Status Epilepticus

Background

• Defined as greater than 5 minutes seizure, or 2+ seizures without returning to consciousness.
• This is a neurological emergency. After five minutes it's less likely to spontaneously terminate and be controlled with medications.
• After 5 minutes, decreases in GABA and increases in glutamine and NMDA receptors leads to ongoing decreased seizure threshold.
• Can be nonconvulsive where the patient is comatose or has fluctuating mental status or confusion, with no overt seizure activity. This diagnosis is difficult and typically made by EEG. Suggested by: prolonged postictal period after generalized seizure, subtle motor signs, fluctuating AMS, unexplained stupor and confusion.

Causes of Status Epilepticus

Consider the following:

• Subtherapeutic antiepileptic levels
• Preexisting neurologic conditions
• Acute stroke
• Hypoxia/anoxia
• Metabolic abnormalities
• ETOH or drug intoxication/withdrawal

Treatment of Status Epilepticus

Supportive Measures

1. ABCs, glucose, IV access, fluids, temperature control
   1. Intubate if necessary
2. Foley catheter, NG tube
3. Treat underlying cause

Established Status Epilepticus

1. Benzodiazepines are first line. Lorazepam 2 -4 mg IV if you have IV access; otherwise, midazolam 10 mg IM is superior without IV access. Lorazepam does last longer (12-24 hours vs. 15 to 60 minutes) and is associated with fewer seizure recurrences.
2. Longer-active antiepileptics should be given within 20 minutes of diagnosis to help prevent recurrence.
   1. Levetiracetam (Keppra) is likely the best choice as it is quick to give, effective, and has few interactions and side effects. Unknown MOA. Initial dose is 20 mg/kg IV.
   2. Fosphenytoin which is phenytoin's prodrug, is the second best choice. It has fewer infusion site reactions and can be given faster than phenytoin. Initial dose is 20 PE/kg infused at 150 PE/minute, over 10-15 minutes.
   3. Valproate which has serious hepatic and pancreatic side effects can be given at 20 mg/kg IV.
   4. Lacosamide has limited use in the literature. Dose is 200 mg IV over 15 minutes.

Refractory Status Epilepticus

Defined by seizures refractory to 2 different IV antiepileptics. 1. Propofol infusion 2. Midazolam infusion 3. Barbiturates 4. Ketamine