EEG in the Emergency Department: When the Neurophysiological Test Cannot Be Considered in the Patient’s Emergency Diagnostic Workup? The EMINENCE Study

Introduction: To investigate if specific emergency physician(EP) admission diagnoses and/or neurological signs/symptoms on admission to the Emergency Department(ED) were associated to normal/not-informative emergency-electroencephalogram(emEEG). Methods: Data from consecutive patients admitted to the ED of our tertiary hospital during two-years period (1 Jan 2023-31 Dic 2024) were retrospectively analyzed. We evaluated the correlation between nor-mal/not-specific emEEG and EP admission diagnoses and neurological signs/symptoms on admission. Epileptic EEGs and EEGs showing triphasic morphology sharp-waves were considered as specific patterns. Results: A total of 2,008 patients underwent emEEG during the study-period. EmEEG was considered not-informative in 100% of global amnesia diagnosis, 100% of mild head trauma, 100% of migraine with aura, 98.3% of transient ischaemic attack(TIA), 95.6% of transient loss of consciousness(TLC) when seizure was not the primary suspected diagnosis and 92.7% of falls of unknown dynamics. Epileptic patterns were detected in 4% of patients presenting with TLC and in 2.4% of those with falls of unknown dynamics, with approximately half of these patients having a pre-existing diagnosis of epilepsy. Triphasic waves were detected in 4.9% pa-tients with falls of unknown dynamic, in 1.7% with TIA and in 0.4% with TLC. All these patients showed fe-ver/sepsis or metabolic/electrolyte disorders. Overall, across all clinical scenarios, emEEG was considered not-informative in 385(19.1%) patients who underwent emEEG. Conclusions: emEEG is almost not-informative in the diagnostic pathway of global amnesia, mild head trauma and migraine with aura, while in patients with TIA, TLC, or falls of unknown dynamics, EP can consider to safely avoid emEEG in the absence of previous epilepsy, fever/sepsis, metabolic/electrolyte disturbances or drug abuse.