(SE) refers to a life threatening condition in which the
Brain is in a state of persistent
Seizure . Definitions vary, but traditionally it is defined as one continuous seizure or recurrent seizures without regaining consciousness between seizures for greater than 30 minutes. Many doctors, however, believe that 5 minutes is sufficient to damage neurons and that seizures are unlikely to self-terminate by that time.
In known epileptics, this condition is associated with poor
Compliance (adherence to medication regimen),
Alcohol withdrawal, and
Metabolic disturbances. As a primary presentation it normally indicates a
Tumour or
Abscess .
It can also be induced by
Nerve Agent s such as
Soman .
Status epilepticus can be divided into two categories—convulsive and nonconvulsive, the latter of which is underdiagnosed.
Epilepsia Partialis Continua is a variant involving
Hour ,
Day , or even
Week -long jerking. It is a consequence of
Vascular Disease ,
Tumour s, or
Encephalitis , and is drug-resistant.
Generalized
Myoclonus is commonly seen in
Coma tose patients following
CPR and is seen by some as an indication of catastrophic damage to the
Neocortex .
Shortly after it was introduced in 1963,
Diazepam became the first choice for SE. Even though other
Benzodiazepine s such as
Clonazepam were useful, diazepam was relied upon almost exclusively. This began to change in 1975 with a preliminary study conducted by
Waltregny and Dargent, who found that its pharmacological effects were longer lasting than those of an equal dose of diazepam. This meant it did not have to be repeatedly injected like diazepam, the effects of which would wear off 5-15 minutes later in spite of its 30-hour
Half-life . It has also been found that patients who were first tried on diazepam were much more likely to require
Endotracheal Tubing than patients who were first tried on
Phenobarbital ,
Phenytoin , or lorazepam.
Today, the benzodiazepine of choice is .
Phenytoin was once another first-line therapy, although the
Prodrug Fosphenytoin can be administered three times as fast and with far fewer injection site reactions. If these or any other
Hydantoin Derivative s are used, then cardiac monitoring is a must if they are administered intravenously. Because the hydantoins take 15-30 minutes to work, a benzodiazepine or barbiturate is often co-administered. Because of diazepam's short duration of action, they were often administered together anyway.
Before the benzodiazepines were invented, there were the barbiturates, which are still used today if benzodiazepines or the hydantoins are not an option. These are used to induce a
Barbituric coma. The barbiturate most commonly used for this is phenobarbital.
Thiopental or
Pentobarbital may also be used for that purpose if the seizures have to be stopped immediately or if the patient has already been compromised by the underlying illness or toxic/metabolic-induced seizures; however, in those situations, thiopental is the agent of choice.
The failure of phenobarbital therapy does not preclude the success of a lengthy comatose state induced by a stronger barbiturate such as
Secobarbital . Such was the case for Ohori, Fujioka, and Ohta ca. 1998, when they induced a 10-month long coma (or "anesthesia" as they called it) in a 26-year-old woman suffering from refractory status epilepticus secondary to
Viral Encephalitis and then tapered her off the secobarbital very slowly while using
Zonisamide at the same time.
If this proves ineffective or if barbiturates cannot be used for some reason, then a
General Anesthetic such as
Propofol is tried; sometimes it is used second after the failure of
Lorazepam . This also means putting the patient on artificial respiration. Propofol has been shown to be effective in suppressing the jerks seen in myoclonus status epilepticus, but
As Of 2002 , there have been no cases of anyone going into myoclonus status epilepticus, undergoing propofol treatment, and then not dying anyway.
The use of
Lidocaine in status epilepticus was first reported in
1955 by Bernhard, Boem and Hojeberg. Since then, it has been used in cases refractory to phenobarbital, diazepam, and phenytoin, and has been studied as an alternative to barbiturates and general anesthetics. Lidocaine is a
Sodium Channel blocker and has been used where sodium channel dysfunction was suspected. However, in some studies, it was either ineffective or even harmful for most patients. The last is not so surprising in light of the fact that lidocaine is has been known to cause seizures in humans and laboratory animals at doses greater than 15 µg/mL or 2-3 mg/kg.
