings to compare different hemodynamic methods with changes in EEG in ten patients with progressive myoclonic epilepsy and 12 healthy controls. We evaluated O 2 Hb, HHb and Blood oxygen level-dependent (BOLD) changes and event-related desynchronization/synchronization (ERD/ERS) in the a and b bands of all of the subjects while they performed a simple motor task. The general linear model was used to obtain comparable fMRI and TDfNIRS activation maps. We also analyzed cortical thickness in order to evaluate any structural changes. In the patients, the TD-NIRS and fMRI data significantly correlated and showed a significant lessening of the increase in O 2 Hb and the decrease in BOLD. The post-movement b rebound was minimal or absent in patients. Cortical thickness was moderately reduced in the motor area of the patients and correlated with the reduction in the hemodynamic signals. The fMRI and TD-NIRS results were consistent, significantly correlated and showed smaller hemodynamic changes in the patients. This finding may be partially attributable to mild cortical thickening. However, cortical hyperexcitability, which is known to generate myoclonic jerks and probably accounts for the lack of EEG b-ERS, did not reflect any increased energy requirement. We hypothesize that this is due to a loss of inhibitory neuronal components that typically fire at high frequencies.

In the last decade, an increasing interest has arisen in investigating the relationship between the electrophysiological and hemodynamic measurements of brain activity, such as EEG and (BOLD) fMRI. In particular, changes in BOLD have been shown to be associated with changes in the spectral profile of neural activity, rather than with absolute power. Concurrently, recent findings showed that different EEG rhythms are independently related to changes in the BOLD signal: therefore, it would be also important to distinguish between the contributions of the different EEG rhythms to BOLD fluctuations when modeling the relationship between the two signals. Here we propose a method to perform EEG-informed fMRI analysis where the changes in the spectral profile are modeled, and, at the same time, the distinction between rhythms is preserved. We compared our model with two other frequency-dependent regressors modeling using simultaneous EEG-fMRI data from healthy subjects performing a motor task. Our results showed that the proposed method better captures the correlations between BOLD signal and EEG rhythms modulations, identifying task-related, well localized activated volumes. Furthermore, we showed that including among the regressors also EEG rhythms not primarily involved in the task enhances the performance of the analysis, even when only correlations with BOLD signal and specific EEG rhythms are explored.

Electroencephalographic (EEG) photoparoxysmal response has been little investigated in very young patients. We studied 5055 patients aged less than 5 years with no acquired brain damage, who underwent EEG recording. We determined the prevalence and significance of photoparoxysmal response induced by 1 to 20 Hz photic stimulation. Fifty-three showed photoparoxysmal response and were diagnosed as having Dravet syndrome (11), epileptic encephalopathy with myoclonic seizures (8), neurodegenerative disorders (8), benign idiopathic epilepsies (9), and static disorders with a known or suspected genetic origin (17). Photoparoxysmal response occurred in response to 1 to 5 Hz trains in 41.5% subjects. In most patients with epileptic encephalopathies, photoparoxysmal response was a transient finding: in 53.2%, it failed to be replicated in the recordings performed more than 6 months after initial evaluation. Photoparoxysmal response is rare in patients aged less than 5 years and has some peculiarities such as occurrence with low-frequency stimuli. Its distribution in specific conditions indicates that photoparoxysmal response may be useful in diagnostic workup.