No abstract

clinicaltrials.gov Identifier: NCT01438697.

RS for unilateral mesial temporal lobe epilepsy offers seizure remission rates comparable with those reported previously for open surgery. There were no major safety concerns with high-dose RS compared with low-dose RS. Additional research is required to determine whether RS may be a treatment option for some patients with mesial temporal lobe epilepsy.

Using a monoclonal antibody directed against a class III beta-tubulin isotype, c beta 4, we studied the time course of the expression of this protein, the morphological differentiation of the immunoreactive cells, and the time course of peripheral axon outgrowth in the chick trigeminal (V) system. The neural crest precursors of the V ganglion neurons do not express the antigen until they begin to differentiate as neurons. The placodal precursors of the V ganglion neurons express the antigen while they still are cuboidal epithelial cells. They continue to be immunoreactive as they migrate from the placode and settle in the ganglion, prior to sprouting axons. The V motoneurons express the antigen near the time of their terminal mitotic division. Using this antibody to visualize axons, we demonstrate that both ganglionic and motoneuron axons grow out as individual fibers, much like pioneer axons. Both halt their extension for several hours once they attain the vicinity of their targets. During this pause many other axons join the nerve bundles. Finally, single pioneer axons split from the main trunk to begin local target innervation.

Seizures do not often strike randomly but may occur in circadian patterns. We compared daily times of partial seizures determined by continuous electroencephalography among patients with mesial temporal lobe epilepsy (MTLE; n = 64), those with extratemporal lobe (XTLE; n = 26) or lesional temporal lobe epilepsy (LTLE; n = 8), and a rat model similar to MTLE in which rats become epileptic after electrically induced limbic status epilepticus (postlimbic status [PLS]; n = 20). Rats were maintained on a 12-hour light/dark cycle with lights on at 0700 hours. The distributions of seizures were fitted by cosinor analysis to determine time of peak seizure incidence +/- 95% confidence interval (95% CI). The mean fraction +/- SD of seizures recorded during light was 63 +/- 17% in PLS animals and 60 +/- 21% in humans. Peak incidence of seizures for PLS rats (547 seizures) was 1645 (95% CI = 1448,1830) and for MTLE subjects (774 seizures) was 1500 (95% CI = 1324,1636). Seizures from XTLE (465 seizures) and LTLE (48 seizures) did not fit a cosinor model and occurred no more frequently during light than dark. In conclusion, limbic seizures in humans and PLS rats occur more often during light than dark and have similar cosinor daily distributions. The chronological similarity between human MTLE and PLS rat epilepsy suggests that limbic seizure occurrence has a relation to the circadian regulatory system.

No abstract

SUMMARYObjective: Previous studies reporting circadian patterns of epileptiform activity and seizures are limited by (1) short-term recording in an epilepsy monitoring unit (EMU) with altered antiepileptic drugs (AEDs) and sleep, or (2) subjective seizure diary reports. We studied circadian patterns using long-term ambulatory intracranial recordings captured by the NeuroPace RNS System. Methods: Retrospective study of RNS System trial participants with stable detection parameters over a continuous 84-day period. We analyzed all detections and long device-detected epileptiform events (long episodes) and defined a subset of subjects in whom long episodes represented electrographic seizures (LE-SZ). Spectrum resampling determined the dominant frequency periodicity and cosinor analysis identified significant circadian peaks in detected activity. Chi-square analysis was used to compare subjects grouped by region of seizure onset. Results: In the 134 subjects, detections showed a strongly circadian and uniform pattern irrespective of region of onset that peaked during normal sleep hours. In contrast, long episodes and LE-SZ patterns varied by region. Neocortical regions had a monophasic, nocturnally dominant rhythm, whereas limbic regions showed a more complex pattern and diurnal peak. Rhythms in some individual limbic subjects were best fit by a dual oscillator (circadian + ultradian) model. Significance: Epileptiform activity has a strong 24 h periodicity with peak nocturnal occurrence. Limbic and neocortical epilepsy show divergent circadian influences. These findings confirm that circadian patterns of epileptiform activity vary by seizureonset zone, with implications for treatment and safety, including SUDEP.

These data suggest that ATL has an advantage over SRS in terms of proportion of seizure remission, and both SRS and ATL appear to have effectiveness and reasonable safety as treatments for MTLE. SRS is an alternative to ATL for patients with contraindications for or with reluctance to undergo open surgery.