From the Guidelines
EEG video monitoring should last for at least 24 hours, but ideally 48 hours, to increase the likelihood of detecting electrographic seizures in patients with impaired or fluctuating level of consciousness. The duration of EEG video monitoring is crucial in capturing diagnostic information, especially in patients with possible seizures contributing to their clinical picture. According to the 2022 guideline for the management of patients with spontaneous intracerebral hemorrhage 1, continuous electroencephalogram monitoring for at least 24 hours is recommended for patients with suspected seizures. However, the same study noted that 28% of those with electrographic seizures were detected after at least 24 hours of continuous monitoring, whereas 94% were detected with at least 48 hours of monitoring.
Key points to consider when determining the duration of EEG video monitoring include:
- The frequency of the patient's events
- The need to capture diagnostic information
- The potential for detecting electrographic seizures
- The importance of continuous monitoring in detecting seizures that may not be apparent through routine EEG recordings
In clinical practice, the monitoring involves continuous recording of brain activity through electrodes attached to the scalp while simultaneously recording video of the patient's behavior. This allows physicians to correlate brain wave patterns with physical manifestations of seizures. The test is performed in a specialized epilepsy monitoring unit (EMU) in a hospital setting where medical staff can respond quickly if seizures occur.
It is essential to note that the evidence from other studies, such as the 2024 international consensus on cardiopulmonary resuscitation and emergency cardiovascular care science 1 and the 2024 American Heart Association focused update on adult advanced cardiovascular life support 1, although relevant to the topic of seizures and EEG monitoring, do not provide specific guidance on the duration of EEG video monitoring. Therefore, the recommendation is based on the most recent and highest-quality study available, which is the 2022 guideline for the management of patients with spontaneous intracerebral hemorrhage 1.
From the Research
EEG Video Monitoring Test Duration
The optimal duration of EEG video monitoring can vary depending on the patient population and the specific goals of the monitoring.
- A study published in 2021 2 found that recording at least 48 hours in duration for children, and at least 72 hours in duration for adult and geriatric samples, is optimal to maximize the likelihood of observing typical clinical events to facilitate diagnosis.
- Another study from 2015 3 suggested that prolonging video EEG monitoring appears useful for the proper classification and localization of epileptic seizures, but did not provide a specific optimal duration.
- A 2023 study 4 found that a 24-hour video EEG monitoring may be sufficient in the diagnostic workup of paroxysmal seizure-like events under most circumstances, but prolonged monitoring may be useful in cases with a high probability of epilepsy.
- A study published in 2016 5 found that 5 days of video-electroencephalographic monitoring is probably sufficient to capture the greatest number of events and diagnose 99% of patients.
- An earlier study from 2012 6 found that ambulatory EEG has a high diagnostic yield (72%) and can be a cost-effective alternative to inpatient video-EEG in adult patients, with a mean duration of recording of 32 hours.
Factors Influencing Test Duration
Several factors can influence the optimal duration of EEG video monitoring, including:
- Patient age: children may require shorter monitoring durations, while adults and geriatric patients may require longer durations 2.
- Type of seizure or event: different types of seizures or events may require different monitoring durations 3, 5.
- Diagnostic goals: the specific goals of the monitoring, such as characterizing seizure type or localization, may influence the optimal duration 4, 6.