Sensory perception requires accurate encoding of stimulus information by sensory receptor cells. Here, we identify NCKX4, a potassium – dependent Na+/Ca2+ exchanger, to be necessary for rapid response termination and proper adaptation of vertebrate olfactory sensory neurons (OSNs). Nckx4−/− mouse OSNs display substantially prolonged responses and stronger adaptation. Single – cell electrophysiological analyses demonstrate that the majority of Na+ – dependent Ca2+ exchange in OSNs relevant to sensory transduction is due to NCKX4 and that Nckx4−/− mouse OSNs are deficient in encoding action potentials upon repeated stimulation. Olfactory – specific Nckx4 knockout mice have a reduced ability to locate an odorous source and lower body weights. These results establish the role of NCKX4 in shaping olfactory responses and suggest that rapid response termination and proper adaptation of peripheral sensory receptor cells tune the sensory system for optimal perception.

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The Neural Engineering Data Consortium (NEDC) is releasing its first major big data corpus -the Temple University Hospital EEG Corpus. This corpus consists of over 25,000 EEG studies, and includes a neurologist's interpretation of the test, a brief patient medical history and demographic information about the patient such as gender and age. For the first time, there is a sufficient amount of data to support the application of state of the art machine learning algorithms. In this paper, we present pilot results of experiments on the prediction of some basic attributes of an EEG from the raw EEG signal data using a 3,762 session subset of the corpus. Standard machine learning approaches are shown to be capable of predicting commonly occurring events from simple features with high accuracy on closed-loop testing, and can deliver error rates below 50% on a 6-way open set classification problem. This is very promising performance since commercial technology fails on this data.

The aim was to determine the prevalence and risk factors for electrographic seizures and other electroencephalographic (EEG) patterns in patients with Coronavirus disease 2019 (COVID-19) undergoing clinically indicated continuous electroencephalogram (cEEG) monitoring and to assess whether EEG findings are associated with outcomes. Methods: We identified 197 patients with COVID-19 referred for cEEG at 9 participating centers. Medical records and EEG reports were reviewed retrospectively to determine the incidence of and clinical risk factors for seizures and other epileptiform patterns. Multivariate Cox proportional hazards analysis assessed the relationship between EEG patterns and clinical outcomes. Results: Electrographic seizures were detected in 19 (9.6%) patients, including nonconvulsive status epilepticus (NCSE) in 11 (5.6%). Epileptiform abnormalities (either ictal or interictal) were present in 96 (48.7%). Preceding clinical seizures during hospitalization were associated with both electrographic seizures (36.4% in those with vs 8.1% in those without prior clinical seizures, odds ratio [OR] 6.51, p = 0.01) and NCSE (27.3% vs 4.3%, OR 8.34, p = 0.01). A pre-existing intracranial lesion on neuroimaging was associated with NCSE (14.3% vs 3.7%; OR 4.33, p = 0.02). In multivariate analysis of outcomes, electrographic seizures were an independent predictor of in-hospital mortality (hazard ratio ], p < 0.01). In competing risks analysis, hospital length of stay increased in the presence of NCSE (30 day proportion discharged with vs without NCSE: HR 0.21 [0.03-0.33] vs 0.43 [0.36-0.49]). Interpretation: This multicenter retrospective cohort study demonstrates that seizures and other epileptiform abnormalities are common in patients with COVID-19 undergoing clinically indicated cEEG and are associated with adverse clinical outcomes.

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Intraoperative EEG monitoring is increasingly used during aortic arch procedures for early detection of acute neurologic dysfunction. In those procedures involving cardiopulmonary bypass, increased neuroprotection may be gained by using hypothermic circulatory arrest and selective cerebral perfusion. Several techniques for cerebral perfusion exist; yet no studies have noted distinct EEG patterns associated with different techniques. In this study, we reviewed EEG records of six aortic arch procedures that used cannulation of the innominate artery to provide selective antegrade cerebral perfusion. In each case, a transient hemispheric asymmetry was noted within 2 minutes of the start of head cooling, consisting of enhanced suppression over the right compared with the left hemisphere, which was confirmed by power analysis. The EEG returned to baseline during passive-head rewarming in five cases, whereas a brief left-sided partial seizure occurred during rewarming in one case. These findings suggest that antegrade cerebral perfusion using cannulation of the innominate artery results in enhanced cooling of the right hemisphere as detected by intraoperative EEG monitoring. Characterization of this finding is necessary to prevent misinterpretation of ischemia by EEG.

Background and ObjectivesTo assess the scope of surgical epilepsy exposure and training among fellows in Epilepsy and Clinical Neurophysiology (CNP) fellowship programs in the United States. Characteristics associated with increased fellow involvement in epilepsy surgery were evaluated.MethodsA 10-question multiple-choice survey was designed to characterize individual fellowship programs, epilepsy surgery programs, trainee involvement, and assessment of trainee performance. The survey was distributed to program directors of adult Epilepsy and CNP-EEG track fellowships between November 2021 and April 2022. Epilepsy surgery procedures included resective approaches, neurostimulation modalities, and palliative interventions approved for drug-resistant epilepsy. Associations between categorical variables were evaluated using the Fisher exact test.ResultsThere were 37 responses from a total of 72 survey recipients (51% response rate). The majority (68%) of surgical programs performed >30 surgical procedures per year. The range of procedures was overall similar across programs. At most programs, fellows were personally involved in 1–10 (49%) or 11–30 (46%) surgical procedures per year. Institutions with >50 surgical cases/year were more likely to expose fellows to >10 cases/y compared with institutions with volumes ≤50 per year (77% vs 33%,p= 0.017). Fellows had the greatest involvement in presurgical planning with more variable involvement in perioperative and postoperative activities. Competency in surgical management was primarily investigated through faculty assessments (97%), whereas oral (46%) and written (30%) assessments were less frequently used.DiscussionHigh-volume epilepsy surgery centers provide trainees with increased exposure despite also having more fellowship positions. There is variability in surgical epilepsy exposure, trainee involvement, and performance evaluation metrics between institutions. We identify specific areas that programs may focus on to improve fellow competency in the surgical management of epilepsy.

Patients presenting to the ED with and without SE requiring ICU admission may have similar acute outcomes, yet differ in risk factors and seizure etiologies.