Putting Electroencephalography (EEG) in the Emergency Department

Formulated Research Question:

Population: ED patients with altered mental status (AMS) Intervention: Micro-EEG Comparison: Standard EEG Outcomes: 1. Sensitivity, specificity, positive/negative likelihood ratios of micro-EEG in identifying non-convulsive seizures and abnormal brain activities 2. The concordance of EEG interpretations between micro-EEG and standard EEGs recordings Design Prospective cross-sectional

Definitions:

Altered Mental Status: Any acute change in level of arousability or responsiveness (e.g. confusion, lethargy, delirium, coma, aphasia, disinhibition, labile/blunted affect or unexpected psychosis).

Types of AMS (for the purpose of the study):

• AMS alone
• AMS with non-specific motor activity (subtle motor movement such as eye blinking, nystagmus, focal motor movements, or myoclonus)
• Prolonged AMS following one or more tonic-clonic seizures suggesting status epilepticus Non-convulsive seizure (NCZ):A seizure without clonic or tonic activity or other convulsive motor activity.

Status Epilepticus (SE):SE is defined as 1. More than 30 minutes of continuous seizure activity or 2. Two or more sequential seizures without recovery of consciousness between seizures.

Inclusion criteria

ED patients ≥ 13 year-old with AMS on arrival to ED

Exclusion criteria

• Patients with apparent and immediately correctable cause of AMS upon presentation (determined by ED attending physician during initial evaluation):

• Patients with finger stick or serum glucose less than 60 mg/dl
• Patients with hypothermia
• Patients with hyperthermia, heat exhaustion or heat stroke
• Patients with opioid overdose responding to Narcan
• Patients who cannot undergo EEG recordings because of severe head and injury, hemodynamic instability, transfer to operating room, etc.)
• Hemodynamically unstable patients (SBP < 90 mmHg)
• Uncooperative or combative patients on whom the EEG simply cannot be obtained.