Postictal psychiatric symptoms: A neurophysiological study.

OBJECTIVE: Postictal psychiatric symptoms (PPS) are a relatively common but understudied phenomenon in epilepsy. The mechanisms by which seizures contribute to worsening in psychiatric symptoms are unclear. We aimed to identify PPS prospectively during and after admission to the epilepsy monitoring unit (EMU) in order to characterize the postictal physiologic changes leading to PPS. METHODS: We prospectively enrolled patients admitted to the EMU and administered repeat psychometric questionnaires during and after their hospital stay in order to assess for postictal exacerbations in four symptom complexes: anger/hostility, anxiety, depression, and paranoia. Electroclinical and electrographic seizures were identified from the EEG recordings, and seizure durations were measured. The severity of postictal slowing was calculated as the proportion of postictal theta/delta activity in the postictal EEG relative to the preictal EEG using the Hilbert transform. RESULTS: Among 33 participants, 8 demonstrated significant increases in at least one of the four symptoms (the PPS+ group) within three days following the first seizure. The most common PPS was anger/hostility, experienced by 7/8 participants with PPS. Among the 8 PPS+ participants, four experienced more than one PPS. As compared to those without PPS (the PPS- group), the PPS+ group demonstrated a greater degree of postictal EEG slowing at 10 min (p = 0.022) and 20 min (p = 0.05) following seizure termination. They also experienced significantly more seizures during the study period (p = 0.005). There was no difference in seizure duration between groups. SIGNIFICANCE: Postictal psychiatric symptoms including anger/hostility, anxiety, depression, and paranoia may be more common than recognized. In particular, postictal increases in anger and irritability may be particularly common. We provide physiological evidence of a biological mechanism as well as a demonstration of the use of quantitative electroencephalography toward a better understanding of postictal neurophysiology.

Percutaneous auricular neuromodulation (nerve stimulation) for the treatment of pain following cholecystectomy and hernia repair: a randomized, double-masked, sham-controlled pilot study.

BACKGROUND: Percutaneous auricular nerve stimulation (neuromodulation) involves implanting electrodes around the ear and administering an electric current. A device is currently available within the USA cleared to treat symptoms from opioid withdrawal, and multiple reports suggest a possible postoperative analgesic effect. The current randomized controlled pilot study was undertaken to (1) determine the feasibility and optimize the protocol for a subsequent definitive clinical trial; and (2) estimate the treatment effect of auricular neuromodulation on postoperative pain and opioid consumption following two ambulatory surgical procedures. METHODS: Within the recovery room following cholecystectomy or hernia repair, an auricular neuromodulation device (NSS-2 Bridge, Masimo, Irvine, California, USA) was applied. Participants were randomized to 5 days of either electrical stimulation or sham in a double-blinded fashion. RESULTS: In the first 5 days, the median (IQR) pain level for active stimulation (n=15) was 0.6 (0.3-2.4) vs 2.6 (1.1-3.7) for the sham group (n=15) (p=0.041). Concurrently, the median oxycodone use for the active stimulation group was 0 mg (0-1), compared with 0 mg (0-3) for the sham group (p=0.524). Regarding the highest pain level experienced over the entire 8-day study period, only one participant (7%) who received active stimulation experienced severe pain, versus seven (47%) in those given sham (p=0.031). CONCLUSIONS: Percutaneous auricular neuromodulation reduced pain scores but not opioid requirements during the initial week after cholecystectomy and hernia repair. Given the ease of application as well as a lack of systemic side effects and reported complications, a definitive clinical trial appears warranted. TRIAL REGISTRATION NUMBER: NCT05521516.

Percutaneous auricular neuromodulation (nerve stimulation) for the treatment of pain following total knee arthroplasty: a randomized, double-masked, sham-controlled pilot study.

BACKGROUND: Percutaneous auricular nerve stimulation (neuromodulation) is an analgesic technique involving the percutaneous implantation of multiple leads at various points on/around the ear followed by the delivery of electric current using an external pulse generator. A device is currently available within the USA cleared to treat symptoms from opioid withdrawal, and multiple reports suggest a possible postoperative analgesic effect. The current randomized, controlled pilot study was undertaken to (1) determine the feasibility and optimize the protocol for a subsequent definitive clinical trial and (2) estimate the treatment effect of auricular neuromodulation on postoperative pain and opioid consumption following total knee arthroplasty. METHODS: Within the recovery room following primary, unilateral, total knee arthroplasty, an auricular neuromodulation device (NSS-2 Bridge, Masimo, Irvine, California, USA) was applied using three percutaneous leads and one ground electrode. Participants were randomized to 5 days of either electrical stimulation or sham stimulation in a double-masked fashion. Participants were discharged with the stimulator in situ and removed the disposable devices at home. The dual primary treatment effect outcome measures were the cumulative opioid use (oral oxycodone) and the mean of the "average" daily pain measured with the Numeric Rating Scale for the first 5 postoperative days. RESULTS: During the first five postoperative days, oxycodone consumption in participants given active stimulation (n=15) was a median (IQR) of 4 mg (2-12) vs 13 mg (5-23) in patients given sham (n=15) treatment (p=0.039). During this same period, the average pain intensity in patients given active stimulation was a median (IQR) of 2.5 (1.5-3.3) vs 4.0 (3.6-4.8) in those given sham (p=0.014). Awakenings due to pain over all eight postoperative nights in participants given active stimulation was a median (IQR) of 5 (3-8) vs 11 (4-14) in those given sham (p<0.001). No device-related localized cutaneous irritation, systemic side effects, or other adverse events were identified. CONCLUSIONS: Percutaneous auricular neuromodulation reduced pain scores and opioid requirements during the initial week after total knee arthroplasty. Given the ease of application as well as the lack of systemic side effects and reported complications, a definitive clinical trial appears warranted. TRIAL REGISTRATION NUMBER: NCT05521516.

Association between postictal EEG suppression, postictal autonomic dysfunction, and sudden unexpected death in epilepsy: Evidence from intracranial EEG.

OBJECTIVE: The association between postictal electroencephalogram (EEG) suppression (PES), autonomic dysfunction, and Sudden Unexpected Death in Epilepsy (SUDEP) remains poorly understood. We compared PES on simultaneous intracranial and scalp-EEG and evaluated the association of PES with postictal heart rate variability (HRV) and SUDEP outcome. METHODS: Convulsive seizures were analyzed in patients with drug-resistant epilepsy at 5 centers. Intracranial PES was quantified using the Hilbert transform. HRV was quantified using root mean square of successive differences of interbeat intervals, low-frequency to high-frequency power ratio, and RR-intervals. RESULTS: There were 64 seizures from 63 patients without SUDEP and 11 seizures from 6 SUDEP patients. PES occurred in 99% and 87% of seizures on intracranial-EEG and scalp-EEG, respectively. Mean PES duration in intracranial and scalp-EEG was similar. Intracranial PES was regional (<90% of channels) in 46% of seizures; scalp PES was generalized in all seizures. Generalized PES showed greater decrease in postictal parasympathetic activity than regional PES. PES duration and extent were similar between patients with and without SUDEP. CONCLUSIONS: Regional intracranial PES can be present despite scalp-EEG demonstrating generalized or no PES. Postictal autonomic dysfunction correlates with the extent of PES. SIGNIFICANCE: Intracranial-EEG demonstrates changes in autonomic regulatory networks not seen on scalp-EEG.

Localized task-invariant emotional valence encoding revealed by intracranial recordings.

The ability to distinguish between negative, positive and neutral valence is a key part of emotion perception. Emotional valence has conceptual meaning that supersedes any particular type of stimulus, although it is typically captured experimentally in association with particular tasks. We sought to identify neural encoding for task-invariant emotional valence. We evaluated whether high-gamma responses (HGRs) to visually displayed words conveying emotions could be used to decode emotional valence from HGRs to facial expressions. Intracranial electroencephalography was recorded from 14 individuals while they participated in two tasks, one involving reading words with positive, negative, and neutral valence, and the other involving viewing faces with positive, negative, and neutral facial expressions. Quadratic discriminant analysis was used to identify information in the HGR that differentiates the three emotion conditions. A classifier was trained on the emotional valence labels from one task and was cross-validated on data from the same task (within-task classifier) as well as the other task (between-task classifier). Emotional valence could be decoded in the left medial orbitofrontal cortex and middle temporal gyrus, both using within-task classifiers and between-task classifiers. These observations suggest the presence of task-independent emotional valence information in the signals from these regions.

Evolution of Volume and Signal Intensity on Fluid-attenuated Inversion Recovery MR Images after Endovascular Stroke Therapy.

Purpose To analyze both volume and signal evolution on magnetic resonance (MR) fluid-attenuated inversion recovery (FLAIR) images between the images after endovascular therapy and day 5 (which was the prespecified end point for infarct volume in the Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution [DEFUSE 2] trial) in a subset of patients enrolled in the DEFUSE 2 study. Materials and Methods This study was approved by the local ethics committee at all participating sites. Informed written consent was obtained from all patients. In this post hoc analysis of the DEFUSE 2 study, 35 patients with FLAIR images acquired both after endovascular therapy (median time after symptom onset, 12 hours) and at day 5 were identified. Patients were separated into two groups based on the degree of reperfusion achieved on time to maximum greater than 6-second perfusion imaging (≥90% vs <90%). After coregistration and signal normalization, lesion volumes and signal intensity were assessed by using FLAIR imaging for the initial lesion (ie, visible after endovascular therapy) and the recruited lesion (the additional lesion visible on day 5, but not visible after endovascular therapy). Statistical significance was assessed by using Wilcoxon signed-rank, Mann-Whitney U, and Fisher exact tests. Results All 35 patients had FLAIR lesion growth between the after-revascularization examination and day 5. Median lesion growth was significantly larger in patients with <90% reperfusion (27.85 mL) compared with ≥90% (8.12 mL; P = .003). In the initial lesion, normalized signal did not change between after endovascular therapy (median, 1.60) and day 5 (median, 1.58) in the ≥90% reperfusion group (P = .97), but increased in the <90% reperfusion group (from 1.60 to 1.73; P = .01). In the recruited lesion, median normalized signal increased significantly in both groups between after endovascular therapy and day 5 (after endovascular therapy, from 1.19 to 1.56, P < .001; and day 5, from 1.18 to 1.63, P < .001). Conclusion Patients with ≥90% reperfusion after endovascular therapy have significantly less lesion growth on FLAIR images between after therapy and day 5 compared with patients who have <90% reperfusion. Therefore, the effect of reperfusion therapies on lesion volumes are likely more apparent at day 5 than after therapy. (©) RSNA, 2016.