Journal of Clinical Neurophysiology最新文献

Purpose: Temporal encephaloceles are a cause of drug-resistant temporal lobe epilepsy; however, their relationship with epileptogenesis is unclear, and optimal surgical resection is uncertain. EEG source localization (ESL) may guide surgical decision-making.

Methods: We reviewed patients at Mayo Clinic Rochester with drug-resistant temporal lobe epilepsy and temporal encephaloceles, who underwent limited resection and had 1-year outcomes. EEG source localization was performed using standard density scalp EEG of ictal and interictal activity. Distance from dipole and standardized low-resolution brain electromagnetic tomography (sLORETA) solutions to the encephalocele were measured. Concordance of ESL with encephalocele and surgical resection was compared with 1-year surgical outcomes.

Results: Seventeen patients met criteria. The mean distances from ESL results to encephalocele center for dipole and sLORETA analyses were 23 mm (SD 9) and 22 mm (SD 11), respectively. Ten patients (55.6%) had Engel I outcomes at 1 year. Dipole-encephalocele distance and sLORETA-encephalocele distance were significantly longer in patients with Engel I outcome and patients whose encephalocele was contained by sLORETA had worse outcome as well; however, multiple logistic regression analysis found that only containment of encephalocele by the sLORETA current density was significant ( P < 0.05), odds ratio 0.12 (95% confidence interval [0.021, 0.71]).

Conclusions: EEG source localization of scalp EEG localizes near encephaloceles, however, typically not in the encephalocele itself; this may be due to scalp EEG sampling propagated activity or alternatively that the seizure onset zone extends beyond the herniated cortex. Surprisingly, we observed increased ESL to encephalocele distances in patients with excellent surgical outcomes. Larger cohort studies including intracranial EEG data are needed to further explore this finding.

Purpose: Motor evoked potential (MEP) amplitude and latency are acquired routinely during neuronavigated transcranial magnetic stimulation, a method of functional mapping of the motor cortex before epilepsy surgery. Although MEP amplitude is routinely used to generate a motor map, MEP latency in patients with focal epilepsy has not been studied systematically. Given that epilepsy may alter myelination, we tested whether intrinsic hand muscle MEPs obtained from the hemisphere containing a seizure focus differ in latency from MEPs collected from the opposite hemisphere.

Methods: Latencies of abductor pollicis brevis MEPs were obtained during routine motor mapping by neuronavigated transcranial magnetic stimulation in children with intractable, unihemispheric focal epilepsy. The primary motor cortex was stimulated bilaterally in all cases. Only data from patients without a lesion involving the corticospinal tract were included. We tested whether abductor pollicis brevis MEP latency varied as a function of seizure focus lateralization.

Results: In the 17 patients who met the inclusion criteria, the mean latency of MEPs with amplitudes in the top and bottom quartiles was shorter in the epileptic hemisphere. Interhemispheric latency difference was greater in patients with lesional epilepsy than in those with nonlesional epilepsy (0.7 ± 0.4 vs. 0.1 ± 0.6 milliseconds, P = 0.02).

Conclusions: Motor evoked potential latency was shortened in the epileptic hemisphere of children with focal epilepsy.

Background: Amblyopia is defined clinically as a difference in best-corrected visual acuity of two or more lines of acuity (0.2 logMAR) between the eyes. Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that can transiently alter the excitability of targeted brain areas in a polarity-specific manner.

Purpose: To detect the effect of tDCS on anisometropic amblyopia.

Methods: This is a randomized controlled trial conducted on 78 patients with anisometropic amblyopia from 4.5 to 12 years of age. All patients presented with monocular amblyopia. They were divided into three groups; each group received five sessions of tDCS (anodal tDCS, cathodal tDCS, and sham tDCS). The active electrode was placed over occipital midline and the reference over central midline. Pattern visual-evoked potentials and contrast sensitivity tests were conducted before, immediately after, and 1 week after tDCS.

Results: The amplitude of P100 was significantly decreased immediately after and 1 week after cathodal tDCS. The latency of P100 immediately after and 1 week after anodal tDCS was significantly decreased and increased significantly after cathodal tDCS. The amplitude of P100 and maximum and minimum contrast sensitivities were significantly increased immediately after and 1 week after anodal tDCS, and maximum contrast sensitivity was significantly decreased immediately after cathodal tDCS.

Conclusion: Anodal tDCS is a promising noninvasive modality for improvement of anisometropic amblyopia.

Purpose: The best possible outcomes in infantile epileptic spasms syndrome require electroclinical remission; however, determining electrographic remission is not straightforward. Although the determination of hypsarrhythmia has inadequate interrater reliability (IRR), the Burden of AmplitudeS and Epileptiform Discharges (BASED) score has shown promise for the reliable interictal assessment of infantile epileptic spasms syndrome. Our aim was to develop a BASED training program and assess the IRR among learners. We hypothesized moderate or better IRR for the final BASED score and the presence or absence of epileptic encephalopathy (+/-EE).

Methods: Using a web-based application, 31 learners assessed 12 unmarked EEGs (length 1-6 hours) from children with infantile epileptic spasms syndrome.

Results: For all readers, the IRR was good for the final BASED score (intraclass correlation coefficient 0.86) and +/-EE (Marginal Multirater Kappa 0.63). For all readers, the IRR was fair to good for all individual BASED score elements.

Conclusions: These findings support the use of our training program to quickly learn the BASED scoring method. The BASED score may be a valuable clinical and research tool. Given that the IRR for the determination of epileptic encephalopathy is not perfect, clinical acumen remains paramount. Additional experience with the BASED scoring technique among learners and advances in collaborative EEG evaluation platforms may improve IRR.

Summary: Stereoelectroencephalography (SEEG) has emerged as a transformative tool in epilepsy surgery, shedding light on the complex network dynamics involved in focal epilepsy. This review explores the role of SEEG in elucidating the role of deep brain structures, namely the basal ganglia and thalamus, in epilepsy. SEEG advances understanding of their contribution to seizure generation, propagation, and control by permitting precise and minimally invasive sampling of these brain regions. The basal ganglia, comprising the subthalamic nucleus, globus pallidus, substantia nigra, and striatum, have gained recognition for their involvement in both focal and generalized epilepsy. Electrophysiological recordings reveal hyperexcitability and increased synchrony within these structures, reinforcing their role as critical nodes within the epileptic network. Furthermore, low-frequency and high-frequency stimulation of the basal ganglia have demonstrated potential in modulating epileptogenic networks. Concurrently, the thalamus, a key relay center, has garnered prominence in epilepsy research. Disrupted thalamocortical connectivity in focal epilepsy underscores its significance in seizure maintenance. The thalamic subnuclei, including the anterior nucleus, centromedian, and medial pulvinar, present promising neuromodulatory targets, suggesting pathways for personalized epilepsy therapies. The prospect of multithalamic SEEG and thalamic SEEG stimulation trials has the potential to revolutionize epilepsy management, offering tailored solutions for challenging cases. SEEG's ability to unveil the dynamics of deep brain structures in epilepsy promises enhanced and personalized epilepsy care in our new era of precision medicine. Until deep brain SEEG is accepted as a standard of care, a rigorous informed consent process remains paramount for patients for whom such an exploration is proposed.

Purpose: In 2011, the authors conducted a survey regarding continuous EEG (CEEG) utilization in critically ill children. In the interim decade, the literature has expanded, and guidelines and consensus statements have addressed CEEG utilization. Thus, the authors aimed to characterize current practice related to CEEG utilization in critically ill children.

Methods: The authors conducted an online survey of pediatric neurologists from 50 US and 12 Canadian institutions in 2022.

Results: The authors assessed responses from 48 of 62 (77%) surveyed institutions. Reported CEEG indications were consistent with consensus statement recommendations and included altered mental status after a seizure or status epilepticus, altered mental status of unknown etiology, or altered mental status with an acute primary neurological condition. Since the prior survey, there was a 3- to 4-fold increase in the number of patients undergoing CEEG per month and greater use of written pathways for ICU CEEG. However, variability in resources and workflow persisted, particularly regarding technologist availability, frequency of CEEG screening, communication approaches, and electrographic seizure management approaches.

Conclusions: Among the surveyed institutions, which included primarily large academic centers, CEEG use in pediatric intensive care units has increased with some practice standardization, but variability in resources and workflow were persistent.

Summary: It took 50 years for stereoelectroencephalography (SEEG) to cross the Atlantic. Conceived and designed before the advent of computers and modern technology, this method turned out to be perfectly suited to brain imaging and modern video and electrophysiological tools. It eventually benefited from robotics and signal processing. However, a critical step remains accurate electrode implantation, which is based on individual patients' noninvasive phase I data. A limiting factor, especially in MRI-negative cases, is a thorough perictal and postictal clinical testing for ensuring meaningful electroclinical correlations. Adapted epilepsy monitoring units' architecture and specific technicians and nurses training are required to improve the granularity of information needed to generate valid hypotheses on localization. SEEG interpretation is based on a knowledge base in neural networks, cognitive/behavioral neuroscience, and electrophysiology quite distinct from electroencephalography. Tailored to the needs of focal epilepsy complexity exploration, SEEG does not fit well with simplification. Specific teaching and development of clinical research inside the epilepsy monitoring units will help to flatten the team learning curve and to build knowledge base from shared clinical experience.

Purpose: To assess the clinical effectiveness of treating acute seizures with midazolam and lidocaine infusion.

Methods: This single-center historical cohort study included 39 term neonates with electrographic seizures who underwent treatment with midazolam (1st line) and lidocaine (2nd line). Therapeutic response was measured using continuous video-EEG monitoring. The EEG measurements included total s eizure burden (minutes), maximum ictal fraction (minutes/hour), and EEG-background (normal/slightly abnormal vs. abnormal). Treatment response was considered good (seizure control with midazolam infusion), intermediate (need to add lidocaine to the control), or no response. Using clinical assessments supplemented by BSID-III and/or ASQ-3 at 2 to 9 years old age, neurodevelopment was classified as normal, borderline, or abnormal.

Results: A good therapeutic response was obtained in 24 neonates, an intermediate response in 15, and no response in any of the neonates. Babies with good response showed lower values in maximum ictal fraction compared with those with intermediate response (95% CI: 5.85-8.64 vs. 9.14-19.14, P = 0.002). Neurodevelopment was considered normal in 24 children, borderline in five, and abnormal in other 10 children. Abnormal neurodevelopment was significantly associated with an abnormal EEG background, maximum ictal fraction >11 minutes, and total s eizure burden >25 minutes (odds ratio 95% CI: 4.74-1708.52, P = 0.003; 1.72-200, P = 0.016; 1.72-142.86, P = 0.026, respectively) but not with the therapeutic response. Serious adverse effects were not recorded.

Conclusions: This retrospective study suggests that the midazolam/lidocaine association could potentially be efficacious in decreasing seizure burden in term neonates with acute seizures. These results would justify testing the midazolam/lidocaine combination as a first-line treatment for neonatal seizures in future clinical trials.

Summary: Although the role of sleep in modulating epileptic activity is well established, many epileptologists overlook the significance of considering sleep during presurgical epilepsy evaluations in cases of drug-resistant epilepsy. Here, we conducted a comprehensive literature review from January 2000 to May 2023 using the PubMed electronic database and compiled evidence to highlight the need to revise the current clinical approach. All articles were assessed for eligibility by two independent reviewers. Our aim was to shed light on the clinical value of incorporating sleep monitoring into presurgical evaluations with stereo-electroencephalography. We present the latest developments on the important bidirectional interactions between sleep and various forms of epileptic activity observed in stereo-electroencephalography recordings. Specifically, epileptic activity is modulated by different sleep stages, peaking in non-rapid eye movement sleep, while being suppressed in rapid eye movement sleep. However, this modulation can vary across different brain regions, underlining the need to account for sleep to accurately pinpoint the epileptogenic zone during presurgical assessments. Finally, we offer practical solutions, such as automated sleep scoring algorithms using stereo-electroencephalography data alone, to seamlessly integrate sleep monitoring into routine clinical practice. It is hoped that this review will provide clinicians with a readily accessible roadmap to the latest evidence concerning the clinical utility of sleep monitoring in the context of stereo-electroencephalography and aid the development of therapeutic and diagnostic strategies to improve patient surgical outcomes.