Validation of Criteria for Identification of Epileptiform Discharges in EEG Recordings of Patients With Epilepsy

NCT03533374 | Completed Results

• 1 other identifier: CIED
• Study Type: observational
• Target: 100
• Locations: 0 countries
• Sites: N/A

Brief Summary

Electroencephalography (EEG) records electric activity of the brain using electrodes placed on the scalp. EEG is an important tool in the diagnostic work-up of patients with epilepsy. Specific types of sharp EEG discharges (epileptiform discharges) are associated with patients with epilepsy. The International Federation of Clinical Neurophysiology (IFCN) has recently published a set of six operational criteria for identifying epileptiform discharges. At least four criteria need to be present in order to classify a discharge as epileptiform. These criteria are largely based on expert opinion and have not been validated yet. It is not clear what the sensitivity and specificity of these criteria are, and which combination of these criteria are optimal. Each criterion is based on visual assessment. However, it is not known what the inter-rater agreement of these criteria are. EEG is traditionally inspected in sensor space, i.e. in the recording channels. Advances in signal analysis made possible reconstructing the electric currents in the regions of the brain generating them, and displaying the signals in the source space, instead of the sensor space. The objectives of this study are: to determine the inter-rater agreement of the IFCN criteria by visual analysis in sensor space, to determine the combination of criteria with the best accuracy (sensitivity and specificity) and assess the accuracy of evaluating the discharges in source space. The raters will analyze EEG recordings from 100 patients, from two groups: consecutive patients with epilepsy and consecutive patients with non-epileptic paroxysmal episodes. EEG was recorded during long-term video-EEG monitoring. As reference standard, the investigators used the evaluation of the patients´ habitual clinical episode. The performance of the criteria in sensor-space and the analysis in source space will be compared with the unrestricted expert scorings.

Conditions

Epilepsy; Non-Epileptic Seizure

Keywords

Accuracy; Inter-ictal EEG Discharges; Inter-rater agreement; Long Term Monitoring; Sensitivity; Sharp transients; Specificity; Source Space; Voltage maps

Outcome Measures

Primary Outcomes (3)

• Inter-rater Agreement of the International Federation of Clinical Neurophysiology (IFCN) Criteria (Cut-off=4) in Sensor Space and of Detection of Epileptiform Discharges (EDs) in Source Space

  Inter-rater agreement of IFCN criteria (cut-off=4) in sensor space and of detection of EDs in source space was calculated using Gwet´s Agreemen Coefficient (AC1). We calculated Gwet's coefficients of agreement AC1 for beyond chance agreement, because, compared with Cohen's Kappa, the Gwet's agreement coefficient is less affected by prevalence and marginal probability and thereby avoids the problem known as the "paradoxes of kappa". Strength of agreement beyond chance was interpreted according to Landis and Koch criteria: poor (\<0), slight (0·01-0·20), fair (0·21-0·40), moderate (0·41-0·60), substantial (0·61-0·80), and almost perfect (0·81-1·00).

  1 year

• Sensitivity and Specificity IFCN Criteria (Cut-off=4)

  This is a diagnostic study, hence sensitivity and specificity must be calculated from different groups: sensitivity form the group of patients with epilepsy and specificity from the gruoup of patients who do not have epilepsy. Sensitivity: the percentage of patients with abnormal index test (true positives) among patients with epilepsy. Specificity: the percentage of patients with normal index test (true negatives) among patients who do not have epilepsy.

  1 year

• The Sensitivity and Specificity of Detecting EDs in Source-space

  This is a diagnostic study, hence sensitivity and specificity must be calculated from different groups: sensitivity form the group of patients with epilepsy and specificity from the group of patients who do not have epilepsy. Sensitivity: the percentage of patients with abnormal index test (true positives) among patients with epilepsy. Specificity: the percentage of patients with normal index test (true negatives) among patients who do not have epilepsy.

  1 year

Study Arms (2)

Patients with epileptic seizures

Electroencephalogram (EEG) and visual evaluation \- Electroencephalogram (EEG) was recorded using Nicolet-One system, and the standard 25-electrode array. Recordings with sharp transients are inspected by experts (physicians).

Diagnostic Test: Electroencephalogram (EEG) and visual evaluation

Patients with non-epileptic seizures

Electroencephalogram (EEG) and visual evaluation \- Electroencephalogram (EEG) was recorded using Nicolet-One system, and the standard 25-electrode array. Recordings with sharp transients are inspected by experts (physicians).

Diagnostic Test: Electroencephalogram (EEG) and visual evaluation

Interventions

Electroencephalogram (EEG) and visual evaluation DIAGNOSTIC_TEST

Electroencephalogram (EEG) was recorded using Nicolet-One system, and the standard 25-electrode array. Recordings with sharp transients are inspected by experts (physicians).

Patients with epileptic seizures; Patients with non-epileptic seizures

Eligibility Criteria

• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patient with epilepsy and patient with non-epileptic seizures (paroxysmal episodes)

You may qualify if:

• Patients who underwent long-term video-EEG monitoring
• Patients who had at least one habitual episode (seizure) recorded on video and EEG.
• Patients with sharp transients.
• For patients with epilepsy: the interictal (epileptiform) sharp transients are concordant with the ictal recording

You may not qualify if:

• Patients with both epileptic seizures and non-epileptic seizures (paroxysmal episodes).

Sponsors & Collaborators

• Sándor Beniczky: lead
• Aarhus University Hospital: collaborator
• Central Denmark Region: collaborator
• Filadelfia Epilepsy Hospital: collaborator
• University Health Network, Toronto: collaborator
• University Hospital Erlangen: collaborator
• Oslo University Hospital: collaborator

MeSH Terms

Conditions

Epilepsy; Seizures; Hypersensitivity

Interventions

Electroencephalography

Condition Hierarchy (Ancestors)

Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Immune System Diseases

Intervention Hierarchy (Ancestors)

Diagnostic Techniques, Neurological; Diagnostic Techniques and Procedures; Diagnosis; Electrodiagnosis

Results Point of Contact

• Title: Professor Sandor Beniczky
• Organization: Aarhus University Hospital

sbz@filadelfia.dk

+4526981536

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: RETROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: professor

Study Record Dates

• First Submitted: May 11, 2018
• First Posted: May 23, 2018
• Study Start: January 1, 2012
• Primary Completion: January 1, 2018
• Study Completion: January 1, 2018
• Last Updated: July 22, 2020
• Results First Posted: July 22, 2020

Record last verified: 2019-07