From the Guidelines
Non-convulsive seizures (NCS) should be diagnosed promptly through electroencephalogram (EEG) monitoring and treated with benzodiazepines as the first-line treatment, followed by anti-seizure medications like fosphenytoin, levetiracetam, or valproate for refractory cases, as recommended by the most recent guidelines 1. The diagnosis of NCS is crucial, as these seizures can cause neurological damage if left untreated. The clinical presentation of NCS can be subtle, manifesting as altered consciousness, confusion, or behavioral changes.
Key Considerations
- Prompt diagnosis through EEG monitoring is essential to identify NCS and initiate treatment.
- First-line treatment typically involves benzodiazepines, such as lorazepam or midazolam.
- For refractory cases, second-line agents like fosphenytoin, levetiracetam, or valproate may be used, as they have similar efficacy 1.
- Continuous EEG monitoring and escalation to anesthetic agents like propofol or midazolam infusion may be necessary for refractory cases.
- Identifying and treating the underlying cause of NCS, whether it's metabolic disturbances, infection, stroke, tumor, or medication effects, is crucial.
Treatment Approach
- Benzodiazepines, such as lorazepam (2-4 mg IV) or midazolam (10 mg IM), are the initial treatment of choice.
- For refractory cases, fosphenytoin, levetiracetam, or valproate may be used as second-line agents, with similar efficacy 1.
- The use of prophylactic anticonvulsant drugs after cardiac arrest in adults has been insufficiently studied, and routine seizure prophylaxis is not recommended due to the risk of adverse effects and poor response to anti-epileptic agents 1.
- Non-convulsive status epilepticus is particularly dangerous and requires ICU management, with prolonged observation necessary after treatment of seizures 1.
From the Research
Diagnosis of Non-Convulsive Seizure (NCS)
- Non-convulsive seizures (NCS) occur in as many as 20% of comatose critically ill patients 2
- NCS is characterized by continuous or recurrent, generalized or focal epileptiform activity on the electroencephalogram (EEG) and diverse clinical symptoms with alterations of mental state and vigilance 3
- Diagnosis of NCS can be challenging, and it is often underdiagnosed 3
Treatment of Non-Convulsive Seizure (NCS)
- Treatment of NCS is crucial, but the urgency and choice of medication are unclear 2
- Nonsedating antiepileptic drugs (AEDs) such as valproic acid and lacosamide may be preferable to sedating medications like phenytoin/fosphenytoin and levetiracetam due to their superior side effect profiles 2
- Levetiracetam has been shown to be effective in treating NCS, with a marked clinical improvement and cessation of ictal EEG activity within 3 days 3
- Lacosamide has also been reported to be successful in treating refractory simple motor status epilepticus in combination with levetiracetam 4
- The choice of treatment may depend on the specific clinical scenario, and further research is needed to determine the optimal treatment strategy 2, 3, 5
Loading Dose of Levetiracetam
- The loading dose of levetiracetam in benzodiazepine-refractory status epilepticus is a topic of debate, with doses ranging from 20 mg/kg to 60 mg/kg 5
- A study found no significant difference in seizure termination rates between different loading doses of levetiracetam, but higher doses were associated with increased intubation rates 5
- Further research is needed to determine the optimal loading dose of levetiracetam in this setting 5
Other Treatment Options
- Other AEDs such as topiramate and pregabalin have been used to treat NCS, but their data is limited, and they do not have an intravenous formulation 2
- Artificial intelligence may have a role in decision-making after a first seizure, and modern therapies such as brivaracetam and fosphenytoin may be effective in treating established status epilepticus 6