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.

SUMMARYObjective: Electrocorticographic (ECoG) recordings from patients with medically intractable partial-onset seizures treated with a responsive neurostimulator system (the RNS System) that detects and stores physician-specified ECoG events provide a new data resource. Interpretation of these recordings has not yet been validated. The purpose was to evaluate the interrater interpretation of chronic ambulatory ECoG recordings obtained by the RNS System. Methods: Five pairs of five experts independently classified 7,221 ECoG recordings obtained from 128 patients with medically intractable partial seizures who participated in a randomized controlled trial of the safety and efficacy of the RNS System. ECoG detections-"long episodes" or "saturations"-were classified as "seizures" or "not seizures" based on a reference definition. Interrater agreement rates and kappa score reliabilities were calculated between rater pairs from the ECoG sample as a whole and within individual patients who had more than the median number of individual ECoG recordings. Results: The overall interrater agreement was 79%, with a reliability j = 0.57 (moderate agreement). Agreement between pairs of reviewers ranged from 0.69 to 0.85. Agreement rates were 94% or better for 50% of patients. Only 25% of patients had ECoG recordings agreement rates worse than 75%. ECoGs with mixed interpretations (one reviewer "seizure"/the other-"not seizure") consisted of periods of low amplitude activity that evolved in amplitude or periodic discharges near 2 Hz. Significance: Although reliability as a whole was moderate, for the majority of patients, detections yielded highly reliably interpreted events of either electrographic seizures or nonictal epileptiform activity.

This pilot series demonstrates that lean principles can standardize surgical workflows and identify waste. Though time and labor intensive, lean principles and PDSA methodology can be applied to operative steps, not just the perioperative period.

No abstract

Resident perception of surgical complexity can be evaluated for procedural steps using a risk matrix survey. For TLIF, residents may assign more risk and may be less comfortable performing steps in a training-level-dependent manner. Identification of particular high-risk or uncomfortable steps should prompt strict faculty oversight to improve patient safety, monitor resident education, and reduce operative time.

No abstract

Introduction Sleep systems are supports used in lying, forming part of 24 h posture management programmes, for children and adults with severe motor disorders. Improved posture reduces likelihood of secondary complications such as pain and poor sleep quality, thus improving quality of life. The study aims are to investigate the effect of sleep systems on sleep quality and quantity, pain for young people with Cerebral Palsy and outcomes for carers. Methods Baseline data were gathered for 1 month prior to sleep system provision. Comparative data with the sleep system in place, were gathered for 5 months. The sample comprised four children with Cerebral Palsy, GMFCS level V, average age of 11.5, who did not have a sleep system. Data on sleep quality and quantity was gathered using the Chailey Sleep Questionnaire and sleep diaries and pain levels using the Paediatric Pain Profile. GAS Light verbal outcome measure was used to measure carer goals. Results Descriptive statistics and paired sample t-tests were used, demonstrating pain levels remained static, improvements in sleep quality and quantity were found and carer goals achieved. Conclusion A small sample size and subjective data collection methods were used; further research is required to obtain more conclusive results.

No abstract