Can untreated seizures cause brainstem herniation?

From the Guidelines

Untreated seizures can potentially lead to brainstem herniation, particularly in cases of status epilepticus, and therefore, prompt treatment is crucial to prevent this life-threatening complication. This is because prolonged seizure activity causes increased metabolic demands, cerebral blood flow, and intracranial pressure, leading to brain swelling and potentially forcing brain tissue downward through the foramen magnum, resulting in brainstem herniation 1. The most recent and highest quality study, published in 2024, recommends treating seizures in post-cardiac arrest patients, although the specific agents and timing of treatment are not clearly defined 1.

Key Considerations

• Status epilepticus, defined as prolonged seizures lasting more than 5 minutes or recurrent seizures without recovery between them, is a medical emergency that requires immediate attention.
• Treatment of seizures should be initiated promptly with benzodiazepines, such as lorazepam (0.1 mg/kg IV) or diazepam (0.15-0.2 mg/kg IV), followed by second-line agents like fosphenytoin (20 mg PE/kg IV), levetiracetam (60 mg/kg IV, max 4500 mg), or valproate (40 mg/kg IV) if seizures persist.
• In cases where increased intracranial pressure is suspected, additional measures including head elevation, hyperventilation, osmotic therapy with mannitol (0.5-1 g/kg IV) or hypertonic saline (3% solution), and in severe cases, sedation with propofol or barbiturates may be necessary.
• Early recognition and aggressive management of seizures is crucial to prevent brainstem herniation and other potentially fatal complications.

Management of Seizures

• The American Clinical Neurophysiology Society defines the ictal-interictal continuum as rhythmic or periodic patterns that are considered to be possible seizure or status epilepticus even without fulfilling strict electrographic criteria 1.
• Patients with patterns on the ictal-interictal continuum who exhibit myoclonus or other clinical manifestations of seizures should be treated with antiseizure medications, although the specific agents and dosing regimens are not clearly defined 1.
• Continuous EEG monitoring may increase sensitivity to detect epileptiform activity, including seizures and status epilepticus, after cardiac arrest compared with brief intermittent recordings 1.

From the Research

Untreated Seizures and Brainstem Herniation

• There is no direct evidence in the provided studies to suggest that untreated seizures can produce brainstem herniation 2, 3, 4, 5, 6.
• The studies primarily focus on the treatment of status epilepticus and seizures using benzodiazepines, such as lorazepam and diazepam, and their efficacy in controlling seizures 2, 3, 4, 5, 6.
• While the studies discuss the importance of prompt treatment for status epilepticus to prevent complications, they do not specifically address the risk of brainstem herniation due to untreated seizures 3, 4, 5.
• It is essential to note that brainstem herniation is a severe and potentially life-threatening complication that can occur in various neurological conditions, including status epilepticus, but the provided studies do not establish a direct link between untreated seizures and brainstem herniation 2, 3, 4, 5, 6.

Treatment of Status Epilepticus

• The studies suggest that benzodiazepines, such as lorazepam and diazepam, are effective in treating status epilepticus and seizures 2, 3, 4, 5, 6.
• Lorazepam is often preferred over diazepam due to its longer duration of action and lower risk of respiratory depression 4, 5, 6.
• The choice of treatment depends on various factors, including the severity of the seizure, the patient's medical history, and the availability of treatment options 2, 3, 4, 5, 6.