A robust seizure prediction methodology would enable a “closed-loop” system that would only activate as impending seizure activity is detected. Such a system would eliminate ongoing stimulation to the brain, thereby eliminating such side effects as coughing, hoarseness, voice alteration, and paresthesias (Murphy et al., 1998; Ben-Menachem, 2001), while preserving overall battery life of the system. The seizure prediction and detection algorithm uses Phase/Amplitude Lock Values (PLV/ALV) which calculate the difference of phase and amplitude between electroencephalogram (EEG) electrodes local and remote to the epileptic event. PLV is used as the seizure prediction marker and signifies the emergence of abnormal neuronal activations through local neuron populations. PLV/ALVs are used as seizure detection markers to demarcate the seizure event, or when the local seizure event has propagated throughout the brain turning into a grand-mal event. We verify the performance of this methodology against the “CHB-MIT Scalp EEG Database” which features seizure attributes for testing. Through this testing, we can demonstrate a high degree of sensivity and precision of our methodology between pre-ictal and ictal events.

Background: Neonatal seizures (NS) are the most common form of neurological dysfunction observed in newborns. Purpose: The purpose of this study in newborn piglets was to determine the effect of cerebral hypothermia (CH) on neural activity during pharmacologically induced NS. We hypothesized that the neuroprotective effects of CH would preserve higher frequencies observed in electrocorticogram (ECoG) recordings. Methods: Power spectral density was employed to determine the levels of brain activity in ECoGs to quantitatively assess the power of each frequency observed in neurological brain states of delta, theta, alpha, and beta-gamma frequencies. Result: The most significant reduction of power occurs in the lower frequency band of delta-theta-alpha of CH cohorts, while t score probabilities imply that high-frequency brain activity in the beta-gamma range is preserved in the CH population. Conclusion: While the overall power density decreases over time in both groups, the decrease is to a lesser degree in the CH population.

Signals measured by electroencephalogram (EEG) arrays were decomposed using Hilbert Transformations to produce the spatial amplitude and phase modulation (AM and PM) patterns. Spatial PM patterns intermittently exhibit synchronization-desynchronization transitions. During desynchronization, the spatial PM patterns intermittently conform to conic shapes. These phase cones mark the onset of emergent AM patterns, which carry cognitive content. In this work, various temporal band pass filters were applied to study the frequency dependence of phase cones in the beta-gamma range (10-40 Hz). The results are interpreted in the context of the cognitive cycle of knowledge generation.

Simulations of EEG data provide the understanding of how the limbic system exhibits normal and abnormal states of the electrical activity of the brain. While brain activity exhibits a type of homeostasis of excitatory and inhibitory mesoscopic neuron behavior, abnormal neural firings found in the seizure state exhibits brain instability due to runaway oscillatory entrained neural behavior. We utilize a model of mesoscopic brain activity, the KIV model, where each network represents the areas of the limbic system, i.e., hippocampus, sensory cortex, and the amygdala. Our model initially demonstrates oscillatory entrained neural behavior as the epileptogenesis, and then by increasing the external weights that join the three networks that represent the areas of the limbic system, seizure activity entrains the entire system. By introducing an external signal into the model, simulating external electrical titration therapy, the modeled seizure behavior can be 'rebalanced' back to its normal state.

BackgroundIn this study, we examined audiovisual (AV) processing in normal and visually impaired individuals who exhibit partial loss of vision due to inherited retinal dystrophies (IRDs).MethodsTwo groups were analyzed for this pilot study: Group 1 was composed of IRD participants: two with autosomal dominant retinitis pigmentosa (RP), two with autosomal recessive cone-rod dystrophy (CORD), and two with the related complex disorder, Bardet-Biedl syndrome (BBS); Group 2 was composed of 15 non-IRD participants (controls). Audiovisual looming and receding stimuli (conveying perceptual motion) were used to assess the cortical processing and integration of unimodal (A or V) and multimodal (AV) sensory cues. Electroencephalography (EEG) was used to simultaneously resolve the temporal and spatial characteristics of AV processing and assess differences in neural responses between groups. Measurement of AV integration was accomplished via quantification of the EEG’s spectral power and event-related brain potentials (ERPs).ResultsResults show that IRD individuals exhibit reduced AV integration for concurrent audio and visual (AV) stimuli but increased brain activity during the unimodal A (but not V) presentation. This was corroborated in behavioral responses, where IRD patients showed slower and less accurate judgments of AV and V stimuli but more accurate responses in the A-alone condition.ConclusionsCollectively, our findings imply a neural compensation from auditory sensory brain areas due to visual deprivation.Electronic supplementary materialThe online version of this article (10.1186/s12886-017-0640-y) contains supplementary material, which is available to authorized users.