Journal of Clinical Neurophysiology最新文献

Summary: The development of clinical practice guidelines is an evolving field. In response to the need for consistent, evidence-based medical practice, the American Clinical Neurophysiology Society identified the need to update the Society's guideline development process. The American Clinical Neurophysiology Society Guidelines Committee created an action plan with the goal of improving transparency and rigor for future guidelines and bringing existing guidelines to current standards. This article provides an overview of the new American Clinical Neurophysiology Society standards for the creation of clinical guidance documents, including clinical guidelines, technical standards, and consensus statements. This process is rooted in the importance of clinical guidance documents and their significance in the context of current behests for updated standards for practicing clinical neurophysiology. The need and rationale for updating the guideline development process from its prior state were described. The updated American Clinical Neurophysiology Society categories for clinical guidance and recommendations were defined and compared. Finally, the new process is summarized, focusing on methodologies, authorship, and conflicts of interest.

Purpose: While spikes and sharp waves are considered as markers of epilepsy in conventional electroencephalography, ictal direct current (DC) shifts and high-frequency oscillations (HFOs) appear to be useful biomarkers for epileptogenicity. We analyzed how ictal DC shifts and HFOs were affected by focal status epilepticus and antiseizure medications (ASMs).

Methods: A 20-year-old female patient who underwent long-term intracranial electrode implantation for epilepsy surgery presented with 72 habitual seizures and a focal status epilepticus episode lasting for 4 h. Ten, 3, and 10 consecutive habitual seizures were analyzed before the status, after the status, and after ASM (valproate) loading, respectively.

Results: Before and immediately after the status, ictal DC shifts remained the same in terms of the amplitude, duration, and slope of DC shifts. High-frequency oscillations also remained the same in terms of the duration, frequency, and power except for the power of the lower frequency band. After ASM loading, the duration, amplitude, and slope of the ictal DC shift were significantly attenuated. The duration, frequency, and power of the HFOs were significantly attenuated. Furthermore, the interval between the DC onset and HFO onset was significantly longer and the interval between the HFO onset and ictal DC shift peak was significantly shorter.

Conclusions: The attenuation of ictal DC shifts and HFOs after ASM loading implies that astrocyte and neuronal activity may be both attenuated by ASMs. This finding may help with our understanding of the pathophysiology of epilepsy and can aid with the discovery of new approaches for epilepsy management.

Purpose: Electrographic seizures (ES) are common in critically ill children undergoing continuous EEG (CEEG) monitoring, and previous studies have aimed to target limited CEEG resources to children at highest risk of ES. However, previous studies have relied on observational data in which the duration of CEEG was clinically determined. Thus, the incidence of late occurring ES is unknown. The authors aimed to assess the incidence of ES for 24 hours after discontinuation of clinically indicated CEEG.

Methods: This was a single-center prospective study of nonconsecutive children with acute encephalopathy in the pediatric intensive care unit who underwent 24 hours of extended research EEG after the end of clinical CEEG. The authors assessed whether there were new findings that affected clinical management during the extended research EEG, including new-onset ES.

Results: Sixty-three subjects underwent extended research EEG. The median duration of the extended research EEG was 24.3 hours (interquartile range 24.0-25.3). Three subjects (5%) had an EEG change during the extended research EEG that resulted in a change in clinical management, including an increase in ES frequency, differential diagnosis of an event, and new interictal epileptiform discharges. No subjects had new-onset ES during the extended research EEG.

Conclusions: No subjects experienced new-onset ES during the 24-hour extended research EEG period. This finding supports observational data that patients with late-onset ES are rare and suggests that ES prediction models derived from observational data are likely not substantially underrepresenting the incidence of late-onset ES after discontinuation of clinically indicated CEEG.

Purpose: Developmental/epileptic encephalopathy with spike wave activation with sleep, formerly known as electrical status epilepticus in sleep, is an electrographic pattern in which the interictal epileptiform activity is augmented by transition to sleep. Recent studies demonstrate the utility of the first 100 seconds of sleep of long-term monitoring (LTM) as a scoring method for electrical status epilepticus in sleep. Our aim was to measure the reliability of the spike-wave index (SWI) of the first 100 seconds of sleep of routine EEG (rEEG) as a tool for diagnosis of developmental/epileptic encephalopathy with spike wave activation with sleep.

Methods: Approximately three hundred forty LTMs were reviewed, and 25 studies from 25 unique patients had comparable rEEGs. Two neurophysiologists calculated the SWI of the first 100 seconds of spontaneous stage II non-random eye movement sleep, the first 5-minute bin of sleep, and three separate 5-minute bins throughout sleep in LTM. This was compared to the SWI of the first 100 seconds of sleep in rEEG. Agreement was analyzed using Lin's concordance correlation coefficient (CCC).

Results: Using 50% as a diagnostic cut-off, we observed moderate agreement between the SWI of the first 100 seconds of sleep of rEEG and three bin LTM (CCC = 0.94, 95% CI: 0.88-0.97). Agreement was slightly higher for the comparison to first bin LTM SWI (CCC = 0.96, 95% CI: 0.92-0.98) and first 100 seconds LTM SWI (CCC = 0.96, 95% CI: 0.92-0.98).

Conclusions: This study demonstrates the first 100 seconds of sleep of rEEG technique as a time efficient diagnostic tool for patients with concern for developmental/epileptic encephalopathy with spike wave activation with sleep.

Purpose: Repetitive transcranial magnetic stimulation (rTMS) is a potentially effective, noninvasive tool for language mapping. However, there is a paucity of data in pediatric patients. In this study, we aimed to map language sites in healthy pediatric participants with navigated rTMS.

Methods: Children aged 5 to 18 years underwent bilateral language mapping. Stimulation was delivered at 5 Hz during visual-naming and auditory verb-generation tasks in 1 to 2 second bursts. We targeted 33 standardized sites per hemisphere. In total, 34 participants completed the visual-naming task, and 27 participants completed the verb-generation task. Lateralization index (LI) and Wilcoxon signed-rank test were used to assess language lateralization. A difference of least squares means model was developed to determine the prevalence of visual-naming and verb-generation errors within lobar and hemispheric regions.

Results: Weak left lateralization was observed for visual naming (LI 0.14; p = 0.038), and no lateralization was observed for verb generation (LI 0.08; p = 0.269). Using multiple least squares regression, left hemisphere errors were more likely to occur than right hemisphere errors for visual naming (OR 1.23; 95% CI 1.06-1.44), but no lateralization effect was observed for verb-generation errors (OR 1.11; 95% CI 0.93-1.27).

Conclusions: rTMS is likely to identify bilateral or weakly left-lateralized language sites in pediatric patients during language tasks. Although rTMS can be a useful noninvasive method for identifying potential language-positive sites, our results in healthy controls suggest that it cannot be used as a singular method for language mapping in the preoperative setting.

Purpose: Delivering optimal care to patients with seizures and epilepsy requires all EEGs to be interpreted accurately and reliably. This study investigated neurology professionals' opinions on the ideal standards for EEG in clinical care.

Methods: We developed an anonymous e-survey targeting practicing and trainee neurologists focused on participants' demographics, clinical practice characteristics, and views on optimal EEG standards of care-including whether an EEG certification test is needed and whether postresidency/fellowship training in EEG/epilepsy is necessary for neurologists who interpret outpatient/routine EEGs in practice. The survey was hosted by the Neurology Clinical Practice-Practice Current, and it was distributed online through the American Academy of Neurology, American Epilepsy Society, American Clinical Neurophysiology Society, and International League Against Epilepsy, and through social media.

Results: Two hundred eighty-three responses were included: 119 from EEG/epilepsy-trained neurologists, 83 from non-EEG/epilepsy-trained neurologists, 75 from trainees, and 6 from advanced care providers. Most participants (78%) agreed that "an objective certification test of ability to interpret EEGs is needed for all those who interpret EEGs in clinical practice." Most participants (71%) believed that outpatient/routine EEGs may be read only by neurologists with EEG/epilepsy training; this opinion was more prevalent among EEG/epilepsy-trained (83%) versus non-EEG/epilepsy-trained neurologists (55%).

Conclusions: Our neurology community should discuss the need to develop and implement a certification test of ability for all neurologists who wish to interpret EEGs in clinical practice. In addition, it is imperative to improve in-residency EEG education to ensure that neurology graduates achieve EEG competence before entering the workforce.

Purpose: The American Clinical Neurophysiology Society has provided a set of recommendations on the use of critical care EEG monitoring (CEEG). However, these recommendations have not been prospectively validated. We aimed to assess the adherence to the American Clinical Neurophysiology Society recommendations for obtaining CEEG for different indications and the yield of obtained CEEG according to these different indications.

Methods: This was a multicenter prospective observational study of critically ill adult patients between April 01, 2022, and June 22, 2022, in two academic medical centers and a large teaching hospital. Indications for CEEG, according to the American Clinical Neurophysiology Society recommendations, were determined based on clinical data at the time of discharge from the intensive care unit. The use of CEEG and detection of electrographic seizures were retrieved from the EEG databases.

Results: A total of 600 patients were enrolled in this study. The primary admission diagnoses were medical (49%), surgical (30%), or neurologic/neurosurgical (21%). Approximately 60% of patients had an altered mental status. A few (6%) patients had a preceding clinical seizure, and 1% had generalized convulsive status epilepticus. Indications were identified in 226 admissions. Of these patients, 88 (39%) underwent CEEG. In addition, 12 patients underwent CEEG without clear indications. Of the 100 patients, 33 (33%) had electrographic seizures. Adherence to recommendations and yields was highest for refractory status epilepticus, altered mental status after any clinical seizure, and acute brain injury. Adherence and yield varied the most and were inversely correlated in the group of patients without acute brain injury, suggesting that additional clinical factors may have contributed to patient selection.

Conclusions: Patients meeting American Clinical Neurophysiology Society indications and receiving CEEG had a high seizure risk. Emerging CEEG programs should focus on epilepsy-related and neurologic diagnosis. Although recommendations effectively identify groups of patients with a high seizure risk, additional clinical factors might further help select candidates in the low-risk group.

Purpose: Recent research on quantitative EEG in coma has proposed several metrics correlating with consciousness level. However, the heterogeneous nature of coma can challenge the generalizability of these measures. This study investigates alpha-coma, an electroclinical pattern characterized by a widespread, nonreactive alpha rhythm often linked to poor outcomes. The aim was to quantify the electrophysiological features of alpha-coma and compare them to the alpha rhythm in awake controls, seeking clearer insights into quantitative EEG analysis in comatose states.

Methods: Fourteen alpha-coma patients were retrospectively selected from University Hospitals of Geneva and age-matched with 14 healthy control subjects from an open-source dataset. EEG data were preprocessed and analyzed to extract power spectra, spectral decay (aperiodic activity), sample entropy, and functional connectivity.

Results: Alpha-coma patients did not differ in alpha power but exhibited significantly higher levels of spectral decay ( p < 0.001), suggesting a convergence toward an inhibitory state. Sample entropy was significantly higher in alpha-coma patients ( p = 0.01), indicating an increase in the cortical complexity in alpha-coma compared with healthy subjects.

Conclusions: Alpha-coma shows increased aperiodic activity and EEG complexity, despite similar alpha power and clustering coefficient. The increased aperiodic activity aligns with findings in other comatose patients, including those sedated or with subcortical dysfunction. However, the increased entropy contradicts existing literature, suggesting that alpha-coma may represent a state of widespread cortical dysfunction likely resulting from nonhierarchical, turbulent brain activity. This indicates that the loss of consciousness does not guarantee consistent cortical measures across the whole spectrum of EEG patterns.