Neonatal seizures; neonatal epilepsy syndromes.
Recommendations for diagnosis, treatment, and monitoring of seizures in neonates.
Seizures in neonates are often multifactorial, ranging from acute brain injury from hypoxic-ischemic events to epilepsy syndromes from structural, metabolic, or genetic etiologies. While broad, diagnosis of seizures, whether clinical or subclinical, acute or refractory, can help direct management and improve morbidity or mortality for the neonate, keeping in mind that outcomes may still largely depend on the underlying disease process and degree of brain injury. While no national guidelines are established for acute treatment of neonatal seizures and institutional practices may differ, treatment options have been published in the literature as described below.
The overall goal of management is to quickly identify and stop electrographic seizures, determine underlying etiology, and prevent secondary brain injury. The priorities for managing seizures are ensuring clinical stability, stopping the seizures, treating easily treatable conditions, and rapidly identifying life-threatening conditions and initiating immediate treatment for them. This should be followed by more detailed attempts to identify the cause of the seizures and underlying conditions. Neonatal seizures are difficult to identify clinically as they are often subclinical. Seizures should be identified and monitored using clinical assessment, bedside cardiorespiratory monitoring, and electroencephalographic monitoring, with close collaboration between neurology, neonatology, and other subspecialists as required. When seizures are refractory to treatment, clinicians often have to weigh the benefits of extinguishing every single seizure against the adverse effects of anticonvulsants. Choice of antiepileptic medications currently used for acute symptomatic seizure treatment is challenging because of a lack of evidence about them. Vitamin-responsive epilepsy should be considered early in those infants that are refractory to treatment.
Practice Option #1: Seizure Monitoring and Detection
Clinical manifestations suggestive of seizures, such as eye deviations, generalized myoclonic jerks, clonic jerking of the extremities associated with autonomic features, etc., are only approximately 30–50% accurate for seizure detection. Neonates often have subclinical seizures in the setting of severe brain injury or receiving anti-epileptic medications. Thus management based on clinical diagnosis alone is not recommended. Neonates at high risk for or with clinical suspicion for seizures can undergo monitoring using the following methods either alone or together:
Conventional video-EEG (cEEG) is the gold standard for seizure detection. Electrode placement is based on the International 10–20 system modified for neonates. Electrographic seizures are defined as a sudden abnormal EEG event characterized by a repetitive evolving pattern with a minimum 2uV amplitude and duration of at least 10 seconds. Status epilepticus is defined as the summed duration of seizures to be ≥50% of an arbitrarily defined 1-hour epoch.
Amplitude-integrated EEG (aEEG) is a ...