Usefulness of video-EEG in the paediatric emergency department

Abstract

Over the past two decades the EEG has technically improved from the use of analog to digital machines and more recently to video-EEG systems. Despite these advances, recording a technically acceptable EEG in an electrically hostile environment such as the emergency department (ED) remains a challenge, particularly with infants or young children. In 1996, a meeting of French experts established a set of guidelines for performing an EEG in the ED based on a review of the available literature. The authors highlighted the most suitable indications for an emergency EEG including clinical suspicion of cerebral death, convulsive and myoclonic status epilepticus, focal or generalized relapsing convulsive seizures as well as follow-up of known convulsive patients. They further recommended emergency EEG in the presence of doubt regarding the epileptic nature of the presentation as well as during the initiation or modification of sedation following brain injury. Subsequently, proposals for expanding the use of EEG in emergency patients have been advocated including trauma, vascular and anoxic-ischemic injury due to cardiorespiratory arrest, postinfective encephalopathy and nonconvulsive status epilepticus. The aim of this review is to show the diagnostic importance of video-EEG, as well as highlighting the predictive prognostic factors for positive and negative outcomes, when utilized in the pediatric ED for seizures as well as other neurological presentations.

Keywords::

• acute differential diagnosis
• diagnostic value
• emergent department
• emergent video EEG
• pediatric
• therapy perspective

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• The different patterns of an EEG obtained from emergency patients, although often nonspecific, can be correlated with the etiology of CNS disease, such as trauma vascular injury as well as anoxic-ischemic injury due to cardiorespiratory arrest. For example, in postinfective encephalopathy, particularly herpes simplex encephalitis, and in nonconvulsive status epilepticus, the EEG is a decisive diagnostic tool and thus guides therapy as well as giving valuable prognostic information.

• Abundant literature from the past few decades exists characterizing the well-defined, routine use of the EEG in emergency departments. Routine use of EEGs in acute settings may advance patient care in certain neurological scenarios, such as acute alteration of mental status and severe traumatic brain injury. In such clinical scenarios, access to cerebral function is often hindered by an unrevealing bedside physical exam in obtund or deeply sedated subjects.

• The EEG technique has improved from the use of analog to digital recording machines and more recently to video-EEG monitoring systems. This latter technique is widely used as a diagnostic and management tool in patients with seizures.

• The performance of video-EEG monitoring, in the context of a comprehensive epilepsy program, requires the involvement of a highly trained multidisciplinary team, including EEG scientists, nursing staff, epileptologists, neuropsychologists, imaging specialists and technicians as well as expensive monitoring equipment.

• The diagnosis of nonepileptic seizures by video-EEGs has been documented to result in a substantial reduction in a variety of direct medical costs in the 6 months after the EEG study compared with the previous 6 months: an average 84% reduction in seizure-related medical charges, a 76% decline in diagnostic test charges, a 69% decrease in medication charges, an 80% decrease in outpatient clinic visits and a 97% decrease in emergency department visits.

• In 1996, a meeting of French experts established a set of guidelines based on a review of the available literature. After this consensus meeting in 1996, no other international consensus with such extensive indications for an emergency EEG has been published and the main recommendations for performing an emergency EEG still refers to those indicated at the French meeting. Nevertheless, the importance of an emergency EEG in the pediatric population has been highlighted by various authors. In children, the published data on the performance of an emergency EEG are limited even though they support its use.

• Our paper highlights the importance of performing an emergency EEG in a wider spectrum of neurological diseases, not only involving epileptic status and/or paroxysmal nonepileptic events but also including other neurological diseases such as those involving persistently depressed consciousness after a prolonged seizure, those in whom nonconvulsive seizures are suspected, patients with minor brain injuries, metabolic syndromes, cerebral strokes, headache and autonomic syndromes.

• An emergency EEG has been demonstrated to be a fundamental diagnostic tool in the pediatric acute and emergency department due to its high predictive value for neurological diseases requiring further diagnostic investigations. This in turn helps the EEG to differentiate these disorders from other neurological diseases that could be treated at the acute and emergency room, thereby avoiding improper hospitalizations.