From the Guidelines
Seizure monitoring should be performed using continuous EEG monitoring in comatose patients after cardiac arrest to detect electrographic seizures and status epilepticus, as recommended by the 2024 international consensus on cardiopulmonary resuscitation and emergency cardiovascular care science with treatment recommendations 1.
Key Points
- The American Clinical Neurophysiology Society definitions should be used consistently in trials to define electrographic seizure, electroclinical seizure, electroclinical status epilepticus, possible ECSE, and ictal-interictal continuum 1.
- Untreated clinical seizure activity may cause additional brain injury, and treatment of clinical seizures is recommended despite the lack of high-certainty evidence 1.
- Rhythmic and periodic EEG patterns that do not meet criteria for electrographic seizures are of unclear significance in patients who are comatose after cardiac arrest 1.
- Indirect evidence from case series suggests sedatives such as propofol are effective in suppressing clinical seizures and electrographic seizures 1.
Monitoring Approach
- Continuous EEG monitoring is labor-intensive and likely to add significant cost to patient care, but it is the preferred method for detecting electrographic seizures and status epilepticus in comatose patients after cardiac arrest 1.
- Video-EEG remains the gold standard for inpatient monitoring, and follow-up with a neurologist every 3-6 months is advised, with more frequent visits for uncontrolled seizures.
- Blood level monitoring for antiseizure medications like valproate and levetiracetam helps ensure therapeutic dosing and may be effective in suppressing epileptiform activity in the EEG 1.
Treatment
- Treatment of clinical seizures is recommended, and antiseizure medications like sodium valproate, levetiracetam, phenytoin, benzodiazepines, propofol, or a barbiturate may be used 1.
- Myoclonus can be particularly difficult to treat, but propofol is effective in suppressing post-anoxic myoclonus, and clonazepam, sodium valproate, and levetiracetam may be effective in post-anoxic myoclonus 1.
Prognosis
- Myoclonus and electrographic seizure activity, including status epilepticus, are related to a poor prognosis, but individual patients may survive with good outcome, and prolonged observation may be necessary after treatment of seizures 1.
From the Research
Seizure Monitoring
- Seizure monitoring is crucial in managing epilepsy, and various studies have investigated the efficacy of different antiepileptic drugs in controlling seizures 2, 3.
- Levetiracetam is a widely prescribed antiepileptic drug that has been shown to be effective in controlling seizures in patients with epilepsy, including those with partial-onset seizures and idiopathic generalized epilepsy 2, 3.
- The mechanisms of action of levetiracetam involve neuronal binding to synaptic vesicle protein 2A, inhibiting calcium release from intraneuronal stores, and opposing the activity of negative modulators of GABA- and glycin-gated currents 2, 3.
- In addition to its efficacy in controlling seizures, levetiracetam has also been shown to improve health-related quality of life in patients with epilepsy 2, 3.
- Status epilepticus is a major clinical emergency that requires prompt treatment, and levetiracetam has been reported to be effective in managing benzodiazepine-resistant status epilepticus 4.
- The evaluation and management of first-time seizures in adults involve careful history and clinical examination, electroencephalography, and brain imaging, as well as consideration of individual risk factors for seizure recurrence and possible complications from seizures 5, 6.
Key Considerations
- The initial clinical evaluation of a first seizure is crucial in determining the diagnosis, treatment, and prognostication of the condition 6.
- Clinical features that may distinguish seizures from alternative diagnoses should be carefully considered in the evaluation of a first seizure 6.
- Antiepileptic drugs should be initiated in patients with newly diagnosed epilepsy, while the decision to prescribe drugs in patients without an epilepsy diagnosis depends on individual risk factors for seizure recurrence and possible complications from seizures 5.