What is Status Epilepticus?
Status epilepticus is a serious brain condition that requires immediate attention to avoid serious illness or even death. In the past, a seizure lasting 30 minutes or more, or multiple seizures without a return to normal mental state, was considered as status epilepticus. According to new standards set in 2012, the definition of status epilepticus now includes a seizure of 5 minutes or more, or repeated seizures even without a break in between.
Status epilepticus can look different in different cases. Sometimes, it involves convulsions, which are uncontrollable muscle movements, and changes in mental state. In “non-convulsive” status epilepticus, seizures are detected with brain scans (EEG), but there are no convulsive movements. In “focal motor” status epilepticus, there is persistent motor activity in a limb or one side of the body, even without loss of consciousness. Meanwhile, “myoclonic” status epilepticus means sudden, brief involuntary muscle jerks. When seizures continue despite the use of seizure-stopping medications, it is referred to as “refractory” status epilepticus.
Status epilepticus is the most common serious brain emergency in children.
What Causes Status Epilepticus?
Status epilepticus, which is a medical emergency where a seizure lasts longer than five minutes or when seizures occur close together without recovery, can be caused by multiple factors. These may include acute or sudden occurrences such as:
- Infections affecting the central nervous system, which involves the brain and spinal cord, like meningitis, encephalitis, and abscesses inside the skull
- Metabolic issues such as low blood sugar (hypoglycemia), low sodium levels (hyponatremia), low calcium levels (hypocalcemia), a condition where the liver affects brain function (hepatic encephalopathy), and metabolic disorders in children
- Stroke
- Head injuries, which can involve internal bleeding in the skull
- Exposure to harmful substances
- Withdrawal from certain drugs like alcohol, benzodiazepines, and barbiturates
- Feeling breathless or experiencing low oxygen levels (hypoxia)
- Severe high blood pressure (hypertensive emergency)
- Conditions where the body’s immune system mistakenly attacks own cells and tissues (autoimmune disorders)
In some cases, people with pre-existing epilepsy can experience status epilepticus. This could be due to severe seizures that aren’t controlled or due to not taking prescribed anti-seizure medicines. Other chronic conditions like withdrawal from alcohol, tumors in the central nervous system, or conditions affecting the brain due to past injury or stroke can also lead to status epilepticus.
Among adults, these sudden processes are usually responsible for most cases of status epilepticus. However, among children, the condition is most commonly caused by fever (referred to as “Febrile status epilepticus”). Central nervous system infections and metabolic disorders are also common causes in children. It is important to note that many children experiencing status epilepticus for the first time have no prior history of seizures.
Risk Factors and Frequency for Status Epilepticus
Status epilepticus, a kind of seizure, commonly occurs in two main age groups: infants and old-aged people. It affects roughly 7 to 40 out of every 100,000 people each year. Males seem to be more prone to this condition. Notably, a substantial number of both children (16 to 38%) and adults (42 to 50%) who experience status epilepticus also have a history of epilepsy. The condition can be serious, with short-term mortality rates (deaths within 30 days) ranging between 7.6 and 22% for all age groups, getting worse with increasing age.
- Status epilepticus most commonly occurs in infants and the elderly.
- Each year, there are about 7 to 40 cases per 100,000 people.
- This type of seizure is more likely to occur in males.
- A considerable number of children (16 to 38%) and adults (42 to 50%) with status epilepticus have previously been diagnosed with epilepsy.
- The short-term mortality rate of status epilepticus varies from 7.6 to 22% across all age groups, with the highest rates found amongst the elderly.
Signs and Symptoms of Status Epilepticus
Status epilepticus is a condition where a person experiences a very long seizure (lasting more than 5 minutes), or has repeated seizures without recovering in between. This sezure activity can be detected either through visible symptoms, or by using specialized medical equipment to measure brain activity.
There are two types of status epilepticus.
- The first type shows visible signs of a seizure, like whole-body shaking (tonic-clonic movements) and confusion or decreased alertness (impaired mental status). After the seizure, they might also experience temporary problems with movement, such as paralysis on one side (Todd paralysis).
- The second type, called non-convulsive status epilepticus, is harder to detect because it might not show visible signs of a seizure. People with non-convulsive status epilepticus might appear confused or less alert, and may have subtle signs of a seizure like abnormal eye movements. For these people, a type of test that measures brain activity, called an electroencephalography (EEG), is used to confirm the seizure activity.
Testing for Status Epilepticus
Diagnosing a severe seizure disorder known as ‘convulsive status epilepticus’ is primarily based on a doctor’s assessment but also needs urgent brain scans and lab tests to help identify the underlying cause. A head CT scan, which produces detailed images of the brain, is often the most practical choice and easiest to carry out. Another type of brain scan, known as an MRI, is better at detecting abnormalities in children but can be harder to conduct and might need the child to be sedated.
Your doctor may also order several lab tests. This could include a test for blood sugar levels, tests to check the balance of essential minerals in your blood (like sodium, potassium, calcium, and magnesium), tests to measure how well your kidneys are working (BUN and creatinine), and a test to see how acidic (or alkaline) your blood is by measuring serum bicarbonate. They might also conduct a full blood count test and a lumbar puncture, which is a test where a small sample of spinal fluid is taken for testing.
If you are already known to have a seizure disorder, your doctor may want to check the levels of any anti-seizure drugs in your system. If they suspect you may have been accidentally or intentionally exposed to harmful substances, toxicology tests might be done. This includes urine tests or blood tests for specific toxins such as theophylline or lithium. Depending on your symptoms, your doctor might also consider other tests such as liver function tests, tests for inherited metabolic disorders, and blood clotting tests. All women who potentially could be pregnant should have a pregnancy test.
Lastly, an EEG should also be performed. This is a test that records electrical activity in the brain. It’s especially important for a condition known as ‘non-convulsive status epilepticus’, which requires not only the above-mentioned brain scans and lab tests to detect its cause but also requires ongoing EEG monitoring to make the diagnosis.
Treatment Options for Status Epilepticus
If someone experiences what’s known as ‘status epilepticus’, a condition where seizures keep happening or a single seizure lasts a long time, it’s crucial to help them as quickly and efficiently as possible. There are several steps that need to be taken at the same time to help the patient.
Firstly, it’s important to make sure the patient can breathe and their blood is circulating properly. This can be achieved by adjusting their position so their airway stays open and making sure they have supplemental oxygen. Additionally, they’ll need to be monitored continuously for their heart rate, breathing rate, blood pressure, and how well they’re being oxygenated.
Medical professionals will check their blood glucose level, the amount of sugar in their blood, at the bedside and treat them if it’s too low. They’ll also give a medication called thiamine before giving any sugar solution, if there’s a chance the patient might be deficient.
In terms of treatment for the seizures, antiepileptic drugs are important. One type of these drugs, called benzodiazepines, is often the first choice for controlling seizures in emergencies. Lorazepam is commonly used here because it works quickly. Diazepam is another option if lorazepam isn’t available. In addition to benzodiazepines, doctors administer other antiepileptic drugs which can include fosphenytoin, phenytoin, levetiracetam, and valproic acid. However, doctors are cautious with valproic acid in young children as it can harm the liver.
Even with these treatments for seizures, some cases are stubborn, and the seizures don’t stop. This is known as refractory status epilepticus. In these cases, the patient needs a continuous infusion of antiepileptic drugs, one of which might be an intravenous (given in a vein) dose of several different medications. For pregnant women with a condition called eclampsia who are also experiencing seizures, the medication magnesium sulfate may also be used.
While they are getting this first-line therapy, a neurologist, a doctor who specializes in neurological conditions, should be consulted. Finally, anyone who experiences status epilepticus needs to be admitted to the hospital, usually to the intensive care unit.
What else can Status Epilepticus be?
When doctors are trying to diagnose a condition known as status epilepticus, they have to rule out several other conditions that could be causing similar symptoms. These include:
- Acute poisoning
- Early severe lack of oxygen in the brain
- Brain disease caused by toxins or abnormal metabolism
- Brain damage caused by a lack of blood supply (ischemic stroke)
- Seizures that are not caused by epilepsy
- Injuries (trauma)
What to expect with Status Epilepticus
The mortality rate, or likelihood of death, for patients experiencing their first episode of a severe seizure disorder known as generalized convulsive status epilepticus is between 16 to 20 percent. The cause of the status epilepticus greatly influences these rates. For instance, anoxic status epilepticus, a type of seizure directly linked to oxygen deprivation, shows a frighteningly high rate approaching 80 percent.
Seizures that are resistant to treatment, known as refractory status epilepticus, have mortality rates ranging from 35 to 60 percent. These patients often require prolonged usage of medications called barbiturates or benzodiazepines, and these specific cases are usually the most affected. Younger patients with an unidentified cause of refractory status epilepticus have a somewhat better prognosis compared to older patients where the cause of condition is known.
Some studies have shown that permanent neurological damage can occur after 30 minutes of continuous seizure activity. Additionally, about 40 percent of patients with their first episode of severe seizure disorder will develop recurrent seizures. After the first episode of status epilepticus, there is a 25 to 30 percent risk of the seizures recurring.
Possible Complications When Diagnosed with Status Epilepticus
Status epilepticus complications can be divided into two categories: medical and neurological, and they can either show up right away or develop over time.
Medical complications are often serious and include heart rhythm problems, heart damage due to adrenaline surge, breathing failure, slow breathing, low oxygen levels, pneumonia due to inhaling food or drink, fluid in the lungs, high body temperature, and increased white blood cell count. These are common in patients experiencing status epilepticus.
On the other hand, neurological complications could lead to regular episodes of epilepsy and repeated status epilepticus. In severe cases of prolonged, medication-resistant status epilepticus, sustained and abnormal electrical activity in the brain could cause permanent neurological damage.
Common Side Effects:
- Heart rhythm problems
- Heart damage due to adrenaline surge
- Respiratory failure
- Slow breathing
- Low oxygen levels
- Pneumonia due to aspiration
- Fluid accumulation in the lungs
- Increased body temperature
- Increased white blood cell count
- Epilepsy
- Recurring status epilepticus
- Permanent neurological damage in severe cases
