IMA virar Newsletter

Seizures – 6 things to know

1. Seizures can produce any symptom

Seizures happen due to uncontrolled electrical activity in the brain. This uncontrolled electrical activity explodes, lasts for about 1 minute and then stops. The brain is stunned by this electrical jolt from the blue!

Seizures can involve only one part of the brain. They usually cause this part of the brain to become hyperactive.

So for example – if the seizure involves the part of the brain that handles smell, you can get a bad smell. If the seizure involves the part of the brain that “sees”, you may have visual hallucinations. Some people get the feeling of floating outside their body (autoscopy). Some may hear songs they had forgotten long ago… and so on.

Sometimes, the uncontrolled electrical activity spreads all over the brain. Then, you get dramatic symptoms. The person loses consciousness. His/her entire body first stiffens up (the tonic phase) after which it starts jerking (the clonic phase).

Do these two phases always happen? Not at all!

Often, the tonic phase is very short or absent. The person only has repetitive jerking during the seizure (a clonic seizure). Some children have purely tonic seizures. Their entire body suddenly stiffens up while walking and they fall down.

So how do you recognize a seizure? Remember: “A seizure is a sudden burst of uncontrolled electrical activity in the brain, which usually produces clinical symptoms.”

Epilepsy is the tendency to have recurrent unprovoked seizures. Some patients with seizures (e.g. alcoholics) may not have Epilepsy. But that is a conversation for another day…

2. Other conditions can produce the same symptoms

Many conditions can cause similar symptoms. Lets forget the uncommon conditions (e.g. Narcolepsy) & talk about 2 common conditions:

1. Syncope (including Cardiac Arrhythmia) &
2. Non-Epileptic seizures

Syncope:

The brain does not get enough blood/oxygen. Hence the patient loses consciousness. For example, this can happen if the patient gets up suddenly (orthostatic hypotension). But a more serious cause is a problem in the pumping of blood – heart problems.

Cardiac arrhythmias are common in the elderly. They can cause syncope. If left untreated, they can also cause sudden death.

Non-Epileptic Seizures:

These are a problem of the mind, rather than the brain. We used to call them pseudoseizures. But this terminology is incorrect. It underestimates the problem. It makes doctors less sympathetic. A better term is Non-Epileptic Seizures (NES).

Non-epileptic seizures (NES) can lead to severe injury, including tongue bite & fractures. They are disabling. A patient with uncontrolled non-epileptic seizures cannot hold a job. Finally, they point to a serious mental health condition. In western studies, 50% of patients with NES have a history of childhood sexual abuse.

Seizures (especially in the frontal lobes) can cause prolonged agitation and antisocial behavior. Some people go to jail because of this behavior. Uncontrolled seizures can lead to severe depression. All these symptoms need to be treated compassionately.

3. It is important to ask about the post-episode phase

How do we determine if some has epileptic seizures, syncope or non-epileptic seizures? Let’s discuss this!

Before the event:

Patients with syncope may report lightheadedness, tunnel vision or sounds becoming distant. Onlookers may report paleness of skin or sweating.

Any other symptoms should arouse suspicion for a seizure disorder.  We call such symptoms before a big seizure an “Aura”. An aura is the symptoms produced by a seizure in a small part of the brain, before it spreads. As noted before, auras can be surpisingly varied. One patient I had reported seeing 3 other people around her before the seizure.

Patients with non-epileptic seizures can report an Aura as well. These are also varied.

During the event:

Everyone is scared! Few people remember details during an event. Thus, spending too much time on this part of the history is not productive.

Yes, you can ask about stiffening, shaking, tongue bite and incontinence. They are more common in Epileptic seizures. But, these symptoms can be present in all 3 conditions: epileptic seizures, NES and syncope. 

The following 2 things are most high-yield:

1. Duration: Non-epileptic seizures can last for a long time (even hours). Most seizures and all syncopal episodes last for 1 minute or less. A longer syncopal episode causes death.

2. Eyes: If their eyes were open during the event, it is likely to be an epileptic seizure. Conversely, if the eyes were closed, it is likely to be a syncope or non-epileptic seizure.

After the event:

Patients with seizures are usually dazed for a long time. It takes at least 5-10 minutes for the patient to come back to normal. Sometimes they can be groggy or sleep for the entire day.

Patients with syncopal episodes wake up abruptly! They suddenly become perfectly alert! They are bewildered to find all the worried people around them, and their first question usually is “Why are all of you staring at me???”

The recovery after Non-epileptic seizures is usually slow, like Epileptic seizures.

In summary, the following things suggest epileptic seizures:

– Strange symptoms before loss of consciousness (Aura)

– Short loss of consciousness with eyes open

– Slow return to baseline

Yes, there are always exceptions. For example, frontal lobe seizures can have a very short recovery period. But these are the rules.

4. Routine EEG and MRI are not very useful for diagnosing Epilepsy

Sometimes, we rely too much on machines. Just like an ECG can be normal in MI, both the MRI and the EEG can be normal in patients with Epilepsy.

In fact:

• 50% of patients with Epilepsy have a normal MRI
• 70% of patients with Epilepsy have a normal routine EEG

Why do these tests then? For a few reasons:

• The MRI may show something nasty in the brain like a tumor.
• An abnormal EEG can confirm the diagnosis of Epilepsy (false positives are uncommon).
• The kind of abnormality seen on EEG can help to determine the type of antiepileptic used. It can help to plan duration of therapy. For example: Juvenile Myoclonic Epilepsy (JME) usually needs life-long treatment with anti-myoclonic antiepileptics.

Never conclude that the patient doesn’t have epilepsy just because the MRI and EEG are normal. All the patients I have described so far had normal MRIs and EEGs!

We treat the patient, not the tests.

5. When the diagnosis is unclear, Video EEG monitoring is useful.

Assume that you have a patient who is having frequent spells, almost daily. You are not sure she has epileptic seizures, or syncope or non-epileptic seizures. You do an EEG and MRI – as expected, both are normal. What next?

If you take a careful history, you may be able to make a preliminary diagnosis of Epileptic seizures. At this stage, a trial of antiepileptic medications such as levetiracetam is useful. If the events stop, great! But what if the events don’t stop?

Video EEG can give you the answer. We admit the patient for 1 to 7 days, and continuously record EEG and video. In contrast to a routine EEG, the EEG and video during an event can diagnose seizures about 95% of the time.

You should consider referring the following patients for video-EEG:

1. Patients with frequent spells, whose diagnosis is not clear.
2. All patients with medically resistant epileptic seizures (see below)
3. Patients with suspected non-epileptic seizures who don’t  improve with psychiatric treatment Video-EEG helps in acceptance of the diagnosis. Sometimes, it uncovers diagnostic errors – some of these patients have Epileptic seizures.
4. Patients with suspected epileptic encephalopathy. For example: If a child gradually stops talking after having seizures.

6. If seizures do not stop, surgery is an excellent option

About 30% of patients keep having seizures no matter how many medications you start. These patients have “Medically resistant Epilepsy”.

In fact, if 2 antiseizure medications don’t stop seizures, the chances of seizure-freedom with more medications is less than 10%. (Per the paper the precise number is 4% – Kwan, Brodie et al published in NEJM)

The first steps in such a patient are:

(1) Confirm that the patient is actually taking medications.

(2) Confirm the diagnosis with video-EEG if needed

Once you rule out these factors, consider seizure surgery. Removal of the bad part of the brain may lead to seizure freedom in upto 80% of patients.

In some patients, many parts of the brain are abnormal. Sometimes, the abnormal areas are near very important parts of the brain e.g. Broca’s area. In these cases, we implant a device called Vagus Nerve Stimulator (VNS). VNS decreases seizures by about 50%.