Nonlinear dynamics of seizure prediction in a rodent model of epilepsy.

Epilepsy is a dynamical disorder with intermittent crises (seizures) that until recently were considered unpredictable. In this study, we investigated the predictability of epileptic seizures in chronically epileptic rats as a first step towards a subsequent timely intervention for seizure control. We look at the epileptic brain as a nonlinear complex system that undergoes spatio-temporal state transitions and the Lyapunov exponents as indices of its stability.

Control of synchronization of brain dynamics leads to control of epileptic seizures in rodents.

We have designed and implemented an automated, just-in-time stimulation, seizure control method using a seizure prediction method from nonlinear dynamics coupled with deep brain stimulation in the centromedial thalamic nuclei in epileptic rats. A comparison to periodic stimulation, with identical stimulation parameters, was also performed. The two schemes were compared in terms of their efficacy in control of seizures, as well as their effect on synchronization of brain dynamics.

EEG stages predict treatment response in experimental status epilepticus.

Progression of severity in experimental status epilepticus (SE), defined as refractoriness to first- and second-line abortive agents, may be related to a five-stage progression of electroencephalography (EEG) patterns. This was tested in the lithium-pilocarpine rat SE model. Abortive treatment with diazepam and phenobarbital was given at EEG stages I, III, and V.

Amphetamine-evoked rotation requires newly synthesized dopamine at 14 days but not 1 day after intranigral 6-OHDA and is consistently dissociated from sensorimotor behavior.

Immediately after unilateral, intranigral 6-hydroxydopamine (6-OHDA), amphetamine (AMPH) evokes "paradoxical" contraversive rotation, whereas 14 days later, AMPH evokes the traditional ipsiversive rotation used to model the chronic Parkinsonian state. In this study, the hypothesis was that accelerated dopamine (DA) synthesis ipsilateral to the lesion augments cytoplasmic DA to produce paradoxical rotation. Therefore, the sensitivity to synthesis inhibition of AMPH-evoked rotation at 1 or 14 days after 6-OHDA was assessed.