Diagnostic yield of continuous video EEG for neonatal seizures

Investigators from the University of California, San Francisco studied the yield of continuous video EEG (vEEG) in diagnosing electrographic seizures in their neonatal intensive care unit. Over a 4.5 year period, 595 neonates were evaluated, of which 66% were term and 67% referred from an outside hospital. Therapeutic hypothermia was completed in 25%. There was a 14% mortality rate. Neonates with electrographic seizures were identified by reviewing clinical vEEG reports. vEEG was clinically indicated for 400/595 (67%) of the neonates, with approximately equal proportions for two or more of the following indications: event concerning for seizure, encephalopathy, or high risk for seizures. Continuous vEEG was performed for a median of 49 hours (interquartile range 22-87). All neonates undergoing therapeutic hypothermia received vEEG until rewarmed. Electrographic seizures were detected in 105/400 (26%), and of those 25/105 (24%) had only electrographic seizures, with no clinical seizures even prior to vEEG. No seizures were detected on vEEG in 52/400 (13%) of those with events concerning for seizure. Phenobarbital was given prior to vEEG in 38/51 (75%) of those patients and to 93/400 (23%) of the entire study population. The indication for vEEG did not affect the likelihood of seizure diagnosis. There was some variability in seizure diagnosis based on etiology. Arterial and venous strokes had the highest proportion with seizures in 58%, and hypoxic-ischemic encephalopathy, intracranial hemorrhage and infection all around 29% and lower rates with brain malformation or genetic syndromes

KCNQ2 encephalopathy

Objective: To advance the understanding of KCNQ2 encephalopathy genotype–phenotype relationships and to begin to assess the potential of selective KCNQ channel openers as targeted treatments. Methods: We retrospectively studied 23 patients with KCNQ2 encephalopathy, including 11 treated with ezogabine (EZO). We analyzed the genotype–phenotype relationships in these and 70 previously described patients. Results: The mean seizure onset age was 1.8 ± 1.6 (SD) days. Of the 20 EEGs obtained within a week of birth, 11 showed burst suppression. When new seizure types appeared in infancy (15 patients), the most common were epileptic spasms (n = 8). At last follow-up, seizures persisted in 9 patients. Development was delayed in all, severely in 14. The KCNQ2 variants identified introduced amino acid missense changes or, in one instance, a single residue deletion. They were clustered in 4 protein subdomains predicted to poison tetrameric channel functions. EZO use (assessed by the treating physicians and parents) was associated with improvement in seizures and/or development in 3 of the 4 treated before 6 months of age, and 2 of the 7 treated later; no serious side effects were observed. Conclusions: KCNQ2 variants cause neonatal-onset epileptic encephalopathy of widely varying severity. Pathogenic variants in epileptic encephalopathy are clustered in “hot spots” known to be critical for channel activity. For variants causing KCNQ2 channel loss of function, EZO appeared well tolerated and potentially beneficial against refractory seizures when started early. Larger, prospective studies are needed to enable better definition of prognostic categories and more robust testing of novel interventions. Classification of evidence: This study provides Class IV evidence that EZO is effective for refractory seizures in patients with epilepsy due to KCNQ2 encephalopathy

Interrater agreement in the interpretation of neonatal electroencephalography in hypoxic‐ischemic encephalopathy

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136482/1/epi13661_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136482/2/epi13661.pd

American Clinical Neurophysiology Society Guideline 3: A Proposal for Standard Montages to Be Used in Clinical EEG

Summary: This revision to the EEG Guidelines is an update incorporating current electroencephalography technology and practice and was previously published as Guideline 6. A discussion of methodology for the appropriate selection of reference electrodes is added. In addition, montages are added to assist with localization of abnormal activity in mesial frontal and anterior temporal regions.PublishedN/

American Clinical Neurophysiology Society Guideline 4: Recording Clinical EEG on Digital Media.

Digital EEG recording systems are now widely available and relatively inexpensive. They offer multiple advantages over previous analog/paper systems, such as higher fidelity recording, signal postprocessing, automated detection, and efficient data storage. This document provides guidance for the creation of digital EEG recordings including (1) documentation of patient information, (2) notation of information during the recording, (3) digital signal acquisition parameters during the recording, (4) storage of digital information, and (5) display of digital EEG signals