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Objective The main aim of this study was to investigate the potential differences in terms of interictal high frequency oscillations (HFOs) between both hippocampi in unilateral (U-MTLE) and bilateral mesial temporal lobe epilepsy (B-MTLE). Methods Sixteen patients with MTLE underwent bilateral hippocampal depth electrode implantation as part of epilepsy surgery evaluation. Interictal HFOs were detected automatically. The analyses entail comparisons of the rates and spatial distributions of ripples and fast ripples (FR) in hippocampi and amygdalae, with respect to the eventual finding of hippocampal sclerosis (HS). Results In U-MTLE, higher ripple and FR rates were found in the hippocampi ipsilateral to the seizure onset than in the contralateral hippocampi. Non-epileptic hippocampi in U-MTLE were distinguished by significantly lower ripple rate than in the remaining analyzed hippocampi. There were not differences between the hippocampi in B-MTLE. In the hippocampi with proven HS, higher FR rates were observed in the ventral than in the dorsal parts. Conclusions Non-epileptic hippocampi in U-MTLE demonstrated significantly lower ripple rates than those epileptic in U-MTLE and B-MTLE. Significance Low interictal HFO occurrence might be considered as a marker of the non-epileptic hippocampi in MTLE.

Objective The purpose of the presented study is to determine whether there are frequency-independent high-frequency oscillation (HFO) parameters which may differ in epileptic and non-epileptic regions. Methods We studied 31 consecutive patients with medically intractable focal (temporal and extratemporal) epilepsies who were examined by either intracerebral or subdural electrodes. Automated detection was used to detect HFO. The characteristics (rate, amplitude, and duration) of HFO were statistically compared within three groups: the seizure onset zone (SOZ), the irritative zone (IZ), and areas outside the IZ and SOZ (nonSOZ/nonIZ). Results In all patients, fast ripples (FR) and ripples (R) were significantly more frequent and shorter in the SOZ than in the nonSOZ/nonIZ region. In the group of patients with favorable surgical outcomes, the relative amplitude of FR was higher in the SOZ than in the IZ and nonIZ/nonSOZ regions; in patients with poor outcomes, the results were reversed. The relative amplitude of R was significantly higher in the SOZ, with no difference between patients with poor and favorable surgical outcomes. Conclusions FR are more frequent, shorter, and have higher relative amplitudes in the SOZ area than in other regions. The study suggests a worse prognosis in patients with higher amplitudes of FR outside the SOZ. Significance Various HFO parameters, especially of FR, differ in epileptic and non-epileptic regions. The amplitude and duration may be as important as the frequency band and rate of HFO in marking the seizure onset region or the epileptogenic area and may provide additional information on epileptogenicity.

Objective: We compared the possible contribution (in the detection of seizure onset zone – SOZ) of simple visual assessment of intracerebrally recorded high-frequency oscillations (HFO) with standard automated detection. Methods: We analyzed stereo-EEG (SEEG) recordings from 20 patients with medically intractable partial seizures (10 temporal/10 extratemporal). Independently using simple visual assessment and automated detection of HFO, we identified the depth electrode contacts with maximum occurrences of ripples (R) and fast ripples (FR). The SOZ was determined by independent visual identification in standard SEEG recordings, and the congruence of results from visual versus automated HFO detection was compared. Results: Automated detection of HFO correctly identified the SOZ in 14 (R)/10 (FR) out of 20 subjects; a simple visual assessment of SEEG recordings in the appropriate frequency ranges correctly identified the SOZ in 13 (R)/9 (FR) subjects. Conclusions: Simple visual assessment of SEEG traces and standard automated detection of HFO seem to contribute comparably to the identification of the SOZ in patients with focal epilepsies. When using macroelectrodes in neocortical extratemporal epilepsies, the SOZ might be better determined by the ripple range. Significance: Standard automated detection of HFO enables the evaluation of HFO characteristics in whole data. This detection allows general purpose and objective evaluation, without any bias from the neurophysiologist’s experiences and practice

Objective Falls are not supposed to be common signs of temporal lobe epilepsy (TLE). The main aim of this study was to identify a group of patients with known history of unexpected falls which could not be explained by presence of ictal asystole or concomitant heart disesase. Methods We retrospectively evaluated the data of all patient who underwent pre-surgical evaluation in Brno Epilepsy Center since 2002. We identified 49 patients with TLE who reported unexpected falls. Thirteen (33%) out of 49 patients (TLE-falls group) underwent surgery which led to disappearance of both seizures and falls. In the next step, the control group of age- and gender- matched patients with TLE (TLE-control group) was formed. We identified RR intervals and following parameters were analyzed duration of RR intervals and heart rate variability (HRV). Results There were no statistically significant differences between TLE-falls group and TLE-surgery group regarding age of epilepsy onset, duration of epilepsy, age at surgery. Both the duration of RR intervals and HRV were statistically significantly different between TLE-falls group and TLE-control group (p = 0.025, respectively p = 0.025). Conclusion It seems that unexpected falls could be a novel rare signs in TLE epilepsy. Their presence could be conditioned by heart rhythms.

Methods. We evaluated prospectively 596 patients with pharmacoresistant seizures. All these patients underwent continuous video-EEG monitoring. In consenting patients, we used suggestive seizure provocation. The seizure semiology, inter-ictal EEG, brain MRI, psychiatric co-morbidities, and the impact of the provocative testing and other parameters on the seizure outcome were assesed. Results. In the sample of 596 monitored patients, we detected 111 (19.3%) patients with PNES. Of the 111 patients with PNES, 86.5% had spontaneous and 76.5% had provoked seizures. The five most typical symptoms – initially closed eyelids (67.6%), rapid tremor (47.7%), asynchronous limb movement (37.8%), preictal pseudosleep (33.3%), and side-to-side head movement (32.4%) – were presented on video. Inter-ictal EEG was rated as abnormal in 46.2% and with epileptiform abnormality in 9%. Brain MRI was abnormal in 32 (28.8%) patients. Personality disorders (46.8%), anxiety (39.6%), and depression (12.6%) were the most frequent additional psychiatric co-morbidities. Psychogenic non-epileptic seizures outcome after at least 2 years is reported; 22.5% of the patients were seizure-free; one third had markedly reduced seizure frequency. The provocative testing had no negative impact on the seizure outcome. We determined eight variables which could affect the seizure outcome. The trend to be the predictor of worse results was PNES duration before appropriate diagnosis (pb0.013). Conclusions. Video-EEG monitoring with suggestive seizure provocation supported by clinical psychiatric and psychological evaluations sig