When do psychogenic nonepileptic seizures occur on a video/EEG telemetry unit?

Area of Science:

• Neurology
• Clinical Neurophysiology

Background:

• Diagnostic video/electroencephalography (EEG) telemetry is crucial for differentiating between psychogenic nonepileptic seizures (PNES) and epileptic seizures (ES).
• Maximizing the efficiency of this diagnostic tool is essential for timely and accurate patient management.

Purpose of the Study:

• To retrospectively analyze the timing and characteristics of clinical events during inpatient video/EEG telemetry.
• To identify patterns that may help differentiate PNES from ES based on event occurrence relative to electrode placement and time of day.

Main Methods:

• Retrospective study of 254 patients undergoing diagnostic video/EEG telemetry.
• Categorization of patients into groups with PNES (n=159) and ES (n=95).
• Analysis of event occurrence in relation to electrode placement and time of admission.

Main Results:

• Events occurred before or during electrode placement in 25 PNES patients but none with ES (P<0.0001).
• Within 48 hours of electrode placement, 98.5% of PNES and 100% of ES patients experienced their initial event.
• Nighttime events (12 AM - 6 AM) were more frequent in ES patients (51.6%) compared to PNES patients (17.1%) (P=0.001).

Conclusions:

• Diagnostic video/EEG telemetry effectively captures clinical events for both PNES and ES within two days of electrode placement.
• While the time to the initial event after electrode placement is similar for both diagnoses, events preceding or during placement are indicative of PNES.
• Nocturnal events during telemetry are more characteristic of ES, aiding in differential diagnosis.